Explorer

Explorer-series
satellites
(except Explorer-1)


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:

InjunSolRadGEOSISEE
  • 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 other single-use names as well, especially for the latter Explorers where the "other" name is more common than the Explorer name and number.

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.

Launch information
(found elsewhere)
Reference images
(found elsewhere)
Launch covers
(including anniversary-of-launch covers, and launch-related event covers)
(farther below)
Other postal items
(stamps, souvenir sheets, aerogrammes, postal cards, etc.)
(immediately below)
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.).

CountryCatalog NumberType of ItemYear of IssueNotes on Content
Explorer-series (except Explorer-1)
AjmanMi264A
Mi264B

Imperforate
1968"Explorer-14"
AjmanMi260A+Mi263A-266A fdcOne of five stamps on FDC
AjmanBL35A
BL35B
Embossed-perforation MS2 (like Mi262A+264A)
Imperforate MS2 (like Mi262B+264B)
AjmanBL35B fdcImperforate MS2 on FDC
Ajman StateMi2781A
Mi2781B
From MS8 (Mi2781A-2788A + 8 labels)
From imperforate MS8 (Mi2781B-2788B + 8 labels)
1973Explorer-20
Ajman StateMi2783A
Mi2783B
Explorer-22/27 type
Ajman StateMi2788A
Mi2788B
Explorer-17
Ajman StateMi2781A 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 StateMi2783A 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-22/27 type
Ajman StateMi2788A 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 StateMi2789A
Mi2789B
From MS16 (Mi2789A-2796A+2677A-2684A)
From imperforate MS16 (Mi2789B-2796B+2677B-2684B)
Explorer-20
Ajman StateMi2791A
Mi2791B
Explorer-22/27 type
Ajman StateMi2796A
Mi2796B
Explorer-17
Angola1108c (Mi1426)One of MS6 (1108 (a-f)) (Mi1424-1429)1999Explorer-42 / "Uhuru"
Angola1110a (Mi1444)One of MS6 (1110 (a-f)) (Mi1444-1449)1999Explorer-17
Antigua and Barbuda2243e (Mi2926)
i2243e
One of MS6 (2243 (a-f)) (Mi2922-2927)
One of imperforate MS6 (i2243 (a-f))
1999Explorer-57 / "IUE"
Antigua and Barbuda3014 (Mi4590-4592)On four of six stamps and in (right) margin of MS6 (3014 (2x (a-c)))2008"Explorer-3"
Antigua and Barbuda3016 (Mi4595-4596)On all stamps and in (right) margin of MS4 (3016 (2x (a-b)))
Antigua and Barbuda3018 (BL655)SS1
Ascension388 (Mi397)1986Explorer-59 / ISEE-3 / ICE
AustriaNoneCancel1962Explorer-12/14/15 type1 (with folded solar panels and last stage attached); design similar to Germany (West) cachet 1965
Barbuda1790e (Mi2386)One of MS6 (1790 (a-f)) (Mi2382-2387), Antigua and Barbuda 2243e overprinted2000Explorer-57 / "IUE"
Belgium670 (Mi1433)1966Explorer-17
Belgium670 fdcStamp and cancel on FDC
Belgium666+669-670 fdc1One of three stamps and cancel and cachet on FDCExplorer-17 (on stamp and cancel), Explorer-20 (on cachet)
Belgium666+669-670 fdc2One of three stamps and cachet on FDCExplorer-17 (on stamp), Explorer-20 (on cachet)
BelgiumNoneIn (lower-left) margin of imperforate MS2 cinderella1963?Explorer-13/16/23 type2 (in lower-left margin)
BeninUnknown c (Mi?)
Unknown ic
One of MS4 (a-d)
One of imperforate MS4 (a-d)
2014Explorer-56 / "ISEE"-1 (also launch date on stamp)
Bernera Islands (Scotland)Local_bOne of local post MS8 (a-h)1978Explorer-20
Bernera Islands (Scotland)Local_b o/p1One of local post MS8 overprinted in black1998Explorer-20
Bernera Islands (Scotland)Local_b o/p2One of local post MS8 overprinted in red
Birobidjan-JewishLocalBernera Islands local b overprinted on Russia 2448 (Mi2440), also overprint template1995Explorer-20
Birobidjan-JewishLocalBernera Islands local b overprinted on Russia 45199 (Mi4496), also overprint template
Birobidjan-JewishLocalBernera Islands local b overprinted on Russia 45209 (Mi4497), also overprint template
Birobidjan-JewishLocalBernera Islands local b overprinted on Russia 57339 (Mi5904), also overprint template
Birobidjan-JewishLocalBernera Islands local b overprinted on Russia 5984 (Mi6177), also overprint template
Bolivia690 (BL146)In (lower-right) margin of imperforate SS11985Explorer-59 / "ISEE"-3 / ICE
Brazil1035 fdc (Mi1128 fdc)(Brasil) cachet on FDC (see this larger but incomplete image)1967Explorer-7
Burkina Faso1015A (BL148)In (upper-left) margin of SS11995Explorer-12/14/15 type1
Burundi588 (Mi1582A)
i588 (Mi1582B)

Imperforate
1981Explorer-20
Burundi588a (BL117C)
i588a (BL117B)
On one of MS3 (586-588)
On one of imperforate MS3 (i586-i588)
BurundiBL496A
BL496B
In (upper-right) margin of SS1 (Mi3478A)
In (upper-right) margin of imperforate SS1 (Mi3478B)
2014"NuSTAR" (Explorer-93)
CamerounC99 (Mi533)1968"Explorer-6" image of Earth
CamerounC99 fdcStamp and (Éditions So.Ge.Im.) cachet on FDC
Central African Republic663 (BL283A)
i663 (BL283B)
In (lower-right) margin of SS1
In (lower-right) margin of imperforate SS1
1984Explorer-66 / "COBE" (early-design)5
Central African Republic843 (Mi1258A)
i843 (Mi1258B)

Imperforate
1986Explorer-59 / ISEE-3 / ICE (depicted in a communications satellite role)
ChadBL249In (upper-left) margin of SS11996Explorer-17 (not "Explorer-23", as in text)
Chad708f (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)
1997Explorer-56 / ISEE-1 and ISEE-23; "ISEE" (in selvedge text)
Comoro IslandsB4f (Mi859A)
iB4f (Mi859B)
One of MS8 (B4 (a-h)) (Mi854A-861A)
One of imperforate MS8 (iB4 (a-h)) (Mi854B-861B)
1988Explorer-59 / ISEE-3 / "ICE" (in text, but Giotto depicted)
Comoro IslandsB4f_ds (BL268A)
iB4f_ds (BL268B)
Deluxe sheet (B4f)
Imperforate deluxe sheet (iB4f)
Comoro Islands737a (BL326A)
i737a (BL326B)
In (upper-left) margin of SS1 (737)
In (upper-left) margin of imperforate SS1 (i737)
1990Explorer-66 / COBE (final-design)5
Congo (Republic)C53 (Mi134)
iC53

Imperforate
1967"Explorer-6"6
Congo RepublicUnknown ss (BL?)
Unknown iss
In (right) margin of SS1
In (right) margin of imperforate SS1
2014Explorer-59 / "ISEE-3" / ICE
Congo RepublicUnknown fdc
Unknown ifdc
SS1 and cachet on FDC
Imperforate SS1 and cachet on FDC
CroatiaNoneCachet on WMD cover2010Explorer-67 / EUVE
Djibouti610a (BL120A)
i610a (BL120B)
In (right) margin of SS1 (610)
In (right) margin of imperforate SS1 (i610)
1986Explorer-59 / ISEE-3 / ICE
Dominica2237a (Mi2902)From MS6 (2237 (a-f)) (Mi2902-2907)2000"Explorer-14"
Dominica2237d (Mi2905)"Explorer-16"
Dominica2237 fdcMS6 on FDC(As above)
Egypt1211 (Mi906)1983Explorer-32 ?
Franklin Mint (USA)None(Bronze) medallion, also reverse1970s"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 TerritoriesC53 (Mi121)1977Explorer-52 / Injun-6 (at left)
French Southern and Antarctic TerritoriesC53 fdcStamp on FDC
FujeiraMi71A
Mi71B

Imperforate
1966Explorer-7
FujeiraMi70A-77A fdcOne of eight stamps on FDC
FujeiraMi150A
Mi150B
Mi71A overprinted new currency
Mi71B overprinted new currency
1967Explorer-7
FujeiraMi347A
Mi347B
Mi71A overprinted "Apollo-8"
Mi71B overprinted "Apollo-8"
1969Explorer-7
FujeiraMi347A inv o/p
Mi347B inv o/p
Mi71A inverted overprint "Apollo-8"
Mi71B inverted overprint "Apollo-8"
FujeiraMiA77A
MiA77B
Mi71A gold foil
Mi71B gold foil
FujeiraMiA77 dsDexlue sheet (Mi71) gold foil
FujeiraMi341A-348A fdcOne of eight stamps on FDC
Gambia609 (Mi615)1986Explorer-59 / ISEE-3 / ICE
Gambia655 (Mi661)609 overprinted in silver1986Explorer-59 / ISEE-3 / ICE
Gambia2170 (Mi3272)1999Explorer-66 / COBE (final-design)5
Gambia2268a (Mi3698)From MS6 (2268 (a-f))2000Explorer-42 / "Uhuru"
Gambia2268c (Mi3700)Explorer-57 / "IUE"
Gambia2268a essayFrom MS6 (2268 imperforate essay (a-f))Explorer-42 / "Uhuru"
Gambia2268c essayExplorer-57 / "IUE"
Gambia2269f (Mi3709)
i2269f
One of MS6 (2269 (a-f)) (Mi3704-3709)
One of imperforate MS6 (i226910 (a-f))
Explorer-18 / "IMP"
Gambia2269f essayOne of MS6 (2269 imperforate essay (a-f))
Gambiai2269 fdc10MS6 on FDC
Germany (West)NoneCachet on cover1964Explorer-8
Germany (West)NoneCachet on cover1965Explorer-8
Germany (West)NoneCachet on cover1965Explorer-12/14/15 type1 (with folded solar panels and last stage attached), design similar to Austria cancel 1962
Germany (West)NoneCancel on cover1970Explorer-59 / ISEE-3 / ICE
Germany (West)NoneCancel1971Explorer-13/16/23 type2
GermanyNoneMeter on cover1995Explorer-66 / COBE (final-design)5
GermanyNoneMeter on cover1997"Jupiter[-1] 1958"; in 1958 the Jupiter-1 rocket was used to launch Explorers-1, 2, 3, 4, and 5; three launches were successful, and two (Explorer-2 and 5) were failures
Ghana166a (BL9)In (lower) margin of imperforate MS4 (4x 166)1964Explorer-13/16/23 type2
Ghana166a fdcImperforate MS4 on FDC
Great BritainNoneCachet on cover back1982Explorer-22/27 type
Grenada Carriacou2205d (Mi3194)One of MS6 (2205 (a-f)) (Mi3191-3196)2000"Explorer-16" (in text, but Mars Express depicted)
Grenada Carriacou2205e (Mi3195)One of MS6 (2205 (a-f)) (Mi3191-3196)Explorer-57 / IUE (not Space Shuttle Challenger, "Astro" payload, as in text)
Grenada Carriacou2205e essayOne of MS6 (2205 essay (a-f))Explorer-57 / "IUE" (correctly labeled)
Grenada Carriacou2206d (Mi3200)One of MS6 (2206 (a-f)) (Mi3197-3202)"Explorer-16"
Grenada Carriacou2206d essayOne of MS6 (2206 essay (a-f))
Guinea RepublicBL1115A
BL1115B
In (upper) margin of MS2 (Mi4537A-4538A)
In (upper) margin of imperforate MS2 (Mi4537B-4538B)
2006Explorer-81 / "RHESSI"
Guinea RepublicBL1115A-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 RepublicMi4541A
Mi4541B

Imperforate
Explorer-73 / "TRACE"
Guinea RepublicBL1117A
BL1117B
On one stamp and in (upper) margin of MS2 (Mi4541A-4542A)
On one stamp and in (upper) margin of imperforate MS2 (Mi4541B-4542B)
Explorer-73 / "TRACE" (on one of MS2), Explorer-81 / "RHESSI" (close-to-final design, "HESSI", in upper margin)
Guinea RepublicMi4544A
Mi4544B

Imperforate
Explorer-71 / "ACE"
Guinea RepublicMi4541A-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 RepublicBL1118A
BL1118B
On one of MS2 (Mi4543A-4544A)
On one of imperforate MS2 (Mi4543B-4544B)
Explorer-71 / "ACE"
Guinea RepublicBL1117A-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 RepublicMi5875A
Mi5875B
From MS6 (Mi5873A-5878A)
From imperforate MS6 (Mi5873B-5878B)
2008Explorer-84 / "Swift"
Guinea RepublicMi5877A
Mi5877B
Guinea RepublicMi5873A-5878A_ms6 fdcMS6 and cachet on FDC
Guinea RepublicMi6515One of MS6 (Mi6512-6517)2009Explorer-80 / "WMAP"
Guinea RepublicBL1963In (lower-right) margin of SS12011Explorer-66 / "COBE"
Guinea RepublicBL1963 fdcSS1 and cachet on FDC
Guinea-BissauBL623A
BL623B
In (lower-left) margin of SS1 (Mi3682A)
In (lower-left) margin of imperforate SS1 (Mi3682B)
2007Explorer-83 / GALEX
Guinea-BissauBL623A fdc
BL623B fdc
SS1 and cachet on FDC
Imperforate SS1 and cachet on FDC
Hungary2972 (Mi3805A)
i2972 (Mi3805B)

Imperforate
1986Explorer-59 / ISEE-3 / "ICE"
Hungary2972 fdcStamp on FDC
Ivory CoastUnknown a (Mi?)
Unknown ia
One of MS4 (2x (a-b))
One of imperforate MS4 (2x (a-b))
2012Explorer-83 / "GALEX"
Ivory CoastUnknown ms fdcMS4 on FDC
Korea (North)1448 (Mi1494A)
i1448 (Mi1494B)

Imperforate
1976Explorer-66
Korea (North)1881 (BL65)
i1881
On stamp of SSe, also detail
On stamp of imperforate SS1
1979Explorer-18/21/28 type
Korea (North)3221a (Mi3429-3430)In (right) margin of MS2 (3221-3222), also annotated1993Explorer-20 (middle of three), Explorer-53 (uppermost of three)
Korea (South)1289 fdc1 (Mi1275 fdc1)(Purple) cancel on FDC1982Explorer-29 / GEOS-1
Korea (South)1289 fdc2 (Mi1275 fdc2)(Blue-black) cancel on FDC (different)
Malagasy Republic797 (Mi1063A)
i797 (Mi1063B)

Imperforate
1987Explorer-59 / ISEE-3 / ICE
Malagasy Republic797a (BL48A)
i797a (BL48B)
On stamp of SS1 (797)
On stamp of imperforate SS1 (i797)
Malagasy Republic1536c (Mi2475)
i1536c
From MS6 (1536 (a-f)) (Mi2473-2478)
From imperforate MS6 (i1536 (a-f))
2000Explorer-59 / ISEE-3 / "ICE"
Malagasy Republic1536d (Mi2476)
i1536d
Explorer-64 / "SME"
Malagasy Republic1536 fdcMS6 and cachet on FDC(As above for stamps); Explorer-59 / ISEE-3 / "ICE" (in cachet)
Malagasy Republic1539f (Mi2496)
i1539f
One of MS6 (1539 (a-f)) (Mi2491-2496)
One of imperforate MS6 (i1539 (a-f))
Explorer-66 / "COBE" (early-design)5
Malagasy Republic1539 proofOn one of imperforate proof MS6
Malagasy Republic1539 fdcMS6 on FDC
Maldive Islands147a (Mi147)In (upper-right) margin of MS9 (9x 147)1965Explorer-18
Maldive Islands148a (Mi148)In (upper-right) margin of MS9 (9x 148)
Maldive Islands149a (Mi149)In (upper-right) margin of MS9 (9x 149)
Maldive Islands150a (Mi150)In (upper-right) margin of MS9 (9x 150)
MaliUnknown b (Mi unlisted)
Unknown ib
One of MS2 (a-b)
One of imperforate MS2 (a-b)
2006Explorer-59 / ISEE-3 / ICE
MaliUnknown ms fdc
Unknown ims fdc
MS2 and cachet on FDC
Imperforate MS2 and cachet on FDC
ManamaMi94A
Mi94B

Imperforate
1968"Explorer-14"
ManamaMi90A+Mi93A-96A fdc
Mi90B+Mi93B-96B fdc
One of five stamps on FDC
One of five imperforate stamps on FDC
ManamaBL8A
BL8B
Embossed-perforation MS2 (like Mi92A+94A)
Imperforate MS2 (like Mi92B+94B)
ManamaBL216A
BL216B
In (upper and left) margin of SS1
In (upper and left) margin of imperforate SS1
1972Explorer-13/16/23 type2
Mauritania619 (Mi889A)
i619 (Mi889B)

Imperforate
1986Explorer-59 / ISEE-3 / ICE
Mauritania619a (BL unlisted)
i619a
On stamp of SS1 (619)
On stamp of imperforate SS1 (i619)
Mauritania622b (BL unlisted)
i622b
One of MS4 (619-622)
One of imperforate MS4 (i619-i622)
Micronesia344p (Mi736)From MS20 (344 (a-t)) (Mi721-740)1999Explorer-59 / ISEE-3 / ICE (not "SMM" repair, as in text)4
Micronesia344q (Mi737)Explorer-59 / ISEE-3 / "ICE" (in text, but SMM repair depicted)4
MongoliaC33d (Mi739)One of MS12 (C33 (a-l))1972"Explorer-6"6
Niger1078e (Mi1930)
i1078e
One of MS9 (1078 (a-i)) (Mi1926-1934)
One of imperforate MS9 (i1078 (a-i))
2001Explorer-77 / "sonde FUSE"
Niger1078 fdcImperforate MS9 on FDC
Nigeria143a (Mi134)In (lower-right) margin of MS12 (12x 143)1963Explorer-12/14/15 type1 (in lower-right margin)
Nigeriai143aIn (lower-right) margin of "imperforate"7 MS12 (12x 143)
Nigeria144a (Mi135)In (lower-right) margin of MS12 (12x 144)
Nigeriai144aIn (lower-right) margin of "imperforate"7 MS12 (12x 144)
Nigeria174 (Mi165)1965Explorer-18
Nigeria174aMS12 (12x 174)
ParaguayC642 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
Poland2715 (Mi3015)One of pair (2715a (2714-2715))1986Explorer-59 / ISEE-3 / ICE
RomaniaNoneCancel and cachet on cover1992Explorer-66 / COBE (final-design)5
Rwanda136 (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))
1965Explorer-11 (in right margin); Explorer-13/16/23 type2 (in lower-right margin)
Satellite Beach FL (USA)LocalSet-C08 (blue)1965"Explorer-16"
Satellite Beach FL (USA)LocalSet-C08 (blue) (in cachet position) on FDC
Satellite Beach FL (USA)LocalSet-D02 (green)"Explorer-14"
Satellite Beach FL (USA)LocalSet-D04 (green)"Explorer-17"
Satellite Beach FL (USA)LocalSet-D06 (green)Explorer-20 / "Topsi"
Satellite Beach FL (USA)LocalSet-D07 (green)"Explorer-10"
Satellite Beach FL (USA)Local fdcSet-D07 (green) (in cachet position) on FDC
Satellite Beach FL (USA)LocalSet-D09 (green)Explorer-18 / "IMP-A"
Satellite Beach FL (USA)LocalSet-D10 (green)"Explorer-9"
Satellite Beach FL (USA)Local o/pSet-C08 (blue) overprinted new value in gold1965"Explorer-16"
Satellite Beach FL (USA)LocalSet-D02 (green) overprinted new value in gold"Explorer-14"
Satellite Beach FL (USA)Local o/pSet-D04 (green) overprinted new value in gold"Explorer-17"
Satellite Beach FL (USA)LocalSet-D06 (green) overprinted new value in goldExplorer-20 / "Topsi"
Satellite Beach FL (USA)Local o/pSet-D07 (green) overprinted new value in gold"Explorer-10"
Satellite Beach FL (USA)Local o/pSet-D09 (green) overprinted new value in goldExplorer-18 / "IMP-A"
Satellite Beach FL (USA)LocalSet-D10 (green) overprinted new value in gold"Explorer-9"
Satellite Beach FL (USA)LocalLocal post stamp?"Explorer-30" / SolRad-8
Sharjah45 (Mi57A)
i45 (Mi57B)

Imperforate
1964"Explorer-13"
Sharjah45A (Mi unlisted)
i45A
45 overprinted new currency
i45 overprinted new currency
1967"Explorer-13"
Sharjah46 (Mi58A)
i46 (Mi58B)

Imperforate
1964"Explorer-12"
Sharjah46A (Mi unlisted)
i46A
46 overprinted new currency
i46 overprinted new currency
1967"Explorer-12"
Sierra Leone1074d (Mi1260)One of MS9 (1074 (a-i)) (Mi1257-1265)1989Explorer-57 / "IUE"
Sierra Leone1074d specimenOne of MS9 (1074 specimen (a-i))
SpainNone(Printed) cachet on cover1984"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)
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/p1One of local post MS8 overprinted in silver (a-h)1998"Explorer-47"
Staffa (Scotland)Local_b o/p2One of local post MS8 overprinted in gold (a-h)
Umm Al QiwainMi85A
Mi85B

Imperforate
1966Explorer-10
Umm Al QiwainMi83A-86A+BL5A fdcOne of four stamps on FDC
Umm Al QiwainMi96A
Mi96B
Mi85A overprinted new currency
Mi85B overprinted new currency
1967Explorer-10
Umm Al QiwainMi94B-97B+BL6A fdcOne of four imperforate stamps on FDC
United Nations112-113 fdc (Mi122-123 fdc)(Orbit Covers) cachet on FDC1962"Explorer-12"
United StatesNoneCachet on cover1961Explorer-66
United StatesNone aFrom Interpex MS4 (a-d) cinderella (blue)1962Explorer-13/16/23 type2 (not "Explorer-S6", as in text)
United StatesNone bExplorer-12 (Explorer-S3, folded solar panels)
United StatesNone cExplorer-S45
United StatesNone aFrom Interpex MS4 (a-d) cinderella (yellow)1962Explorer-13/16/23 type2 (not "Explorer-S6", as in text)
United StatesNone bExplorer-12 (Explorer-S3, folded solar panels)
United StatesNone cExplorer-S45
United StatesNone(Astro Covers) cachet on cover1962"Explorer" (in text)
United StatesNone(Black rubber-stamp) cachet on cover1967"Explorer-XX", "Explorer-XXII"
United StatesNoneCachet1971Explorer-45
United StatesNone(Rockpex) cachet (with design similar to Centennial black rocket, type-1) cachet) on cover1971Explorer-6/Pioneer-56
United StatesNone(GSFC blue rubber-stamp) cachet on cover1974Explorer-57 / IUE
United StatesNone(Printed) cachet on cover1977Explorer-53
United States1915 fdc (Mi1484 fdc)(?) cachet on FDC1981Explorer-64 / SME
United StatesNone(ASDA) cachet (with reproduction of Belgium 670) on cover1983
United StatesNoneInsert back from cover, also insert front and cover front1986"International Sun-Earth Explorer (ISEE)-3" renamed "International Cometary Explorer (ICE)" / Explorer-59
United StatesNone(Blue text under printed) cachet on cover1994"IUE" (Explorer-57)
United States3187d fdc (Mi3126 fdc)(Printed) cachet on FDC1999"the Van Allen radiation belt[s] discovered by the Explorer satellites" (refers to Explorer-1 and Explorer-3)
United StatesNoneCachet on cover2008Explorer-77 / FUSE (in text)
United StatesNone(Zazzle.com) personalized postage2010Explorer-92 / "WISE"
United StatesNone(Zazzle.com) personalized postage (different)Explorer-92 / WISE launch
Yemen Arab Republic260_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
1969Explorer-66
Yemen Arab Republic260A_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 Republic260B_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 Republic260C (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 Republic260D_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 Republic260E_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 Republic260F (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 type1 (not "Explorer-7", as in text), Explorer-66
Yemen Arab Republic261A (Mi922)
261h (Mi929)

Imperforate with changed colors
1969"Explorer-10"
Yemen Arab RepublicC87 (Mi1698)1982Explorer-13/16/23 type2
Yemen Arab RepublicC87 dsDeluxe sheet (C87)
Yemen Arab RepublicC87 proofChromalin proof
Yemen Arab RepublicC90ae (Mi1706)On one of MS4 (C90a (b-e)) (BL218)Explorer-66
Yemen Arab RepublicC90ae proofChromalin proof
Yemen Arab RepublicC91 (Mi1702)Explorer-12/14/15 type1
Yemen Arab RepublicC91 dsDeluxe sheet (C91)
Yemen Arab RepublicC91 proofChromalin proof
Yemen RepublicC141 (Mi87)Yemen Arab Republic C91 overprinted1993Explorer-12/14/15 type1

1Explorer-12, 14, and 15, Electrostatic Particle Explorers (EPE-A/B/C) 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.


Below is a list of Explorer-series satellite launch covers (including anniversary-of-launch covers, and launch-related event covers).

CountryCancel DateCancel LocationType of ItemNotes 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 States1958-03-26Port Canaveral FL(Sarzin) cachet on coverExplorer-3 launch
United States1958-03-26Patrick AFB, FL(Fleetwood printed and Epps blue rubber-stamp) cachets on coverExplorer-3 launch
United States1958-03-26Patrick AFB, FL(Goldcraft Cachets) cachet on coverExplorer-3 launch
United States1958-03-26Patrick AFB, FL(Goldcraft Cachets) cachet (different) on coverExplorer-3 launch (mis-identified as "Vanguard-3" in text)
United States1958-03-26Patrick AFB, FL(Swanson blue rubber-stamp) cachet on (airmail) coverExplorer-3 launch
United States1958-03-26Patrick AFB, FL(Flick) cachet on (airmail) coverExplorer-3 launch
1958-07-26: Explorer-4
United States1958-07-26Patrick AFB, FL(Flick) cachet on coverExplorer-4 launch
United States1958-07-26Patrick AFB, FL(Flick) cachet (same) on (airmail) coverExplorer-4 launch
United States1958-07-26Patrick AFB, FL(Goldcraft Cachets) cachet on coverExplorer-4 launch (Vanguard-2 depicted)
United States1958-07-26Patrick AFB, FL(C. Swanson red rubber-stamp) cachet on (airmail) coverExplorer-4 launch
United States1958-07-26Patrick AFB, FL(Artmaster) cachet on coverExplorer-4 launch
United States1958-07-26Port Canaveral FL(Printed) cachet on coverExplorer-4 launch
United States1958-07-26Port Canaveral FL(Sarzin) cachet on coverExplorer-4 launch
United States1958-07-26Patrick AFB, FL(Rubber-stamp) cachet on coverExplorer-4 launch
United States1958-07-26Port Canaveral FL(Black printed) cachet on coverExplorer-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 States1959-08-07Patrick AFB, FL(Flick) cachet on cover(poorly-depicted) Explorer-6 (S2) launch
United States1959-08-07Merritt Island FL(Highway Stamp Club) cachet on coverExplorer-6 (S2) launch
United States1959-08-07Port Canaveral FL(Goldcraft Cachets) cachet on coverExplorer-6 (S2) launch
United States1959-08-07Port Canaveral FL(Sarzin) cachet on coverExplorer-6 (S2) launch
United States1959-08-07Patrick AFB, FL(Swanson red rubber-stamp) cachet on (airmail) coverExplorer-6 (S2) launch
Explorer-6 (anniversaries)
United States1974-08-14Cape Canaveral FL(MoF no.18) cachet on cover, also insert and insert back15th anniv. Explorer-6 (S2) first televised image
United States2009-08-07Cape Canaveral FL(Mission 57) cachet on cover, also back50th anniv. Explorer-6 (S2) launch
1959-10-13: Explorer-7 (S1A)
United States1959-10-13Port Canaveral FL(Printed) cachet on coverExplorer-7 (S1A) launch
United States1959-10-13Port Canaveral FL(Sarzin) cachet on coverExplorer-7 (S1A) launch
United States1959-10-13Port Canaveral FL(Sarzin) cachet (and signatures) on coverExplorer-7 (S1A) launch
United States1959-10-13Port Canaveral FL(Goldcraft Cachets) cachet on coverExplorer-7 (S1A) launch
United States1959-10-13Port Canaveral FLCancel on picture postcardExplorer-7 (S1A) launch
United States1959-10-13Port Canaveral FLCancel (same) on picture postcard (different)Explorer-7 (S1A) launch
United States1959-10-13Port Canaveral FLCancel (same) on picture postcard (different)Explorer-7 (S1A) launch (Vanguard-2 depicted)
United States1959-10-13Port Canaveral FLCancel (same) on picture postcard (different)Explorer-7 (S1A) launch
United States1959-10-13Port Canaveral FLCancel (same) on picture postcard (different)Explorer-7 (S1A) launch
United States1959-10-13Port Canaveral FLCancel (same) on picture postcard (different)Explorer-7 (S1A) launch
United States1959-10-13Port Canaveral FLCancel (same) on picture postcard (different)Explorer-7 (S1A) launch
Explorer-7 (anniversaries)
United States2009-10-13Cape Canaveral FL(Mission 57) cachet on cover, also back50th 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 States1960-11-03Patrick AFB, FL(Blue rubber-stamp) cachet on coverExplorer-8 (S30) launch
United States1960-11-03Port Canaveral FL(No) cachet on coverExplorer-8 (S30) launch
United States1960-11-03Patrick AFB, FL(Swanson blue rubber-stamp) cachet on (airmail) coverExplorer-8 (S30) launch
United States1960-11-03Port Canaveral FL(Goldcraft Cachets) cachet on coverExplorer-8 (S30) launch
United States1960-11-03Port Canaveral FL(C. Swanson red rubber-stamp) cachet on coverExplorer-8 (S30) launch
United States1960-11-03Patrick AFB, FL(Red rubber-stamp) cachet on (airmail) coverExplorer-8 (S30) launch
United States1960-11-03Port Canaveral FL(Hand-written) cachet on postcard, also backExplorer-8 (S30) launch
United States1960-11-03Patrick AFB, FL(Zaso) cachet on coverExplorer-8 (S30) launch
United States1960-11-03Port Canaveral FL(Zaso) cachet (same) on coverExplorer-8 (S30) launch
United States1960-11-03Port Canaveral FL(Sarzin) cachet on coverExplorer-8 (S30) launch
1960-12-04: Explorer-S56 [failed]
United States1960-12-04Wallops Island VA (hand cancel)(Blue and black rubber-stamp) cachet on coverExplorer-S56 launch [failed]
United States1960-12-04Wallops Island VA (machine cancel)(Hudson rubber-stamp) cachet on coverExplorer-S56 launch [failed]
United States1960-12-04Wallops Island VA (machine cancel)(Hudson rubber-stamp) cachet (same) on (airmail) coverExplorer-S56 launch [failed]
United States1960-12-04Wallops Island VA (machine cancel)(Hudson rubber-stamp) cachet (and signature) on (airmail) coverExplorer-S56 launch [failed]
1961-02-16: Explorer-9 (S56A)
United States1961-02-16Wallops Island VA (machine cancel)(Hudson rubber-stamp) cachet on coverExplorer-9 (S56A) launch
United States1961-02-16Wallops Island VA (hand cancel)(Hudson rubber-stamp) cachet (different) on (airmail) coverExplorer-9 (S56A) launch
United States1961-02-16Wallops Island VA(Hudson rubber-stamp and typed) cachet on coverExplorer-9 (S56A) launch
United States1961-02-16Wallops Island VA(Goldcraft Cachets) cachet on coverExplorer-9 (S56A) launch
1961-02-24: Explorer-S45 [failed]
United States1961-02-24Patrick AFB, FL(Red and black rubber-stamp) cachet on (airmail) coverExplorer-S45 launch [failed]
United States1961-02-24Patrick AFB, FL(Typed) cachet on coverExplorer-S45 launch [failed]
1961-03-25: Explorer-10 (P14)
United States1961-03-25 (inverted hour "2" )Patrick AFB, FL(SpaceCraft no.1) cachet on coverExplorer-10 (P14) launch
United States1961-03-25Patrick AFB, FL(SpaceCraft no.1) cachet (and signature) on coverExplorer-10 (P14) launch
United States1961-03-25Patrick AFB, FL(Swanson black rubber-stamp) cachet on coverExplorer-10 (P14) launch
1961-04-27: Explorer-11 (S15)
United States1961-04-27Port Canaveral FL(Goldcraft Cachets) cachet on coverExplorer-11 (S15) launch
United States1961-04-27Patrick AFB, FL(SpaceCraft/C. Swanson printed) cachet on coverExplorer-11 (S15) launch
United States1961-04-27Port Canaveral FL(Sarzin) cachet on coverExplorer-11 (S15) launch
United States1961-04-27Patrick AFB, FL(Swanson black rubber-stamp) cachet on coverExplorer-11 (S15) launch
1961-05-24: Explorer-S45A [failed]
United States1961-05-24Patrick AFB, FL(Rubber-stamp and hand-written) cachet on coverExplorer-S45A launch [failed]
1961-06-30: Explorer-S55 [failed]
United States1961-06-30Wallops Island VA(Hudson purple rubber-stamp) cachet on coverExplorer-S55 launch [failed]
United States1961-06-30Wallops Island VA (hand cancel)(Swanson magenta rubber-stamp) cachet (different) on coverExplorer-S55 launch [failed]
United States1961-06-30Wallops Island VA (machine cancel)(Swanson magenta rubber-stamp) cachet (same) on coverExplorer-S55 launch [failed]
1961-08-16: Explorer-12 (EPE-A)
United States1961-08-15Port Canaveral FL(Goldcraft Cachets) cachet on coverExplorer-12 (EPE-A) launch
United States1961-08-16Patrick AFB, FL(SpaceCraft) cachet on cover, also insertExplorer-12 (EPE-A) launch
United States1961-08-16Patrick AFB, FL(SpaceCraft) cachet (and signature) on cover, also insertExplorer-12 (EPE-A) launch
1961-08-25: Explorer-13 (S55A)
United States1961-08-25Wallops Island VA(SpaceCraft/C. Swanson printed) cachet on coverExplorer-13 (S55A) launch
United States1961-08-25Wallops Island VA (hand cancel)(Swanson magenta rubber-stamp) cachet on coverExplorer-13 (S55A, not S55) launch
United States1961-08-25Wallops Island VA (machine cancel)(Swanson magenta rubber-stamp) cachet (same) on coverExplorer-13 (S55A, not S55) launch
United States1961-08-25Wallops Island VA(Black and red rubber-stamp and typed) cachet on coverExplorer-13 (S55A) launch
1962-10-02: Explorer-14 (EPE-B)
United States1962-10-02Cape Canaveral FL(Printed) cachet on coverExplorer-14 (EPE-B) launch (TIROS depicted)
United States1962-10-03Cape Canaveral FL(Rank velvet) cachet on coverExplorer-14 (EPE-B) launch
United States1962-10-03Cape Canaveral FL(SpaceCraft) cachet on cover, also insert and insert variation (minor differences)Explorer-14 (EPE-B) launch
United States1962-10-03Patrick AFB, FL(SpaceCraft) cachet on cover, also insert and insert variation (minor differences)Explorer-14 (EPE-B) launch
United States1962-10-03Cape Canaveral FL(Sarzin) cachet on coverExplorer-14 (EPE-B) launch
United States1962-10-03Cape Canaveral FL(C. Swanson purple and red rubber-stamp) cachet on (airmail) coverExplorer-14 (EPE-B) launch
United States1962-10-03
1964-12-21
Cape Canaveral FL
Satellite Beach FL
(Rank velvet) cachet on coverExplorer-14 (EPE-B) launch
Explorer-26 (EPE-D) launch
1962-10-28: Explorer-15 (EPE-C)
United States1962-10-28Cape Canaveral FL(Centennial) cachet on coverExplorer-15 (EPE-C) launch
United States1962-10-29Cape Canaveral FL(Sarzin) cachet on coverExplorer-15 (EPE-C) launch
United States1962-10-29Cape Canaveral FL(SpaceCraft) cachet on coverExplorer-15 (EPE-C) launch
United States1962-10-29Cape Canaveral FL(SpaceCraft Type-B general-purpose) cachet on coverExplorer-15 (EPE-C) launch
United States1962-10-29Cape Canaveral FL(Swanson purple rubber-stamp) cachet on coverExplorer-15 (EPE-C) launch
1962-12-16: Explorer-16 (S55B)
United States1962-12-16Wallops Island VA(SpaceCraft) cachet on cover, also insertExplorer-16 (S55B) launch
United States1962-12-16Wallops Island VA(Swanson green and magenta rubber-stamp) cachet on coverExplorer-16 (S55B) launch
United States1962-12-16Wallops Island VA(Swanson green and magenta rubber-stamp) cachet on (airmail) coverExplorer-16 (S55B) launch
United States1962-12-16Wallops Island VA(Rank velvet) cachet on cover, also insertExplorer-16 (S55B) launch
United States1962-12-16
1964-11-06
Wallops Island VA (machine cancel)
Wallops Island VA (hand cancel)
(Rank velvet) cachet on cover, also insertExplorer-16 (S55B) launch
Explorer-23 (S55C) launch
1963-04-03: Explorer-17 (AE-A)
United States1963-04-02Satellite Beach FL(Swanson blue rubber-stamp and typed) cachet on coverExplorer-17 (AE-A) launch
United States1963-04-02Cape Canaveral FL(Goldcraft Cachets) cachet on coverExplorer-17 (AE-A) launch
United States1963-04-02Satellite Beach FL(Rank velvet) cachet on coverExplorer-17 (AE-A) launch
United States1963-04-02Satellite Beach FL(SpaceCraft/Swanson) cachet on cover, also insertExplorer-17 (AE-A) launch
United States1963-04-02Satellite Beach FL(Printed) cachet on coverExplorer-17 (AE-A) launch (mis-spelled "Explored-17")
United States1963-04-03Cape Canaveral FL(Printed) cachet (same) on coverExplorer-17 (AE-A) launch (mis-spelled "Explored-17")
United States1963-04-03Cape Canaveral FL(Rank velvet) cachet on coverExplorer-17 (AE-A) launch
United States1963-04-03Cape Canaveral FL(Rank velvet, different) cachet on coverExplorer-17 (AE-A) launch
United States1963-04-03Cape Canaveral FL(SpaceCraft/Swanson) cachet on cover, also insertExplorer-17 (AE-A) launch
United States1963-04-03Patrick AFB, FL(SpaceCraft/Swanson) cachet on cover, also insertExplorer-17 (AE-A) launch
United States1963-04-03Cape Canaveral FL(Sarzin) cachet on coverExplorer-17 (AE-A) launch (Explorer-12/14/15 type depicted)
United States1963-04-03Cape Canaveral FL (machine cancel)(Centennial) cachet on coverExplorer-17 (AE-A) launch
United States1963-04-03Cape Canaveral FL (hand cancel)(Centennial) cachet on coverExplorer-17 (AE-A) launch
United States1963-04-03Cape Canaveral FL(C. Swanson purple rubber-stamp) cachet on coverExplorer-17 (AE-A) launch
United States1963-04-03Cape Canaveral FL(Black printed and typed) cachet on coverExplorer-17 (AE-A) launch
1963-11-26: Explorer-18 (IMP-A/IMP-1)
United States1963-11-26
1964-10-04
Satellite Beach FL
Satellite Beach FL
(Printed) cachet on coverExplorer-18 (IMP-A/IMP-1) launch
Explorer-21 (IMP-B/IMP-2) launch
United States1963-11-26Satellite Beach FL(Rank velvet) cachet on coverExplorer-18 (IMP-A/IMP-1) launch
United States1963-11-27Cape Canaveral FL(Rank velvet) cachet on coverExplorer-18 (IMP-A/IMP-1) launch
United States1963-11-27Cape Canaveral FL(SpaceCraft/Swanson) cachet on cover, also insertExplorer-18 (IMP-A/IMP-1) launch
United States1963-11-27Patrick AFB, FL(SpaceCraft/Swanson) cachet on cover, also insertExplorer-18 (IMP-A/IMP-1) launch
United States1963-11-27Cape Canaveral FL (machine cancel)(Centennial) cachet on coverExplorer-18 (IMP-A/IMP-1) launch
United States1963-11-27Cape Canaveral FL (hand cancel)(Centennial) cachet on coverExplorer-18 (IMP-A/IMP-1) launch
United States1963-11-27Cape Canaveral FL(Sarzin) cachet on coverExplorer-18 (IMP-A/IMP-1) launch
United States1963-11-27Cape Canaveral FL(Red printed and typed) cachet on coverExplorer-18 (IMP-A/IMP-1) launch
United States1963-11-27Cape Canaveral FL(Swanson blue rubber-stamp) cachet on coverExplorer-18 (IMP-A/IMP-1) launch
United States1963-11-27Cape Canaveral FL(Swanson blue rubber-stamp) cachet (and signature) on coverExplorer-18 (IMP-A/IMP-1) launch
United States1963-11-27
1964-10-04
Cape Canaveral FL
Satellite Beach FL
(Rank velvet) cachet on coverExplorer-18 (IMP-A/IMP-1) launch
Explorer-21 (IMP-B/IMP-2) launch
1963-12-19: Explorer-19 (AED-A)
United States1963-12-19Vandenberg AFB, CA(Swanson blue rubber-stamp) cachet on coverExplorer-19 (AED-A) launch
United States1963-12-19Vandenberg AFB, CA(SpaceCraft/Swanson) cachet on cover, also insertExplorer-19 (AED-A) launch
United States1963-12-19Vandenberg AFB, CA(Sarzin?) cachet on coverExplorer-19 (AED-A) launch
United States1963-12-19Vandenberg AFB, CA(Rank velvet) cachet on coverExplorer-19 (AED-A) launch
1964-03-19: Explorer-S66 [failed]
United States1964-03-19Cape Canaveral FL(Sarzin) cachet on coverExplorer-S66 launch [failed] (OAO-1 depicted)
United States1964-03-19Cape Canaveral FL(Sokolsky) cachet on coverExplorer-S66 launch [failed]
United States1964-03-19Cape Canaveral FL (hand cancel)(C. Swanson black rubber-stamp) cachet on coverExplorer-S66 launch [failed]
United States1964-03-19Cape Canaveral FL (machine cancel)(C. Swanson black rubber-stamp) cachet on coverExplorer-S66 launch [failed]
United States1964-03-19Cape Canaveral FL(C. Swanson purple rubber-stamp) cachet on coverExplorer-S66 launch [failed]
United States1964-03-19Patrick AFB, FL(C. Swanson black rubber-stamp and dark-green printed) cachet on coverExplorer-S66 launch [failed]
United States1964-03-19Cape Canaveral FL (machine cancel)(Centennial black rocket, type-1) cachet on coverExplorer-S66 launch [failed] (Pioneer-3/4 type, Pioneer-5/Explorer-62, and Vanguard-2 depicted)
United States1964-03-19Cape Canaveral FL (hand cancel)(Centennial black rocket, type-1) cachet (same) on coverExplorer-S66 launch [failed] (Pioneer-3/4 type, Pioneer-5/Explorer-62, and Vanguard-2 depicted)
United States1964-03-19Satellite Beach FL(Goldcraft brown) cachet on coverExplorer-S66 launch [failed]
United States1964-03-20Cape Canaveral FL(Goldcraft red) cachet on coverExplorer-S66 launch [failed]
1964-08-25: Explorer-20 (IE-A, Topsi)
United States1964-08-25Vandenberg AFB, CA(SpaceCraft/Swanson) cachet on cover, also insertExplorer-20 (IE-A) launch
United States1964-08-25Vandenberg AFB, CA(Sarzin?) cachet on cover, also (hand-written) insertExplorer-20 (IE-A) launch
United States1964-08-25Vandenberg AFB, CA(Swanson blue rubber-stamp) cachet on coverExplorer-20 (IE-A) launch
1964-10-04: Explorer-21 (IMP-B/IMP-2)
United States1964-10-04Patrick AFB, FL(Sarzin) cachet on coverExplorer-21 (IMP-B/IMP-2) launch
United States1964-10-04Patrick AFB, FL(SpaceCraft/Swanson) cachet on cover, also insertExplorer-21 (IMP-B/IMP-2) launch
United States1964-10-04Cape Canaveral FL(Centennial) cachet on cover, also (hand-written) insertExplorer-21 (IMP-B/IMP-2) launch
United States1964-10-04Patrick AFB, FL(C. Swanson purple rubber-stamp) cachet on coverExplorer-21 (IMP-B/IMP-2) launch
United States1964-10-04
1963-11-26
Satellite Beach FL
Satellte Beach FL
(Printed) cachet on coverExplorer-21 (IMP-B/IMP-2) launch
Explorer-18 (IMP-A/IMP-1) launch
United States1964-10-04
1963-11-27
Satellite Beach FL
Cape Canaveral FL
(Rank velvet) cachet on coverExplorer-21 (IMP-B/IMP-2) launch
Explorer-18 (IMP-A/IMP-1) launch
1964-10-09: Explorer-22 (S66A, BE-B)
United States1964-10-09Vandenberg AFB, CA(Sarzin?) cachet on coverExplorer-22 (BE-B) launch
United States1964-10-09Vandenberg AFB, CA(SpaceCraft/Swanson) cachet (and signature) on cover, also insertExplorer-22 (BE-B) launch
United States1964-10-09Vandenberg AFB, CA(SpaceCraft/Swanson) cachet on cover, also insertExplorer-22 (BE-B) launch
United States1964-10-09Vandenberg AFB, CA(Swanson/DuBeau? blue rubber-stamp) cachet on coverExplorer-22 (BE-B) launch
United States1964-10-09Vandenberg AFB, CA(Orbit Covers) cachet on cover, also (hand-written) insertExplorer-22 (BE-B) launch
1964-11-06: Explorer-23 (S55C)
United States1964-11-06Wallops Island VA(SpaceCraft/Swanson) cachet on cover, also insertExplorer-23 (S55C) launch
United States1964-11-06Wallops Island VA(Sarzin?) cachet on coverExplorer-23 (S55C) launch (wrong depiction)
United States1964-11-06Wallops Island VA(Swanson blue rubber-stamp) cachet on coverExplorer-23 (S55C) launch
United States1964-11-06Wallops Island VA(Swanson blue rubber-stamp) cachet on (airmail) coverExplorer-23 (S55C) launch
United States1964-11-06
1962-12-16
Wallops Island VA
Wallops Island VA
(Rank velvet) cachet on cover, also insertExplorer-23 (S55C) launch
Explorer-16 (S55B) launch
1964-11-21: Explorer-24 (ADE-B) and Explorer-25 (Injun-4)
United States1964-11-21Vandenberg AFB, CA(SpaceCraft/Swanson) cachet (and signature) on cover, also insert and insert variation (different arrows) and insert variation2 (different arrows and slightly different line lengths)Explorer-24 (ADE-B) and Explorer-25 (Injun-4) launch
United States1964-11-21Vandenberg AFB, CA(SpaceCraft/Swanson) cachet on cover, also insert and insert variation (different arrows) and insert variation2 (different arrows and slightly different line lengths)Explorer-24 (ADE-B) and Explorer-25 (Injun-4) launch
United States1964-11-21Vandenberg AFB, CA(Sarzin?) cachet on cover, also (hand-written) insertExplorer-24 (ADE-B) and Explorer-25 (Injun-4) launch (Vela images)
United States1964-11-21Vandenberg AFB, CA(Goldcraft Cachets) cachet on coverExplorer-24 (ADE-B) and Explorer-25 (Injun-4) launch
United States1964-11-21Vandenberg AFB, CA(Swanson red rubber-stamp) cachet on coverExplorer-24 (ADE-B) and Explorer-25 (Injun-4) launch
United States1964-11-21Vandenberg AFB, CA(DuBeau? red and blue printed) cachet on coverExplorer-24 (ADE-B) and Explorer-25 (Injun-4) launch
1964-12-21: Explorer-26 (EPE-D)
United States1964-12-21Patrick AFB, FL(SpaceCraft/Swanson) cachet on cover, also insertExplorer-26 (EPE-D) launch
United States1964-12-21Cape Canaveral FL(SpaceCraft/Swanson) cachet on cover, also insertExplorer-26 (EPE-D) launch
United States1964-12-21Cape Canaveral FL(Sokolsky) cachet on coverExplorer-26 (EPE-D) launch
United States1964-12-21Cape Canaveral FL (hand cancel)(Centennial orange earth) cachet on coverExplorer-26 (EPE-D) launch (Relay, Vanguard-2, Pioneer-3/4 type, Explorer-1, TIROS/ESSA depicted)
United States1964-12-21Cape Canaveral FL (machine cancel)(Centennial orange earth) cachet (same) on coverExplorer-26 (EPE-D) launch (Relay, Vanguard-2, Pioneer-3/4 type, Explorer-1, TIROS/ESSA depicted)
United States1964-12-21Cape Canaveral FL(Sarzin) cachet on coverExplorer-26 (EPE-D) launch (wrong images)
United States1964-12-21Patrick AFB, FL(C. Swanson purple rubber-stamp) cachet on coverExplorer-26 (EPE-D) launch
United States1964-12-21Cape Canaveral FL(C. Swanson purple rubber-stamp) cachet (slightly-different) on coverExplorer-26 (EPE-D) launch
United States1964-12-21Cape Canaveral FL(C. Swanson purple rubber-stamp) cachet (slightly different) on (airmail) coverExplorer-26 (EPE-D) launch
United States1964-12-21Patrick AFB, FL(Zaso sticker and rubber-stamp) cachet on coverExplorer-26 (EPE-D) launch
United States1964-12-21
1962-10-03
Satellite Beach FL
Cape Canaveral FL
(Rank velvet) cachet on coverExplorer-26 (EPE-D) launch
Explorer-14 (EPE-B) launch
1965-04-29: Explorer-27 (BE-C)
United States1965-04-29Wallops Island VA(Sarzin?) cachet on coverExplorer-27 (BE-C) launch
United States1965-04-29Wallops Island VA(SpaceCraft/Swanson) cachet on cover, also insertExplorer-27 (BE-C) launch
United States1965-04-29Wallops Island VA(Rank velvet) cachet on coverExplorer-27 (BE-C) launch
United States1965-04-29Wallops Island VA(Rank silkscreened?) cachet on coverExplorer-27 (BE-C) launch
United States1965-04-29Wallops Island VA(Centennial) cachet on coverExplorer-27 (BE-C) launch
United States1965-04-29Wallops Island VA(Swanson blue and magenta rubber-stamp) cachet on (airmail) coverExplorer-27 (BE-C) launch
United States1965-04-29Wallops Island VA(Swanson green and magenta rubber-stamp) cachet on coverExplorer-27 (BE-C) launch
United States1965-04-29Wallops Island VA(Swanson green and magenta rubber-stamp) cachet (different) on coverExplorer-27 (BE-C) launch
1965-05-29: Explorer-28 (IMP-C/IMP-3)
United States1965-05-29Cape Canaveral FL(SpaceCraft/Swanson) cachet on cover, also insertExplorer-28 (IMP-C/IMP-3) launch
United States1965-05-29Cape Canaveral FL(Celestial) cachet on coverExplorer-28 (IMP-C/IMP-3) launch
United States1965-05-29Cape Canaveral FL(Swanson blue rubber-stamp) cachet on coverExplorer-28 (IMP-C/IMP-3) launch
United States1965-05-29Cape Canaveral FL(Sarzin) cachet on coverExplorer-28 (IMP-C/IMP-3) launch
United States1965-05-29Cape Canaveral FL(C. Swanson red and black rubber-stamp) cachet on coverExplorer-28 (IMP-C/IMP-3) launch
1965-11-06: Explorer-29 (GEOS-1)
United States1965-11-06Patrick AFB, FL(SpaceCraft/Swanson) cachet (and signature) on cover, also insert and insert variation (slightly different line lengths)Explorer-29 (GEOS-1) launch
United States1965-11-06Patrick AFB, FL(SpaceCraft/Swanson) cachet on cover, also insert and insert variation (slightly different line lengths)Explorer-29 (GEOS-1) launch
United States1965-11-06Cape Canaveral FL (machine cancel)(Centennial) cachet on coverExplorer-29 (GEOS-1) launch
United States1965-11-06Cape Canaveral FL (hand cancel)(Centennial) cachet on coverExplorer-29 (GEOS-1) launch
United States1965-11-06Patrick AFB, FL(Sarzin) cachet on coverExplorer-29 (GEOS-1) launch (Explorer-17 depicted)
United States1965-11-06Patrick AFB, FL(Rank velvet) cachet on coverExplorer-29 (GEOS-1) launch
United States1965-11-06Cape Canaveral FL(Celestial) cachet on coverExplorer-29 (GEOS-1) launch
United States1965-11-06Cape Canaveral FL(Artopages) cachet on coverExplorer-29 (GEOS-1) launch
1965-11-19: Explorer-30 (SolRad-8)
United States1965-11-19Wallops Island VA(SpaceCraft/Swanson) cachet on cover, also insertExplorer-30 (SolRad-8) launch; also IQSY
United States1965-11-19Wallops Island VA(Sarzin?) cachet on coverExplorer-30 (SolRad-8) launch (wrong depiction); also IQSY
United States1965-11-19Wallops Island VA(Rank velvet) cachet on coverExplorer-30 (SolRad-8) launch; also IQSY
United States1965-11-19Wallops Island VA(Rank velvet, trial with overlay) cachet on coverExplorer-30 (SolRad-8) launch; also IQSY
United States1965-11-19Wallops Island VA(Swanson blue and magenta rubber-stamp) cachet on coverExplorer-30 (SolRad-8) launch; also IQSY
United States1965-11-19Wallops Island VA(Centennial black rocket, type-1) cachet on coverExplorer-30 (SolRad-8) launch (Pioneer-3/4 type, Pioneer-5/Explorer-62, and Vanguard-2 depicted)
1965-11-28: Explorer-31 (ISIS-X) (and Alouette-2)
United States1965-11-28Vandenberg AFB, CA(SpaceCraft/Swanson) cachet (and signature) on cover, also insertExplorer-31 (ISIS-X) launch
United States1965-11-28Vandenberg AFB, CA(SpaceCraft/Swanson) cachet on cover, also insertExplorer-31 (ISIS-X) launch
United States1965-11-28Vandenberg AFB, CA(Sarzin) cachet on coverExplorer-31 (ISIS-X) launch (wrong depiction)
United States1965-11-28Vandenberg AFB, CA(AAMS no.3916) cachet on cover, also backExplorer-31 (ISIS-X) launch; reproduction of Canada 445 (in cachet)
United States1965-11-28Vandenberg AFB, CA(Vandy?/DuBeau? blue rubber-stamp) cachet on coverExplorer-31 (ISIS-X) launch
United States1965-11-28Vandenberg AFB, CA(Astro Covers) cachet on coverExplorer-31 (ISIS-X) launch
United States1965-11-28
1962-09-28
Vandenberg AFB, CA
Vandenberg AFB, CA
(Rank velvet) cachet on coverExplorer-31 (ISIS-X)
Alouette-1 launch
1966-05-25: Explorer-32 (AE-B)
United States1966-05-25Cape Canaveral FL(SpaceCraft/Swanson) cachet on cover, also insertExplorer-32 (AE-B) launch
United States1966-05-25Patrick AFB, FL(SpaceCraft/Swanson) cachet on cover, also insertExplorer-32 (AE-B) launch
United States1966-05-25Cape Canaveral FL(Sarzin?) cachet on coverExplorer-32 (AE-B) launch (wrong depiction)
United States1966-05-25Cape Canaveral FL (hand cancel)(Centennial) cachet on coverExplorer-32 (AE-B) launch
United States1966-05-25Cape Canaveral FL (machine cancel)(Centennial) cachet on coverExplorer-32 (AE-B) launch
United States1966-05-25Cape Canaveral FL(Orbit Covers) cachet on coverExplorer-32 (AE-B) launch
1966-07-01: Explorer-33 (IMP-D/AIMP-1)
United States1966-07-01Patrick AFB, FL(Sarzin) cachet on coverExplorer-33 (IMP-D/AIMP-1) launch
United States1966-07-01Patrick AFB, FL(SpaceCraft/Swanson) cachet on cover, also insert and insert variation (slightly different line lengths)Explorer-33 (IMP-D/AIMP-1) launch
United States1966-07-01Cape Canaveral FL(SpaceCraft/Swanson) cachet on cover, also insert and insert variation (slightly different line lengths)Explorer-33 (IMP-D/AIMP-1) launch
United States1966-07-01Cape Canaveral FL (machine cancel)(Orbit Covers) cachet on coverExplorer-33 (IMP-D/AIMP-1) launch
United States1966-07-01Cape Canaveral FL (hand cancel)(Orbit Covers) cachet on coverExplorer-33 (IMP-D/AIMP-1) launch
United States1966-07-01Cape Canaveral FL(Astro Covers) cachet on coverExplorer-33 (IMP-D/AIMP-1) launch
United States1966-07-01Cape Canaveral FL(Swanson purple rubber-stamp) cachet on coverExplorer-33 (IMP-D/AIMP-1) launch
United States1966-07-01Cape Canaveral FL(Black printed and typed) cachet on coverExplorer-33 (IMP-D/AIMP-1) launch
United States1966-07-01Cape Canaveral FL(Printed, but not directly relevant) cachet on coverExplorer-33 (IMP-D/AIMP-1) launch
United States1966-07-01Cape Canaveral FL(Centennial) cachet on coverExplorer-33 (IMP-D/AIMP-1) launch
United States1966-07-01Cape Canaveral FL(Orbit Covers) cachet on coverExplorer-33 (IMP-D/AIMP-1) launch
1967-05-24: Explorer-34 (IMP-F/IMP-4)
United States1967-05-24Cape Canaveral FL(Orbit Covers) cachet on coverExplorer-34 (IMP-F/IMP-4) launch
United States1967-05-24Cape Canaveral FL(Orbit Covers) cachet (different) on coverExplorer-34 (IMP-F/IMP-4) launch
United States1967-05-24Vandenberg AFB, CA(SpaceCraft/Swanson) cachet on cover, also insertExplorer-34 (IMP-F/IMP-4) launch
United States1967-05-24Vandenberg AFB, CA(Centennial) cachet on coverExplorer-34 (IMP-F/IMP-4) launch
United States1967-05-24Vandenberg AFB, CA(Swanson blue rubber-stamp) cachet on (airmail) coverExplorer-34 (IMP-F/IMP-4) launch
1967-07-19: Explorer-35 (IMP-E/AIMP-2)
United States1967-07-19Kennedy Space Center FL(R. DuBeau rubber-stamp) cachet on coverExplorer-35 (IMP-E/AIMP-2) launch
United States1967-07-19Patrick AFB, FL(SpaceCraft/Swanson) cachet on cover, also insertExplorer-35 (IMP-E/AIMP-2) launch
United States1967-07-19Cape Canaveral FL(SpaceCraft/Swanson) cachet on cover, also insertExplorer-35 (IMP-E/AIMP-2) launch
United States1967-07-19Kennedy Space Center FL(no) cachet on coverExplorer-35 (IMP-E/AIMP-2) launch
United States1967-07-19Cape Canaveral FL(Orbit Covers) cachet on coverExplorer-35 (IMP-E/AIMP-2) launch
United States1967-07-19Cape Canaveral FL(Orbit Covers) cachet (changed colors) on coverExplorer-35 (IMP-E/AIMP-2) launch
United States1967-07-19Cape Canaveral FL(HJM black) cachet on coverExplorer-35 (IMP-E/AIMP-2) launch; also "Explorer"-10 (upper-middle)
United States1967-07-19Cape Canaveral FL(Sarzin) cachet on coverExplorer-35 (IMP-E/AIMP-2) launch
United States1967-07-19Cape Canaveral FL(Rubber-stamp and typed) cachet on coverExplorer-35 (IMP-E/AIMP-2) launch
United States1967-07-19Cape Canaveral FL(Boudwin? rubber-stamp) cachet on coverExplorer-35 (IMP-E/AIMP-2) launch
Australia1967-07-20Canberra ACT(Blue printed and typed) cachet on coverExplorer-35 (IMP-E/AIMP-2) launch
Explorer-35 (events)
United States1967-07-22Cape Canaveral FL(Orbit Covers) cachet on coverExplorer-35 in lunar orbit
1968-01-11: Explorer-36 (GEOS-2)
United States1968-01-11Vandenberg AFB, CA(Orbit Covers) cachet on coverExplorer-36 (GEOS-2) launch
United States1968-01-11Vandenberg AFB, CA(Swanson blue rubber-stamp) cachet on coverExplorer-36 (GEOS-2) launch
United States1968-01-11Lompoc CA, Vandenberg AFB(SpaceCraft/Swanson) cachet on cover, also insertExplorer-36 (GEOS-2) launch
United States1968-01-11Vandenberg AFB, CA(SpaceCraft/Swanson) cachet on cover, also insert and insert backExplorer-36 (GEOS-2) launch; also "Explorer-29" (in text on insert back)
United States1968-01-11Vandenberg AFB, CA(Centennial brown rocket, type-2 and black text) cachet on coverExplorer-36 (GEOS-2) launch (Transit-2A, Pioneer-5/Explorer-6, TIROS/ESSA, and Vanguard-2 depicted)
1968-03-05: Explorer-37 (SolRad-9)
United States1968-03-05Wallops Island VA(Orbit Covers) cachet on coverExplorer-37 (SolRad-9) launch
United States1968-03-05Wallops Island VA (hand cancel)(SpaceCraft/Swanson) cachet on cover, also insertExplorer-37 (SolRad-9) launch
United States1968-03-05Wallops Island VA (machine cancel)(SpaceCraft/Swanson) cachet on cover, also insertExplorer-37 (SolRad-9) launch
United States1968-03-05Wallops Island VA(Swanson green and magenta rubber-stamp) cachet on coverExplorer-37 (SolRad-9) launch
United States1968-03-05Wallops Island VA(Swanson green and magenta rubber-stamp) cachet (different) on coverExplorer-37 (SolRad-9) launch
United States1968-03-05Wallops Island VA(Swanson blue and magenta rubber-stamp) cachet on coverExplorer-37 (SolRad-9) launch
United States1968-03-05Wallops Island VA(Swanson blue and magenta rubber-stamp) cachet on (airmail) coverExplorer-37 (SolRad-9) launch
United States1968-03-05Wallops Island VA(Swanson blue and magenta rubber-stamp) cachet (different) on coverExplorer-37 (SolRad-9) launch
United States1968-03-05Wallops Island VA(Centennial) cachet on coverExplorer-37 (SolRad-9) launch
1968-07-04: Explorer-383 (RAE-1)
United States1968-07-04Vandenberg AFB, CA(Orbit Covers) cachet on coverExplorer-38 (RAE-1) launch
United States1968-07-04Vandenberg AFB, CA(SpaceCraft/Swanson) cachet on cover, also insert1, insert2, insert2 backExplorer-38 (RAE-1) launch
United States1968-07-04Vandenberg AFB, CA(Sarzin?) cachet on coverExplorer-38 (RAE-1) (mis-labeled "Explorer-36") launch (wrong depiction)
United States1968-07-04Vandenberg AFB, CA(Swanson blue rubber-stamp) cachet on coverExplorer-38 (RAE-1) launch
United States1968-07-04Vandenberg AFB, CA(Centennial) cachet on coverExplorer-38 (RAE-1) launch
1968-08-08: Explorer-39 (ADE-C) and Explorer-40 (Injun-5)
United States1968-08-08Vandenberg AFB, CA(SpaceCraft/Swanson) cachet on cover, also insertExplorer-39 (ADE-C) and Explorer-40 (Injun-5) launch (wrong image for Explorer-40)
United States1968-08-08Lompoc CA, Vandenberg AFB(SpaceCraft/Swanson sticker) cachet on cover, also insertExplorer-39 (ADE-C) and Explorer-40 (Injun-5) launch (wrong image for Explorer-40)
United States1968-08-08Vandenberg AFB, CA(Orbit Covers) cachet on coverExplorer-39 (ACE-C) and Explorer-40 (Injun-5) launch
United States1968-08-08Vandenberg AFB, CA(Swanson blue rubber-stamp) cachet on coverExplorer-39 (ADE-C) and Explorer-40 (Injun-5) launch
United States1968-08-08Vandenberg AFB, CA(Sarzin?) cachet on coverExplorer-39 (ADE-C) and Explorer-40 (Injun-5) launch
United States1968-08-08Vandenberg AFB, CA(Centennial) cachet on coverExplorer-39 (ADE-C) and Explorer-40 (Injun-5) launch
1969-06-21: Explorer-41 (IMP-G/IMP-5)
United States1969-06-21Vandenberg AFB, CA(Orbit Covers) cachet on coverExplorer-41 (IMP-G/IMP-5) launch; incorrectly noted as "IMP-7" (in text)
United States1969-06-21Vandenberg AFB, CA(Sarzin) cachet on coverExplorer-41 (IMP-G/IMP-5) launch
United States1969-06-21Lompoc CA, Vandenberg AFB(SpaceCraft/Swanson) cachet on cover, also insertExplorer-41 (IMP-G/IMP-5) launch
United States1969-06-21Vandenberg AFB, CA(SpaceCraft/Swanson) cachet on cover, also insertExplorer-41 (IMP-G/IMP-5) launch
United States1969-06-21Lompoc CA, Vandenberg AFB(DuBeau?/Swanson blue and red rubber-stamp) cachet on coverExplorer-41 (IMP-G/IMP-5) launch (ESRO-2A depicted)1
United States1969-06-21Vandenberg AFB, CA(Centennial red rocket, type-1) cachet on coverExplorer-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 States1970-12-12Cape Canaveral FL(Space Voyage) cachet on cover, also insertExplorer-42 (Uhuru) launch
1971-03-13: Explorer-43 (IMP-H/IMP-6)
United States1971-03-13Cape Canaveral FL (hand cancel)(Orbit Covers) cachet on coverExplorer-43 (IMP-H/IMP-6) launch
United States1971-03-13Cape Canaveral FL (machine cancel)(Orbit Covers) cachet on coverExplorer-43 (IMP-H/IMP-6) launch
United States1971-03-13Kennedy Space Center FL(Space Voyage) cachet on cover, also insertExplorer-43 (IMP-H/IMP-6) launch; incorrectly noted as "IMP-I" (in text)
United States1971-03-13Cape Canaveral FL(Space Voyage) cachet on cover, also insertExplorer-43 (IMP-H/IMP-6) launch; incorrectly noted as "IMP-I" (in text)
United States1971-03-13Kennedy Space Center FL(InterSpace Cover) cachet on coverExplorer-43 (IMP-H/IMP-6) launch; incorrectly noted as "IMP-I" (in text)
United States1971-03-13Cape Canaveral FL(Space Voyage/InterSpace Cover black-and-white printed - Sarzin hybrid) cachet on coverExplorer-43 (IMP-H/IMP-6) launch; incorrectly noted as "IMP-I" (in text)
United States1971-03-13Cape Canaveral FL(Fleetwood) cachet on coverExplorer-43 (IMP-H/IMP-6) launch; incorrectly noted as "IMP-8" (in text)
United States1971-03-13Cape Canaveral FL(Centennial) cachet on coverExplorer-43 (IMP-H/IMP-6) launch; incorrectly noted as "IMP-8" (in text)
1971-07-09: Explorer-44 (SolRad-10)
United States1971-07-09Wallops Island VA(Swanson green and magenta rubber-stamp) cachet on coverExplorer-44 (SolRad-10) launch
United States1971-07-09Wallops Island VA(Swanson blue and magenta rubber-stamp) cachet on coverExplorer-44 (SolRad-10) launch
United States1971-07-09Wallops Island VA (machine cancel)(Space Voyage) cachet on coverExplorer-44 (SolRad-10) launch
United States1971-07-09Wallops Island VA (hand cancel)(Space Voyage) cachet on coverExplorer-44 (SolRad-10) launch
United States1971-07-09Wallops Island VA(Swanson black rubber-stamp and printed - Sarzin hybrid) cachet on coverExplorer-44 (SolRad-10) launch
United States1971-07-09Wallops Island VA(Centennial) cachet on coverExplorer-44 (SolRad-10) launch
United States1971-07-09Wallops Island VA(Orbit Covers) cachet on coverExplorer-44 (SolRad-10) launch
1971-11-15: Explorer-45 (SSS-A)
Kenya1971-11-15Malindi (smaller cancel)(Blue printed) cachet on coverExplorer-45 (SSS-A) launch
Kenya1971-11-15Malindi (larger cancel)(Blue printed) cachet on coverExplorer-45 (SSS-A) launch
Kenya1971-11-15Malindi(Space Voyage) cachet on cover, also insertExplorer-45 (SSS-A) launch
Kenya1971-11-15Malindi(Cura della printed and red rubber-stamp) cachets on coverExplorer-45 (SSS-A) launch
Kenya1971-11-15Malindi(Cura della printed and blue rubber-stamp) cachets on cover, also insert and insert backExplorer-45 (SSS-A) launch; "Explorer-44" (incorrectly given in text); Explorer-48 (incorrectly depicted)
United States1971-11-15Greenbelt MD(GSFC Stamp Club) cachet on coverExplorer-45 (SSS-A) launch
1972-08-13: Explorer-46 (MTS)
United States1972-08-14Wallops Island VA(Space Voyage) cachet on cover, also insertExplorer-46 (MTS) launch
United States1972-08-14Wallops Island VA(InterSpace Cover) cachet on cover, also insertExplorer-46 (MTS) launch
United States1972-08-14Wallops Islands VA(Sarzin) cachet on coverExplorer-46 (MTS) launch
United States1972-08-14Wallops Islands VA(Orbit Covers) cachet on coverExplorer-46 (MTS) launch
United States1972-08-14Wallops Islands VA(Andromeda/Riser/Cygnus no.29) cachet on coverExplorer-46 (MTS) launch
United States1972-08-14Wallops Islands VA(Swanson blue and magenta rubber-stamp) cachet on coverExplorer-46 (MTS) launch
1972-09-22: Explorer-47 (IMP-I/IMP-7)
United States1972-09-22Cape Canaveral FL(Sarzin) cachet on coverExplorer-47 (IMP-I/IMP-7) launch (Explorer-33/35 (AIMP-1/2) type depicted)
United States1972-09-22Kennedy Space Center FL(Space Voyage) cachet on coverExplorer-47 (IMP-I/IMP-7) launch; incorrectly noted as "IMP-H" (in text)
United States1972-09-22Cape Canaveral FL(Space Voyage) cachet on coverExplorer-47 (IMP-I/IMP-7) launch; incorrectly noted as "IMP-H" (in text)
United States1972-09-22Kennedy Space Center FL(InterSpace Cover) cachet on coverExplorer-47 (IMP-I/IMP-7) launch; incorrectly noted as "IMP-H" (in text)
United States1972-09-22Cape Canaveral FL(InterSpace Cover) cachet on coverExplorer-47 (IMP-I/IMP-7) launch; incorrectly noted as "IMP-H" (in text)
United States1972-09-22Cape Canaveral FL(Blue printed) cachet on coverExplorer-47 (IMP-I/IMP-7) launch; incorrectly noted as "IMP-H" (in text)
United States1972-09-22Cape Canaveral FL(Orbit Covers) cachet on coverExplorer-47 (IMP-I/IMP-7) launch; drawing is incomplete
United States1972-09-22Kennedy Space Center FL(Sokolsky? black and red rubber-stamp) cachet on coverExplorer-47 (IMP-I/IMP-7) launch; incorrectly noted as "IMP-H" (in text)
United States1972-09-22Kennedy Space Center FL(no) cachet on coverExplorer-47 (IMP-I/IMP-7) launch
United States1972-09-22Patrick AFB, FL(Whitney grey and purple) cachet on coverExplorer-47 (IMP-I/IMP-7) launch; incorrectly noted as "Interplanetary Monitoring Platform-H" (in text)
United States1972-09-23Cape Canaveral FL (hand cancel)(Whitney black and purple) cachet on coverExplorer-47 (IMP-I/IMP-7) launch; incorrectly noted as "Interplanetary Monitoring Platform-H" (in text)
United States1972-09-23Cape Canaveral FL (machine cancel)(Whitney black and purple) cachet on cover, also backExplorer-47 (IMP-I/IMP-7) launch; incorrectly noted as "Interplanetary Monitoring Platform-H" (in text)
United States1972-09-23Greenbelt MD(GSFC Stamp Club) cachet on coverExplorer-47 (IMP-I/IMP-7) launch; incorrectly noted as "IMP-H" (in text)
United States1972-09-25Kennedy Space Center FL(CISCO/Fydo EtS no.5?) cachet on cover, also insertExplorer-47 (IMP-I/IMP-7) launch; incorrectly noted as "IMP-H" (in text)
United States1972-09-25Kennedy Space Center FL(Cygnus no.33/Andromeda/Riser) cachet on (airmail) cover, also insertExplorer-47 (IMP-I/IMP-7) launch
1972-11-15: Explorer-48 (SAS-B)
United States1972-11-15Greenbelt MD(GSFC Stamp Club) cachet on coverExplorer-48 (SAS-B) launch
Kenya1972-11-16Malindi(Space Voyage) cachet on cover, also insertExplorer-48 (SAS-B) launch
Kenya1972-11-16Malindi(InterSpace Cover) cachet on cover, also insertExplorer-48 (SAS-B) launch
Kenya1972-11-16Malindi(Printed and rubber-stamp) cachet on coverExplorer-48 (SAS-B) launch
Kenya1972-11-16Malindi(Cura della printed and blue rubber-stamp) cachets on coverExplorer-48 (SAS-B) launch
Kenya1972-11-16Malindi(Purple rubber-stamp and hand-written) cachet on coverExplorer-48 (SAS-B) launch
Australia1972-11-20?Canberra ACT(Red rubber-stamp) cachet on coverExplorer-48 (SAS-B) launch
1973-06-10: Explorer-49 (RAE-2)
Spain1973-06-10Madrid(Rubber-stamp) cachet on coverExplorer-49 (RAE-2) launch
United States1973-06-10Cape Canaveral FL(Orbit Covers) cachet on coverExplorer-49 (RAE-2) launch
United States1973-06-10Cape Canaveral FL(Whitney orange) cachet on coverExplorer-49 (RAE-2) launch
United States1973-06-10Patrick AFB, FL(Whitney orange) cachet (same) on coverExplorer-49 (RAE-2) launch
United States1973-06-10Greenbelt MD(GSFC Stamp Club) cachet on coverExplorer-49 (RAE-2) launch
United States1973-06-10Cape Canaveral FL(Andromeda/Riser/Cygnus no.51) cachet on coverExplorer-49 (RAE-2) launch
United States1973-06-10Cape Canaveral FL(InterSpace Cover) cachet on cover, also insertExplorer-49 (RAE-2) launch
United States1973-06-11Kennedy Space Center FL(InterSpace Cover) cachet (same) on cover, also insertExplorer-49 (RAE-2) launch
United States1973-06-11Kennedy Space Center FL(Space Voyage) cachet (same) on cover, also insertExplorer-49 (RAE-2) launch
United States1973-06-11Kennedy Space Center FL(SCPS) cachet on coverExplorer-49 (RAE-2) launch
United States1973-06-11Kennedy Space Center FL(SCPS) cachet (and logo) on coverExplorer-49 (RAE-2) launch
1973-10-25: Explorer-50 (IMP-J/IMP-8)
United States1973-10-25Greenbelt MD(GSFC Stamp Club) cachet on coverExplorer-50 (IMP-J/IMP-8) launch
United States1973-10-25Greenbelt MD(GSFC green rubber-stamp) cachet on coverExplorer-50 (IMP-J/IMP-8) launch
United States1973-10-25Kennedy Space Center FL(SCPS) cachet on coverExplorer-50 (IMP-J/IMP-8) launch
United States1973-10-25Kennedy Space Center FL(SCPS and red logo) cachet on coverExplorer-50 (IMP-J/IMP-8) launch
United States1973-10-25Kennedy Space Center FL(SCPS and blue logo) cachet (and signature) on coverExplorer-50 (IMP-J/IMP-8) launch
United States1973-10-25Kennedy Space Center FL(Space Voyage) cachet on coverExplorer-50 (IMP-J/IMP-8) launch
United States1973-10-25Cape Canaveral FL(Cyan printed) cachet on coverExplorer-50 (IMP-J/IMP-8) launch
United States1973-10-26Cape Canaveral FL(Orbit Covers) cachet on coverExplorer-50 (IMP-J/IMP-8) launch; also IQSY
United States1973-10-26Kennedy Space Center FL(Centennial) cachet on coverExplorer-50 (IMP-J/IMP-8) launch
United States1973-10-26Cape Canaveral FL(Centennial) cachet on coverExplorer-50 (IMP-J/IMP-8) launch
United States1973-10-26Cape Canaveral FL(Space Voyage) cachet on coverExplorer-50 (IMP-J/IMP-8) launch
United States1973-10-26Cape Canaveral FL(InterSpace) cachet on coverExplorer-50 (IMP-J/IMP-8) launch
United States1973-10-26Kennedy Space Center FL(Sokolsky? brown and black rubber-stamp) cachet on coverExplorer-50 (IMP-J/IMP-8) launch
United States1973-10-26Cape Canaveral FL (machine cancel)(Whitney red) cachet on coverExplorer-50 (IMP-J/IMP-8) launch
United States1973-10-26Cape Canaveral FL (machine cancel)(Whitney red and black) cachet on coverExplorer-50 (IMP-J/IMP-8) launch
United States1973-10-26Cape Canaveral FL (hand cancel)(Whitney red and black) cachet on (airmail) coverExplorer-50 (IMP-J/IMP-8) launch
1973-12-16: Explorer-51 (AE-C)
United States1973-12-15Vandenberg AFB, CA(Orbit Covers) cachet on coverExplorer-51 (AE-C) launch
United States1973-12-15Vandenberg AFB, CA(InterSpace Cover) cachet on coverExplorer-51 (AE-C) launch
United States1973-12-15Vandenberg AFB, CA(Space Voyage) cachet on coverExplorer-51 (AE-C) launch
United States1973-12-15Vandenberg AFB, CA(Centennial) cachet on coverExplorer-51 (AE-C) launch
United States1973-12-15Vandenberg AFB, CA(DuBeau?/(Swanson blue rubber-stamp) cachet on coverExplorer-51 (AE-C) launch (ESRO-2A depicted)1
Great Britain1973-12-16Ascot, Berkshire(Black rubber-stamp) cachet on coverExplorer-51 (AE-C) launch
United States1973-12-16Greenbelt MD(GSFC Stamp Club) cachet on coverExplorer-51 (AE-C) launch
1974-06-03: Explorer-52 (Hawkeye) (Injun-6)
United States1974-06-03Vandenberg AFB, CA(Centennial) cachet on coverExplorer-52 (Hawkeye / Injun-6) launch
United States1974-06-03Vandenberg AFB, CA(Orbit Covers) cachet on coverExplorer-52 (Hawkeye / Injun-6) launch
United States1974-06-03Vandenberg AFB, CA(Swanson geography/DuBeau? black rubber-stamp) cachet on coverExplorer-52 (Hawkeye / Injun-6) launch
United States1974-06-03Fairbanks AK(NASA rubber-stamp) cachet (and signature) on coverExplorer-52 (Hawkeye / Injun-6) launch
United States1974-06-03Vandenberg AFB, CA(Space Voyage) cachet on coverExplorer-52 (Hawkeye / Injun-6) launch
United States1974-06-03Vandenberg AFB, CA(InterSpace Cover) cachet on coverExplorer-52 (Hawkeye / Injun-6) launch
United States1974-06-03Vandenberg AFB, CA(Sarzin?) cachet on coverExplorer-52 (Hawkeye / Injun-6) launch
1975-05-07: Explorer-53 (SAS-C)
Kenya1975-05-07Malindi(Blue printed and green rubber-stamp) cachet on coverExplorer-53 (SAS-C) launch
Kenya1975-05-07Malindi(Space Voyage) cachet on coverExplorer-53 (SAS-C) launch
United States1975-05-07Greenbelt MD(GSFC Stamp Club) cachet (and signature) on coverExplorer-53 (SAS-C) launch
United States1975-05-07Greenbelt MD(GSFC Stamp Club) cachet on coverExplorer-53 (SAS-C) launch
United States1975-05-07Greenbelt MD(GSFC blue rubber-stamp) cachet on coverExplorer-53 (SAS-C) launch
1975-10-06: Explorer-54 (AE-D)
United States1975-10-06Vandenberg AFB, CA(Space Voyage) cachet on coverExplorer-54 (AE-D) launch
United States1975-10-06Greenbelt MD(GSFC Stamp Club) cachet on coverExplorer-54 (AE-D) launch
United States1975-10-06Greenbelt MD(GSFC Stamp Club) cachet (and signature) on coverExplorer-54 (AE-D) launch
United States1975-10-06Vandenberg AFB, CA(NASA KSC-WLOD black rubber-stamp) cachet on coverExplorer-54 (AE-D) launch
United States1975-10-06Vandenberg AFB, CA(NASA red rubber-stamp) cachet on coverExplorer-54 (AE-D) launch
United States1975-10-06Vandenberg AFB, CA(Centennial) cachet on coverExplorer-54 (AE-D) launch
United States1975-10-06Vandenberg AFB, CA(Orbit Covers) cachet on coverExplorer-54 (AE-D) launch
1975-11-20: Explorer-55 (AE-E)
United States1975-11-19Kennedy Space Center FL(Space Voyage) cachet on coverExplorer-55 (AE-E) launch
United States1975-11-19Cape Canaveral FL(Space Voyage) cachet on coverExplorer-55 (AE-E) launch
United States1975-11-19Greenbelt MD(GSFC Stamp Club) cachet on coverExplorer-55 (AE-E) launch
United States1975-11-19Kennedy Space Center FL(Centennial) cachet on coverExplorer-55 (AE-E) launch
United States1975-11-19Cape Canaveral FL(Centennial) cachet on coverExplorer-55 (AE-E) launch
United States1975-11-19Kennedy Space Center FL(SCPS) cachet on coverExplorer-55 (AE-E) launch
United States1975-11-19Patrick AFB, FL(Whitney green and black) cachet on coverExplorer-55 (AE-E) launch
United States1975-11-19Cape Canaveral FL(Whitney green-blue) cachet on coverExplorer-55 (AE-E) launch
United States1975-11-19Satellite Beach FL (hand cancel)(Whitney green and black) cachet on coverExplorer-55 (AE-E) launch
United States1975-11-19Satellite Beach FL (machine cancel)(Whitney green and black) cachet on (airmail) coverExplorer-55 (AE-E) launch
United States1975-11-19Cape Canaveral FL(Orbit Covers) cachet on coverExplorer-55 (AE-E) launch
United States1975-11-20USPS, CA(NASA Goldstone) cachet on coverExplorer-55 (AE-E) launch
1975-12-05: Dual Air Density (DAD) Explorer [failed]
United States1975-12-05Vandenberg AFB, CA(Centennial) cachet on coverExplorer: DAD launch [failed]
United States1975-12-05Vandenberg AFB, CA(Space Voyage) cachet on coverExplorer: DAD launch [failed]
United States1975-12-05Vandenberg AFB, CA(Vandy? red rubber-stamp) cachet on coverExplorer: DAD launch [failed]
United States1975-12-05Lompoc CA, Vandenberg AFB(Vandy? red rubber-stamp) cachet on coverExplorer: DAD launch [failed]
United States1975-12-05Vandenberg AFB, CA(NASA KSC-WLOD magenta rubber-stamp) cachet on coverExplorer: DAD launch [failed]
United States1975-12-05Vandenberg AFB, CA(Orbit Covers) cachet on coverExplorer: DAD launch [failed] (incorrectly noted as "Explorers 56 & 57"; Explorer AE-C/D/E type in lower-right logo)
1977-10-22: Explorer-56 (ISEE-1) (and ISEE-2)
United States1977-10-22Cape Canaveral FL(Orbit Covers) cachet on coverExplorer-56 (ISEE-1) launch (Explorer-51/54/55 depicted)
United States1977-10-22Cape Canaveral FL(ESA) cachet on coverExplorer-56 (ISEE-1) launch
United States1977-10-22Cape Canaveral FL(Whitney green and black) cachet on (airmail) coverExplorer-56 (ISEE-1) launch
United States1977-10-22Greenbelt MD(GSFC Stamp Club) cachet on coverExplorer-56 (ISEE-1) launch
United States1977-10-22Cape Canaveral FL(Space Voyage) cachet on coverExplorer-56 (ISEE-1) launch
United States1977-10-25Kennedy Space Center FL(Space Voyage) cachet on coverExplorer-56 (ISEE-1) launch
United States1977-10-25Kennedy Space Center FL(SCPS) cachet on coverExplorer-56 (ISEE-1) launch
1978-01-26: Explorer-57 (IUE)
France1978-01-26Paris(ESA) cachet on coverExplorer-57 (IUE) launch
Spain1978-01-26Madrid(Printed) cachet on coverExplorer-57 (IUE) launch
United States1978-01-26Cape Canaveral FL(ESA) cachet on coverExplorer-57 (IUE) launch
United States1978-01-26Cape Canaveral FL(Orbit Covers) cachet on coverExplorer-57 (IUE) launch (OAO-B depicted)
United States1978-01-26Kennedy Space Center FL(Space Voyage) cachet on coverExplorer-57 (IUE) launch
United States1978-01-26Cape Canaveral FL(Space Voyage) cachet on coverExplorer-57 (IUE) launch
United States1978-01-26GSFC, MD(GSFC Stamp Club) cachet on coverExplorer-57 (IUE) launch
United States1978-01-26Cape Canaveral FL(Whitney purple) cachet on (airmail) coverExplorer-57 (IUE) launch
United States1978-01-26Kennedy Space Center FL(Centennial) cachet on coverExplorer-57 (IUE) launch
United States1978-01-26Kennedy Space Center FL(SCPS) cachet on coverExplorer-57 (IUE) launch
United States1978-01-26Kennedy Space Center FL(SCPS) cachet (and signature) on cover, also backExplorer-57 (IUE) launch
Germany (West)1978-01-28Darmstadt(ESA) cachet on coverExplorer-57 (IUE) launch
1978-04-26: Explorer-58 (HCMM)
United States1978-04-26Vandenberg AFB, CA(Space Voyage) cachet on coverExplorer-58 (HCMM) launch
United States1978-04-26Vandenberg AFB, CA(Centennial) cachet on coverExplorer-58 (HCMM) launch
United States1978-04-26Vandenberg AFB, CA(NASA KSC-WOSO purple rubber-stamp) cachet on coverExplorer-58 (HCMM) launch
United States1978-04-26Vandenberg AFB, CA(NASA KSC-WOSO cyan rubber-stamp) cachet on coverExplorer-58 (HCMM) launch
United States1978-04-26GSFC, MD(GSFC black rubber-stamp) cachet on coverExplorer-58 (HCMM) launch
1978-08-12: Explorer-59 (ISEE-3 / ICE4)
Spain1978-08-12Madrid(Printed) cachet on coverExplorer-59 (ISEE-3 / ICE) launch
United States1978-08-12Cape Canaveral FL(Orbit Covers) cachet on coverExplorer-59 (ISEE-3 / ICE) launch (Explorer-51/54/55 depicted)
United States1978-08-12Cape Canaveral FL(Whitney orange and blue) cachet on (airmail) coverExplorer-59 (ISEE-3 / ICE) launch
United States1978-08-12Cape Canaveral FL(Centennial) cachet on coverExplorer-59 (ISEE-3 / ICE) launch
United States1978-08-12Cape Canaveral FL(Space Voyage) cachet on coverExplorer-59 (ISEE-3 / ICE) launch
United States1978-08-14Kennedy Space Center FL(Space Voyage) cachet on coverExplorer-59 (ISEE-3 / ICE) launch
United States1978-08-14Kennedy Space Center FL(SCPS) cachet on coverExplorer-59 (ISEE-3 / ICE) launch
Explorer-59 (ISEE-3 / ICE4) (events)
United States1983-03-30Greenbelt MD(Space Voyage) cachet on cover"first lunar swingby"
Australia1983-12-22Canberra ACT(Zaso) cachet on cover"ICE Moonloop"
United States1985-09-11Greenbelt MD(Space Voyage) cachet on cover"encounter with Giacobini-Zinner Comet"
Australia1986-03-25Canberra ACT(Space Voyage) cachet on cover"closest approach...Halley's Comet"
Spain1986-03-25Madrid(Space Voyage) cachet on cover"closest approach...Halley's Comet"
United States1986-03-25Pasadena CA(Space Voyage) cachet on cover"closest approach...Halley's Comet"
United States1986-03-25Barstow CA(Space Voyage) cachet on cover"closest approach...Halley's Comet"
United States1986-03-25Greenbelt MD(Space Voyage) cachet on cover"closest approach...Halley's Comet"
United States1986-03-25Greenbelt MD(GSFC blue rubber-stamp) cachet on coverclosest approach to Halley's Comet
1979-02-18: Explorer-60 (SAGE)
United States1979-02-18Wallops Island VA(Space Voyage) cachet on coverExplorer-60 (SAGE) launch
1979-10-30: Explorer-61 (MagSat)
United States1979-10-30Vandenberg AFB, CA(NASA KSC-WOSO purple rubber-stamp) cachet on coverExplorer-61 (MagSat) launch
United States1979-10-30Greenbelt MD(GSFC Stamp Club) cachet on coverExplorer-61 (MagSat) launch
United States1979-10-30Vandenberg AFB, CA(Space Voyage) cachet on coverExplorer-61 (MagSat) launch
United States1979-10-30Lompoc CA, Vandenberg AFB(KSC-WOSO black rubber-stamp) cachet on coverExplorer-61 (MagSat) launch
1981-08-03: Explorer-62 (DE-1) and Explorer-63 (DE-2)
United States1981-08-03Greenbelt MD(GSFC blue rubber-stamp) cachet on (airmail) coverExplorer-62/63 (DE-1/2) launch
United States1981-08-03Greenbelt MD(GSFC Stamp Club) cachet on coverExplorer-62/63 (DE-1/2) launch
1981-10-06: Explorer-64 (SME) (and OSCAR-9)
United States1981-10-06Greenbelt MD(GSFC Stamp Club) cachet on coverExplorer-64 (SME) launch
United States1981-10-06Pasadena CA(JPL Stamp Club) cachet on cover, also insertExplorer-64 (SME) launch
1984-08-16: Explorer-65 (AMPTE: CCE, IRM, and UKS)
Chile1984-08-16Santiago(Space Voyage) cachet on coverExplorer-65 (AMPTE) launch
United States1984-08-16Greenbelt MD(GSFC Stamp Club) cachet on coverExplorer-65 (AMPTE) launch
United States1984-08-16Cape Canaveral FL(Printed) cachet on coverExplorer-65 (AMPTE) launch
United States1984-08-16Greenbelt MD(Space Voyage) cachet on coverExplorer-65 (AMPTE) launch
United States1984-08-16Merritt Island FL(Space Voyage) cachet on coverExplorer-65 (AMPTE) launch
Explorer-65 (events)
United States1984-12-27Pasadena CA(Space Voyage) cachet on coverUKS barium release
1989-11-18: Explorer-66 (COBE)
United States1989-11-18Lompoc CA, Vandenberg AFB(sticker) cachet on coverExplorer-66 (COBE) launch
1992-06-07: Explorer-67 (EUVE)
United States1992-06-07Kennedy Space Center FL(DuBeau blue rubber-stamp) cachet on coverExplorer-67 (EUVE) launch
United States1992-06-07Kennedy Space Center FL(stickers and blue rubber-stamp) cachet on coverExplorer-67 (EUVE) launch
1992-07-03: Explorer-68 (SAMPEX)
United States1992-07-03Lompoc CA, Vandenberg AFB(Sarmiento) cachet on coverExplorer-68 (SAMPEX) launch
1995-12-30: Explorer-69 (XTE)
United States1995-12-30Kennedy Space Center FL(SCP) cachet on coverExplorer-69 (XTE) launch
1996-08-21: Explorer-70 (FAST)
United States1996-08-21Lompoc CA, Vandenberg AFB(Sarmiento) cachet on coverExplorer-70 (FAST) launch
1997-08-25: Explorer-71 (ACE)
United States1997-08-25Kennedy Space Center FL(Sarmiento) cachet on coverExplorer-71 (ACE) launch
1998-02-26: Explorer-72 (SNOE) (and BATSat)
United States1998-02-25Lompoc CA, Vandenberg AFB(Printed) cachet on coverExplorer-72 (SNOE) launch
1998-04-02: Explorer-73 (TRACE)
United States1998-04-01Lompoc CA, Vandenberg AFB(B&D) cachet on coverExplorer-73 (TRACE) launch
United States1998-04-01Lompoc CA, Vandenberg AFB(Printed) cachet on coverExplorer-73 (TRACE) launch
1998-12-06: Explorer-74 (SWAS)
United States1998-12-05Lompoc CA, Vandenberg AFB(Printed) cachet on coverExplorer-74 (SWAS) launch
1999-03-05: Explorer-75 (WIRE) [failed]
United States1999-03-04Lompoc CA, Vandenberg AFB(SCPS) cachet on coverExplorer-75 (WIRE) launch [failed]
United States1999-03-04Lompoc CA, Vandenberg AFB(Printed) cachet on coverExplorer-75 (WIRE) launch [failed]
United States1999-03-04Lompoc CA, Vandenberg AFB(Printed) cachet (different) on coverExplorer-75 (WIRE) launch [failed]
United States1999-03-04Lompoc CA, Vandenberg AFB(Mission patch) cachet on coverExplorer-75 (WIRE) launch [failed]
United States1999-03-04Lompoc CA, Vandenberg AFB(Printed) cachet on coverExplorer-75 (WIRE) launch [failed]
1999-05-18: Explorer-76 (TERRIERS) (and MUBLCOM) [failed]
United States1999-05-17Lompoc CA, Vandenberg AFB(Printed) cachet on coverExplorer-76 (TERRIERS) launch [failed]
United States1999-05-17Lompoc CA, Vandenberg AFB(B&D) cachet on coverExplorer-76 (TERRIERS) launch [failed]
United States1999-05-17Lompoc CA, Vandenberg AFB(SCP) cachet on coverExplorer-76 (TERRIERS) launch [failed]
1999-06-23: Explorer-77 (FUSE)
United States1999-06-24Kennedy Space Center FL(Printed) cachet on coverExplorer-77 (FUSE) launch
United States1999-06-24Cape Canaveral FL(B&D) cachet on coverExplorer-77 (FUSE) launch
United States1999-06-24Cape Canaveral FL(SCP) cachet on coverExplorer-77 (FUSE) launch
Explorer-77 (events)
United States2007-10-18Pasadena CA(Printed) cachet on coverExplorer-77 (FUSE) end 8+year mission
2000-03-25: Explorer-78 (IMAGE)
United States2000-03-25Vandenberg AFB, Lompoc CA(SCP) cachet on coverExplorer-78 (IMAGE) launch
United States2000-03-25Vandenberg AFB, Lompoc CA(B&D) cachet on coverExplorer-78 (IMAGE) launch
2000-10-09: Explorer-79 (HETE-2)
United States2000-10-09Army Postal Service(B&D) cachet on coverExplorer-79 (HETE-2) launch
2001-06-30: Explorer-80 (MAP)
United States2001-06-30Cape Canaveral FL(B&D) cachet on coverExplorer-80 (MAP) launch
2002-02-05: Explorer-81 (HESSI / RHESSI)
United States2002-02-05Cape Canaveral FL(B&D) cachet on coverExplorer-81 (HESSI) launch
United States2002-02-05Cape Canaveral FL(SCP) cachet on coverExplorer-81 (HESSI) launch
2003-01-12: Explorer-82 (CHIPSat) (and ICESat)
United States2003-01-12Vandenberg AFB, Lompoc CA(Lollini) cachet on coverExplorer-82 (CHIPSat) launch (ICESat depicted)
United States2003-01-12Vandenberg AFB, Lompoc CA(Printed) cachet on coverExplorer-82 (CHIPSat) launch (ICESat depicted)
United States2003-01-12Vandenberg AFB, Lompoc CA(Printed) cachet on coverExplorer-82 (CHIPSat) launch
United States2003-01-12Vandenberg AFB, Lompoc CA(SCP) cachet on coverExplorer-82 (CHIPSat) launch (also ICESat depicted)
2003-04-28: Explorer-83 (GALEX)
United States2003-04-28Pasadena CA(JPL Stamp Club) cachet on coverExplorer-83 (GALEX) launch
United States2003-04-28Kennedy Space Center FL(B&D?) cachet on coverExplorer-83 (GALEX) launch
United States2003-04-28Cape Canaveral FL(Lollini) cachet on coverExplorer-83 (GALEX) launch
United States2003-04-28Cape Canaveral FL(Printed) cachet on coverExplorer-83 (GALEX) launch
United States2003-04-28Cape Canaveral FL(Printed) cachet (different photo) on coverExplorer-83 (GALEX) launch
United States2003-04-28Cape Canaveral FL(B&D) cachet on coverExplorer-83 (GALEX) launch
United States2003-04-28Cape Canaveral FL(SCP) cachet on coverExplorer-83 (GALEX) launch
2004-11-20: Explorer-84 (Swift)
United States2004-11-20Cape Canaveral FL(B&D) cachet on coverExplorer-84 (Swift) launch
United States2004-11-20Cape Canaveral FL(SCP) cachet on coverExplorer-84 (Swift) launch
2007-02-17: Explorer-85 — Explorer-89 (THEMIS)
United States2007-02-17Kennedy Space Center FL (machine cancel)(Lollini) cachet on coverExplorer-85/89 (THEMIS) launch
United States2007-02-17Kennedy Space Center FL (hand cancel)(Lollini) cachet on coverExplorer-85/89 (THEMIS) launch
United States2007-02-17Cape Canaveral FL(Mission 57) cachet on cover, also backExplorer-85/89 (THEMIS) launch
United States2007-02-17Cape Canaveral FL(B&D) cachet on coverExplorer-85/89 (THEMIS) launch
2007-04-25: Explorer-90 (AIM)
United States2007-04-25VAFB Contract Station, Lompoc CA(RESCC Covers) cachet on coverExplorer-90 (AIM) launch
United States2007-04-25Vandenberg AFB, CA(Mission 57) cachet on cover, also backExplorer-90 (AIM) launch
United States2007-04-25Vandenberg AFB, CA(Printed) cachet on coverExplorer-90 (AIM) launch
United States2007-04-25Vandenberg AFB, CA(B&D) cachet on coverExplorer-90 (AIM) launch
2008-10-19: Explorer-91 (IBEX)
United StatesNone (2008-10-19)None (Kwajalein)(Sarmiento) cachet on (un-canceled) coverExplorer-91 (IBEX) launch
2009-12-14: Explorer-92 (WISE)
United States2009-12-14Pasadena CA(Lollini) cachet on coverExplorer-92 (WISE) launch
United States2009-12-14Vandenberg AFB, CA(Lollini) cachet on coverExplorer-92 (WISE) launch
United States2009-12-14Vandenberg AFB, CA(Printed) cachet on coverExplorer-92 (WISE) launch
2012-06-13: Explorer-93 (NuSTAR)
United States2012-06-13Pasadena CA(Mission 57) cachet on cover, also backExplorer-93 (NuSTAR) launch
Explorer (on other than Explorer launch covers)
United States1959-09-18Patrick AFB, FL(Highway Stamp Club) cachet on Vanguard-3 launch coverExplorer-6
United States1965-05-18WSMR, NM(HJM black) cachet on (sub-orbital) rocket launch cover"Explorer"-10 (upper-middle)
United States1965-07-24Cape Canaveral FL(Printed) cachet on (sub-orbital) rocket launch cover, also annotatedExplorer-7 and Explorer-18
United States1965-10-13Edwards CA(HJM black) cachet on X-15 test flight cover"Explorer"-10 (upper-middle)
United States1965-10-25
1965-12-07
(Date from rubber-stamp cachet)
St. John's, Antigua, WI
(HJM black) cachet on Gemini Agena Test Vehicle (GATV) [failed] launch cover"Explorer"-10 (upper-middle)
United States1965-12-06Vandenberg AFB, CA(Sarzin?) cachet on FR-1 launch coverExplorer-38/49 type
United States1966-04-08
1966-04-08
Cape Canaveral FL (hand cancel)
Cape Canaveral FL (machine cancel)
(HJM black) cachet on Surveyor-SD3 launch cover"Explorer"-10 (upper-middle)
United States1966-04-08Cape Canaveral FL (hand cancel)(Centennial and black rubber-stamp) cachets on OAO-1 launch coverIncorrectly noted as "Explorer-31" (in rubber-stamp cachet)
United States1966-05-12Edwards CA(HJM blue) cachet on LLRV test cover"Explorer"-10 (upper-middle)
United States1966-06-07Cape Canaveral FL(HJM black) cachet on OGO-3 launch cover"Explorer"-10 (upper-middle)
United States1966-06-16Cape Canaveral FL(HJM black) cachet on GGTS-1 and IDCSP-1/7 launch cover"Explorer"-10 (upper-middle)
United States1966-08-17Cape Canaveral FL(Centennial black rocket, type-1) cachet on Pioneer-7 launch coverExplorer-62
United States1966-08-17Cape Canaveral FL(Centennial green rocket, type-1) cachet on Pioneer-7 launch coverExplorer-62
United States1966-08-17Cape Canaveral FL(HJM black) cachet on Pioneer-7 launch cover"Explorer"-10 (upper-middle)
United States1966-08-26Cape Canaveral FL(HJM blue) cachet on GGTS-2 and IDCSP-8/14 [failed] launch cover"Explorer"-10 (upper-middle)
United States1966-09-14Edwards CA(HJM blue) cachet on X-15 test flight cover"Explorer"-10 (upper-middle)
United States1966-12-07Cape Canaveral FL(HJM black) cachet on ATS-1 launch cover"Explorer"-10 (upper-middle)
United States1967-01-11Cape Canaveral FL(HJM blue/Swanson blue rubber-stamp) cachet on Intelsat-2-2 launch cover"Explorer"-10 (upper-middle)
United States1967-03-08Cape Canaveral FL(HJM black) cachet on OSO-3 launch cover"Explorer"-10 (upper-middle)
United States1967-04-06Cape Canaveral FL(HJM black) cachet on ATS-2 launch cover"Explorer"-10 (upper-middle)
United States1967-06-22Edwards CA(HJM blue) cachet on X-15 test flight cover"Explorer"-10 (upper-middle)
United States1967-10-18Cape Canaveral FL(HJM black) cachet on OSO-4 launch cover"Explorer"-10 (upper-middle)
United States1967-11-06Cape Canaveral FL(HJM black) cachet on ATS-3 launch cover"Explorer"-10 (upper-middle)
United States1968-03-04Cape Canaveral FL(HJM black) cachet on OGO-5 launch cover"Explorer"-10 (upper-middle)
United States1968-09-26Cape Canaveral FL(HJM black) cachet on LES-6 and OV2-5 and OV5-2/4 launch cover"Explorer"-10 (upper-middle)
United States1968-11-08Cape Canaveral FL(Sarzin) cachet on Pioneer-9 and TETR-2 launch cover, also annotatedExplorer-29/36 type
United States1968-12-07Cape Canaveral FL(HJM black) cachet on OAO-2 launch cover"Explorer"-10 (upper-middle)
United States1969-01-22Cape Canaveral FL(HJM black) cachet on OSO-5 launch cover"Explorer"-10 (upper-middle)
United States1969-01-22Kennedy Space Center FL(Centennial red rocket, type-2 and black typed) cachet on OSO-5 launch coverExplorer-62
United States1969-01-29Vandenberg AFB, CA(Orbit Covers) cachet on ISIS-1 launch cover"Explorer-41" (in text)
United States1969-01-29Lompoc CA, Vandenberg AFB(SpaceCraft/Swanson) insert2 back from ISIS-1 launch cover, also insert2 front and insert1 and cover front"Explorer-31" (in text)
United States1969-01-29Vandenberg AFB, CA(SpaceCraft/Swanson) insert2 back from ISIS-1 launch cover, also insert2 front and insert1 and cover front
United States1969-02-26Cape Canaveral FL(HJM black) cachet on ESSA-9 launch cover"Explorer"-10 (upper-middle)
United States1969-04-13Vandenberg AFB, CA(Centennial brown rocket, type-2 and black text) cachet on Nimbus-3 and SECOR-13 launch coverExplorer-62
United States1969-05-22Cape Canaveral FL(HJM blue/Whitney red and black) cachet on Intelsat-3-4 launch cover"Explorer"-10 (upper-middle)
United States1969-11-07Vandenberg AFB, CA(SpaceCraft/Swanson) insert2 back from Azur launch cover, also insert2 front and insert1 and cover front"NASA Explorer-series satellites" (in text)
United States1969-11-07Lompoc CA, Vandenberg AFB(SpaceCraft/Swanson) insert2 back from Azur launch over, also insert2 front and insert1 and cover front
United States1971-06-29Vandenberg AFB, CA(Black rubber-stamp) cachet on (sub-orbital) rocket launch cover"Direct Measurement Explorer" (Explorer-31)
United States1972-01-31Lompoc CA, Vandenberg AFB(Centennial gray rocket, type-2 and red text) cachet on HEOS-2 launch coverExplorer-62
Australia1972-12-07Tharwa ACTCachet on Apollo-17 launch coverExplorer-18/21/28 type (rightmost of three satellites)
United States1973-01-31Redstone Arsenal AL(MoF no.3) insert from Explorer-1 anniversary cover, also insert back and cover"Explorer-III" (Explorer-3)
United States1974-06-30Wallops Island VA(Space Voyage) cachet on (sub-orbital) rocket launch coverExplorer-51 (AE-C) data comparison
United States1975-02-14Kennedy Space Center FL(MoF no.24) insert from Pegasus-1 anniversary cover, also cover front"Explorer-XVI" and "Explorer-XXIII" (in text)
United States1976-03-16Auburn MA(GSFC Stamp Club 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", "Explorer-28", "Explorer-32", "Explorer-35", "Explorer-38"
United States1977-12-14Cape Canaveral FL(Orbit Covers) cachet on CS-1 launch coverExplorer-38/49 type
United States1978-04-07Cape Canaveral FL(Orbit Covers) cachet on Yuri-1 / BSE launch cover"Radio Astronomy Explorer" (Explorer-38/49 type)
United States1978-05-20GSFC, MD(GSFC blue rubber-stamp) cachet (same design as two above) on Pioneer-12 launch cover"Explorer-6", "Explorer-7", "Explorer-10", "Explorer-11", "Explorer-17", "Explorer-20", "Explorer-27", "Explorer-28", "Explorer-32", "Explorer-35", "Explorer-38"
United States1978-08-14Kennedy Space Center FL(Space Voyage) cachet on ISEE-3 launch coverExplorer-56 / ISEE-1 (lower-right)
United States1978-10-24GSFC, MD(GSFC 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", "Explorer-28", "Explorer-32", "Explorer-35", "Explorer-38"
United States1983-01-25Greenbelt MD(GSFC 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", "Explorer-28", "Explorer-32", "Explorer-35", "Explorer-38"
United States1985-03-12Lompoc CA, Vandenberg AFB(Magenta and black printed) cachet on Geosat-1 launch coverExplorer-38/49 type, and Explorer-43/47/50 type
United States2007-11-06WSMR, NM(Printed) cachet on (sub-orbital) rocket launch coverExplorer-73 / "TRACE" (in text)

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.
3Explorer-38 newspaper article.
4Explorer-59 / ISEE-3 was renamed ICE (International Cometary Explorer) in 1983.
5Pioneer-3 and 4 are basically identical.


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