|
Explorer-series
|
|
|---|---|---|
| Explorer-6 | Explorer-7 |
|
|
Explorer-series
|
|
|---|---|---|
| Explorer-6 | Explorer-7 |
This page contains philatelic information on the Explorer-series satellites. Catalog numbers, years of issue, and notes on the satellites featured are given when available. If readers know of additional information or images, please contact the authors using the e-mail addresses at the bottom of this page.
This page includes all of the Explorer-series, except the Explorer-1 satellite which is covered separately.
Some of the Explorer-series satellites had additional names that make them part of other satellite series: Injun, SolRad, GEOS, and ISEE / ICE. When applicable these additional names are included in the table below. In particular, the following satellite names and numbers were synonymous:
| Injun | SolRad | GEOS | ISEE |
|---|---|---|---|
|
Explorer-25 = Injun-4 Explorer-40 = Injun-5 Explorer-52 = Injun-6 |
Explorer-30 = SolRad-8 Explorer-37 = SolRad-9 Explorer-44 = SolRad-10 |
Explorer-29 = GEOS-1 Explorer-36 = GEOS-2 |
Explorer-56 = ISEE-1 Explorer-59 = ISEE-3/ICE8 |
Many other Explorers had single-use names, especially for the latter Explorers where the "other" name is more common than the Explorer name and number. Plus, some of the latter Explorers belong to the following short satellite series: SMall EXplorer (SMEX), Medium-class EXplorer (MIDEX), UNiversity-class EXplorer (UNEX), and STudent Explorer Demonstration Initiative (STEDI).
The numbering of the Explorer-series satellites is consistent among sources only through Explorer-55. Beyond that number there is controversy over what constitutes an Explorer satellite. Of the numbered Explorer satellites, only Explorer-2 and Explorer-5 failed but were numbered in sequence. This occurred before it was common practice to delay final numbering until a launch was successful.
All Explorer-numbered satellites are listed here only, not double-listed on other pages because of their mission.
Note: Explorer-94, the USA version of IRIS should not be confused with the other satellites with the same name: IRIS/ESRO-2, IRIS/Akari/Astro-F, and a Russian version of IRIS.
| Launch information (found elsewhere) |
Reference images (found elsewhere) |
Launch covers (including anniversary-of-launch covers, and launch-related event covers) (farther below or elsewhere) |
Other postal items (stamps, souvenir sheets, aerogrammes, postal cards, etc.) (immediately below or elsewhere) |
|---|---|---|---|
| Explorer | Explorer | Explorer-1 | Explorer-1 |
| Explorer (except Explorer-1) | Explorer (except Explorer-1) | ||
| Explorer (on other than Explorer launch covers) |
Below is a list of Explorer-series satellite postal items (stamps, souvenir sheets, aerogrammes, postal cards, etc.).
| Country | Catalog Number | Type of Item | Year of Issue | Notes on Content |
|---|---|---|---|---|
| Explorer-series (except Explorer-1) | ||||
| Ajman | Mi264A Mi264B | Imperforate | 1968 | "Explorer-14" |
| Ajman | Mi260A+Mi263A-266A fdc | One of five stamps on FDC | ||
| Ajman | BL35A BL35B | Embossed-perforation MS2 (like Mi262A+264A) Imperforate MS2 (like Mi262B+264B) | ||
| Ajman | BL35B fdc | Imperforate MS2 on FDC | ||
| Ajman State | Mi2781A Mi2781B | From MS8 (Mi2781A-2788A + 8 labels) From imperforate MS8 (Mi2781B-2788B_white-border + 8 labels or Mi2781B-2788B_pink-border + 8 labels) | 1973 | Explorer-20 |
| Ajman State | Mi2783A Mi2783B | Explorer-S66/22/27 type11 | ||
| Ajman State | Mi2788A Mi2788B | Explorer-17 | ||
| Ajman State | Mi2781A ds1 Mi2781A ds2 Mi2781B ds1 Mi2781B ds2 Mi2781B ds3 | Deluxe sheet (Mi2781A), gold on white background Deluxe sheet (Mi2781A), gold on blue background Imperforate deluxe sheet (Mi27841B), gold on white background Imperforate deluxe sheet (Mi27841B), gold on pink background Imperforate deluxe sheet (Mi27841B), silver on white background | Explorer-20 | |
| Ajman State | Mi2783A ds1 Mi2783A ds2 Mi2783B ds1 Mi2783B ds2 Mi2783B ds3 | Deluxe sheet (Mi2783A), gold on white background Deluxe sheet (Mi2783A), gold on blue background Imperforate deluxe sheet (Mi2783B), gold on white background Imperforate deluxe sheet (Mi2783B), gold on pink background Imperforate deluxe sheet (Mi2783B), silver on white background | Explorer-S66/22/27 type11 | |
| Ajman State | Mi2788A ds1 Mi2788A ds2 Mi2788B ds1 Mi2788B ds2 Mi2788B ds3 | Deluxe sheet (Mi2788A), gold on white background Deluxe sheet (Mi2788A), gold on blue background Imperforate deluxe sheet (Mi2788B), gold on white background Imperforate deluxe sheet (Mi2788B), gold on pink background Imperforate deluxe sheet (Mi2788B), silver on white background | Explorer-17 | |
| Ajman State | Mi2789A Mi2789B | From MS16 (Mi2789A-2796A+2677A-2684A) From imperforate MS16 (Mi2789B-2796B+2677B-2684B) | Explorer-20 | |
| Ajman State | Mi2791A Mi2791B | Explorer-S66/22/27 type11 | ||
| Ajman State | Mi2796A Mi2796B | Explorer-17 | ||
| Angola | 1108c (Mi1426) | One of MS6 (1108 (a-f)) (Mi1424-1429) | 1999 | "Uhuru" (Explorer-42) |
| Angola | 1110a (Mi1444) | One of MS6 (1110 (a-f)) (Mi1444-1449) | 1999 | Explorer-17 |
| Antigua and Barbuda | 2243e (Mi2926) i2243e | One of MS6 (2243 (a-f)) (Mi2922-2927) One of imperforate MS6 (i2243 (a-f)) | 1999 | "IUE" (Explorer-57) |
| Antigua and Barbuda | 3014 (Mi4590-4592) | On four of six stamps and in (right) margin of MS6 (3014 (2x (a-c))) | 2008 | "Explorer-3" |
| Antigua and Barbuda | 3016 (Mi4595-4596) | On all stamps and in (right) margin of MS4 (3016 (2x (a-b))) | ||
| Antigua and Barbuda | 3018 (BL655) | SS1 | ||
| Ascension Island | 388 (Mi397) | 1986 | Explorer-59 / ISEE-3 / ICE | |
| Barbuda | 1790e (Mi2386) | One of MS6 (1790 (a-f)) (Mi2382-2387), Antigua and Barbuda 2243e overprinted | 2000 | "IUE" (Explorer-57) |
| Belgium | 670 (Mi1433) | 1966 | Explorer-17 | |
| Belgium | 670 fdc | Stamp and (pictorial) cancel on FDC | ||
| Belgium | 666+669-670 fdc1 | One of three stamps and (pictorial) cancel and (?) cachet on FDC | Explorer-17 (on stamp and pictorial cancel), Explorer-20 (on cachet) | |
| Belgium | 666+669-670 fdc2 | One of three stamps and (?) cachet (same) on FDC | Explorer-17 (on stamp), Explorer-20 (on cachet) | |
| Belgium | 664-670 fdc | One of seven stamps and (pictorial) cancel on FDC card (Belgium Post? cachet) | Explorer-17 (on stamp and pictorial cancel) | |
| Belgium | None | In (lower-left) margin of imperforate MS2 cinderella | 1963? | Explorer-13/16/23 type2 (in lower-left margin) |
| Benin | Unknown d (Mi?) | One of MS4 (a-d) | 2013 | "IRIS" (Explorer-94) |
| Benin | Unknown c (Mi?) Unknown ic | One of MS4 (a-d) [known illegal issue] One of imperforate MS4 (a-d) | 2014 | Explorer-56 / "ISEE"-1 (also launch date in text) |
| Benin | Unknown a-d fdc | One of four stamps on FDC | ||
| Benin | Unknown c proof Unknown ic proof | One of MS4 proof (a-d) One of imperforate MS4 proof (a-d) | ||
| Benin | Unknown ms proof | Signed-proof MS4 (a-d) | ||
| Benin | Unknown ms proof fdc Unknown ims proof fdc | MS4 proof on FDC Imperforate MS4 proof and cachet on FDC | ||
| Benin | Unknown c (Mi?) Unknown ic | One of MS4 (a-d) [known illegal issue] One of imperforate MS4 (a-d) | 2014 | "IUE" (Explorer-57) |
| Benin | Unknown a-d fdc | One of four stamps on FDC | ||
| Benin | Unknown c proof Unknown ic proof | One of MS4 proof (a-d) One of imperforate MS4 proof (a-d) | ||
| Benin | Unknown ms proof | Signed-proof MS4 (a-d) | ||
| Benin | Unknown ms proof fdc Unknown ims proof fdc | MS4 proof on FDC Imperforate MS4 proof and cachet on FDC | ||
| Benin | Unknown ss (BL none) | SS1 [known illegal issue] | 2018 | "TESS" (Explorer-95) |
| Benin | Unknown ss fdc | SS1 and (multi-color printed) cachet on FDC | ||
| Bernera Islands (Scotland) | Local_b | One of local post MS8 (a-h) | 1978 | Explorer-20 |
| Bernera Islands (Scotland) | Local_b o/p1 | One of local post MS8 overprinted in black | 1998 | Explorer-20 |
| Bernera Islands (Scotland) | Local_b o/p2 | One of local post MS8 overprinted in red | ||
| Birobidjan-Jewish | Local | Bernera Islands Local_b overprinted on Russia 2448 (Mi2440), also overprint template | 1995 | Explorer-20 |
| Birobidjan-Jewish | Local | Bernera Islands Local_b overprinted on Russia 45199 (Mi4496), also overprint template | ||
| Birobidjan-Jewish | Local | Bernera Islands Local_b overprinted on Russia 45209 (Mi4497), also overprint template | ||
| Birobidjan-Jewish | Local | Bernera Islands Local_b overprinted on Russia 57339 (Mi5904), also overprint template | ||
| Birobidjan-Jewish | Local | Bernera Islands Local_b overprinted on Russia 5984 (Mi6177), also overprint template | ||
| Bolivia | 690 (BL146) | In (lower-right) margin of imperforate SS1 | 1985 | Explorer-59 / "ISEE"-3 / ICE |
| Brazil | 1035 fdc (Mi1128 fdc) | (Brasil) cachet on FDC (see this larger but incomplete image) | 1967 | Explorer-7 |
| Burkina Faso | 1015A (BL148) | In (upper-left) margin of SS1 | 1995 | Explorer-12/14/15/26 type1 |
| Burundi | 588 (Mi1582A) i588 (Mi1582B) | Imperforate | 1981 | Explorer-20 |
| Burundi | 588a (BL117C) i588a (BL117B) | On one of MS3 (586-588) On one of imperforate MS3 (i586-i588) | ||
| Burundi | BL496A BL496B | In (upper-right) margin of SS1 (Mi3478A) In (upper-right) margin of imperforate SS1 (Mi3478B) | 2014 | "NuSTAR" (Explorer-93) |
| Cameroun | C99 (Mi533) | 1968 | "Explorer-6" image of Earth | |
| Cameroun | C99 fdc | Stamp and (Éditions So.Ge.Im.) cachet on FDC | ||
| Central African Republic | 663 (BL283A) i663 (BL283B) | In (lower-right) margin of SS1 In (lower-right) margin of imperforate SS1 | 1984 | "COBE" (early-design)5 (Explorer-66) |
| Central African Republic | 843 (Mi1258A) i843 (Mi1258B) | Imperforate | 1986 | Explorer-59 / ISEE-3 / ICE (depicted in a communications satellite role) |
| Chad | BL249A BL249B | In (upper-left) margin of SS1 In (upper-left) margin of imperforate SS1 | 1996 | Explorer-17 (not "Explorer-23", as in text) |
| Chad | 708f (Mi1510A) i708f (Mi1510B) | One stamp and in selvedge of MS6 (708 (a-f)) (Mi1505A-1510A) One stamp and in selvedge of imperforate MS6 (i708 (a-f)) (Mi1505B-1510B) | 1997 | Explorer-56 / ISEE-1 and ISEE-23; "ISEE" (in selvedge text) |
| Chad | Unknown c (Mi?) Unknown ic | One of MS4 (a-d) One of imperforate MS4 (a-d) | 2013 | "IRIS" (Explorer-94) |
| Chad | Unknown proof | Signed-proof MS4 (a-d) | ||
| Chad | Unknown ms fdc Unknown ims fdc | MS4 on FDC Imperforate MS4 on FDC | ||
| Chad | Unknown a-d fdc | One of four stamps on FDC | ||
| China (People's Republic) | None | (Cyan and red and black printed) cachet on cover, also annotated cachet, and back | 1991 | (possible) Explorer-62/63 type |
| Comoro Islands | B4f (Mi859A) iB4f (Mi859B) | One of MS8 (B4 (a-h)) (Mi854A-861A) One of imperforate MS8 (iB4 (a-h)) (Mi854B-861B) | 1988 | Explorer-59 / ISEE-3 / "ICE" (but Giotto depicted) |
| Comoro Islands | B4f_ds (BL268A) iB4f_ds (BL268B) | Deluxe sheet (B4f) Imperforate deluxe sheet (iB4f) | ||
| Comoro Islands | 737a (BL326A) i737a (BL326B) | In (upper-left) margin of SS1 (737) In (upper-left) margin of imperforate SS1 (i737) | 1990 | Explorer-66 / "COBE" (final-design)5 |
| Comoro Islands | 816Qw (Mi1130) | One of pair (816Q (v-w)) (Mi1126+1130), B4f overprinted with a silver bar to remove the surtax | 1996 | Explorer-59 / ISEE-3 / "ICE" (but Giotto depicted) |
| Congo (Democratic Republic) | 534-537 fdc (Mi227-230 fdc) | (Congo Post?) cachet on FDC | 1965 | (possible) Explorer-13/16/23 type2 |
| Congo (Democratic Republic) | 538-541 fdc (Mi221-234 fdc) | (Congo Post?) cachet on FDC | (possible) Explorer-13/16/23 type2 | |
| Congo Republic | C53 (Mi134) iC53 | Imperforate | 1967 | "Explorer-6"6 |
| Congo Republic | C53 fdc | Stamp and (Congo Post) cachet on FDC | ||
| Congo Republic | Unknown ss (BL?) Unknown iss | In (right) margin of SS1 [known illegal issue] In (right) margin of imperforate SS1 | 2014 | Explorer-59 / "ISEE-3" / ICE |
| Congo Republic | Unknown ss fdc Unknown iss fdc | SS1 and cachet on FDC Imperforate SS1 and cachet on FDC | ||
| Congo (Republic) | Unknown c (Mi?) Unknown ic | One of MS4 (a-d) One of imperforate MS4 (a-d) | 2015 | "IUE" / Explorer-57 launched "26 jan. 1978" and observed the impact of "Comète Shoemaker-Levy [with] Jupiter [in] juil. 1994" |
| Congo (Republic) | Unknown ms fdc Unknown ims fdc | MS4 on FDC Imperforate MS4 on FDC | ||
| Congo (Republic) | Unknown ms proof | MS4 proof | ||
| Congo (Republic) | Unknown a-d fdc | One of four stamps on FDC | ||
| Congo Republic | Unknown ss (BL?) | In (upper-right) margin of SS1 [known illegal issue] | 2016 | Explorer-59 / "ISEE-3" / ICE |
| Croatia | None | (Black printed) cachet on WMD cover | 2010 | Explorer-67 / EUVE |
| Djibouti | 610a (BL120A) i610a (BL120B) | In (right) margin of SS1 (610), also annotated In (right) margin of imperforate SS1 (i610) | 1986 | Explorer-59 / ISEE-3 / ICE |
| Djibouti | 1588a (Mi2678) | One of MS4 (1588 (a-d)) (Mi2678-2681) | 2018 | "TESS" (Explorer-95) |
| Djibouti | 1607 (BL1257) | In (lower) margin of SS1 | ||
| Dominica | 2237a (Mi2902) | From MS6 (2237 (a-f)) (Mi2902-2907) | 2000 | "Explorer-14" |
| Dominica | 2237d (Mi2905) | "Explorer-16" | ||
| Dominica | 2237 fdc | MS6 on FDC | (As above for stamps) | |
| East Siberia | Local | Image of unknown origin overprinted on 4x Russia 45192 (Mi4496), from strip of 5, also overprint template | 1996 | Explorer-66 |
| East Siberia | Local | Image of unknown origin overprinted on 4x Russia 5984 (Mi6177), from strip of 5, also overprint template | ||
| East Siberia | Local | Image of unknown origin overprinted on 4x Russia 6066A (Mi262), from strip of 5, also overprint template | ||
| East Siberia | Local | Image of unknown origin overprinted on 4x Russia 6067A (Mi252), from strip of 5, also overprint template | ||
| Egypt | 1211 (Mi1433) | 1983 | (possible) Explorer-32 | |
| Equatorial Guinea | BL277 o/p1 fdc | (Multi-color printed) cachet on (airmail) FDC | 1977 | ISEE-1 / Explorer-56 (lower part of black sticker) |
| Franklin Mint (USA) | None | (Bronze) medallion, also reverse | 1970s | "Hawkeye-1" (Explorer-52) |
| Franklin Mint (USA) | None | (Bronze) medallion, also reverse | "AE-C" (Explorer-51) | |
| Franklin Mint (USA) | None | (Bronze) medallion, also reverse | "SAS-3" (SAS-C, Explorer-53) | |
| Franklin Mint (USA) | None | (Bronze) medallion, also reverse | "AE-D" (Explorer-54) | |
| French Southern and Antarctic Territories | C53 (Mi121) | 1977 | Explorer-52 / Injun-6 (at left) | |
| French Southern and Antarctic Territories | C53 fdc | Stamp on FDC Éditions P.J. cachet) | ||
| French Southern and Antarctic Territories | C52-C53 fdc | One of two stamps on FDC (TAAF Official cachet) | ||
| Fujeira | Mi71A Mi71B | Imperforate | 1966 | Explorer-7 |
| Fujeira | Mi70A-77A fdc | One of eight stamps on FDC | ||
| Fujeira | Mi150A Mi150B | Mi71A overprinted new currency Mi71B overprinted new currency | 1967 | Explorer-7 |
| Fujeira | Mi347A Mi347B | Mi71A overprinted "Apollo-8" Mi71B overprinted "Apollo-8" | 1969 | Explorer-7 |
| Fujeira | Mi347A inv o/p Mi347B inv o/p | Mi71A inverted overprint "Apollo-8" Mi71B inverted overprint "Apollo-8" | ||
| Fujeira | MiA77A MiA77B | Mi71A gold foil Mi71B gold foil | ||
| Fujeira | MiA77 ds | Deluxe sheet (Mi71) gold foil | ||
| Fujeira | Mi341A-348A fdc | One of eight stamps on FDC | ||
| Gabon | Unknown a (Mi none) Unknown ia | One of MS4 (a-d) [known illegal issue] One of imperforate MS4 (a-d) | 2016 | "Themis" (Explorer-85/89) (launch date in text) |
| Gabon | Unknown ms fdc Unknown ims fdc | MS4 on FDC Imperforate MS4 and (multi-color printed) cachet on FDC | ||
| Gambia | 609 (Mi615) | 1986 | Explorer-59 / ISEE-3 / ICE | |
| Gambia | 655 (Mi661) | 609 overprinted in silver | 1986 | Explorer-59 / ISEE-3 / ICE |
| Gambia | 2170 (Mi3272) i2170 | Imperforate | 1999 | "COBE" (final-design)5 (Explorer-66) |
| Gambia | 2268a (Mi3698) | From MS6 (2268 (a-f)) (Mi3698-3703) | 2000 | "Uhuru" (Explorer-42) |
| Gambia | 2268c (Mi3700) | "IUE" (Explorer-57) | ||
| Gambia | 2268a essay | From MS6 (2268 imperforate essay (a-f)) | "Uhuru" (Explorer-42) | |
| Gambia | 2268c essay | "IUE" (Explorer-57) | ||
| Gambia | 2268 essay fdc | MS6 (2268 imperforate essay) on FDC | (As above for stamps) | |
| Gambia | 2269f (Mi3709) i2269f | One of MS6 (2269 (a-f)) (Mi3704-3709) One of imperforate MS6 (i226910 (a-f)) | "IMP" (Explorer-18) | |
| Gambia | 2269f essay | One of MS6 (2269 imperforate essay (a-f)) | ||
| Gambia | i2269 fdc10 | Imperforate MS6 on FDC | ||
| Germany (Berlin) | 9N359 cover (Mi494 cover) | (Green printed) cachet on cover | 1979 | Explorer-6 (in right side of cachet) |
| Germany (West) | None | (Black printed) cachet on cover | 1964 | Explorer-8 |
| Germany (West) | None | (Black printed) cachet on cover | 1965 | Explorer-8 |
| Germany (West) | None | (Herman Oberth Gesellschaft) cachet on cover, also back | 1965 | Explorer-12/14/15/26 type1 (with folded solar panels and last stage attached); design similar to cancels on Sputnik-1 5th and 10th anniversary covers |
| Germany (West) | None | (Herman Oberth Gesellschaft) cachet on cover, also back | 1965 | "Explorer-III" (Explorer-3) |
| Germany (West) | None | Cinderella (poster stamp), from MS30 cinderella | ~1966 | "Explorer-6" |
| Germany (West) | None | "Explorer-7" | ||
| Germany (West) | None | (Pictorial) cancel on cover (GH cachet) | 1970 | Explorer-59 / ISEE-3 / ICE |
| Germany (West) | None | (Pictorial) cancel on cover (Herman Oberth Gesellschaft cachet) | 1970 | Explorer-59 / ISEE-3 / ICE |
| Germany (West) | None | (Pictorial) cancel and (Herman Oberth Gesellschaft) cachet on cover | 1970 | Explorer-59 / ISEE-3 / ICE |
| Germany (West) | None | (Pictorial) cancel | 1971 | Explorer-13/16/23 type2 |
| Germany | None | (Black pictorial) meter on cover | 1995 | Explorer-66 / COBE (final-design)5 |
| Germany | None | (Black pictorial) meter on cover | 1997 | "Jupiter[-C] 1958"; in 1958 the Jupiter-C rocket was used to launch Explorer-1, 2, 3, 4, and 5; three launches were successful, and two (Explorer-2 and 5) were failures |
| Ghana | 166a (BL9) | In (lower) margin of imperforate MS4 (4x 166) | 1964 | Explorer-13/16/23 type2 |
| Ghana | 166a fdc | Imperforate MS4 on FDC | ||
| Great Britain | 1000-1001 fdc (Mi927-928 fdc) | (Benham) back of FDC, also front | 1982 | Explorer-S66/22/27 type11 |
| Grenada Carriacou | 2205d (Mi3194) | One of MS6 (2205 (a-f)) (Mi3191-3196) | 2000 | "Explorer-16" (but Mars Express depicted) |
| Grenada Carriacou | 2205e (Mi3195) | One of MS6 (2205 (a-f)) (Mi3191-3196) | Explorer-57 / IUE (not Space Shuttle "Challenger", "Astro" payload, as in text) | |
| Grenada Carriacou | 2205e essay | One of MS6 (2205 essay (a-f)) | "IUE" (Explorer-57) (correctly labeled) | |
| Grenada Carriacou | 2206d (Mi3200) | One of MS6 (2206 (a-f)) (Mi3197-3202) | "Explorer-16" | |
| Grenada Carriacou | 2206d essay | One of MS6 (2206 essay (a-f)) | ||
| Guinea Republic | B43a (BL332A, Mi1254A) | In (upper-left and left) margins of SS1 (B43) | 1989 | Explorer-59 / "ICE (ISEE-3)"; also schematic "trajet de la sonde ICE (ISEE-3)" |
| Guinea Republic | BL1115A BL1115B | In (upper) margin of MS2 (Mi4537A-4538A) In (upper) margin of imperforate MS2 (Mi4537B-4538B) | 2006 | "RHESSI" (Explorer-81) |
| Guinea Republic | BL1115A-1116A fdc BL1115B-1116B fdc | On one of two MS2 on FDC On one of two imperforate MS2 on FDC | (As above for stamps) | |
| Guinea Republic | Mi4541A Mi4541B | Imperforate | "TRACE" (Explorer-73) | |
| Guinea Republic | BL1117A BL1117B | On one stamp and in (upper) margin of MS2 (Mi4541A-4542A) On one stamp and in (upper) margin of imperforate MS2 (Mi4541B-4542B) | "TRACE" (Explorer-73) (on one of MS2), "RHESSI" (Explorer-81) (close-to-final design, "HESSI", in upper margin) | |
| Guinea Republic | Mi4544A Mi4544B | Imperforate | "ACE" (Explorer-71) | |
| Guinea Republic | Mi4541A-4544A fdc Mi4541B-4544B fdc | Two of four stamps on FDC Two of four imperforate stamps and cachet on FDC | (As above for stamps); Explorer-71 / ACE (in cachet) | |
| Guinea Republic | BL1118A BL1118B | On one of MS2 (Mi4543A-4544A) On one of imperforate MS2 (Mi4543B-4544B) | "ACE" (Explorer-71) | |
| Guinea Republic | BL1117A-1118A fdc BL1117B-1118B fdc | On two MS2 on FDC On two imperforate MS2 and cachet on FDC | (As above for stamps); Explorer-73 / TRACE (in cachet) | |
| Guinea Republic | Mi5875A Mi5875B | From MS6 (Mi5873A-5878A) From imperforate MS6 (Mi5873B-5878B) | 2008 | "Swift" (Explorer-84) |
| Guinea Republic | Mi5877A Mi5877B | |||
| Guinea Republic | Mi5873A-5878A_ms6 fdc | MS6 and cachet on FDC | ||
| Guinea Republic | Mi6515A Mi6515B | One of MS6 (Mi6512A-6517A) Imperforate | 2009 | "WMAP" (Explorer-80) |
| Guinea Republic | BL1843 | In (upper-right) margin of SS1 (Mi7647) | 2010 | "Télescope Wide-field Infrared Survey Explorer" (WISE, Explorer-92) |
| Guinea Republic | BL1843 fdc | SS1 and cachet on FDC | ||
| Guinea Republic | BL1963 | In (lower-right) margin of SS1 | 2011 | "COBE" (Explorer-66) |
| Guinea Republic | BL1963 fdc | SS1 and cachet on FDC | ||
| Guinea-Bissau | BL623A BL623B | In (lower-left) margin of SS1 (Mi3682A) In (lower-left) margin of imperforate SS1 (Mi3682B) | 2007 | Explorer-83 / GALEX |
| Guinea-Bissau | BL623A fdc BL623B fdc | SS1 and cachet on FDC Imperforate SS1 and cachet on FDC | ||
| Hungary | 2972 (Mi3805A) i2972 (Mi3805B) | Imperforate | 1986 | Explorer-59 / ISEE-3 / "ICE" |
| Hungary | 2972 fdc | Stamp on FDC | ||
| Ivory Coast | Unknown a (Mi?) Unknown ia | One of MS4 (2x (a-b)) [known illegal issue] One of imperforate MS4 (2x (a-b)) | 2012 | "GALEX" (Explorer-83) |
| Ivory Coast | Unknown ms fdc | MS4 on FDC | ||
| Korea (North) | 1448 (Mi1494A) i1448 (Mi1494B) | Imperforate | 1976 | Explorer-66 |
| Korea (North) | 1881 (BL65) i1881 | On stamp of SS1, also detail On stamp of imperforate SS1 | 1979 | Explorer-18/21/28 type |
| Korea (North) | 3221a (Mi3429-3430) | In (right) margin of MS2 (3221-3222), also annotated | 1993 | Explorer-20 (middle of three), Explorer-53 / SAS-C (uppermost of three) |
| Korea (South) | 1289 fdc1 (Mi1275 fdc1) | (Purple pictorial) cancel on FDC | 1982 | Explorer-29 / GEOS-1 |
| Korea (South) | 1289 fdc2 (Mi1275 fdc2) | (Blue-black pictorial) cancel on FDC (different) | ||
| Malagasy (DR) | 797 (Mi1063A) i797 (Mi1063B) | Imperforate | 1987 | Explorer-59 / ISEE-3 / ICE |
| Malagasy (DR) | 797a (BL48A) i797a (BL48B) | On stamp of SS1 (797) On stamp of imperforate SS1 (i797) | ||
| Madagascar | 1536c (Mi2475) i1536c | From MS6 (1536 (a-f)) (Mi2473-2478) From imperforate MS6 (i1536 (a-f)) | 2000 | Explorer-59 / ISEE-3 / "ICE" |
| Madagascar | 1536d (Mi2476) i1536d | "SME" (Explorer-64) | ||
| Madagascar | 1536 fdc | MS6 and cachet on FDC | (As above for stamps); Explorer-59 / ISEE-3 / "ICE" (in cachet) | |
| Madagascar | 1539f (Mi2496) i1539f | One of MS6 (1539 (a-f)) (Mi2491-2496) One of imperforate MS6 (i1539 (a-f)) | "COBE" (Explorer-66) (early-design)5 | |
| Madagascar | 1539 proof | On one of imperforate proof MS6 | ||
| Madagascar | 1539 fdc | MS6 on FDC | ||
| Maldive Islands | 147a (Mi147) | In (upper-right) margin of MS9 (9x 147) | 1965 | Explorer-18 |
| Maldive Islands | 148a (Mi148) | In (upper-right) margin of MS9 (9x 148) | ||
| Maldive Islands | 149a (Mi149) | In (upper-right) margin of MS9 (9x 149) | ||
| Maldive Islands | 150a (Mi150) | In (upper-right) margin of MS9 (9x 150) | ||
| Mali | Unknown b (Mi none) Unknown ib | One of MS2 (a-b) One of imperforate MS2 (a-b) | 2006 | Explorer-59 / ISEE-3 / ICE |
| Mali | Unknown ms fdc Unknown ims fdc | MS2 and cachet on FDC Imperforate MS2 and cachet on FDC | ||
| Mali | Unknown ss (BL?) | SS1 | 2020 | "Swift" (Explorer-84) |
| Mali | Unknown ss fdc | SS1 and (multi-color printed) cachet on FDC | ||
| Manama | Mi94A Mi94B | Imperforate | 1968 | "Explorer-14" |
| Manama | Mi90A+Mi93A-96A fdc Mi90B+Mi93B-96B fdc | One of five stamps on FDC One of five imperforate stamps on FDC | ||
| Manama | BL8A BL8B | Embossed-perforation MS2 (like Mi92A+94A) Imperforate MS2 (like Mi92B+94B) | ||
| Manama | BL216A BL216B | In (upper and left) margins of SS1 In (upper and left) margins of imperforate SS1 | 1972 | Explorer-13/16/23 type2 |
| Mauritania | 619 (Mi889A) i619 (Mi889B) | Imperforate | 1986 | Explorer-59 / ISEE-3 / ICE |
| Mauritania | 619a (BL none) i619a | On stamp of SS1 (619) On stamp of imperforate SS1 (i619) | ||
| Mauritania | 622b (Mi889-892) i622b | One of MS4 (619-622) One of imperforate MS4 (i619-i622) | ||
| Micronesia | 344p (Mi736) | From MS20 (344 (a-t)) (Mi721-740) | 1999 | Explorer-59 / ISEE-3 / ICE (not "SMM" repair, as in text)4 |
| Micronesia | 344q (Mi737) | Explorer-59 / ISEE-3 / "ICE" (but SMM repair depicted)4 | ||
| Mongolia | C33d (Mi739) | One of MS12 (C33 (a-l)) (Mi736-747) | 1972 | "Explorer-6"6 |
| Niger | 1078e (Mi1930A) i1078e (Mi1930B) | One of MS9 (1078 (a-i)) (Mi1926A-1934A) One of imperforate MS9 (i1078 (a-i)) | 2001 | "sonde FUSE" (Explorer-77) |
| Niger | 1078 fdc | Imperforate MS9 on FDC | ||
| Nigeria | 143a (Mi134) i143a | In (lower-right) margin of MS12 (12x 143) In (lower-right) margin of "imperforate"7 MS12 (12x 143) | 1963 | Explorer-12/14/15/26 type1 (in lower-right margin) |
| Nigeria | 144a (Mi135) i144a | In (lower-right) margin of MS12 (12x 144) In (lower-right) margin of "imperforate"7 MS12 (12x 144) | ||
| Nigeria | 174 (Mi165) | 1965 | Explorer-18 | |
| Nigeria | 174a | MS12 (12x 174) | ||
| Nigeria | 312 essay1 | Essay | 1975 | (possible) Explorer-20 |
| Nigeria | 312 essay2 | Essay (different) | ||
| Paraguay | C642 label (Mi3974 label) | One label and in (lower-right) margin of MS9 (C642a (5x C642 + 4 labels)) | 1986 | (poorly-depicted) Explorer-59 / ISEE-3 / ICE |
| Poland | 2715 (Mi3015) | One of pair (2715a (2714-2715)) | 1986 | Explorer-59 / ISEE-3 / ICE |
| Romania | None | (Pictorial) cancel and cachet on cover | 1992 | Explorer-66 / COBE (final-design)5 |
| Rwanda | 109-112 fdc (Mi113A-116A fdc) | (Rwanda Post?) cachet on FDC | 1965 | (possible) Explorer-13/16/23 type2 |
| Rwanda | 113 fdc (BL4A fdc) | (Rwanda Post?) cachet on FDC | ||
| Rwanda | 136 (BL5A) i136 (BL5B) | In (right and lower-right) margin of MS2 (136 (a-b)) In (right and lower-right) margin of imperforate MS2 (i136 (a-b)) | 1965 | Explorer-11 (in right margin); Explorer-13/16/23 type2 (in lower-right margin) |
| Rwanda | 809-812 fdc (Mi873-876 fdc) | (Rwanda Post?) cachet on FDC | 1977 | (possible) Explorer-13/16/23 type2 |
| Rwanda | 913-914 fdc (Mi982-983 fdc) | (Rwanda Post?) cachet on FDC | 1979 | (possible) Explorer-13/16/23 type2 |
| St. Thomas and Prince Islands | 906 (BL221) | In (extreme upper-right) margin of SS1 | 1989 | (poorly-depicted) Explorer-6/Pioneer-56 |
| Satellite Beach FL (USA) | Local | Set-C08 (blue) | 1964 | "Explorer-16" |
| Satellite Beach FL (USA) | Local | Set-C08 (blue) (in cachet position) on FDC | ||
| Satellite Beach FL (USA) | Local | Set-D02 (green) | 1965 | "Explorer-14" |
| Satellite Beach FL (USA) | Local | Set-D04 (green) | "Explorer-17" | |
| Satellite Beach FL (USA) | Local | Set-D06 (green) | "Topsi" (Explorer-20 | |
| Satellite Beach FL (USA) | Local fdc | Set-D06 (green) (in cachet position) on local post FDC | ||
| Satellite Beach FL (USA) | Local | Set-D07 (green) | "Explorer-10" | |
| Satellite Beach FL (USA) | Local fdc | Set-D07 (green) (in cachet position) on local post FDC | ||
| Satellite Beach FL (USA) | Local | Set-D09 (green) | "IMP-A" (Explorer-18) | |
| Satellite Beach FL (USA) | Local | Set-D10 (green) | "Explorer-9" | |
| Satellite Beach FL (USA) | Local o/p | Set-C08 (blue) overprinted new value in gold | 1965 | "Explorer-16" |
| Satellite Beach FL (USA) | Local | Set-D02 (green) overprinted new value in gold | 1965 | "Explorer-14" |
| Satellite Beach FL (USA) | Local o/p | Set-D04 (green) overprinted new value in gold | "Explorer-17" | |
| Satellite Beach FL (USA) | Local | Set-D06 (green) overprinted new value in gold | "Topsi" (Explorer-20 | |
| Satellite Beach FL (USA) | Local o/p | Set-D07 (green) overprinted new value in gold | "Explorer-10" | |
| Satellite Beach FL (USA) | Local o/p | Set-D09 (green) overprinted new value in gold | "IMP-A" (Explorer-18) | |
| Satellite Beach FL (USA) | Local | Set-D10 (green) overprinted new value in gold | "Explorer-9" | |
| Satellite Beach FL (USA) | Local | Local post stamp | ? | "Explorer-30" / SolRad-8 |
| Satellite Beach FL (USA) | Local cover1 | Set-C03 and C08 (blue) (in cachet position) on local post cover | 1988 | "Explorer-16" |
| Satellite Beach FL (USA) | Local cover2 | Set-D04 and D09 (green) (in cachet position) on local post cover | "Explorer-17" and "IMP-A" (Explorer-18) | |
| Sharjah | 45 (Mi57A) i45 (Mi57B) | Imperforate | 1964 | "Explorer-13" |
| Sharjah | 45_op (Mi57A_op) i45_op (Mi57B_op) | 45 overprinted new currency i45 overprinted new currency | 1967 | "Explorer-13" |
| Sharjah | 46 (Mi58A) i46 (Mi58B) | Imperforate | 1964 | "Explorer-12" |
| Sharjah | 46_op (Mi58A_op) i46_op (Mi58B_op) | 46 overprinted new currency i46 overprinted new currency | 1967 | "Explorer-12" |
| Sierra Leone | 1074d (Mi1260) | One of MS9 (1074 (a-i)) (Mi1257-1265) | 1989 | "IUE" (Explorer-57) |
| Sierra Leone | 1074d specimen | One of MS9 (1074 specimen (a-i)) | ||
| Spain | None | (Orange and blue and black printed) cachet on cover | 1984 | "AE" (Explorer-17/32/51/54/55 type), "RAE" (Explorer-38/39 type), "ISEE" (Explorer-56/59 type), "HCMM" (Explorer-58), "SAGE" (Explorer-60), and "Magsat" (Explorer-61) (all in text only) |
| Spain | None | (Multi-color printed) cachet on (un-canceled) (Spanish Post) stamped envelope (from 2011) | 2013 | "IRIS" / "SMEX-12" (Explorer-94) |
| Staffa (Scotland) | Local_b Local_ib | One of local post MS8 (a-h) One of imperforate local post MS8 (a-h) | 1974 | "Explorer-47" |
| Staffa (Scotland) | Local_b o/p1 | One of local post MS8 overprinted in silver (a-h) | 1998 | "Explorer-47" |
| Staffa (Scotland) | Local_b o/p2 | One of local post MS8 overprinted in gold (a-h) | ||
| Togo | Mi10226-10229_ms4 | MS4 (Mi10226-10229) | 2019 | 60th anniv. launch Explorer-7, 1959 |
| Togo | BL1844 | SS1 (Mi10230) | ||
| Umm Al Qiwain | Mi85A Mi85B | Imperforate | 1966 | Explorer-10 |
| Umm Al Qiwain | Mi83A-86A+BL5A fdc | One of four stamps on FDC | ||
| Umm Al Qiwain | Mi96A Mi96B | Mi85A overprinted new currency Mi85B overprinted new currency | 1967 | Explorer-10 |
| Umm Al Qiwain | Mi94B-97B+BL6A fdc | One of four imperforate stamps on FDC | ||
| United Nations | 112-113 fdc (Mi122-123 fdc) | (Orbit Covers) cachet on FDC | 1962 | "Explorer-XII" (Explorer-12) |
| United Nations (Geneva) | 655 (BL?) | SS1 | 2018 | "Comet 65P/Gunn seen by WISE [Explorer-92]" (in French text) |
| United Nations (Geneva) | 655 fdc | SS1 on FDC | ||
| United States | 1173 insert | Insert from FDC (ATA Space Unit cachet), and detail, also front | 1960 | Explorer-7 (at lower right, but antennas are different) |
| United States | None | (Red and black printed) cachet on cover | 1961 | Explorer-66 |
| United States | None a | From Interpex MS4 (a-d) cinderella (blue) | 1962 | Explorer-13/16/23 type2 (not "Explorer-S6", as in text) |
| United States | None b | Explorer-12 (Explorer-S3, folded solar panels) | ||
| United States | None c | Explorer-S45 | ||
| United States | None a | From Interpex MS4 (a-d) cinderella (yellow) | 1962 | Explorer-13/16/23 type2 (not "Explorer-S6", as in text) |
| United States | None b | Explorer-12 (Explorer-S3, folded solar panels) | ||
| United States | None c | Explorer-S45 | ||
| United States | None | (Astro Covers) cachet on cover | 1962 | "Explorer" |
| United States United Nations | 1193 cover 112 cover | (Orbit Covers) cachet on cover | 1963 | "Explorer-12" |
| United States | None | (Black rubber-stamp) cachet on cover | 1967 | "Explorer-XX" (Explorer-20), "Explorer-XXII" (Explorer-22) |
| United States | None | (Purple rubber-stamp) cachet | 1971 | Explorer-45 |
| United States | None | (Rockpex) cachet (with design similar to Centennial black rocket, type-1) cachet) on cover | 1971 | Explorer-6/Pioneer-56 |
| United States | 1529 fdc (Mi1136 fdc) | (GSFC Operation Kohoutek cyan rubber-stamp) cachet on FDC | 1974 | Explorer-57 / IUE |
| United States | None | (GSFC Operation Kohoutek blue rubber-stamp) cachet on cover | 1974 | Explorer-57 / IUE |
| United States | None | (Green and yellow and black printed) cachet on cover | 1977 | Explorer-53 / SAS-C |
| United States | 1759 fdc 1710 cover | (Aeropex'77) cachet on FDC, also annotated cachet | 1978 1977 | "Explorer" |
| United States | None | (RCA) cachet on cover | 1978 | [#6] Explorer-51; [#8] Explorer-62/63 type |
| United States | None | (Black printed) cachet on cover, also annotated cachet | 1978 | (possible) Explorer-S66/22/27 type11 |
| United States | None | (GSFC multi-satellite blue rubber-stamp) cachet on cover | 1979 | "Explorer-6", "Explorer-7", "Explorer-10", "Explorer-11", "Explorer-17", "Explorer-20", "Explorer-27", "IMP (Explorer-28)", "Explorer-32", "AIMP[-2] (Explorer-35)", "RAE (Explorer-38)" |
| United States | 1915 fdc (Mi1484 fdc) | (Bazaar no.394-5) cachet on FDC | 1981 | Explorer-64 / SME |
| United States | 1919a fdc (Mi1481-1488 fdc) | (RCA) cachet on FDC, also annotated | 1981 | Explorer-62/63 type |
| United States | None | (Colorano silk/ASDA) cachet (with reproduction of Belgium 670) on cover, also annotated cachet | 1983 | Explorer-17 |
| United States | None | Insert back from cover, also insert front and cover front | 1986 | "International Sun-Earth Explorer (ISEE)-3" renamed "International Cometary Explorer (ICE)" (Explorer-59) |
| United States | 2634a fdc (Mi2235-2238 fdc) | (CW Ray hand-painted) cachet on FDC | 1992 | Explorer-57 / IUE |
| United States | 2571 cover (Mi2186 cover) | (MCSCC) cachet on cover | 1991 | "Explorer" |
| United States | None | (Blue text under printed) cachet on cover | 1994 | "IUE" (Explorer-57) |
| United States | 3187d fdc1 (Mi3126 fdc1) | (Collins) cachet on FDC | 1999 | "the Van Allen radiation belt[s] discovered by the Explorer satellites" (refers to Explorer-1 and Explorer-3) |
| United States | 3187d fdc2 (Mi3126 fdc2) | (Artmaster) back of FDC, also front | "Explorer-6" | |
| United States | None | (Multi-color printed) cachet on cover | 2008 | Explorer-77 / FUSE (in text) |
| United States | None | (Zazzle.com) personalized postage | 2010 | "WISE" (Explorer-92) |
| United States | None | (Zazzle.com) personalized postage (different) | Explorer-92 / WISE launch | |
| Vanuatu | 1122f (Mi1598) | One of MS6 (1122 (a-f)) (BL80, Mi1593-1598) | 2021 | Explorer-39 and 40 mockup (found atop the Scout-D rocket displayed at the Smithsonian National Air and Space Museum) |
| Yemen Arab Republic | 260_ms12 (Mi903A_ms) i260_ms12 (Mi903B_ms) 260g_ms12 (Mi910_ms) | In (lower-right) margin of MS12 (12x 260) In (lower-right) margin of imperforate MS12 (12x i260) In (lower-right) margin of imperforate MS12 (12x 260g) with changed colors | 1969 | Explorer-66 |
| Yemen Arab Republic | 260A_ms12 (Mi904A_ms) i260A_ms12 (Mi904B_ms) 260h_ms12 (Mi911_ms) | In (lower-right) margin of MS12 (12x 260A) In (lower-right) margin of imperforate MS12 (12x i260A) In (lower-right) margin of imperforate MS12 (12x 260h) with changed colors | Explorer-66 | |
| Yemen Arab Republic | 260B_ms12 (Mi905A_ms) i260B_ms12 (Mi905B_ms) 260i_ms12 (Mi912_ms) | In (lower-right) margin of MS12 (12x 260B) In (lower-right) margin of imperforate MS12 (12x i260B) In (lower-right) margin of imperforate MS12 (12x 260i) with changed colors | Explorer-66 | |
| Yemen Arab Republic | 260C (Mi906A) i260C (Mi906B) 260j (Mi913) | Stamp and in (lower-right) margin of MS12 (12x 260C) Stamp and in (lower-right) margin of imperforate MS12 (12x i260C) Stamp and in (lower-right) margin of imperforate MS12 (12x 260j) with changed colors | "Explorer-6"6 | |
| Yemen Arab Republic | 260D_ms12 (Mi907A_ms) i260D_ms12 (Mi907B_ms) 260k_ms12 (Mi914_ms) | In (lower-right) margin of MS12 (12x 260D) In (lower-right) margin of imperforate MS12 (12x i260D) In (lower-right) margin of imperforate MS12 (12x 260k) with changed colors | Explorer-66 | |
| Yemen Arab Republic | 260E_ms12 (Mi908A_ms) i260E_ms12 (Mi908B_ms) 260l_ms12 (Mi915_ms) | In (lower-right) margin of MS12 (12x 260E) In (lower-right) margin of imperforate MS12 (12x i260E) In (lower-right) margin of imperforate MS12 (12x 260l) with changed colors | Explorer-66 | |
| Yemen Arab Republic | 260F (Mi909A) i260F (Mi909B) 260m (Mi916) | Stamp and in (lower-right) margin of MS12 (12x 260F) Stamp and in (lower-right) margin of imperforate MS12 (12x i260F) Stamp and in (lower-right) margin of imperforate MS12 (12x 260m) with changed colors | Explorer-12/14/15/26 type1 depicted (not "Explorer-7", as in text on stamp), Explorer-66 (in MS12 margin) | |
| Yemen Arab Republic | 261A (Mi922) 261h (Mi929) | Imperforate with changed colors | 1969 | "Explorer-10" |
| Yemen Arab Republic | C87 (Mi1698) | 1982 | Explorer-13/16/23 type2 | |
| Yemen Arab Republic | C87 ds | Deluxe sheet (C87) | ||
| Yemen Arab Republic | C87 proof | Chromalin proof | ||
| Yemen Arab Republic | C90ae (Mi1706) | One of MS4 (C90a (b-e)) (BL218) | Explorer-6/Pioneer-56 | |
| Yemen Arab Republic | C90ae proof | Chromalin proof | ||
| Yemen Arab Republic | C91 (Mi1702) | Explorer-12/14/15/26 type1 | ||
| Yemen Arab Republic | C91 ds | Deluxe sheet (C91) | ||
| Yemen Arab Republic | C91 proof | Chromalin proof | ||
| Yemen Republic | C141 (Mi87) | Yemen Arab Republic C91 overprinted | 1993 | Explorer-12/14/15/26 type1 |
1Explorer-12, 14, 15, and 26: Electrostatic Particle Explorers (EPE-A/B/C/D) are all basically identical.
2Explorer-13, 16, and 23 (Explorer-S55-A/B/C) are all basically identical.
3Two satellites stacked together (Explorer-56 / ISEE-1, and ISEE-2).
4The captions on Micronesia 344p and 344q are transposed: SMM repair, and Explorer-59 / ISEE-3 / ICE.
5COBE (early-design) was intended for Space Shuttle launch; COBE (final-design) was intended for rocket launch.
6Explorer-6 and Pioneer-5 were similar "paddlewheel" satellites. It is believed that Explorer-6 contained two short antennas on its "top", whereas Pioneer-5 contained only a single short antenna. When there are no antennas on top, the distinction is unclear, but of the two, Pioneer-5 is assumed.
7The "imperforate" sheets from Nigeria, i143a and i144a, are imperforate only in the surrounding margins, otherwise the stamps in both sheets are perforated on all sides.
8Explorer-59 / ISEE-3 was renamed ICE (International Cometary Explorer) in 1983.
9See here for a list of engraved/lithographed Russian definitive pairs known to exist with satellite overprints.
10The Gambia imperforate i2269 (also seen in i2269 fdc) does not perfectly match the perforated version 2269, but rather is quite similar to the essay 2269 essay. The authors believe that the perforated version 2269 includes the final design of these sheets that was actually issued.
11Explorer-S66, 22 (S66a), and 27: Beacon Explorers (BE-A/B/C) are all basically identical.
Below is a list of Explorer-series satellite launch covers (including anniversary-of-launch covers, and launch-related event covers).
| Country | Cancel Date | Cancel Location | Type of Item | Notes on Content |
|---|---|---|---|---|
| Explorer-series (except Explorer-1) | ||||
| 1958-03-05: Explorer-2 [failed] | ||||
| No launch covers are known to exist! | ||||
| 1958-03-26: Explorer-3 | ||||
| United States | 1958-03-26 | Port Canaveral FL | (Sarzin) cachet on cover | Explorer-3 launch |
| United States | 1958-03-26 | Patrick AFB, FL | (Fleetwood printed and Epps blue rubber-stamp) cachet on cover | Explorer-3 launch |
| United States | 1958-03-26 | Patrick AFB, FL | (Goldcraft Cachets) cachet on cover | Explorer-3 launch |
| United States | 1958-03-26 | Patrick AFB, FL | (Goldcraft Cachets) cachet (different) on cover | Explorer-3 launch (mis-identified as "Vanguard-3" in text) |
| United States | 1958-03-26 | Patrick AFB, FL | (Swanson/DuBeau? purple rubber-stamp) cachet on (airmail) cover | Explorer-3 launch |
| United States | 1958-03-26 | Patrick AFB, FL | (Swanson/DuBeau? dark purple rubber-stamp) cachet on (airmail) cover | Explorer-3 launch |
| United States | 1958-03-26 | Patrick AFB, FL | (Swanson/DuBeau? magenta rubber-stamp) cachet on (airmail) cover | Explorer-3 launch |
| United States | 1958-03-26 | Patrick AFB, FL | (H. Flick) cachet on cover, also back | Explorer-3 launch |
| United States | 1958-03-26 | Patrick AFB, FL | (H. Flick) cachet on (airmail) cover | Explorer-3 launch |
| 1958-07-26: Explorer-4 | ||||
| United States | 1958-07-26 | Patrick AFB, FL | (H. Flick) cachet on cover | Explorer-4 launch |
| United States | 1958-07-26 | Patrick AFB, FL | (H. Flick) cachet on (airmail) cover | Explorer-4 launch |
| United States | 1958-07-26 | Patrick AFB, FL | (Goldcraft Cachets) cachet on cover | Explorer-4 launch (but Vanguard-2 depicted) |
| United States | 1958-07-26 | Patrick AFB, FL | (C. Swanson red rubber-stamp) cachet on (airmail) cover | Explorer-4 launch |
| United States | 1958-07-26 | Patrick AFB, FL | (Artmaster) cachet on cover | Explorer-4 launch |
| United States | 1958-07-26 | Port Canaveral FL | (Multi-color printed and black rubber-stamp and black typed) cachet on cover | Explorer-4 launch |
| United States | 1958-07-26 | Port Canaveral FL | (Sarzin) cachet on cover | Explorer-4 launch (but the satellite was launched by a Juno-1 rocket rather than the Jupiter-C rocket specified in the text and depicted in the cachet; that image of a Jupiter IRBM (Intermediate Range Ballistic Missile) was taken from this postcard (see also the postcard front)) |
| United States | 1958-07-26 | Patrick AFB, FL | (Green rubber-stamp) cachet on cover | Explorer-4 launch |
| United States | 1958-07-26 | Port Canaveral FL | (Black printed) cachet on cover | Explorer-4 launch |
| United States | 1958-07-26 | Patrick AFB, FL | (Jim Fitzpatrick purple rubber-stamp) cachet on (airmail) cover | Explorer-4 launch |
| 1958-08-24: Explorer-5 [failed] | ||||
| No launch covers are known to exist! | ||||
| 1959-07-16: Explorer-S1 [failed] | ||||
| No launch cover images are available yet. | ||||
| 1959-08-07: Explorer-6 (S2) | ||||
| United States | 1959-08-07 | Patrick AFB, FL | (H. Flick) cachet on cover | (poorly-depicted) Explorer-6 (S2) launch |
| United States | 1959-08-07 | Patrick AFB, FL | (H. Flick) cachet on (airmail) cover, also back | (poorly-depicted) Explorer-6 (S2) launch |
| United States | 1959-08-07 | Merritt Island FL | (Highway Stamp Club) cachet on cover | Explorer-6 (S2) launch |
| United States | 1959-08-07 | Port Canaveral FL | (Goldcraft Cachets) cachet on cover | Explorer-6 (S2) launch |
| United States | 1959-08-07 | Port Canaveral FL | (Sarzin) cachet on cover | Explorer-6 (S2) launch |
| United States | 1959-08-07 | Patrick AFB, FL | (Swanson red rubber-stamp) cachet on (airmail) cover | Explorer-6 (S2) launch |
| United States | 1959-08-07 | Patrick AFB, FL | (Jim Fitzpatrick unknown-color rubber-stamp) cachet on (airmail) cover | Explorer-6 (S2) launch |
| Explorer-6 (anniversaries) | ||||
| United States | 1974-08-14 | Cape Canaveral FL | (MoF no.18) cachet on cover, also insert and insert back | 15th anniv. Explorer-6 (S2) first televised image |
| United States | 2009-08-07 | Cape Canaveral FL | (Mission 57) cachet on cover, also back | 50th anniv. Explorer-6 (S2) launch |
| 1959-10-13: Explorer-7 (S1A) | ||||
| United States | 1959-10-13 | Port Canaveral FL | (Black printed) cachet on cover | Explorer-7 (S1A) launch |
| United States | 1959-10-13 | Port Canaveral FL | (Sarzin) cachet on cover | Explorer-7 (S1A) launch |
| United States | 1959-10-13 | Port Canaveral FL | (Sarzin) cachet (and signatures) on cover | Explorer-7 (S1A) launch |
| United States | 1959-10-13 | Port Canaveral FL | (Goldcraft Cachets) cachet on cover | Explorer-7 (S1A) launch |
| United States | 1959-10-13 | Port Canaveral FL | Picture postcard | Explorer-7 (S1A) launch |
| United States | 1959-10-13 | Port Canaveral FL | Picture postcard (different) | Explorer-7 (S1A) launch |
| United States | 1959-10-13 | Port Canaveral FL | Picture postcard (different) | Explorer-7 (S1A) launch (but Vanguard-2 depicted) |
| United States | 1959-10-13 | Port Canaveral FL | Picture postcard (different) | Explorer-7 (S1A) launch |
| United States | 1959-10-13 | Port Canaveral FL | Picture postcard (different), also back | Explorer-7 (S1A) launch |
| United States | 1959-10-13 | Port Canaveral FL | Picture postcard (different) | Explorer-7 (S1A) launch |
| United States | 1959-10-13 | Port Canaveral FL | Picture postcard (different) | Explorer-7 (S1A) launch |
| Explorer-7 (anniversaries) | ||||
| United States | 2009-10-13 | Cape Canaveral FL | (Mission 57) cachet on cover, also back | 50th anniv. Explorer-7 (S1A) launch |
| United States | 2019-10-12 | Sagamore Beach MA | (Coverscape) cachet on cover | 60th anniv. Explorer-7 (S1A) launch |
| 1960-03-23: Explorer-S46 [failed] | ||||
| No launch cover images are available yet. | ||||
| 1960-11-03: Explorer-8 (S30) | ||||
| United States | 1960-11-03 | Patrick AFB, FL | (Blue rubber-stamp) cachet on cover | Explorer-8 (S30) launch |
| United States | 1960-11-03 | Port Canaveral FL | (blank/no) cachet on cover | Explorer-8 (S30) launch |
| United States | 1960-11-03 | Patrick AFB, FL | (Swanson blue rubber-stamp) cachet on (airmail) cover | Explorer-8 (S30) launch |
| United States | 1960-11-03 | Patrick AFB, FL | (Swanson magenta rubber-stamp and different text) cachet on (airmail) cover | Explorer-8 (S30) launch |
| United States | 1960-11-03 | Port Canaveral FL | (Goldcraft Cachets) cachet on cover | Explorer-8 (S30) launch |
| United States | 1960-11-03 | Port Canaveral FL | (C. Swanson red rubber-stamp) cachet on cover | Explorer-8 (S30) launch |
| United States | 1960-11-03 | Patrick AFB, FL | (Jim Fitzpatrick red rubber-stamp) cachet on (airmail) cover | Explorer-8 (S30) launch |
| United States | 1960-11-03 | Port Canaveral FL | (Hand-written) cachet on postcard, also back | Explorer-8 (S30) launch |
| United States | 1960-11-03 | Port Canaveral FL | (Zaso photo/sticker) cachet on cover | Explorer-8 (S30) launch |
| United States | 1960-11-03 | Patrick AFB, FL | (Zaso photo/sticker) cachet on (airmail) cover | Explorer-8 (S30) launch |
| United States | 1960-11-03 | Port Canaveral FL | (Sarzin) cachet on cover | Explorer-8 (S30) launch |
| United States | 1960-11-03 | Port Canaveral FL | (Rank, based on a Boudwin rubber-stamp design) cachet on cover | Explorer-8 (S30) launch |
| 1960-12-04: Explorer-S56 [failed] | ||||
| United States | 1960-12-04 | Wallops Island VA (hand cancel) | (Blue and black rubber-stamp) cachet on cover | Explorer-S56 launch [failed] |
| United States | 1960-12-04 | Wallops Island VA (machine cancel) | (Hudson rubber-stamp) cachet on cover | Explorer-S56 launch [failed] |
| United States | 1960-12-04 | Wallops Island VA (machine cancel) | (Hudson rubber-stamp) cachet on (airmail) cover | Explorer-S56 launch [failed] |
| United States | 1960-12-04 | Wallops Island VA (machine cancel) | (Hudson rubber-stamp) cachet (and signature) on (airmail) cover | Explorer-S56 launch [failed] |
| 1961-02-16: Explorer-9 (S56A) | ||||
| United States | 1961-02-16 | Wallops Island VA (machine cancel) | (Hudson rubber-stamp) cachet on cover | Explorer-9 (S56A) launch |
| United States | 1961-02-16 | Wallops Island VA (hand cancel) | (Hudson rubber-stamp) cachet (different) on (airmail) cover | Explorer-9 (S56A) launch |
| United States | 1961-02-16 | Wallops Island VA | (Hudson magenta rubber-stamp and black typed) cachet on cover | Explorer-9 (S56A) launch |
| United States | 1961-02-16 | Wallops Island VA | (Goldcraft Cachets/Space Age Cover) cachet on cover | Explorer-9 (S56A) launch |
| United States | 1961-02-16 | Wallops Island VA | (Multi-color printed (like USA cinderella) and Holden magenta rubber-stamp) cachet on (airmail) cover | Explorer-9 (S56A) launch |
| 1961-02-24: Explorer-S45 [failed] | ||||
| United States | 1961-02-24 | Patrick AFB, FL | (Jim Fitzpatrick magenta and black rubber-stamp) cachet on (airmail) cover | Explorer-S45 launch [failed] |
| United States | 1961-02-24 | Patrick AFB, FL | (Black typed) cachet on cover | Explorer-S45 launch [failed] |
| United States | 1961-02-24 | Patrick AFB, FL | (Swanson black rubber-stamp) cachet on cover | Explorer-S45 launch [failed] |
| 1961-03-25: Explorer-10 (P14) | ||||
| United States | 1961-03-25 (inverted hour "2") | Patrick AFB, FL | (SpaceCraft no.1, no logo) cachet on cover | Explorer-10 (P14) launch |
| United States | 1961-03-25 | Patrick AFB, FL | (SpaceCraft no.1, no logo) cachet on cover | Explorer-10 (P14) launch |
| United States | 1961-03-25 | Patrick AFB, FL | (SpaceCraft no.1, no logo) cachet (and signature) on cover | Explorer-10 (P14) launch |
| United States | 1961-03-25 | Patrick AFB, FL | (Swanson black rubber-stamp) cachet on cover | Explorer-10 (P14) launch |
| United States | 1961-03-25 | Port Canaveral FL | (Goldcraft Cachets) cachet on cover | Explorer-10 (P14) launch |
| 1961-04-27: Explorer-11 (S15) | ||||
| United States | 1961-04-27 | Port Canaveral FL | (Goldcraft Cachets) cachet on cover | Explorer-11 (S15) launch (but Mercury boilerplate capsule depicted) |
| United States | 1961-04-27 | Patrick AFB, FL | (SpaceCraft/C. Swanson printed) cachet on cover | Explorer-11 (S15) launch |
| United States | 1961-04-27 | Port Canaveral FL | (Sarzin) cachet on cover | Explorer-11 (S15) launch |
| United States | 1961-04-27 | Patrick AFB, FL | (Swanson black and magenta rubber-stamp and red hand-written) cachet on cover | Explorer-11 (S15) launch |
| United States | 1961-04-27 | Patrick AFB, FL | (Black printed) cachet on cover | Explorer-11 (S15) launch |
| 1961-05-24: Explorer-S45A [failed] | ||||
| United States | 1961-05-24 | Patrick AFB, FL | (Jim Fitzpatrick purple rubber-stamp and hand-printed) cachet on cover | Explorer-S45A launch [failed] |
| United States | 1961-05-24 | Patrick AFB, FL | (Swanson black and magenta rubber-stamp) cachet on cover | Explorer-S45A launch [failed] |
| 1961-06-30: Explorer-S55 [failed] | ||||
| United States | 1961-06-30 | Wallops Island VA | (Hudson magenta rubber-stamp) cachet on cover | Explorer-S55 launch [failed] |
| United States | 1961-06-30 | Wallops Island VA (machine cancel) | (Swanson magenta rubber-stamp) cachet on cover | Explorer-S55 launch [failed] |
| United States | 1961-06-30 | Wallops Island VA (hand cancel) | (Swanson magenta rubber-stamp) cachet on cover | Explorer-S55 launch [failed] |
| United States | 1961-06-30 | Wallops Island VA (hand cancel) | (Swanson magenta rubber-stamp) cachet (and signature) on (airmail) cover | Explorer-S55 launch [failed] |
| 1961-08-16: Explorer-12 (EPE-A) | ||||
| United States | 1961-08-15 | Port Canaveral FL | (Goldcraft Cachets) cachet on cover | Explorer-12 (EPE-A) launch |
| United States | 1961-08-15 | Port Canaveral FL | (Goldcraft Cachets) cachet (and signature) on cover | Explorer-12 (EPE-A) launch |
| United States | 1961-08-15 | Port Canaveral FL | (Sarzin) cachet on cover | Explorer-12 (EPE-A) launch (but Explorer-6/Pioneer-5 depicted) |
| United States | 1961-08-16 | Patrick AFB, FL | (SpaceCraft) cachet on cover, also insert | Explorer-12 (EPE-A) launch |
| United States | 1961-08-16 | Patrick AFB, FL | (SpaceCraft) cachet (and signature) on cover, also insert | Explorer-12 (EPE-A) launch |
| 1961-08-25: Explorer-13 (S55A) | ||||
| United States | 1961-08-25 | Wallops Island VA | (SpaceCraft/C. Swanson printed) cachet on cover | Explorer-13 (S55A) launch |
| United States | 1961-08-25 | Wallops Island VA (hand cancel) | (Swanson magenta rubber-stamp) cachet on cover | Explorer-13 (S55A, not S55) launch |
| United States | 1961-08-25 | Wallops Island VA (machine cancel) | (Swanson magenta rubber-stamp) cachet on cover | Explorer-13 (S55A, not S55) launch |
| United States | 1961-08-25 | Wallops Island VA (machine cancel) | (Swanson magenta rubber-stamp) cachet on (airmail) cover | Explorer-13 (S55A, not S55) launch |
| United States | 1961-08-25 | Wallops Island VA | (Black and red rubber-stamp and black typed) cachet on cover | Explorer-13 (S55A) launch |
| 1962-10-02: Explorer-14 (EPE-B) | ||||
| United States | 1962-10-02 | Cape Canaveral FL | (AW/Boerger and hand-printed) cachet on cover | Explorer-14 (EPE-B) launch (but TIROS depicted) |
| United States | 1962-10-02 | Cape Canaveral FL | (GoldCraft Cachets) cachet on cover | Explorer-14 (EPE-B) launch (not "Explorer XV" as in text) (but Mercury boilerplate capsule depicted) |
| United States | 1962-10-02 | Cape Canaveral FL | (GoldCraft Cachets) cachet (slightly different) on cover | Explorer-14 (EPE-B) launch (not "Explorer XV" as in text) (but Mercury boilerplate capsule depicted) |
| United States | 1962-10-03 | Cape Canaveral FL | (Rank velvet) cachet on cover | Explorer-14 (EPE-B) launch |
| United States | 1962-10-03 | Cape Canaveral FL | (SpaceCraft) cachet on cover, also insert or insert variation (minor differences) | Explorer-14 (EPE-B) launch |
| United States | 1962-10-03 | Patrick AFB, FL | (SpaceCraft) cachet on cover, also insert or insert variation (minor differences) | Explorer-14 (EPE-B) launch |
| United States | 1962-10-03 | Patrick AFB, FL | (SpaceCraft) cachet (and signature) on cover, also insert or insert variation (minor differences) | Explorer-14 (EPE-B) launch |
| United States | 1962-10-03 | Cape Canaveral FL | (Sarzin) cachet on cover | Explorer-14 (EPE-B) launch |
| United States | 1962-10-03 | Cape Canaveral FL | (C. Swanson purple and red rubber-stamp) cachet on (airmail) cover | Explorer-14 (EPE-B) launch |
| United States | 1962-10-03 | Cape Canaveral FL | (Swanson/DuBeau? purple and red rubber-stamp) cachet on cover | Explorer-14 (EPE-B) launch |
| United States | 1962-10-03 1964-12-21 | Cape Canaveral FL Satellite Beach FL | (Rank velvet) cachet on cover | Explorer-14 (EPE-B) launch Explorer-26 (EPE-D) launch |
| 1962-10-28: Explorer-156 (EPE-C) | ||||
| United States | 1962-10-28 | Cape Canaveral FL | (Centennial) cachet on cover | Explorer-15 (EPE-C) launch |
| United States | 1962-10-28 | Cape Canaveral FL | (Blue rubber-stamp) cachet on (airmail) cover | Explorer-15 (EPE-C) launch |
| United States | 1962-10-29 (AM cancel) | Cape Canaveral FL | (Sarzin) cachet on cover | Explorer-15 (EPE-C) launch |
| United States | 1962-10-29 (PM cancel) | Cape Canaveral FL | (Sarzin) cachet on cover | Explorer-15 (EPE-C) launch |
| United States | 1962-10-29 | Cape Canaveral FL | (SpaceCraft) cachet on cover | Explorer-15 (EPE-C) launch |
| United States | 1962-10-29 | Cape Canaveral FL | (SpaceCraft Type-B general-purpose and magenta rubber-stamp) cachet on cover | Explorer-15 (EPE-C) launch |
| United States | 1962-10-29 | Cape Canaveral FL | (Swanson purple rubber-stamp) cachet on cover | Explorer-15 (EPE-C) launch |
| 1962-12-16: Explorer-16 (S55B) | ||||
| United States | 1962-12-16 | Wallops Island VA | (SpaceCraft) cachet on cover, also insert | Explorer-16 (S55B) launch |
| United States | 1962-12-16 | Wallops Island VA | (Swanson green and magenta rubber-stamp) cachet on cover | Explorer-16 (S55B) launch |
| United States | 1962-12-16 | Wallops Island VA | (Swanson green and magenta rubber-stamp) cachet on (airmail) cover | Explorer-16 (S55B) launch |
| United States | 1962-12-16 | Wallops Island VA | (Rank velvet) cachet on cover, also insert | Explorer-16 (S55B) launch |
| United States | 1962-12-16 1964-11-06 | Wallops Island VA (machine cancel) Wallops Island VA (hand cancel) | (Rank velvet) cachet on cover, also insert | Explorer-16 (S55B) launch Explorer-23 (S55C) launch |
| 1963-04-03: Explorer-17 (AE-A) | ||||
| United States | 1963-04-02 | Satellite Beach FL | (Swanson blue rubber-stamp and black typed) cachet on cover | Explorer-17 (AE-A) launch |
| United States | 1963-04-02 | Cape Canaveral FL | (Goldcraft Cachets) cachet on cover | Explorer-17 (AE-A) launch (but Mercury boilerplace capsule depicted) |
| United States | 1963-04-02 | Satellite Beach FL | (Rank velvet) cachet on cover | Explorer-17 (AE-A) launch |
| United States | 1963-04-02 | Satellite Beach FL | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-17 (AE-A) launch |
| United States | 1963-04-02 | Satellite Beach FL | (Black printed) cachet on cover | Explorer-17 (AE-A) launch (mis-spelled "Explored-17") |
| United States | 1963-04-03 | Cape Canaveral FL | (Black printed) cachet (same) on cover | Explorer-17 (AE-A) launch (mis-spelled "Explored-17") |
| United States | 1963-04-03 | Cape Canaveral FL | (Rank velvet) cachet (different) on cover | Explorer-17 (AE-A) launch |
| United States | 1963-04-03 | Cape Canaveral FL | (Rank silkscreened) cachet on cover | Explorer-17 (AE-A) launch |
| United States | 1963-04-03 | Patrick AFB, FL | (Rank silkscreened) cachet (different) on cover | Explorer-17 (AE-A) launch |
| United States | 1963-04-03 | Patrick AFB, FL | (Rank silkscreened) cachet (different) on cover | Explorer-17 (AE-A) launch |
| United States | 1963-04-03 | Patrick AFB, FL | (Rank silkscreened) cachet (different) on cover | Explorer-17 (AE-A) launch |
| United States | 1963-04-03 | Patrick AFB, FL | (Rank silkscreened) cachet (different) on cover | Explorer-17 (AE-A) launch |
| United States | 1963-04-03 | Patrick AFB, FL | (Rank silkscreened) cachet (different) on cover | Explorer-17 (AE-A) launch |
| United States | 1963-04-03 | Cape Canaveral FL | (Rank silkscreened) cachet (different) on cover | Explorer-17 (AE-A) launch |
| United States | 1963-04-03 | Cape Canaveral FL | (Rank silkscreened) cachet (different) on cover | Explorer-17 (AE-A) launch |
| United States | 1963-04-03 | Cape Canaveral FL | (Rank? silkscreened) cachet (different) on cover | Explorer-17 (AE-A) launch |
| United States | 1963-04-03 | Cape Canaveral FL | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-17 (AE-A) launch |
| United States | 1963-04-03 | Patrick AFB, FL | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-17 (AE-A) launch |
| United States | 1963-04-03 | Cape Canaveral FL | (Sarzin) cachet on cover | Explorer-17 (AE-A) launch (but Explorer-12/14/15/26 type depicted) |
| United States | 1963-04-03 | Cape Canaveral FL (machine cancel) | (Centennial) cachet on cover | Explorer-17 (AE-A) launch |
| United States | 1963-04-03 | Cape Canaveral FL (hand cancel) | (Centennial) cachet on cover | Explorer-17 (AE-A) launch |
| United States | 1963-04-03 | Cape Canaveral FL | (C. Swanson purple rubber-stamp) cachet on cover | Explorer-17 (AE-A) launch |
| United States | 1963-04-03 | Cape Canaveral FL | (Black printed and black typed) cachet on cover | Explorer-17 (AE-A) launch |
| 1963-11-26: Explorer-18 (IMP-A/IMP-1) | ||||
| United States | 1963-11-26 1964-10-04 | Satellite Beach FL Satellite Beach FL | (Black printed) cachet on cover | Explorer-18 (IMP-A/IMP-1) launch Explorer-21 (IMP-B/IMP-2) launch |
| United States | 1963-11-26 | Satellite Beach FL | (Rank velvet) cachet on cover | Explorer-18 (IMP-A/IMP-1) launch |
| United States | 1963-11-27 | Cape Canaveral FL | (Rank velvet) cachet on cover | Explorer-18 (IMP-A/IMP-1) launch |
| United States | 1963-11-27 | Cape Canaveral FL | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-18 (IMP-A/IMP-1) launch |
| United States | 1963-11-27 | Patrick AFB, FL | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-18 (IMP-A/IMP-1) launch |
| United States | 1963-11-27 | Cape Canaveral FL (machine cancel) | (Centennial) cachet on cover | Explorer-18 (IMP-A/IMP-1) launch |
| United States | 1963-11-27 | Cape Canaveral FL (hand cancel) | (Centennial) cachet on cover | Explorer-18 (IMP-A/IMP-1) launch |
| United States | 1963-11-27 | Cape Canaveral FL | (Sarzin) cachet on cover | Explorer-18 (IMP-A/IMP-1) launch |
| United States | 1963-11-27 | Cape Canaveral FL | (Red printed and black typed) cachet on cover | Explorer-18 (IMP-A/IMP-1) launch |
| United States | 1963-11-27 | Cape Canaveral FL (machine cancel) | (Swanson/DuBeau? purple rubber-stamp and black hand-printed) cachet on cover | Explorer-18 (IMP-A/IMP-1) launch |
| United States | 1963-11-27 | Cape Canaveral FL (machine cancel) | (Swanson/DuBeau? purple rubber-stamp and black hand-printed) cachet (and signature) on cover | Explorer-18 (IMP-A/IMP-1) launch |
| United States | 1963-11-27 | Cape Canaveral FL (hand cancel) | (Swanson/DuBeau? black and purple rubber-stamp) cachet on cover | Explorer-18 (IMP-A/IMP-1) launch |
| United States | 1963-11-27 | Cape Canaveral FL | (Orbit Covers, no logo) cachet on cover | Explorer-18 (IMP-A/IMP-1) launch |
| United States | 1963-11-27 1964-10-04 | Cape Canaveral FL Satellite Beach FL | (Rank velvet) cachet on cover | Explorer-18 (IMP-A/IMP-1) launch Explorer-21 (IMP-B/IMP-2) launch |
| 1963-12-19: Explorer-19 (AED-A) | ||||
| United States | 1963-12-19 | Vandenberg AFB, CA | (Swanson/DuBeau? blue rubber-stamp) cachet on cover | Explorer-19 (AED-A) launch |
| United States | 1963-12-19 | Vandenberg AFB, CA (double cancel) | (Swanson/DuBeau? blue rubber-stamp) cachet on cover | Explorer-19 (AED-A) launch |
| United States | 1963-12-19 | Vandenberg AFB, CA | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-19 (AED-A) launch |
| United States | 1963-12-19 | Vandenberg AFB, CA | (Sarzin?) cachet on cover | Explorer-19 (AED-A) launch |
| United States | 1963-12-19 | Vandenberg AFB, CA | (Rank velvet) cachet on cover | Explorer-19 (AED-A) launch |
| 1964-03-19: Explorer-S66 [failed] | ||||
| United States | 1964-03-19 | Cape Canaveral FL | (Sarzin) cachet on cover | Explorer-S66 launch [failed] (but OAO-1 depicted) |
| United States | 1964-03-19 | Cape Canaveral FL | (Sokalsky red) cachet on cover | Explorer-S66 launch [failed] |
| United States | 1964-03-19 | Cape Canaveral FL | (Sokalsky green) cachet (different) on cover | Explorer-S66 launch [failed] |
| United States | 1964-03-19 | Cape Canaveral FL (hand cancel) | (C. Swanson black rubber-stamp) cachet on cover | Explorer-S66 launch [failed] |
| United States | 1964-03-19 | Cape Canaveral FL (machine cancel) | (C. Swanson black rubber-stamp) cachet on cover | Explorer-S66 launch [failed] |
| United States | 1964-03-19 | Cape Canaveral FL (machine cancel) | (C. Swanson black rubber-stamp) cachet (slightly different) on cover | Explorer-S66 launch [failed] |
| United States | 1964-03-19 | Cape Canaveral FL (machine cancel) | (C. Swanson black rubber-stamp) cachet (slightly different) on cover | Explorer-S66 launch [failed] |
| United States | 1964-03-19 | Cape Canaveral FL | (C. Swanson purple rubber-stamp) cachet on cover | Explorer-S66 launch [failed] |
| United States | 1964-03-19 | Patrick AFB, FL | (C. Swanson black rubber-stamp and dark-green printed) cachet on cover | Explorer-S66 launch [failed] |
| United States | 1964-03-19 | Cape Canaveral FL (machine cancel) | (Centennial black rocket, type-1) cachet on cover | Explorer-S66 launch [failed] (Pioneer-3/4 type, Pioneer-5/Explorer-62, and Vanguard-2 depicted) |
| United States | 1964-03-19 | Cape Canaveral FL (hand cancel) | (Centennial black rocket, type-1) cachet on cover | Explorer-S66 launch [failed] (Pioneer-3/4 type, Pioneer-5/Explorer-62, and Vanguard-2 depicted) |
| United States | 1964-03-19 | Satellite Beach FL | (Goldcraft brown) cachet on cover | Explorer-S66 launch [failed] |
| United States | 1964-03-20 | Cape Canaveral FL | (Goldcraft red) cachet on cover | Explorer-S66 launch [failed] |
| 1964-08-25: Explorer-20 (IE-A, Topsi) | ||||
| United States | 1964-08-25 | Vandenberg AFB, CA | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-20 (IE-A) launch |
| United States | 1964-08-25 | Vandenberg AFB, CA | (Sarzin?) cachet on cover, also (hand-written) insert | Explorer-20 (IE-A) launch |
| United States | 1964-08-25 | Vandenberg AFB, CA | (Swanson/DuBeau? blue rubber-stamp) cachet on cover | Explorer-20 (IE-A) launch |
| 1964-10-04: Explorer-21 (IMP-B/IMP-2) | ||||
| United States | 1964-10-04 | Patrick AFB, FL | (Sarzin) cachet on cover | Explorer-21 (IMP-B/IMP-2) launch |
| United States | 1964-10-04 | Patrick AFB, FL | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-21 (IMP-B/IMP-2) launch |
| United States | 1964-10-04 | Patrick AFB, FL | (SpaceCraft/Swanson) cachet (and signature) on cover, also insert | Explorer-21 (IMP-B/IMP-2) launch |
| United States | 1964-10-04 | Cape Canaveral FL | (Centennial) cachet on cover, also (hand-written) insert | Explorer-21 (IMP-B/IMP-2) launch |
| United States | 1964-10-04 | Patrick AFB, FL | (C. Swanson purple and blue rubber-stamp) cachet on cover | Explorer-21 (IMP-B/IMP-2) launch |
| United States | 1964-10-04 1963-11-26 | Satellite Beach FL Satellite Beach FL | (Black printed) cachet on cover | Explorer-21 (IMP-B/IMP-2) launch Explorer-18 (IMP-A/IMP-1) launch |
| United States | 1964-10-04 1963-11-27 | Satellite Beach FL Cape Canaveral FL | (Rank velvet) cachet on cover | Explorer-21 (IMP-B/IMP-2) launch Explorer-18 (IMP-A/IMP-1) launch |
| 1964-10-09: Explorer-22 (S66A, BE-B) | ||||
| United States | 1964-10-09 | Vandenberg AFB, CA | (Sarzin?) cachet on cover | Explorer-22 (BE-B) launch |
| United States | 1964-10-09 | Vandenberg AFB, CA | (SpaceCraft/Swanson) cachet (and signature) on cover, also insert | Explorer-22 (BE-B) launch |
| United States | 1964-10-09 | Vandenberg AFB, CA | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-22 (BE-B) launch |
| United States | 1964-10-09 | Vandenberg AFB, CA | (Swanson/DuBeau? blue rubber-stamp) cachet on cover | Explorer-22 (BE-B) launch |
| United States | 1964-10-09 | Vandenberg AFB, CA | (Orbit Covers, no logo) cachet on cover, also (hand-written) insert | Explorer-22 (BE-B) launch |
| 1964-11-06: Explorer-23 (S55C) | ||||
| United States | 1964-11-06 | Wallops Island VA | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-23 (S55C) launch |
| United States | 1964-11-06 | Wallops Island VA | (Sarzin?) cachet on cover | Explorer-23 (S55C) launch (fantasy depiction) |
| United States | 1964-11-06 | Wallops Island VA | (Swanson blue rubber-stamp) cachet on cover | Explorer-23 (S55C) launch |
| United States | 1964-11-06 | Wallops Island VA | (Swanson blue rubber-stamp) cachet on (airmail) cover | Explorer-23 (S55C) launch |
| United States | 1964-11-06 1962-12-16 | Wallops Island VA Wallops Island VA | (Rank velvet) cachet on cover, also insert | Explorer-23 (S55C) launch Explorer-16 (S55B) launch |
| 1964-11-21: Explorer-24 (ADE-B) and Explorer-25 / Injun-4 | ||||
| United States | 1964-11-21 | Vandenberg AFB, CA | (SpaceCraft/Swanson) cachet (and signature) on cover, also insert or insert variation (different arrows) or insert variation2 (different arrows and slightly different line lengths) | Explorer-24 (ADE-B) and Explorer-25 (Injun-4) launch |
| United States | 1964-11-21 | Vandenberg AFB, CA | (SpaceCraft/Swanson) cachet on cover, also insert or insert variation (different arrows) or insert variation2 (different arrows and slightly different line lengths) | Explorer-24 (ADE-B) and Explorer-25 (Injun-4) launch |
| United States | 1964-11-21 | Vandenberg AFB, CA | (Sarzin?) cachet on cover, also (hand-written) insert | Explorer-24 (ADE-B) and Explorer-25 (Injun-4) launch (but Vela depicted) |
| United States | 1964-11-21 | Vandenberg AFB, CA | (Goldcraft Cachets) cachet on cover | Explorer-24 (ADE-B) and Explorer-25 (Injun-4) launch |
| United States | 1964-11-21 | Vandenberg AFB, CA | (Swanson red rubber-stamp) cachet on cover | Explorer-24 (ADE-B) and Explorer-25 (Injun-4) launch |
| United States | 1964-11-21 | Vandenberg AFB, CA | (DuBeau? red and blue printed) cachet on cover | Explorer-24 (ADE-B) and Explorer-25 (Injun-4) launch |
| United States | 1964-11-21 | Vandenberg AFB, CA | (Swanson/DuBeau? magenta and blue printed) cachet on cover | Explorer-24 (ADE-B) and Explorer-25 (Injun-4) launch |
| 1964-12-21: Explorer-26 (EPE-D) | ||||
| United States | 1964-12-21 | Patrick AFB, FL | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-26 (EPE-D) launch |
| United States | 1964-12-21 | Cape Canaveral FL | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-26 (EPE-D) launch |
| United States | 1964-12-21 | Cape Canaveral FL | (Sokalsky red) cachet on cover | Explorer-26 (EPE-D) launch |
| United States | 1964-12-21 | Cape Canaveral FL (hand cancel) | (Centennial red earth) cachet on cover | Explorer-26 (EPE-D) launch (but Relay, Vanguard-2, Pioneer-3/4 type, Explorer-1, TIROS/ESSA type depicted) |
| United States | 1964-12-21 | Cape Canaveral FL (machine cancel) | (Centennial red earth) cachet on cover | Explorer-26 (EPE-D) launch (but Relay, Vanguard-2, Pioneer-3/4 type, Explorer-1, TIROS/ESSA type depicted) |
| United States | 1964-12-21 | Cape Canaveral FL | (Sarzin) cachet on cover | Explorer-26 (EPE-D) launch (fantasy manned satellite depicted) |
| United States | 1964-12-21 | Patrick AFB, FL | (C. Swanson purple rubber-stamp) cachet on cover | Explorer-26 (EPE-D) launch |
| United States | 1964-12-21 | Cape Canaveral FL | (C. Swanson purple rubber-stamp) cachet (slightly-different) on cover | Explorer-26 (EPE-D) launch |
| United States | 1964-12-21 | Cape Canaveral FL | (C. Swanson purple rubber-stamp) cachet (slightly different) on (airmail) cover | Explorer-26 (EPE-D) launch |
| United States | 1964-12-21 | Patrick AFB, FL | (Zaso black-and-white sticker and purple rubber-stamp) cachet on cover | Explorer-26 (EPE-D) launch |
| United States | 1964-12-21 | Cape Canaveral FL | (Orbit Covers, no logo) cachet on cover | Explorer-26 (EPE-D) launch (but Vela depicted) |
| United States | 1964-12-21 | Cape Canaveral FL | (Goldcraft Cachets and red rubber-stamp) cachet on cover | Explorer-26 (EPE-D) launch (but Pioneer-5/Explorer-62 depicted) |
| United States | 1964-12-21 1962-10-03 | Satellite Beach FL Cape Canaveral FL | (Rank velvet) cachet on cover | Explorer-26 (EPE-D) launch Explorer-14 (EPE-B) launch |
| 1965-04-29: Explorer-27 (BE-C) | ||||
| United States | 1965-04-29 | Wallops Island VA | (Sarzin?) cachet on cover | Explorer-27 (BE-C) launch |
| United States | 1965-04-29 | Wallops Island VA | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-27 (BE-C) launch |
| United States | 1965-04-29 | Wallops Island VA | (Rank velvet) cachet on cover | Explorer-27 (BE-C) launch |
| United States | 1965-04-29 | Wallops Island VA | (Rank silkscreened?) cachet on cover | Explorer-27 (BE-C) launch |
| United States | 1965-04-29 | Wallops Island VA | (Centennial) cachet on cover | Explorer-27 (BE-C) launch |
| United States | 1965-04-29 | Wallops Island VA | (Swanson blue and magenta rubber-stamp) cachet on cover | Explorer-27 (BE-C) launch |
| United States | 1965-04-29 | Wallops Island VA | (Swanson blue and magenta rubber-stamp) cachet on (airmail) cover | Explorer-27 (BE-C) launch |
| United States | 1965-04-29 | Wallops Island VA | (Swanson blue and magenta rubber-stamp) cachet (different) on cover | Explorer-27 (BE-C) launch |
| United States | 1965-04-29 | Wallops Island VA | (Swanson green and magenta rubber-stamp) cachet on cover | Explorer-27 (BE-C) launch |
| United States | 1965-04-29 | Wallops Island VA | (Swanson green and magenta rubber-stamp) cachet (different) on cover | Explorer-27 (BE-C) launch |
| 1965-05-29: Explorer-28 (IMP-C/IMP-3) | ||||
| United States | 1965-05-29 | Cape Canaveral FL | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-28 (IMP-C/IMP-3) launch |
| United States | 1965-05-29 | Cape Canaveral FL | (Celestial) cachet on cover | Explorer-28 (IMP-C/IMP-3) launch |
| United States | 1965-05-29 | Cape Canaveral FL | (Swanson cyan rubber-stamp) cachet on cover | Explorer-28 (IMP-C/IMP-3) launch |
| United States | 1965-05-29 | Cape Canaveral FL | (Swanson blue rubber-stamp and black typed) cachet on cover | Explorer-28 (IMP-C/IMP-3) launch |
| United States | 1965-05-29 | Cape Canaveral FL | (Sarzin) cachet on cover | Explorer-28 (IMP-C/IMP-3) launch |
| United States | 1965-05-29 | Cape Canaveral FL | (C. Swanson red and black rubber-stamp) cachet on cover | Explorer-28 (IMP-C/IMP-3) launch |
| United States | 1965-05-29 | Cape Canaveral FL | (Orbit Covers, no logo) cachet on cover | Explorer-28 (IMP-C/IMP-3) launch |
| United States | 1965-05-29 | Cape Canaveral FL | (Hand-printed) cachet on cover | Explorer-28 (IMP-C/IMP-3) launch |
| 1965-11-06: Explorer-29 / GEOS-1 | ||||
| United States | 1965-11-06 | Patrick AFB, FL | (SpaceCraft/Swanson) cachet (and signature) on cover, also insert or insert variation (slightly different line lengths) | Explorer-29 (GEOS-1) launch |
| United States | 1965-11-06 | Patrick AFB, FL | (SpaceCraft/Swanson) cachet on cover, also insert or insert variation (slightly different line lengths) | Explorer-29 (GEOS-1) launch |
| United States | 1965-11-06 | Cape Canaveral FL (machine cancel) | (Centennial) cachet on cover | Explorer-29 (GEOS-1) launch (fantasy depiction) |
| United States | 1965-11-06 | Cape Canaveral FL (hand cancel) | (Centennial) cachet on cover | Explorer-29 (GEOS-1) launch (fantasy depiction) |
| United States | 1965-11-06 | Patrick AFB, FL | (Sarzin) cachet on cover | Explorer-29 (GEOS-1) launch (but Explorer-17 depicted) |
| United States | 1965-11-06 | Patrick AFB, FL | (Rank velvet) cachet on cover | Explorer-29 (GEOS-1) launch |
| United States | 1965-11-06 | Cape Canaveral FL | (Celestial) cachet on cover | Explorer-29 (GEOS-1) launch |
| United States | 1965-11-06 | Cape Canaveral FL | (Artopages) cachet on cover | Explorer-29 (GEOS-1) launch |
| 1965-11-19: Explorer-30 / SolRad-8 | ||||
| United States | 1965-11-19 | Wallops Island VA | (SpaceCraft/Swanson) cachet on cover, also insert or insert variation (text length variation) and back | Explorer-30 (SolRad-8) launch; also IQSY |
| United States | 1965-11-19 | Wallops Island VA | (Sarzin?) cachet on cover | Explorer-30 (SolRad-8) launch (fantasy depiction); also IQSY |
| United States | 1965-11-19 | Wallops Island VA | (Rank velvet) cachet on cover | Explorer-30 (SolRad-8) launch; also IQSY |
| United States | 1965-11-19 | Wallops Island VA | (Rank velvet, trial with overlay) cachet on cover | Explorer-30 (SolRad-8) launch; also IQSY |
| United States | 1965-11-19 | Wallops Island VA | (Swanson blue and magenta rubber-stamp) cachet on cover | Explorer-30 (SolRad-8) launch; also IQSY |
| United States | 1965-11-19 | Wallops Island VA | (Swanson blue and magenta rubber-stamp) cachet (different) on cover | Explorer-30 (SolRad-8) launch; also IQSY |
| United States | 1965-11-19 | Wallops Island VA | (HJM black and Swanson blue and magenta rubber-stamp) cachet on cover | Explorer-30 (SolRad-8) launch; also IQSY |
| United States | 1965-11-19 | Wallops Island VA | (Centennial black rocket, type-1) cachet on cover | Explorer-30 (SolRad-8) launch (Pioneer-3/4 type, Pioneer-5/Explorer-62, and Vanguard-2 depicted) |
| United States | 1965-11-19 | Wallops Island VA | (Red printed) cachet on cover | Explorer-30 (SolRad-8) launch; also IQSY |
| 1965-11-28: Explorer-31 / ISIS-X (and Alouette-2) | ||||
| United States | 1965-11-28 | Vandenberg AFB, CA | (SpaceCraft/Swanson) cachet (and signature) on cover, also insert | Explorer-31 (ISIS-X) launch |
| United States | 1965-11-28 | Vandenberg AFB, CA | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-31 (ISIS-X) launch |
| United States | 1965-11-28 | Vandenberg AFB, CA | (Sarzin) cachet on cover | Explorer-31 (ISIS-X) launch (fantasy depiction) |
| United States | 1965-11-28 | Vandenberg AFB, CA | (H.D.W.) cachet on cover, also back | Explorer-31 (ISIS-X) launch; reproduction of Canada 445 (in cachet) |
| United States | 1965-11-28 | Vandenberg AFB, CA | (Vandy?/DuBeau? blue satellite-launch and blue rubber-stamp) cachet on cover | Explorer-31 (ISIS-X) launch |
| United States | 1965-11-28 | Vandenberg AFB, CA | (Astro Covers, no logo) cachet on cover | Explorer-31 (ISIS-X) launch |
| United States | 1965-11-28 | Vandenberg AFB, CA | (Orbit Covers, no logo) cachet on cover | Explorer-31 launch |
| United States | 1965-11-28 1962-09-28 | Vandenberg AFB, CA Vandenberg AFB, CA | (Rank velvet) cachet on cover | Explorer-31 (ISIS-X) Alouette-1 launch |
| 1966-05-25: Explorer-32 (AE-B) | ||||
| United States | 1966-05-25 | Cape Canaveral FL | (SpaceCraft/Swanson) cachet on cover, also insert or insert variation (slightly different line lengths) | Explorer-32 (AE-B) launch |
| United States | 1966-05-25 | Patrick AFB, FL | (SpaceCraft/Swanson) cachet on cover, also insert or insert variation (slightly different line lengths) | Explorer-32 (AE-B) launch |
| United States | 1966-05-25 | Cape Canaveral FL | (Sarzin) cachet on cover | Explorer-32 (AE-B) launch (fantasy depiction) |
| United States | 1966-05-25 | Cape Canaveral FL (hand cancel) | (Centennial) cachet on cover | Explorer-32 (AE-B) launch |
| United States | 1966-05-25 | Cape Canaveral FL (machine cancel) | (Centennial) cachet on cover | Explorer-32 (AE-B) launch |
| United States | 1966-05-25 | Cape Canaveral FL | (Orbit Covers, no logo) cachet on cover | Explorer-32 (AE-B) launch |
| United States | 1966-05-25 | Cape Canaveral FL | (Swanson/DuBeau? blue and purple rubber-stamp) cachet on (airmail) cover | Explorer-32 (AE-B) launch |
| 1966-07-01: Explorer-33 (IMP-D/AIMP-1) | ||||
| United States | 1966-07-01 | Patrick AFB, FL | (Sarzin) cachet on cover | Explorer-33 (IMP-D/AIMP-1) launch |
| United States | 1966-07-01 | Patrick AFB, FL | (SpaceCraft/Swanson) cachet on cover, also insert or insert variation (slightly different line lengths) | Explorer-33 (IMP-D/AIMP-1) launch |
| United States | 1966-07-01 | Cape Canaveral FL | (SpaceCraft/Swanson) cachet on cover, also insert or insert variation (slightly different line lengths) | Explorer-33 (IMP-D/AIMP-1) launch |
| United States | 1966-07-01 | Cape Canaveral FL (machine cancel) | (Orbit Covers, no logo) cachet on cover | Explorer-33 (IMP-D/AIMP-1) launch |
| United States | 1966-07-01 | Cape Canaveral FL (hand cancel) | (Orbit Covers, no logo) cachet on cover | Explorer-33 (IMP-D/AIMP-1) launch |
| United States | 1966-07-01 | Cape Canaveral FL | (Astro Covers, no logo) cachet on cover | Explorer-33 (IMP-D/AIMP-1) launch |
| United States | 1966-07-01 | Cape Canaveral FL | (Swanson purple rubber-stamp) cachet on cover | Explorer-33 (IMP-D/AIMP-1) launch |
| United States | 1966-07-01 | Cape Canaveral FL | (Black printed and black typed) cachet on cover | Explorer-33 (IMP-D/AIMP-1) launch |
| United States | 1966-07-01 | Cape Canaveral FL | (Grey and tan and blue printed) cachet on cover | Explorer-33 (IMP-D/AIMP-1) launch |
| United States | 1966-07-01 | Cape Canaveral FL | (Centennial) cachet on cover | Explorer-33 (IMP-D/AIMP-1) launch |
| United States | 1966-07-01 | Cape Canaveral FL | (Red and black rubber-stamp) cachet on cover | Explorer-33 (IMP-D/AIMP-1) launch |
| 1967-05-24: Explorer-34 (IMP-F/IMP-4) | ||||
| United States | 1967-05-24 | Cape Canaveral FL | (Orbit Covers) cachet on cover | Explorer-34 (IMP-F/IMP-4) launch |
| United States | 1967-05-24 | Cape Canaveral FL | (Orbit Covers) cachet (different) on cover | Explorer-34 (IMP-F/IMP-4) launch |
| United States | 1967-05-24 | Vandenberg AFB, CA | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-34 (IMP-F/IMP-4) launch |
| United States | 1967-05-24 | Vandenberg AFB, CA | (Centennial) cachet on cover | Explorer-34 (IMP-F/IMP-4) launch |
| United States | 1967-05-24 | Vandenberg AFB, CA | (Swanson/Vandy? blue rubber-stamp) cachet on cover | Explorer-34 (IMP-F/IMP-4) launch |
| United States | 1967-05-24 | Vandenberg AFB, CA | (Swanson/Vandy? blue rubber-stamp) cachet on (airmail) cover | Explorer-34 (IMP-F/IMP-4) launch |
| United States | 1967-05-24 | Vandenberg AFB, CA | (Swanson/Vandy? black rubber-stamp) cachet on cover | Explorer-34 (IMP-F/IMP-4) launch |
| 1967-07-19: Explorer-35 (IMP-E/AIMP-2) | ||||
| United States | 1967-07-19 | Kennedy Space Center FL | (R. DuBeau cyan rubber-stamp) cachet on cover | Explorer-35 (IMP-E/AIMP-2) launch |
| United States | 1967-07-19 | Patrick AFB, FL | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-35 (IMP-E/AIMP-2) launch |
| United States | 1967-07-19 | Cape Canaveral FL | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-35 (IMP-E/AIMP-2) launch |
| United States | 1967-07-19 | Kennedy Space Center FL | (blank/no) cachet on cover | Explorer-35 (IMP-E/AIMP-2) launch |
| United States | 1967-07-19 | Cape Canaveral FL | (Orbit Covers grey and dark-magenta) cachet on cover | Explorer-35 (IMP-E/AIMP-2) launch |
| United States | 1967-07-19 | Cape Canaveral FL | (Orbit Covers blue-gray and black) cachet on cover | Explorer-35 (IMP-E/AIMP-2) launch |
| United States | 1967-07-19 | Cape Canaveral FL | (Orbit Covers gray and black and brown) cachet on cover | Explorer-35 (IMP-E/AIMP-2) launch |
| United States | 1967-07-19 | Cape Canaveral FL | (HJM black and black typed) cachet on cover | Explorer-35 (IMP-E/AIMP-2) launch; also "Explorer"-10 (upper-middle) |
| United States | 1967-07-19 | Cape Canaveral FL | (Sarzin) cachet on cover | Explorer-35 (IMP-E/AIMP-2) launch |
| United States | 1967-07-19 | Cape Canaveral FL | (Jim Fitzpatrick cyan rubber-stamp and black typed) cachet on cover | Explorer-35 (IMP-E/AIMP-2) launch |
| United States | 1967-07-19 | Cape Canaveral FL | (Jim Fitzpatrick purple and magenta rubber-stamp) cachet on cover | Explorer-35 (IMP-E/AIMP-2) launch |
| United States | 1967-07-19 | Cape Canaveral FL | (Jim Fitzpatrick cyan rubber-stamp and magenta hand-printed) cachet on cover | Explorer-35 (IMP-E/AIMP-2) launch |
| United States | 1967-07-19 | Cape Canaveral FL (hand cancel) | (Centennial) cachet on cover | Explorer-35 (IMP-E/AIMP-2) launch |
| United States | 1967-07-19 | Cape Canaveral FL (machine cancel) | (Centennial) cachet on cover | Explorer-35 (IMP-E/AIMP-2) launch |
| United States | 1967-07-19 | Cape Canaveral FL (machine cancel) | (Centennial) cachet (slightly different) on cover | Explorer-35 (IMP-E/AIMP-2) launch |
| United States | 1967-07-19 | Kennedy Space Center FL | (Cyan and magenta typed) cachet on cover | Explorer-35 (IMP-E/AIMP-2) launch |
| United States | 1967-07-19 | Cape Canaveral FL (hand cancel) | (Sokalsky red) cachet on cover | Explorer-35 (IMP-E/AIMP-2) launch |
| United States | 1967-07-19 | Cape Canaveral FL (machine cancel) | (Sokalsky green) cachet (different) on cover | Explorer-35 (IMP-E/AIMP-2) launch |
| Australia | 1967-07-20 | Canberra ACT | (Blue printed/sticker and black typed) cachet on cover | Explorer-35 (IMP-E/AIMP-2) launch |
| Explorer-35 (events) | ||||
| United States | 1967-07-22 | Cape Canaveral FL | (Orbit Covers, no logo) cachet on cover | Explorer-35 in lunar orbit |
| 1968-01-11: Explorer-36 / GEOS-2 | ||||
| United States | 1968-01-11 | Vandenberg AFB, CA | (Orbit Covers) cachet on cover | Explorer-36 (GEOS-2) launch |
| United States | 1968-01-11 | Vandenberg AFB, CA | (Swanson/DuBeau? blue rubber-stamp) cachet on cover | Explorer-36 (GEOS-2) launch |
| United States | 1968-01-11 | Lompoc CA, Vandenberg AFB | (SpaceCraft/Swanson) cachet on cover, also insert or insert variation (slightly different line lengths) | Explorer-36 (GEOS-2) launch |
| United States | 1968-01-11 | Vandenberg AFB, CA | (SpaceCraft/Swanson) cachet on cover, also insert and insert back | Explorer-36 (GEOS-2) launch; also "Explorer-29" (in text on insert back) |
| United States | 1968-01-11 | Vandenberg AFB, CA | (SpaceCraft/Swanson) cachet (and signature) on cover, also insert and insert back | Explorer-36 (GEOS-2) launch; also "Explorer-29" (in text on insert back) |
| United States | 1968-01-11 | Vandenberg AFB, CA | (Centennial brown rocket, type-2 and black text) cachet on cover | Explorer-36 (GEOS-2) launch (Transit-2A, Pioneer-5/Explorer-62, TIROS/ESSA, and Vanguard-2 depicted) |
| 1968-03-05: Explorer-37 / SolRad-9 | ||||
| United States | 1968-03-05 | Wallops Island VA | (Orbit Covers) cachet on cover | Explorer-37 (SolRad-9) launch (but Explorer-7 depicted) |
| United States | 1968-03-05 | Wallops Island VA (hand cancel) | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-37 (SolRad-9) launch |
| United States | 1968-03-05 | Wallops Island VA (machine cancel) | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-37 (SolRad-9) launch |
| United States | 1968-03-05 | Wallops Island VA | (Swanson green and magenta rubber-stamp) cachet on cover | Explorer-37 (SolRad-9) launch |
| United States | 1968-03-05 | Wallops Island VA | (Swanson green and magenta rubber-stamp) cachet (different) on cover | Explorer-37 (SolRad-9) launch |
| United States | 1968-03-05 | Wallops Island VA | (Swanson blue and magenta rubber-stamp) cachet on cover | Explorer-37 (SolRad-9) launch |
| United States | 1968-03-05 | Wallops Island VA | (Swanson blue and magenta rubber-stamp) cachet on (airmail) cover | Explorer-37 (SolRad-9) launch |
| United States | 1968-03-05 | Wallops Island VA | (Swanson blue and magenta rubber-stamp) cachet (different) on cover | Explorer-37 (SolRad-9) launch |
| United States | 1968-03-05 | Wallops Island VA | (Centennial) cachet on cover | Explorer-37 (SolRad-9) launch |
| 1968-07-04: Explorer-38 (RAE-1) | ||||
| United States | 1968-07-04 | Vandenberg AFB, CA | (Orbit Covers) cachet on cover | Explorer-38 (RAE-1) launch |
| United States | 1968-07-04 | Vandenberg AFB, CA | (SpaceCraft/Swanson) cachet on cover, also insert1, insert2, insert2 back | Explorer-38 (RAE-1) launch |
| United States | 1968-07-04 | Vandenberg AFB, CA | (Sarzin?) cachet on cover | Explorer-38 (RAE-1) (mis-labeled "Explorer-36") launch (fantasy depiction) |
| United States | 1968-07-04 | Vandenberg AFB, CA | (Swanson/DuBeau? blue rubber-stamp) cachet on cover | Explorer-38 (RAE-1) launch |
| United States | 1968-07-04 | Vandenberg AFB, CA | (Centennial) cachet on cover | Explorer-38 (RAE-1) launch |
| 1968-08-08: Explorer-39 (ADE-C) and Explorer-40 / Injun-5 | ||||
| United States | 1968-08-08 | Vandenberg AFB, CA | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-39 (ADE-C) and Explorer-40 (Injun-5) launch (but other Explorer depicted) |
| United States | 1968-08-08 | Lompoc CA, Vandenberg AFB | (SpaceCraft/Swanson sticker) cachet on cover, also insert | Explorer-39 (ADE-C) and Explorer-40 (Injun-5) launch (but other Explorer depicted) |
| United States | 1968-08-08 | Vandenberg AFB, CA | (Orbit Covers) cachet on cover | Explorer-39 (ACE-C) and Explorer-40 (Injun-5) launch |
| United States | 1968-08-08 | Vandenberg AFB, CA | (Swanson/DuBeau? blue rubber-stamp) cachet on cover | Explorer-39 (ADE-C) and Explorer-40 (Injun-5) launch |
| United States | 1968-08-08 | Vandenberg AFB, CA | (Sarzin?) cachet on cover | Explorer-39 (ADE-C) and Explorer-40 (Injun-5) launch |
| United States | 1968-08-08 | Vandenberg AFB, CA | (Centennial) cachet on cover | Explorer-39 (ADE-C) and Explorer-40 (Injun-5) launch |
| 1969-06-21: Explorer-41 (IMP-G/IMP-5) | ||||
| United States | 1969-06-21 | Vandenberg AFB, CA | (Orbit Covers) cachet on cover | Explorer-41 (IMP-G/IMP-5) launch; (incorrectly noted as "IMP-7" in text) |
| United States | 1969-06-21 | Vandenberg AFB, CA | (Sarzin) cachet on cover | Explorer-41 (IMP-G/IMP-5) launch |
| United States | 1969-06-21 | Lompoc CA, Vandenberg AFB | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-41 (IMP-G/IMP-5) launch |
| United States | 1969-06-21 | Vandenberg AFB, CA | (SpaceCraft/Swanson) cachet on cover, also insert | Explorer-41 (IMP-G/IMP-5) launch |
| United States | 1969-06-21 | Lompoc CA, Vandenberg AFB | (DuBeau?/Swanson blue and magenta rubber-stamp) cachet on cover | Explorer-41 (IMP-G/IMP-5) launch (but ESRO-2A depicted)1 |
| United States | 1969-06-21 | Vandenberg AFB, CA | (Centennial red rocket, type-1) cachet on cover | Explorer-41 (IMP-G/IMP-5) launch (Pioneer-3/4 type, Pioneer-5/Explorer-62, and Vanguard-2 depicted) |
| 1970-12-12: Explorer-42 (Uhuru) | ||||
| United States | 1970-12-12 | Cape Canaveral FL | (Space Voyage) cachet on cover, also insert | Explorer-42 (Uhuru) launch |
| United States | 1970-12-12 | Satellite Beach FL | (Space Voyage) cachet on cover, also insert | Explorer-42 (Uhuru) launch |
| 1971-03-13: Explorer-43 (IMP-H/IMP-6) | ||||
| United States | 1971-03-12 | Kennedy Space Center FL | (Cyan printed, based on a Sokalsky design) cachet on cover | Explorer-43 (IMP-H/IMP-6) launch |
| United States | 1971-03-13 | Cape Canaveral FL (machine cancel) | (Orbit Covers) cachet on cover | Explorer-43 (IMP-H/IMP-6) launch |
| United States | 1971-03-13 | Cape Canaveral FL (hand cancel) | (Orbit Covers) cachet on cover | Explorer-43 (IMP-H/IMP-6) launch |
| United States | 1971-03-13 | Cape Canaveral FL (hand cancel) | (Orbit Covers) cachet (and signatures) on cover | Explorer-43 (IMP-H/IMP-6) launch |
| United States | 1971-03-13 | Kennedy Space Center FL | (Space Voyage) cachet on cover, also insert | Explorer-43 (IMP-H/IMP-6) launch; (incorrectly noted as "IMP-I" in text) |
| United States | 1971-03-13 | Cape Canaveral FL | (Space Voyage) cachet on cover, also insert | Explorer-43 (IMP-H/IMP-6) launch; (incorrectly noted as "IMP-I" in text) |
| United States | 1971-03-13 | Cape Canaveral FL | (Space Voyage) cachet (and signatures) on cover, also insert | Explorer-43 (IMP-H/IMP-6) launch; (incorrectly noted as "IMP-I" in text) |
| United States | 1971-03-13 | Kennedy Space Center FL | (InterSpace Cover) cachet on cover | Explorer-43 (IMP-H/IMP-6) launch; (incorrectly noted as "IMP-I" in text) |
| United States | 1971-03-13 | Cape Canaveral FL | (Space Voyage/InterSpace Cover black printed - Sarzin hybrid) cachet on cover | Explorer-43 (IMP-H/IMP-6) launch; (incorrectly noted as "IMP-I" in text) |
| United States | 1971-03-13 | Cape Canaveral FL | (Fleetwood) cachet on cover | Explorer-43 (IMP-H/IMP-6) launch; (incorrectly noted as "IMP-8" in text) |
| United States | 1971-03-13 | Cape Canaveral FL | (Centennial) cachet on cover | Explorer-43 (IMP-H/IMP-6) launch; (but Explorer-18/21/28 depicted, and incorrectly noted as "IMP-8" in text) |
| United States | 1971-03-13 | Cape Canaveral FL | (Swanson/DuBeau? blue and black and red rubber-stamp) cachet on cover | Explorer-43 (IMP-H/IMP-6) launch; (incorrectly noted as "IMP-8" in text) |
| United States | 1971-03-13 | Kennedy Space Center FL | (Yellow and grey printed) cachet on cover | Explorer-43 (IMP-H/IMP-6) launch |
| 1971-07-09: Explorer-44 / SolRad-10 | ||||
| United States | 1971-07-09 | Wallops Island VA | (Swanson green and magenta rubber-stamp) cachet on cover | Explorer-44 (SolRad-10) launch |
| United States | 1971-07-09 | Wallops Island VA | (Swanson blue and magenta rubber-stamp) cachet on cover | Explorer-44 (SolRad-10) launch |
| United States | 1971-07-09 | Wallops Island VA (hand cancel) | (Space Voyage) cachet on cover | Explorer-44 (SolRad-10) launch |
| United States | 1971-07-09 | Wallops Island VA (machine cancel) | (Space Voyage) cachet on cover | Explorer-44 (SolRad-10) launch |
| United States | 1971-07-09 | Wallops Island VA (machine cancel) | (InterSpace Cover) cachet on cover | Explorer-44 (SolRad-10) launch |
| United States | 1971-07-09 | Wallops Island VA | (Swanson black rubber-stamp and printed - Sarzin hybrid) cachet on cover | Explorer-44 (SolRad-10) launch |
| United States | 1971-07-09 | Wallops Island VA | (Centennial) cachet on cover | Explorer-44 (SolRad-10) launch |
| United States | 1971-07-09 | Wallops Island VA | (Orbit Covers) cachet on cover | Explorer-44 (SolRad-10) launch |
| 1971-11-15: Explorer-45 (SSS-A) | ||||
| Kenya | 1971-11-15 | Malindi (smaller cancel) | (Blue printed) cachet on cover | Explorer-45 (SSS-A) launch |
| Kenya | 1971-11-15 | Malindi (larger cancel) | (Blue printed) cachet on cover | Explorer-45 (SSS-A) launch |
| Kenya | 1971-11-15 | Malindi | (Space Voyage) cachet on cover, also insert | Explorer-45 (SSS-A) launch |
| Kenya | 1971-11-15 | Malindi | (Cura della printed and red rubber-stamp) cachet on cover, also insert and insert back | Explorer-45 (SSS-A) launch |
| Kenya | 1971-11-15 | Malindi | (Cura della printed and red rubber-stamp) cachet (and signature) on cover, also insert and insert back | Explorer-45 (SSS-A) launch |
| Kenya | 1971-11-15 | Malindi | (Cura della printed and blue rubber-stamp) cachet on cover, also insert and insert back | Explorer-45 (SSS-A) launch; "Explorer-44" (incorrectly given in text); (but Explorer-48 depicted) |
| United States | 1971-11-15 | Greenbelt MD | (GSFC Stamp Club) cachet on cover | Explorer-45 (SSS-A) launch |
| 1972-08-13: Explorer-46 (MTS) | ||||
| United States | 1972-08-14 | Wallops Island VA | (Space Voyage) cachet on cover, also insert | Explorer-46 (MTS) launch |
| United States | 1972-08-14 | Wallops Island VA | (InterSpace Cover) cachet on cover, also insert | Explorer-46 (MTS) launch |
| United States | 1972-08-14 | Wallops Island VA | (Sarzin) cachet on cover | Explorer-46 (MTS) launch |
| United States | 1972-08-14 | Wallops Island VA | (Orbit Covers) cachet on cover | Explorer-46 (MTS) launch |
| United States | 1972-08-14 | Wallops Island VA | (Riser/Andromeda/Cygnus Cover no.29) cachet on (airmail) cover, also insert | Explorer-46 (MTS) launch |
| United States | 1972-08-14 | Wallops Island VA | (Swanson blue and magenta rubber-stamp) cachet on cover | Explorer-46 (MTS) launch |
| United States | 1972-08-14 | Wallops Island VA | (CISCO/Fydo "Eyewitness to Space" Cover no.5) cachet on cover, also insert | Explorer-46 (MTS) launch |
| Explorer-47 (pre-launch events) | ||||
| United States | 1972-09-14 | Barstow CA | (Red pictorial) meter and (black and magenta rubber-stamp) cachet on cover | Explorer-47 (IMP-I/IMP-7) pre-launch (incorrectly noted as "IMP-H" in text): possible testing of tracking equipment and procedures |
| 1972-09-22: Explorer-47 (IMP-I/IMP-7) | ||||
| United States | 1972-09-22 | Cape Canaveral FL | (Sarzin) cachet on cover | Explorer-47 (IMP-I/IMP-7) launch (but Explorer-33/35 (AIMP-1/2) type depicted) |
| United States | 1972-09-22 | Kennedy Space Center FL | (Space Voyage) cachet on cover, also insert | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "IMP-H" in text) |
| United States | 1972-09-22 | Kennedy Space Center FL | (InterSpace Cover) cachet on cover, also insert | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "IMP-H" in text) |
| United States | 1972-09-22 | Cape Canaveral FL | (Space Voyage) cachet on cover, also insert | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "IMP-H" in text) |
| United States | 1972-09-22 | Cape Canaveral FL | (InterSpace Cover) cachet on cover, also insert | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "IMP-H" in text) |
| United States | 1972-09-22 | Patrick AFB, FL (inverted) | (Space Voyage) cachet on cover, also insert | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "IMP-H" in text) |
| United States | 1972-09-22 | Cape Canaveral FL | (Blue printed) cachet on cover | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "IMP-H" in text) |
| United States | 1972-09-22 | Cape Canaveral FL | (Orbit Covers) cachet on cover | Explorer-47 (IMP-I/IMP-7) launch; drawing is incomplete |
| United States | 1972-09-22 | Kennedy Space Center FL | (Black and magenta rubber-stamp, based on a Sokalsky design) cachet on cover | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "IMP-H" in text) |
| United States | 1972-09-22 | Kennedy Space Center FL | (Magenta printed, based on a Sokalsky design) cachet on cover | Explorer-47 (IMP-I/IMP-7) launch |
| United States | 1972-09-22 | Kennedy Space Center FL | (blank/no) cachet on cover | Explorer-47 (IMP-I/IMP-7) launch |
| United States | 1972-09-22 | Patrick AFB, FL (machine cancel) | (Whitney black and purple) cachet on cover | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "Interplanetary Monitoring Platform-H" in text) |
| United States | 1972-09-22 | Patrick AFB, FL (hand cancel) | (Whitney black and purple) cachet on cover | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "Interplanetary Monitoring Platform-H" in text) |
| United States | 1972-09-22 | Cape Canaveral FL | (Centennial) cachet on cover | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "IMP-9" in text) |
| United States | 1972-09-22 | Kennedy Space Center FL | (R. DuBeau blue rubber-stamp) cachet on cover | Explorer-47 (IMP-I/IMP-7) launch |
| United States | 1972-09-22 | Jackass Flats AK | (Black printed and green rubber-stamp) cachet on cover | Explorer-47 (IMP-I/IMP-7) launch |
| Australia | 1972-09-23 | Canberra City ACT | (Orroral Valley STADAN Station sticker) cachet (and signature) on (airmail) cover | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "IMP-H" in text) |
| United States | 1972-09-23 | Cape Canaveral FL (hand cancel) | (Whitney black and purple) cachet on cover | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "Interplanetary Monitoring Platform-H" in text) |
| United States | 1972-09-23 | Cape Canaveral FL (hand cancel) | (Whitney black and purple) cachet on (airmail) cover | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "Interplanetary Monitoring Platform-H" in text) |
| United States | 1972-09-23 | Cape Canaveral FL (machine cancel) | (Whitney black and purple) cachet on cover, also back | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "Interplanetary Monitoring Platform-H" in text) |
| United States | 1972-09-23 | Greenbelt MD | (GSFC Stamp Club) cachet on cover | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "IMP-H" in text) |
| United States | 1972-09-23 | Greenbelt MD | (GSFC red rubber-stamp) cachet on cover | Explorer-47 (IMP-I/IMP-7) launch |
| United States | 1972-09-25 | Kennedy Space Center FL | (CISCO/Fydo "Eyewitness to Space" Cover no.8) cachet on cover, also insert | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "IMP-H" in text) |
| United States | 1972-09-25 | Kennedy Space Center FL | (CISCO/Fydo "Eyewitness to Space" Cover no.8) cachet (and signature) on cover, also insert | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "IMP-H" in text) |
| United States | 1972-09-25 | Kennedy Space Center FL | (CISCO/Fydo "Eyewitness to Space" Cover no.8) cachet (and signature, different) on cover, also insert | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "IMP-H" in text) |
| United States | 1972-09-25 | Kennedy Space Center FL | (CISCO/Fydo "Eyewitness to Space" Cover no.8) cachet (and signature, different) on cover, also insert | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "IMP-H" in text) |
| United States | 1972-09-25 | Kennedy Space Center FL | (Riser/Andromeda/Cygnus Cover no.33) cachet on (airmail) cover, also insert | Explorer-47 (IMP-I/IMP-7) launch |
| United States | 1972-09-25 | Kennedy Space Center FL | (Centennial) cachet on cover | Explorer-47 (IMP-I/IMP-7) launch |
| United States | 1972-09-25 | Kennedy Space Center FL | (Black hand-printed) cachet on (airmail) cover | Explorer-47 (IMP-I/IMP-7) launch; (incorrectly noted as "IMP-H" in text) |
| 1972-11-15: Explorer-48 (SAS-B) | ||||
| United States | 1972-11-15 | Greenbelt MD | (GSFC Stamp Club) cachet on cover | Explorer-48 (SAS-B) launch |
| Kenya | 1972-11-16 | Malindi | (Space Voyage) cachet on cover, also insert | Explorer-48 (SAS-B) launch |
| Kenya | 1972-11-16 | Malindi | (InterSpace Cover) cachet on cover, also insert | Explorer-48 (SAS-B) launch |
| Kenya | 1972-11-16 | Malindi | (Multi-color printed and blue and green rubber-stamp) cachet on cover | Explorer-48 (SAS-B) launch |
| Kenya | 1972-11-16 | Malindi | (Cura della printed and blue rubber-stamp) cachet on cover | Explorer-48 (SAS-B) launch |
| Kenya | 1972-11-16 | Malindi | (Purple rubber-stamp and hand-written) cachet on cover | Explorer-48 (SAS-B) launch |
| Australia | 1972-11-20? | Canberra City ACT | (Orroral Valley STADAN Station sticker and red rubber-stamp) cachet (and signature) on cover | Explorer-48 (SAS-B) launch |
| 1973-06-10: Explorer-49 (RAE-2) | ||||
| Spain | 1973-06-10 | Madrid | (Purple rubber-stamp) cachet on cover | Explorer-49 (RAE-2) launch |
| United States | 1973-06-10 | Cape Canaveral FL | (Orbit Covers) cachet on cover | Explorer-49 (RAE-2) launch |
| United States | 1973-06-10 | Cape Canaveral FL | (Whitney orange) cachet on cover | Explorer-49 (RAE-2) launch |
| United States | 1973-06-10 | Patrick AFB, FL | (Whitney orange) cachet on cover | Explorer-49 (RAE-2) launch |
| United States | 1973-06-10 | Greenbelt MD | (GSFC Stamp Club) cachet on cover | Explorer-49 (RAE-2) launch |
| United States | 1973-06-10 | Cape Canaveral FL | (Riser/Andromeda/Cygnus Cover no.51) cachet on (airmail) cover, also insert | Explorer-49 (RAE-2) launch |
| United States | 1973-06-10 | Cape Canaveral FL | (InterSpace Cover) cachet on cover, also insert | Explorer-49 (RAE-2) launch |
| United States | 1973-06-11 | Kennedy Space Center FL | (InterSpace Cover) cachet on cover, also insert | Explorer-49 (RAE-2) launch |
| United States | 1973-06-11 | Kennedy Space Center FL | (Space Voyage) cachet on cover, also insert | Explorer-49 (RAE-2) launch |
| United States | 1973-06-11 | Kennedy Space Center FL | (SCPS) cachet on cover | Explorer-49 (RAE-2) launch |
| United States | 1973-06-11 | Kennedy Space Center FL | (SCPS) cachet (and logo) on cover | Explorer-49 (RAE-2) launch |
| 1973-10-25: Explorer-50 (IMP-J/IMP-8) | ||||
| United States | 1973-10-25 | Greenbelt MD | (GSFC Stamp Club) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-25 | Greenbelt MD | (GSFC green rubber-stamp) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-25 | Kennedy Space Center FL | (SCPS) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-25 | Kennedy Space Center FL | (SCPS and red logo) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-25 | Kennedy Space Center FL | (SCPS and blue logo) cachet (and signature) on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-25 | Kennedy Space Center FL | (Space Voyage) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-25 | Cape Canaveral FL | (Cyan printed) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-25 | Patrick AFB, FL | (Whitney magenta and black) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-25 | Patrick AFB, FL | (Quadracolor?) cachet on (airmail) cover | Explorer-50 (IMP-J/IMP-8) launch (but TIP-2/3 type depicted) |
| United States | 1973-10-26 | Cape Canaveral FL (machine cancel) | (Whitney magenta) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-26 | Cape Canaveral FL (machine cancel) | (Whitney magenta and black) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-26 | Cape Canaveral FL (hand cancel) | (Whitney magenta and black) cachet on (airmail) cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-26 | Cape Canaveral FL | (Orbit Covers) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch; also IQSY |
| United States | 1973-10-26 | Kennedy Space Center FL | (Centennial) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-26 | Kennedy Space Center FL | (Centennial and black rubber-stamp) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-26 | Cape Canaveral FL | (Centennial) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-26 | Cape Canaveral FL | (Centennial and black rubber-stamp) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-26 | Cape Canaveral FL | (Centennial-like) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-26 | Cape Canaveral FL | (Centennial-like) cachet (different) on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-26 | Cape Canaveral FL | (Space Voyage) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-26 | Cape Canaveral FL | (InterSpace Cover) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch |
| United States | 1973-10-26 | Kennedy Space Center FL | (Brown and black rubber-stamp, based on a Sokalsky design) cachet on cover | Explorer-50 (IMP-J/IMP-8) launch |
| 1973-12-16: Explorer-51 (AE-C) | ||||
| United States | 1973-12-15 | Vandenberg AFB, CA | (Orbit Covers) cachet on cover | Explorer-51 (AE-C) launch |
| United States | 1973-12-15 | Vandenberg AFB, CA | (InterSpace Cover purple and cyan) cachet on cover | Explorer-51 (AE-C) launch |
| United States | 1973-12-15 | Vandenberg AFB, CA | (Space Voyage purple and green) cachet on cover | Explorer-51 (AE-C) launch |
| United States | 1973-12-15 | Vandenberg AFB, CA | (Centennial) cachet on cover | Explorer-51 (AE-C) launch |
| United States | 1973-12-15 | Vandenberg AFB, CA | (DuBeau?/Swanson blue rubber-stamp) cachet on cover | Explorer-51 (AE-C) launch (but ESRO-2A depicted)1 |
| Great Britain | 1973-12-16 | Ascot, Berkshire | (Black rubber-stamp) cachet on cover | Explorer-51 (AE-C) launch |
| United States | 1973-12-16 | Greenbelt MD | (GSFC Stamp Club) cachet on cover | Explorer-51 (AE-C) launch |
| 1974-06-03: Explorer-52 / Hawkeye (Injun-6) | ||||
| United States | 1974-06-03 | Vandenberg AFB, CA | (Centennial) cachet on cover | Explorer-52 (Hawkeye / Injun-6) launch |
| United States | 1974-06-03 | Vandenberg AFB, CA | (Orbit Covers) cachet on cover | Explorer-52 (Hawkeye / Injun-6) launch |
| United States | 1974-06-03 | Vandenberg AFB, CA | (Swanson/DuBeau? black rubber-stamp) cachet on cover | Explorer-52 (Hawkeye / Injun-6) launch |
| United States | 1974-06-03 | Fairbanks AK | (NASA rubber-stamp) cachet (and signature) on cover | Explorer-52 (Hawkeye / Injun-6) launch |
| United States | 1974-06-03 | Vandenberg AFB, CA | (Space Voyage) cachet on cover | Explorer-52 (Hawkeye / Injun-6) launch |
| United States | 1974-06-03 | Vandenberg AFB, CA | (InterSpace Cover) cachet on cover | Explorer-52 (Hawkeye / Injun-6) launch |
| United States | 1974-06-03 | Vandenberg AFB, CA | (Sarzin?) cachet on cover | Explorer-52 (Hawkeye / Injun-6) launch |
| 1975-05-07: Explorer-53 (SAS-C) [Anik-A3 launched separately on same day at Cape Canaveral FL] |
||||
| Kenya | 1975-05-07 | Malindi | (Blue printed and green rubber-stamp) cachet on cover | Explorer-53 (SAS-C) launch |
| Kenya | 1975-05-07 | Malindi | (Space Voyage) cachet on cover | Explorer-53 (SAS-C) launch |
| United States | 1975-05-07 | Greenbelt MD | (GSFC Stamp Club) cachet (and signature) on cover | Explorer-53 (SAS-C) launch |
| United States | 1975-05-07 | Greenbelt MD | (GSFC Stamp Club) cachet on cover | Explorer-53 (SAS-C) launch |
| United States | 1975-05-07 | Greenbelt MD | (GSFC STDN blue rubber-stamp) cachet on cover | Explorer-53 (SAS-C) launch |
| 1975-10-06: Explorer-54 (AE-D) | ||||
| United States | 1975-10-06 | Vandenberg AFB, CA | (Space Voyage) cachet on cover | Explorer-54 (AE-D) launch |
| United States | 1975-10-06 | Greenbelt MD | (GSFC Stamp Club) cachet on cover | Explorer-54 (AE-D) launch |
| United States | 1975-10-06 | Greenbelt MD | (GSFC Stamp Club) cachet (and signature) on cover | Explorer-54 (AE-D) launch |
| United States | 1975-10-06 | Vandenberg AFB, CA | (NASA KSC-WLOD black rubber-stamp) cachet on cover | Explorer-54 (AE-D) launch |
| United States | 1975-10-06 | Lompoc CA, Vandenberg AFB | (Vandy?/DuBeau? red rubber-stamp) cachet on cover | Explorer-54 (AE-D) launch |
| United States | 1975-10-06 | Vandenberg AFB, CA | (Vandy?/DuBeau? red rubber-stamp) cachet on cover | Explorer-54 (AE-D) launch |
| United States | 1975-10-06 | Vandenberg AFB, CA | (Vandy?/DuBeau? red rubber-stamp) cachet on (airmail) cover | Explorer-54 (AE-D) launch |
| United States | 1975-10-06 | Vandenberg AFB, CA | (Centennial) cachet on cover | Explorer-54 (AE-D) launch |
| United States | 1975-10-06 | Vandenberg AFB, CA | (Orbit Covers) cachet on cover | Explorer-54 (AE-D) launch |
| 1975-11-20: Explorer-55 (AE-E) | ||||
| United States | 1975-11-19 | Kennedy Space Center FL | (Space Voyage) cachet on cover | Explorer-55 (AE-E) launch |
| United States | 1975-11-19 | Cape Canaveral FL | (Space Voyage) cachet on cover | Explorer-55 (AE-E) launch |
| United States | 1975-11-19 | Greenbelt MD | (GSFC Stamp Club) cachet on cover | Explorer-55 (AE-E) launch |
| United States | 1975-11-19 | Greenbelt MD | (GSFC STDN blue rubber-stamp) cachet on cover | Explorer-55 (AE-E) launch |
| United States | 1975-11-19 | Kennedy Space Center FL | (Centennial) cachet on cover | Explorer-55 (AE-E) launch |
| United States | 1975-11-19 | Cape Canaveral FL | (Centennial) cachet on cover | Explorer-55 (AE-E) launch |
| United States | 1975-11-19 | Kennedy Space Center FL | (SCPS) cachet on cover | Explorer-55 (AE-E) launch |
| United States | 1975-11-19 | Patrick AFB, FL | (Whitney green and black) cachet on cover | Explorer-55 (AE-E) launch |
| United States | 1975-11-19 | Cape Canaveral FL | (Whitney green-blue) cachet on cover | Explorer-55 (AE-E) launch |
| United States | 1975-11-19 | Satellite Beach FL (hand cancel) | (Whitney green and black) cachet on cover | Explorer-55 (AE-E) launch |
| United States | 1975-11-19 | Satellite Beach FL (machine cancel) | (Whitney green and black) cachet on (airmail) cover | Explorer-55 (AE-E) launch |
| United States | 1975-11-19 | Cape Canaveral FL | (Orbit Covers) cachet on cover | Explorer-55 (AE-E) launch |
| United States | 1975-11-19 | Kennedy Space Center FL | (Havekotte blue rubber-stamp) cachet on cover | Explorer-55 (AE-E) launch |
| United States | 1975-11-19 | Kennedy Space Center FL | (Havekotte blue rubber-stamp) cachet on (airmail) cover | Explorer-55 (AE-E) launch |
| United States | 1975-11-19 | Orlando FL, Kennedy Space Center Branch | (Havekotte blue and red comsat and rocket rubber-stamp) cachet on cover | Explorer-55 (AE-E) launch (but Westar-1/2/3 type or similar depicted with a rocket8) |
| United States | 1975-11-19 1975-11-24 | Orlando FL, Kennedy Space Center Branch USPS, IL | (Havekotte blue rubber-stamp) cachet on cover | Explorer-55 (AE-E) launch |
| United States | 1975-11-20 | USPS, CA | (NASA Goldstone blue rubber-stamp) cachet (and signature) on cover | Explorer-55 (AE-E) launch |
| Dual Air Density (DAD) Explorer (pre-launch events) | ||||
| United States | 1975-11-21 | Vandenberg AFB, CA | (NASA South Pole Tracking Station) cachet (and signature) on cover | Explorer: DAD pre-launch |
| 1975-12-05: Dual Air Density (DAD) Explorer [failed] | ||||
| United States | 1975-12-05 | Vandenberg AFB, CA | (Centennial) cachet on cover | Explorer: DAD launch [failed] |
| United States | 1975-12-05 | Vandenberg AFB, CA | (Space Voyage) cachet on cover | Explorer: DAD launch [failed] |
| United States | 1975-12-05 | Vandenberg AFB, CA | (Vandy? red rubber-stamp) cachet on cover | Explorer: DAD launch [failed] |
| United States | 1975-12-05 | Lompoc CA, Vandenberg AFB | (Vandy? red rubber-stamp) cachet on cover | Explorer: DAD launch [failed] |
| United States | 1975-12-05 | Vandenberg AFB, CA | (NASA KSC-WLOD magenta rubber-stamp) cachet on cover | Explorer: DAD launch [failed] |
| United States | 1975-12-05 | Vandenberg AFB, CA | (Orbit Covers) cachet on cover | Explorer: DAD launch [failed] (incorrectly noted as "Explorers 56 & 57"; Explorer AE-C/D/E type depicted in lower-right logo) |
| 1977-10-22: Explorer-56 / ISEE-1 (and ISEE-2) | ||||
| United States | 1977-10-22 | Cape Canaveral FL | (Orbit Covers) cachet on cover | Explorer-56 (ISEE-1) launch (but Explorer-51/54/55 depicted) |
| United States | 1977-10-22 | Cape Canaveral FL | (ESA) cachet on cover | Explorer-56 (ISEE-1) launch |
| United States | 1977-10-22 | Cape Canaveral FL | (Whitney green and black) cachet on (airmail) cover | Explorer-56 (ISEE-1) launch |
| United States | 1977-10-22 | Greenbelt MD | (GSFC Stamp Club) cachet on cover | Explorer-56 (ISEE-1) launch |
| United States | 1977-10-22 | Cape Canaveral FL | (Space Voyage) cachet on cover | Explorer-56 (ISEE-1) launch |
| United States | 1977-10-22 | Cape Canaveral FL | (Centennial) cachet on cover | Explorer-56 (ISEE-1) launch |
| United States | 1977-10-25 | Kennedy Space Center FL | (Space Voyage) cachet on cover | Explorer-56 (ISEE-1) launch |
| United States | 1977-10-25 | Kennedy Space Center FL | (SCPS) cachet on cover | Explorer-56 (ISEE-1) launch |
| 1978-01-26: Explorer-57 (IUE) | ||||
| France | 1978-01-26 | Paris | (ESA) cachet on cover | Explorer-57 (IUE) launch |
| Spain | 1978-01-26 | Madrid | (Red printed) cachet on cover | Explorer-57 (IUE) launch |
| United States | 1978-01-26 | Cape Canaveral FL | (ESA) cachet on cover | Explorer-57 (IUE) launch |
| United States | 1978-01-26 | Cape Canaveral FL | (Orbit Covers) cachet on cover | Explorer-57 (IUE) launch (but OAO-B depicted) |
| United States | 1978-01-26 | Kennedy Space Center FL | (Space Voyage) cachet on cover | Explorer-57 (IUE) launch |
| United States | 1978-01-26 | Cape Canaveral FL | (Space Voyage) cachet on cover | Explorer-57 (IUE) launch |
| United States | 1978-01-26 | GSFC, MD | (GSFC Stamp Club) cachet on cover | Explorer-57 (IUE) launch |
| United States | 1978-01-26 | Cape Canaveral FL | (Whitney purple) cachet on (airmail) cover | Explorer-57 (IUE) launch |
| United States | 1978-01-26 | Kennedy Space Center FL | (Centennial) cachet on cover | Explorer-57 (IUE) launch |
| United States | 1978-01-26 | Kennedy Space Center FL | (SCPS ser.78/11) cachet on cover | Explorer-57 (IUE) launch |
| United States | 1978-01-26 | Kennedy Space Center FL | (SCPS ser.78/11) cachet (and signature) on cover, also back | Explorer-57 (IUE) launch |
| United States | 1978-01-26 | Kennedy Space Center FL | (Havekotte blue and red comsat and rocket rubber-stamp) cachet on (airmail) cover | Explorer-57 (IUE) launch (but Westar-1/2/3 type or similar depicted with a rocket8) |
| Germany (West) | 1978-01-28 | Darmstadt | (ESA) cachet on cover | Explorer-57 (IUE) launch |
| 1978-04-26: Explorer-58 (HCMM) | ||||
| United States | 1978-04-26 | Vandenberg AFB, CA | (Space Voyage) cachet on cover | Explorer-58 (HCMM) launch |
| United States | 1978-04-26 | Vandenberg AFB, CA | (Centennial) cachet on cover | Explorer-58 (HCMM) launch |
| United States | 1978-04-26 | Vandenberg AFB, CA | (NASA KSC-WOSO purple rubber-stamp) cachet on cover | Explorer-58 (HCMM) launch |
| United States | 1978-04-26 | Vandenberg AFB, CA | (NASA KSC-WOSO purple rubber-stamp) cachet on (airmail) cover | Explorer-58 (HCMM) launch |
| United States | 1978-04-26 | Vandenberg AFB, CA | (NASA KSC-WOSO purple rubber-stamp) cachet on (airmail, different) cover | Explorer-58 (HCMM) launch |
| United States | 1978-04-26 | Vandenberg AFB, CA | (Vandy/DuBeau? cyan rubber-stamp) cachet on cover | Explorer-58 (HCMM) launch |
| United States | 1978-04-26 | Vandenberg AFB, CA | (Vandy/DuBeau? cyan rubber-stamp) cachet (and signatures) on cover | Explorer-58 (HCMM) launch |
| United States | 1978-04-26 | Vandenberg AFB, CA | (Vandy/DuBeau? cyan rubber-stamp) cachet on (airmail) cover | Explorer-58 (HCMM) launch |
| United States | 1978-04-26 | GSFC, MD | (GSFC STDN dark-blue rubber-stamp) cachet on cover | Explorer-58 (HCMM) launch |
| United States | 1978-04-26 | GSFC, MD | (GSFC Stamp Club) cachet on cover | Explorer-58 (HCMM) launch |
| 1978-08-12: Explorer-59 / ISEE-3 / ICE4 | ||||
| Spain | 1978-08-12 | Madrid | (Orange printed) cachet on cover | Explorer-59 (ISEE-3 / ICE) launch |
| United States | 1978-08-12 | Cape Canaveral FL | (Orbit Covers) cachet on cover | Explorer-59 (ISEE-3 / ICE) launch (but Explorer-51/54/55 depicted) |
| United States | 1978-08-12 | Cape Canaveral FL | (Whitney orange and blue) cachet on (airmail) cover | Explorer-59 (ISEE-3 / ICE) launch |
| United States | 1978-08-12 | Cape Canaveral FL | (Centennial) cachet on cover | Explorer-59 (ISEE-3 / ICE) launch |
| United States | 1978-08-12 | Cape Canaveral FL | (Space Voyage) cachet on cover | Explorer-59 (ISEE-3 / ICE) launch |
| United States | 1978-08-14 | Kennedy Space Center FL | (Space Voyage) cachet on cover | Explorer-59 (ISEE-3 / ICE) launch |
| United States | 1978-08-14 | Kennedy Space Center FL | (SCPS) cachet on cover | Explorer-59 (ISEE-3 / ICE) launch |
| Explorer-59 / ISEE-3 / ICE4 (events) | ||||
| United States | 1983-02-08 | Greenbelt MD | (Space Voyage) cachet on cover | "Maneuver correction of orbit for March 30 lunar swingby" |
| Australia | 1983-12-22 | Canberra ACT | (Zaso silk and red-brown printed) cachet on cover | "ICE Moonloop" |
| United States | 1985-09-11 | Greenbelt MD | (Space Voyage) cachet on cover | "encounter with Giacobini-Zinner Comet" |
| United States | 1985-09-11 | Greenbelt MD | (Zaso silk) cachet on cover | "Giacobini-Zinner Flyby" |
| Australia | 1986-03-25 | Canberra ACT | (Space Voyage) cachet on cover | "closest approach...Halley's Comet" |
| Spain | 1986-03-25 | Madrid | (Space Voyage) cachet on cover | "closest approach...Halley's Comet" |
| United States | 1986-03-25 | Pasadena CA | (Space Voyage) cachet on cover | "closest approach...Halley's Comet" |
| United States | 1986-03-25 | Barstow CA | (Space Voyage) cachet on cover | "closest approach...Halley's Comet" |
| United States | 1986-03-25 | Greenbelt MD | (Space Voyage) cachet on cover | "closest approach...Halley's Comet" |
| United States | 1986-03-25 | Greenbelt MD | (NASA GSFC blue rubber-stamp) cachet on cover | closest approach to Halley's Comet |
| United States | 1986-03-25 | Greenbelt MD | (Brown and cyan printed) cachet on cover | closest approach to Halley's Comet |
| United States | 1986-03-25 | Greenbelt MD | (Zaso silk) cachet on cover | closest approach to Halley's Comet |
| 1979-02-18: Explorer-60 (SAGE) | ||||
| United States | 1979-02-18 | Wallops Island VA | (Space Voyage) cachet on cover | Explorer-60 (SAGE) launch |
| 1979-10-30: Explorer-61 (MagSat) | ||||
| United States | 1979-10-30 | Vandenberg AFB, CA | (NASA KSC-WOSO purple rubber-stamp) cachet on cover | Explorer-61 (MagSat) launch |
| United States | 1979-10-30 | Greenbelt MD | (GSFC Stamp Club) cachet on cover | Explorer-61 (MagSat) launch |
| United States | 1979-10-30 | Greenbelt MD | (GSFC STDN blue rubber-stamp) cachet on cover | Explorer-61 (MagSat) launch |
| United States | 1979-10-30 | Vandenberg AFB, CA | (Space Voyage) cachet on cover | Explorer-61 (MagSat) launch |
| United States | 1979-10-30 | Vandenberg AFB, CA | (NASA KSC-WOSO black rubber-stamp) cachet on cover | Explorer-61 (MagSat) launch |
| United States | 1979-10-30 | Lompoc CA, Vandenberg AFB | (NASA KSC-WOSO black rubber-stamp) cachet on (airmail) cover | Explorer-61 (MagSat) launch |
| 1981-08-03: Explorer-62 (DE-1) and Explorer-63 (DE-2) | ||||
| United States | 1981-08-03 | Greenbelt MD | (NASA GSFC blue rubber-stamp) cachet on (airmail) cover | Explorer-62/63 (DE-1/2) launch |
| United States | 1981-08-03 | Greenbelt MD | (GSFC Stamp Club) cachet on cover | Explorer-62/63 (DE-1/2) launch |
| United States | 1981-08-03 | Greenbelt MD | (Space Voyage) cachet on cover | Explorer-62/63 (DE-1/2) launch |
| 1981-10-06: Explorer-64 / SME (and OSCAR-9) | ||||
| United States | 1981-10-06 | Pasadena CA | (JPL Stamp Club) cachet on cover, also insert | Explorer-64 (SME) launch |
| United States | 1981-10-06 | Vandenberg AFB, CA | (NASA magenta rubber-stamp) cachet on cover | Explorer-64 (SME) launch |
| United States | 1981-10-06 | Greenbelt MD | (GSFC Stamp Club) cachet on cover | Explorer-64 (SME) launch |
| United States | 1981-10-06 1981-10-06 | Greenbelt MD Prince Georges MD | (NASA GSFC blue rubber-stamp) cachet on cover | Explorer-64 (SME) launch |
| 1984-08-16: Explorer-65 (AMPTE: CCE, IRM, and UKS) | ||||
| Chile | 1984-08-16 | Santiago | (Space Voyage) cachet on cover | Explorer-65 (AMPTE) launch |
| United States | 1984-08-16 | Greenbelt MD | (GSFC Stamp Club) cachet on cover | Explorer-65 (AMPTE) launch |
| United States | 1984-08-16 | Cape Canaveral FL | (Multi-color printed) cachet on cover | Explorer-65 (AMPTE) launch |
| United States | 1984-08-16 | Greenbelt MD | (Space Voyage) cachet on cover | Explorer-65 (AMPTE) launch |
| United States | 1984-08-16 | Merritt Island FL | (Space Voyage) cachet on cover | Explorer-65 (AMPTE) launch |
| United States | 1984-08-16 | Patrick AFB, FL | (Whitney blue and orange and black and purple) cachet on cover | Explorer-65 (AMPTE) launch |
| United States | 1984-08-16 | Cape Canaveral FL | (Whitney blue and orange and black and purple) cachet on (airmail) cover | Explorer-65 (AMPTE) launch |
| Explorer-65 (events) | ||||
| United States | 1984-12-27 | Pasadena CA | (Space Voyage) cachet on cover | UKS barium release |
| 1989-11-18: Explorer-66 (COBE) | ||||
| United States | 1989-11-18 | Lompoc CA, Vandenberg AFB | (Edwin J. Isler? multi-color sticker) cachet on cover | Explorer-66 (COBE) launch |
| United States | 1989-11-18 | Lompoc CA, Vandenberg AFB | (Swanson/DuBeau? purple and black rubber-stamp) cachet on (airmail) cover | Explorer-66 (COBE) launch |
| 1992-06-07: Explorer-67 (EUVE) | ||||
| United States | 1992-06-07 | Kennedy Space Center FL | (Blue printed) cachet on cover | Explorer-67 (EUVE) launch |
| United States | 1992-06-07 | Kennedy Space Center FL | (Small mission-patch stickers and blue rubber-stamp) cachet on cover | Explorer-67 (EUVE) launch |
| United States | 1992-06-07 | Kennedy Space Center FL | (Mission patch) cachet on cover | Explorer-67 (EUVE) launch |
| 1992-07-03: Explorer-68 (SAMPEX) | ||||
| United States | 1992-07-03 | Lompoc CA, Vandenberg AFB | (Sarmiento) cachet on cover | Explorer-68 (SAMPEX) launch |
| 1995-12-30: Explorer-69 (XTE) | ||||
| United States | 1995-12-30 | Kennedy Space Center FL | (SCP mission-patch sticker) cachet on cover | Explorer-69 (XTE) launch |
| 1996-08-21: Explorer-70 (FAST) | ||||
| United States | 1996-08-21 | Lompoc CA, Vandenberg AFB | (Sarmiento) cachet on cover | Explorer-70 (FAST) launch |
| 1997-08-25: Explorer-71 (ACE) | ||||
| United States | 1997-08-25 | Kennedy Space Center FL | (Sarmiento) cachet on cover | Explorer-71 (ACE) launch |
| 1998-02-26: Explorer-72 / SNOE (and BATSat) | ||||
| United States | 1998-02-25 | Lompoc CA, Vandenberg AFB | (Black typed) cachet on cover | Explorer-72 (SNOE) launch |
| 1998-04-02: Explorer-73 (TRACE) | ||||
| United States | 1998-04-01 | Lompoc CA, Vandenberg AFB | (B&D) cachet on cover | Explorer-73 (TRACE) launch |
| United States | 1998-04-01 | Lompoc CA, Vandenberg AFB | (Black printed) cachet on cover | Explorer-73 (TRACE) launch |
| United States | 1998-04-01 | Lompoc CA, Vandenberg AFB | (Red monochrome mission patch) cachet on cover | Explorer-73 (TRACE) launch |
| 1998-12-06: Explorer-74 (SWAS) | ||||
| United States | 1998-12-05 | Lompoc CA, Vandenberg AFB | (Multi-color printed) cachet on cover | Explorer-74 (SWAS) launch |
| 1999-03-05: Explorer-75 (WIRE) [failed] | ||||
| United States | 1999-03-04 | Lompoc CA, Vandenberg AFB | (SCPS) cachet on cover | Explorer-75 (WIRE) launch [failed] |
| United States | 1999-03-04 | Lompoc CA, Vandenberg AFB | (Multi-color printed) cachet on cover | Explorer-75 (WIRE) launch [failed] |
| United States | 1999-03-04 | Lompoc CA, Vandenberg AFB | (Multi-color printed) cachet (different) on cover | Explorer-75 (WIRE) launch [failed] |
| United States | 1999-03-04 | Lompoc CA, Vandenberg AFB | (Mission patch) cachet on cover | Explorer-75 (WIRE) launch [failed] |
| United States | 1999-03-04 | Lompoc CA, Vandenberg AFB | (Multi-color printed) cachet on cover | Explorer-75 (WIRE) launch [failed] |
| 1999-05-18: Explorer-76 / TERRIERS (and MUBLCOM) [failed] | ||||
| United States | 1999-05-17 | Lompoc CA, Vandenberg AFB | (Black printed) cachet on cover | Explorer-76 (TERRIERS) launch [failed] |
| United States | 1999-05-17 | Lompoc CA, Vandenberg AFB | (B&D) cachet on cover | Explorer-76 (TERRIERS) launch [failed] |
| United States | 1999-05-17 | Lompoc CA, Vandenberg AFB | (SCP mission-patch sticker) cachet on cover | Explorer-76 (TERRIERS) launch [failed] |
| 1999-06-23: Explorer-77 (FUSE) | ||||
| United States | 1999-06-24 | Kennedy Space Center FL | (Multi-color printed) cachet on cover | Explorer-77 (FUSE) launch |
| United States | 1999-06-24 | Cape Canaveral FL | (B&D) cachet on cover | Explorer-77 (FUSE) launch |
| United States | 1999-06-24 | Cape Canaveral FL | (SCP sticker) cachet on cover | Explorer-77 (FUSE) launch |
| Explorer-77 (events) | ||||
| United States | 2007-10-18 | Pasadena CA | (Multi-color printed) cachet on cover | Explorer-77 (FUSE) end 8+year mission |
| 2000-03-25: Explorer-78 (IMAGE) | ||||
| United States | 2000-03-25 | Vandenberg AFB, Lompoc CA | (SCP mission-patch sticker) cachet on cover | Explorer-78 (IMAGE) launch |
| United States | 2000-03-25 | Vandenberg AFB, Lompoc CA | (B&D) cachet on cover | Explorer-78 (IMAGE) launch |
| 2000-10-09: Explorer-79 (HETE-2) | ||||
| United States | 2000-10-09 | Army Postal Service | (B&D) cachet on cover | Explorer-79 (HETE-2) launch |
| 2001-06-30: Explorer-80 (WMAP) | ||||
| United States | 2001-06-30 | Cape Canaveral FL | (B&D) cachet on cover | Explorer-80 (WMAP) launch |
| 2002-02-05: Explorer-81 (HESSI / RHESSI) | ||||
| United States | 2002-02-05 | Cape Canaveral FL | (B&D) cachet on cover | Explorer-81 (HESSI) launch |
| United States | 2002-02-05 | Cape Canaveral FL | (SCP mission-patch sticker) cachet on cover | Explorer-81 (HESSI) launch |
| 2003-01-12: Explorer-82 / CHIPSat (and ICESat) | ||||
| United States | 2003-01-12 | Vandenberg AFB, Lompoc CA | (Lollini) cachet on cover | Explorer-82 (CHIPSat) launch (but ICESat depicted) |
| United States | 2003-01-12 | Vandenberg AFB, Lompoc CA | (Mission patch) cachet on cover | Explorer-82 (CHIPSat) launch (but ICESat depicted) |
| United States | 2003-01-12 | Vandenberg AFB, Lompoc CA | (Multi-color printed) cachet (different) on cover | Explorer-82 (CHIPSat) launch |
| United States | 2003-01-12 | Vandenberg AFB, Lompoc CA | (SCP sticker) cachet on cover | Explorer-82 (CHIPSat) launch (also ICESat depicted) |
| 2003-04-28: Explorer-83 (GALEX) | ||||
| United States | 2003-04-28 | Pasadena CA | (JPL Stamp Club) cachet on cover | Explorer-83 (GALEX) launch |
| United States | 2003-04-28 | Kennedy Space Center FL | (B&D?) cachet on cover | Explorer-83 (GALEX) launch |
| United States | 2003-04-28 | Cape Canaveral FL | (Lollini) cachet on cover | Explorer-83 (GALEX) launch |
| United States | 2003-04-28 | Cape Canaveral FL | (Multi-color printed) cachet on cover | Explorer-83 (GALEX) launch |
| United States | 2003-04-28 | Cape Canaveral FL | (Multi-color printed) cachet (different photo) on cover | Explorer-83 (GALEX) launch |
| United States | 2003-04-28 | Cape Canaveral FL | (B&D) cachet on cover | Explorer-83 (GALEX) launch |
| United States | 2003-04-28 | Cape Canaveral FL | (SCP sticker) cachet on cover | Explorer-83 (GALEX) launch |
| United States | 2003-04-28 | Pasadena CA | (Purple and orange rubber-stamp) cachet on cover | Explorer-83 (GALEX) launch |
| 2004-11-20: Explorer-84 (Swift) | ||||
| United States | 2004-11-20 | Cape Canaveral FL | (B&D) cachet on cover | Explorer-84 (Swift) launch |
| United States | 2004-11-20 | Cape Canaveral FL | (SCP mission-patch sticker) cachet on cover | Explorer-84 (Swift) launch |
| 2007-02-17: Explorer-85 — Explorer-89 (THEMIS-A/E) | ||||
| United States | 2007-02-17 | Kennedy Space Center FL (machine cancel) | (Lollini) cachet on cover | Explorer-85/89 (THEMIS-A/E) launch |
| United States | 2007-02-17 | Kennedy Space Center FL (hand cancel) | (Lollini) cachet on cover | Explorer-85/89 (THEMIS-A/E) launch |
| United States | 2007-02-17 | Cape Canaveral FL | (Mission 57) cachet on cover, also back | Explorer-85/89 (THEMIS-A/E) launch |
| United States | 2007-02-17 | Cape Canaveral FL | (B&D) cachet on cover | Explorer-85/89 (THEMIS-A/E) launch |
| 2007-04-25: Explorer-90 (AIM) | ||||
| United States | 2007-04-25 | VAFB Contract Station, Lompoc CA | (RESCC Covers) cachet on cover | Explorer-90 (AIM) launch |
| United States | 2007-04-25 | Vandenberg AFB, CA | (Mission 57) cachet on cover, also back | Explorer-90 (AIM) launch |
| United States | 2007-04-25 | Vandenberg AFB, CA | (Multi-color printed) cachet on cover | Explorer-90 (AIM) launch |
| United States | 2007-04-25 | Vandenberg AFB, CA | (B&D) cachet on cover | Explorer-90 (AIM) launch |
| 2008-10-19: Explorer-91 (IBEX) | ||||
| United States | None (2008-10-19) | None (Kwajalein) | (Sarmiento) cachet on (un-stamped and un-canceled) cover | Explorer-91 (IBEX) launch |
| 2009-12-14: Explorer-92 (WISE) / now NEOWISE | ||||
| United States | 2009-12-14 | Pasadena CA | (Lollini) cachet on cover | Explorer-92 (WISE) launch |
| United States | 2009-12-14 | Vandenberg AFB, CA | (Lollini) cachet on cover | Explorer-92 (WISE) launch |
| United States | 2009-12-14 | Vandenberg AFB, CA | (Multi-color printed) cachet on cover | Explorer-92 (WISE) launch |
| United States | 2009-12-14 | VAFB Contract Station, Lompoc CA | (Multi-color printed) cachet on cover | Explorer-92 (WISE) launch |
| United States | 2009-12-14 | Vandenberg AFB, CA | (Mission 57) cachet on cover, also back | Explorer-92 (WISE) launch; also "COBE" (Explorer-66), "WMAP" (Explorer-80) |
| Explorer-92 (WISE) (events) | ||||
| United States | 2020-03-29 | Pasadena CA | (Multi-color printed) cachet on cover | "Discovery of the Comet NEOWISE" (by the WISE satellite, on 27 March 2020) |
| 2012-06-13: Explorer-93 (NuSTAR) | ||||
| United States | 2012-01-27 | Vandenberg AFB, CA | (Multi-color printed) cachet on cover | Explorer-93 (NuSTAR) "delivered to VAFB" |
| United States | 2012-06-13 | Pasadena CA | (Mission 57) cachet on cover, also back | Explorer-93 (NuSTAR) launch |
| United States | 2012-06-13 | Pasadena CA | (Lollini) cachet on cover | Explorer-93 (NuSTAR) launch |
| 2013-06-28: Explorer-94 / IRIS | ||||
| United States | 2013-06-27 | Vandenberg AFB, CA | (Lollini) cachet on cover | Explorer-94 (IRIS) launch |
| Explorer-95 / TESS (pre-launch events) | ||||
| United States | 2018-04-11 | Kennedy Space Center FL | (Red Eagle) cachet on cover | Explorer-95 (TESS) pre-launch: "SpaceX Falcon static fire test" |
| 2018-04-18: Explorer-95 / TESS | ||||
| United States | 2018-04-18 | GSFC, Greenbelt MD | (Red Eagle) cachet on cover | Explorer-95 (TESS) launch |
| United States | 2018-04-18 | Kennedy Space Center FL | (Red Eagle) cachet on cover | Explorer-95 (TESS) launch |
| United States | 2018-04-18 | Hawthorne CA | (Red Eagle) cachet on cover | Explorer-95 (TESS) launch |
| United States | 2018-04-18 | GSFC, Greenbelt MD | (Multi-color printed) cachet on cover | Explorer-95 (TESS) launch |
| 2019-10-11: Explorer-96 / ICON | ||||
| United States | 2018-10-19 | Cape Canaveral FL | (Red Eagle) cachet on cover | Explorer-96 (ICON) arrival at Cape Canaveral FL |
| United States | 2019-10-10 | Cape Canaveral FL | (Red Eagle) cachet on cover | Explorer-96 (ICON) launch |
| United States | 2019-10-10 | Cape Canaveral FL | (Mission patch) cachet on cover | Explorer-96 (ICON) launch |
| United States | 2019-10-10 | Cape Canaveral FL | (Mission patch and black printed) cachet on cover | Explorer-96 (ICON) launch |
| United States | 2019-10-10 | Cape Canaveral FL | (Ranski) cachet on cover | Explorer-96 (ICON) launch |
| United States | 2019-10-10 | Kennedy Space Center FL | (Ranski) cachet on cover | Explorer-96 (ICON) launch |
| 2021-12-09: Explorer-97 / IXPE | ||||
| United States | 2021-12-09 | Kennedy Space Center FL | (Ranski) cachet on cover, also back | IXPE (Explorer-97) launch |
| United States | 2021-12-09 | Kennedy Space Center FL | (Norwood Covers) cachet on cover | IXPE (Explorer-97) launch |
| United States | 2021-12-09 | Kennedy Space Center FL | (SAS) cachet on cover | IXPE (Explorer-97) launch |
| Explorer-97 / IXPE (events) | ||||
| United States | 2022-01-11 | Kennedy Space Center FL | (Ranski) cachet on cover, also back | IXPE (Explorer-97) "Imaging X-ray Polarimetry Explorer begins science studes" |
| United States | 2022-01-11 | Kennedy Space Center FL | (Ranski) cachet (different) on cover, also back | IXPE (Explorer-97) "Imaging X-ray Polarimetry Explorer begins science studes" |
| Explorer (on other than Explorer launch covers) | ||||
| There exist a large number of covers with an HJM cachet depicting Explorer-10. Details about the cachet, as well as images of the covers, are found in the HJM page. | ||||
| United States | 1959-09-18 | Patrick AFB, FL | (Highway Stamp Club) cachet on Vanguard-3 launch cover | Explorer-6 |
| United States | 1959-10-13 | Port Canaveral FL | (Goldcraft Cachets) cachet on (sub-orbital) Bold-Orion aircraft-launch cover | "Explorer-IV" (but more likely Explorer-6)5 |
| United States | 1960-12-07 | Vandenberg AFB, CA | (Goldcraft Cachets) cachet on Discoverer-18 launch cover | Explorer-62 |
| United States | 1962-10-03 | Patrick AFB, FL | (SpaceCraft) insert2 from Mercury-MA-8 launch cover, also insert1 and front | "the Explorer[-14] satellite was hurled into space by a towering Thor-Delta rocket at 5:11 p.m., E.S.T., 2 Oct 1962, minutes after the post office closed for the day." |
| Austria | 1962-10-04 | Gmünd | (Blue pictorial) cancel on Sputnik-1 anniversary cover, also back | "Explorer"-12/14/15/26 type7 (with folded solar panels and last stage attached); design similar to Germany (West) (orange) cachet 1965 |
| United States | 1965-07-24 | Cape Canaveral FL | (Brown printed) cachet on (sub-orbital) rocket launch cover, also annotated | Explorer-7 and Explorer-18 |
| United States | 1965-12-06 | Vandenberg AFB, CA | (Sarzin?) cachet on FR-1 launch cover | Explorer-38/49 type |
| United States | 1966-04-08 | Cape Canaveral FL (hand cancel) | (Centennial and black rubber-stamp) cachet on OAO-1 launch cover | (incorrectly noted as "Explorer-31" in rubber-stamp cachet) |
| United States | 1966-08-17 | Cape Canaveral FL | (Centennial black rocket, type-1) cachet on Pioneer-7 launch cover | Explorer-62 |
| United States | 1966-08-17 | Cape Canaveral FL | (Centennial grey rocket, type-1) cachet on Pioneer-7 launch cover | Explorer-62 |
| Austria | 1967-10-04 | Gmünd | (Black pictorial) cancel on Sputnik-1 anniversary cover | "Explorer"-12/14/15/26 type7 (with folded solar panels and last stage attached); design similar to Germany (West) (orange) cachet 1965 |
| Austria | 1967-10-04 | Gmünd | (Black pictorial) cancel on Sputnik-1 anniversary cover (different) | |
| Austria | 1967-10-04 | Gmünd | (Black pictorial) cancel on Sputnik-1 anniversary cover (different) | |
| Austria | 1967-10-04 | Gmünd | (Black pictorial) cancel on Sputnik-1 anniversary cover (different) | |
| Norway | 1968-09-20 | Andenes | (Black printed) cachet on Nike-Tomahawk (sub-orbital) rocket launch cover | Explorer-8 |
| United States | 1968-11-08 | Cape Canaveral FL | (Sarzin) cachet on Pioneer-9 and TETR-2 launch cover, also annotated | Explorer-29/36 type [#8]; Explorer-38/49 type [#10]; Explorer-18/21/28 type [#11] |
| United States | 1969-01-22 | Kennedy Space Center FL | (Centennial-like red rocket, type-2 and black typed) cachet on OSO-5 launch cover | Explorer-62 |
| United States | 1969-01-29 | Vandenberg AFB, CA | (Orbit Covers) cachet on ISIS-1 launch cover | "Explorer-41" |
| United States | 1969-01-29 | Lompoc CA, Vandenberg AFB | (SpaceCraft/Swanson) insert2 back from ISIS-1 launch cover, also insert2 front and insert1 and cover front | "Explorer-31" |
| United States | 1969-01-29 | Vandenberg AFB, CA | (SpaceCraft/Swanson) insert2 back from ISIS-1 launch cover, also insert2 front and insert1 and cover front | |
| United States | 1969-03-27 | Kennedy Space Center FL | (Centennial red-orange rocket, type-1 and blue text) cachet on Mariner-7 launch cover | Explorer-62 |
| United States | 1969-04-13 | Vandenberg AFB, CA | (Centennial brown rocket, type-2 and black text) cachet on Nimbus-3 and SECOR-13 launch cover | Explorer-62 |
| United States | 1969-05-22 | Cape Canaveral FL | (Centennial-like red rocket, type-2) cachet on Intelsat-3-4 launch cover | Explorer-62 |
| United States | 1969-05-22 | Cape Canaveral FL (hand cancel) | (Centennial red rocket, type-1) cachet on Intelsat-3-4 launch cover | Explorer-62 |
| United States | 1969-05-22 | Cape Canaveral FL (machine cancel) | (Centennial red rocket, type-1 and magenta rubber-stamp) cachet on Intelsat-3-4 launch cover | |
| United States | 1969-11-07 | Vandenberg AFB, CA | (SpaceCraft/Swanson) insert2 back from Azur launch cover, also insert2 front and insert1 and cover front | "NASA Explorer-series satellites" |
| United States | 1969-11-07 | Lompoc CA, Vandenberg AFB | (SpaceCraft/Swanson) insert2 back from Azur launch cover, also insert2 front and insert1 and cover front | |
| United States | 1969-11-07 | Lompoc CA, Vandenberg AFB | (SpaceCraft/Swanson) insert2 back from Azur launch cover, also insert2 front and insert1 and cover front (with signature) | |
| United States | 1971-06-29 | Vandenberg AFB, CA | (Swanson/DuBeau? black rubber-stamp) cachet on (sub-orbital) rocket launch cover | "Direct Measurement Explorer" (Explorer-31) |
| United States | 1972-01-31 | Lompoc CA, Vandenberg AFB | (Centennial grey rocket, type-2 and red text) cachet on HEOS-2 launch cover | Explorer-62 |
| Germany (West) | 1972-04-16 | Bochum | (Green printed) cachet (and signature) on Apollo-16 launch cover, also detail | (possible) Explorer-12/14/15/26 type |
| Australia | 1972-12-07 | Tharwa ACT | (Orroral Valley Tracking Station) cachet (and signature) on Apollo-17 launch cover | Explorer-12/14/15/26 type or Explorer-18/21/28 type (top right of cachet) |
| United States | 1973-01-31 | Redstone Arsenal AL | (MoF no.3) insert from Explorer-1 anniversary cover, also insert back and cover front | "Explorer-III" (Explorer-3) |
| United States | 1973-08-06 | Cape Canaveral FL | (Centennial red rocket, type-1) cachet cachet on Skylab-3 event cover | Explorer-62 |
| United States | 1974-06-30 | Wallops Island VA | (Space Voyage) cachet on (sub-orbital) rocket launch cover | Explorer-51 (AE-C) data comparison |
| United States | 1974-12-19 | Cape Canaveral FL | (Centennial red rocket, type-1) cachet on Symphonie-1 launch cover | Explorer-62 |
| United States | 1975-02-14 | Kennedy Space Center FL | (MoF no.24) insert from Pegasus-1 anniversary cover, also cover front | "Explorer-XVI" and "Explorer-XXIII" |
| Australia | 1975-07-15 | Torrens ACT | (Orroral Valley Tracking Station) cachet on Apollo-ASTP launch and Soyuz-19 ASTP launch cover | Explorer-12/14/15/26 type or Explorer-18/21/28 type (top right of cachet) |
| Germany (West) | 1975-07-21 | Bochum | (Black rubber-stamp and red printed) cachet on ASTP (Soyuz returns to earth, Apollo remains in orbit) cover, also annotated cachet | Explorer-12/14/15/26 type or Explorer-18/21/28 type |
| Germany (West) | 1975-08-27 | Bochum | (Red-brown printed and green rubber-stamp) cachet on Symphonie-2 launch cover, also annotated cachet | Explorer-12/14/15/26 type, or Explorer-18/21/28 type |
| United States | 1976-03-16 | Auburn MA | (GSFC Stamp Club blue printed) cachet on 50th anniv. first liquid fuel rocket flight/launch cover | "Explorer-6", "Explorer-7", "Explorer-10", "Explorer-11", "Explorer-17", "Explorer-20", "Explorer-27", "IMP (Explorer-28)", "Explorer-32", "AIMP[-2] (Explorer-35)", "RAE (Explorer-38)" |
| United States | 1977-12-14 | Cape Canaveral FL | (Orbit Covers, no logo) cachet on CS-1 launch cover | Explorer-38/49 type |
| United States | 1978-04-07 | Cape Canaveral FL | (Orbit Covers) cachet on Yuri-1 / BSE launch cover | "Radio Astronomy Explorer" (Explorer-38/49 type) |
| United States | 1978-05-20 | GSFC, MD | (GSFC multi-satellite blue rubber-stamp) cachet (same design as three above) on Pioneer-12 launch cover | "Explorer-6", "Explorer-7", "Explorer-10", "Explorer-11", "Explorer-17", "Explorer-20", "Explorer-27", "IMP (Explorer-28)", "Explorer-32", "AIMP[-2] (Explorer-35)", "RAE (Explorer-38)" |
| United States | 1978-08-14 | Kennedy Space Center FL | (Space Voyage) cachet on ISEE-3 launch cover | Explorer-56 / ISEE-1 (lower-right) |
| United States | 1978-10-24 | GSFC, MD | (GSFC multi-satellite blue rubber-stamp) cachet (same as two above) on Nimbus-7 and CAMEO launch cover | "Explorer-6", "Explorer-7", "Explorer-10", "Explorer-11", "Explorer-17", "Explorer-20", "Explorer-27", "IMP (Explorer-28)", "Explorer-32", "AIMP[-2] (Explorer-35)", "RAE (Explorer-38)" |
| United States | 1983-01-25 | Greenbelt MD | (GSFC multi-satellite blue rubber-stamp) cachet (same) on IRAS and PIX-2 launch cover | "Explorer-6", "Explorer-7", "Explorer-10", "Explorer-11", "Explorer-17", "Explorer-20", "Explorer-27", "IMP (Explorer-28)", "Explorer-32", "AIMP[-2] (Explorer-35)", "RAE (Explorer-38)" |
| United States | 1983-08-30 | Kennedy Space Center FL | (Centennial red rocket, type-1 and blue printed and blue hand-printed) cachet on STS-8 launch cover | Explorer-62 |
| United States | 1985-03-12 | Lompoc CA, Vandenberg AFB | (Magenta and black printed) cachet on Geosat-1 launch cover | Explorer-38/49 type, and Explorer-43/47/50 type |
| United States | 2007-11-06 | WSMR, NM | (Multi-color printed) cachet on (sub-orbital) rocket launch cover | "TRACE" (Explorer-73) |
| United States | '2022-05-25' (from cachet) | no cancel | (Ranski) cachet on back of (un-stamped and un-canceled) NuSat-28/31 cover, also front | "IXPE" (Explorer-97) |
1This Swanson blue rubber-stamp cachet has radial antennas like those on ESRO-2A.
2Explorer-6 and Pioneer-5 were similar "paddlewheel" satellites. It is believed that Explorer-6 contained two short antennas on its "top", whereas Pioneer-5 contained only a single short antenna. When there are no antennas on top, the distinction is unclear, but of the two, Pioneer-5 is assumed.
4Explorer-59 / ISEE-3 was renamed ICE (International Cometary Explorer) in 1983.
5The Bold Orion mission of 13 Oct 1959 was a test of the rocket's capabilities in an ASAT (anti-satellite) role. Launched from a B-47 aircraft at 11,000 m, the rocket passed within about 6 km of the Explorer-6 satellite at an altitude of 251 km. This was considered a successful intercept. The 1959-10-13 launch cover refers to Explorer-IV as the target satellite, but that appears to be an error: all documentation about the mission found by the authors refers to Explorer-6 (Explorer-VI) rather than Explorer-4. The Bold Orion ASAT test was the first interception of a satellite by any method, proving that anti-satellite missiles were feasible.
6Titan-2 newspaper article notes: "The [Titan-2 rocket] shot came within hours after the United States had called off a planned attempt to send a 98-pound satellite [Explorer-15] into orbit to measure two and possibly more man-made radiation belts around the Earth".
7Explorer-12, 14, 15, and 26: Electrostatic Particle Explorers (EPE-A/B/C/D) are all basically identical.
8The rocket in this cachet is based on a Whitney-design cachet as found on covers such as this GOES-1_cover; the comsat design is similar to that of the Westar-1/2/3 type or Palapa-A1/A2 type or Anik-A1/A2 type satellites, all of which are essentially identical.
Back to scientific/research/technology satellites.
Back to Un-manned Satellite Philately.
