Scientific/research satellites

Below are checklists of scientific/research satellites, launch dates, and images of the satellites. This is a work in progress, and completeness is our goal. If readers know of additional information or images, please contact the authors using the e-mail addresses at the bottom of this page.

More-specific scientific/research disciplines/categories are covered elsewhere on this Website.

Satellite series covered on this page:

U.S. Explorer-series satellites:

Notes on the Explorer series: 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. (Similarly, Pioneer-2 was numbered even though it failed to reach orbit.) Explorer satellites that failed to orbit are noted in the listing.

Satellite	Launch Date	Images
		reference	launch covers	postal items
Explorer-1	1958-01-31	Explorer-1 Explorer-1 Explorer-1	Explorer-1	Explorer-1
Explorer-2 [failed]	1958-03-05		Explorer	Explorer
Explorer-3	1958-03-26
Explorer-4	1958-07-26	Explorer-4
Explorer-5 [failed]	1958-08-24
Explorer-S1 / Explorer-7X [failed]	1959-07-16
Explorer-6 (S2, like Pioneer-5)1	1959-08-07	Explorer-6 Explorer-6 Explorer-6 Explorer-6
Explorer-7 (S1A)	1959-10-13	Explorer-7 Explorer-7 Explorer-7
Explorer-S46 [failed]	1960-03-23	Explorer-S46
Explorer-8 (S30)	1960-11-03	Explorer-8 Explorer-8
Explorer-S56 [failed]	1960-12-04
Explorer-9 (S56A) (identical to Explorer-19)	1961-02-16
Explorer-S45 [failed]	1961-02-24	Explorer-S45
Explorer-10 (P14)	1961-03-25	Explorer-10 Explorer-10
Explorer-11 (S15)	1961-04-27	Explorer-11 Explorer-11
Explorer-S45A [failed]	1961-05-24
Explorer-S55 [failed]	1961-06-30
Explorer-12 (EPE-A, S3)	1961-08-16	Explorer-12
Explorer-13 (S55A)	1961-08-25	Explorer-13 Explorer-13
Explorer-14 (EPE-B, S3A)	1962-10-02
Explorer-15 (EPE-C, S3B)	1962-10-29
Explorer-16 (S55B)	1962-12-16
Explorer-17 (AE-A, S6)	1963-04-03	Explorer-17
Explorer-18 / IMP-1 (IMP-A)	1963-11-27	Explorer-18 Explorer-18/21
Explorer-19 (ADE-A, S56B) (identical to Explorer-9)	1963-12-19
Explorer-S66 (BE-A) [failed]	1964-03-19
Explorer-20 (IE-A, S48)	1964-08-25	Explorer-20
Explorer-21 / IMP-2 (IMP-B)	1964-10-04	Explorer-18/21 Explorer-21
Explorer-22 (BE-B)	1964-10-09	Explorer-22
Explorer-23 (S55C)	1964-11-06
Explorer-24 (ADE-B, S56C)	1964-11-21	Explorer-24 Explorer-24+25
Explorer-25 (IE-B) / Injun-4	1964-11-21	Explorer-25 Explorer-25 Explorer-24+25
Explorer-26 (EPE-D)	1964-12-21
Explorer-27 (BE-C)	1965-04-29	Explorer-27
Explorer-28 / IMP-3 (IMP-C)	1965-05-29
Explorer-29 / GEOS-1 (GEOS-A)	1965-11-06	Explorer-29 Explorer-29
Explorer-30 (SE-A) / SolRad-8	1965-11-19	Explorer-30
Explorer-31 (DME-A) / ISIS-X	1965-11-28
Explorer-32 (AE-B)	1966-05-25	Explorer-32
Explorer-33 / AIMP-1 (IMP-D)	1966-07-01	Explorer-33 Explorer-33/35
Explorer-34 / IMP-4 (IMP-F)	1967-05-24	Explorer-34
Explorer-35 / AIMP-2 (IMP-E)	1967-07-19	Explorer-35 Explorer-33/35
Explorer-36 / GEOS-2 (GEOS-B)	1968-01-11
Explorer-37 (SE-B) / SolRad-9	1968-03-05	Explorer-37
Explorer-38 / RAE-1 (RAE-A)	1968-07-04	Explorer-38/49 Explorer-38/49
Explorer-39 (ADE-C)	1968-08-08
Explorer-40 (IE-C) / Injun-5	1968-08-08	Explorer-40 Explorer-40
Explorer-41 / IMP-5 (IMP-G)	1969-06-21	Explorer-41
Explorer-42 (SAS-A) / Uhuru	1970-12-12	Explorer-42 (Uhuru) Explorer-42
Explorer-43 / IMP-6 (IMP-I)	1971-03-13	Explorer-43
Explorer-44 (SE-C) / SolRad-10	1971-07-09	Explorer-44
Explorer-45 (SSS-A / S-Cubed-A)	1971-11-15	Explorer-45
Explorer-46 / MTS	1972-08-14	Explorer-46
Explorer-47 / IMP-7 (IMP-H)	1972-09-25
Explorer-48 (SAS-B)	1972-11-15	Explorer-48
Explorer-49 / RAE-2 (RAE-B)	1973-06-10	Explorer-38/49 Explorer-38/49 Explorer-49
Explorer-50 / IMP-8 (IMP-J)	1973-10-26	Explorer-50 Explorer-50
Explorer-51 (AE-C)	1973-12-16	Explorer-51
Explorer-52 (IE-D) / Hawkeye-1 / Injun-6	1974-06-03	Explorer-52
Explorer-53 (SAS-C)	1975-05-07	Explorer-53
Explorer-54 (AE-D)	1975-10-06	Explorer-54
Explorer-55 (AE-E)	1975-11-20
Explorer: DAD-A (DADE-A), DAD-B (DADE-B) [failed]	1975-12-05
Explorer-56 / ISEE-1 (ISEE-A)	1977-10-25	ISEE-1 ISEE-1+2
Explorer-57 / IUE	1978-01-26	Explorer-57 (IUE) Explorer-57 (IUE)
Explorer-58 / HCMM / AEM-1 (AEM-A)	1978-04-26	Explorer-58/60
Explorer-59 / ISEE-3 (ISEE-C) / ICE2	1978-08-14	ISEE-3 ISEE-3 ISEE-3
Explorer-60 / SAGE / AEM-2 (AEM-B)	1979-02-18	Explorer-58/60
Explorer-61 / MagSat	1979-10-30	Explorer-61
Explorer-62 (DE-1)	1981-08-03	Explorer-62/63 Explorer-62/63
Explorer-63 (DE-2)	1981-08-03	Explorer-62/63 Explorer-62/63
Explorer-64 / SME	1981-10-06	Explorer-64 (SME) Explorer-64 (SME)
Explorer-65 / AMPTE (CCE, IRM, UKS)	1984-08-16	Explorer-65 (AMPTE) UKS
Explorer-66 / COBE	1989-11-18	Explorer-66 (COBE, final design3) Explorer-66 (COBE, final design3)
Explorer-67 / EUVE	1992-06-07	Explorer-67 (EUVE) Explorer-67 (EUVE)
Explorer-68 / SMEX-1 / SAMPEX	1992-07-03	Explorer-68 (SAMPEX) Explorer-68 (SAMPEX)
Explorer-69 / XTE / RXTE	1995-12-30	Explorer-69 (XTE) Explorer-69 (XTE)
Explorer-70 / SMEX-2 / FAST	1996-08-21	Explorer-70 (FAST) Explorer-70 (FAST)
Explorer-71 / ACE	1997-08-25	Explorer-71 (ACE) Explorer-71 (ACE) Explorer-71 (ACE)
Explorer-72 / STEDI-1 / SNOE	1998-02-26	Explorer-72 (SNOE)
Explorer-73 / SMEX-4 / TRACE	1998-04-02	Explorer-73 (TRACE)
Explorer-74 / SMEX-3 / SWAS	1998-12-06	Explorer-74 (SWAS) Explorer-74 (SWAS)
Explorer-75 / SMEX-5 / WIRE [failed]	1999-03-05	Explorer-75 (WIRE)
Explorer-76 / STEDI-2 / TERRIERS [failed]	1999-05-18	Explorer-76 (TERRIERS)
Explorer-77 / MIDEX-0 / FUSE	1999-06-23	Explorer-77 (FUSE) Explorer-77 (FUSE)
Explorer-78 / MIDEX-1 / IMAGE	2000-03-25	Explorer-78 (IMAGE)
Explorer-79 / HETE-2	2000-10-09	Explorer-79 (HETE-2)
Explorer-80 / MIDEX-2 / MAP / WMAP	2001-06-30	Explorer-80 (MAP)
Explorer-81 / SMEX-6 / HESSI / RHESSI	2002-02-05	Explorer-81 (HESSI) Explorer-81 (HESSI)
Explorer-82 / UNEX-1 / CHIPSat	2003-01-12	Explorer-82 (CHIPSat)
Explorer-83 / SMEX-7 / GALEX	2003-04-28	Explorer-83 (GALEX)
Explorer-84 / MIDEX-3 / Swift	2004-11-20	Explorer-84 (Swift)
Explorer-85 — 89 / MIDEX-5A/E / THEMIS-A/E	2007-02-17	Explorer-85/89 (THEMIS)
Explorer-90 / SMEX-9 / AIM	2007-04-25	Explorer-90 (AIM)

¹Both Explorer-6 and Pioneer-5 were "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.
²Explorer-59 / ISEE-3 was renamed ICE in 1983.
³COBE (first design) was intended for Space Shuttle launch; COBE (final design) was intended for rocket launch.

U.S. Injun-series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
Injun-1	1961-06-29	Injun-1+SolRad-3 Transit-4a+Injun-1+SolRad-3	Injun	Injun
Injun-2	1962-01-24	Injun-2
Injun-3	1962-12-13	Injun-3
Injun-4 / Explorer-25 (IE-B)	1964-11-21	Explorer-25 Explorer-25 Explorer-24+25
Injun-5 / Explorer-40 (IE-C)	1968-08-08	Explorer-40 Explorer-40
Injun-6 / Explorer-52 (IE-D) / Hawkeye-1	1974-06-03	Explorer-52
Injun	Unspecified	Injun

U.S. Geodetic Earth Orbiting Satellite (GEOS-1/2), PAssive Geodetic Earth Orbiting Satellite (PAGEOS-1), and Geodynamics Experimental Ocean Satellite (GEOS-3) series:

Satellite	Launch Date	Images
		reference	launch covers	postal items
GEOS-1 (GEOS-A) / Explorer-29	1965-11-06	Explorer-29 Explorer-29	GEOS	GEOS
PAGEOS-1	1966-06-23	PAGEOS
GEOS-2 (GEOS-B) / Explorer-36	1968-01-11
GEOS-3 (GEOS-C)	1975-04-09

U.S. International Sun-Earth Explorer (ISEE) series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
ISEE-1 (ISEE-A) / Explorer-56	1977-10-25	ISEE-1 ISEE-1+2	ISEE	ISEE
ISEE-2 (ISEE-B)	1977-10-25	ISEE-2 ISEE-1+2
ISEE-3 (ISEE-C) / Explorer-59 / ICE*	1978-08-14	ISEE-3 ISEE-3 ISEE-3

^*ISEE-3 / Explorer-59 was renamed ICE in 1983.

U.S. Vanguard-series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
Vanguard-TV0 (sub-orbital)	1956-12-08		Vanguard	Vanguard
Vanguard-TV1 (sub-orbital)	1957-05-01
Vanguard-TV2 (sub-orbital)	1957-10-23
Vanguard-TV3 [failed]	1957-12-06	Vanguard-TV3
Vanguard-TV3 (backup) [failed]	1958-02-05
Vanguard-1 (TV4)	1958-03-17	Vanguard-1 Vanguard-1 Vanguard-1
Vanguard-TV5 [failed]	1958-04-28	Vanguard-TV5
Vanguard-SLV1 [failed]	1958-05-27
Vanguard-SLV2 [failed]	1958-06-26	Vanguard-SVL2
Vanguard-SLV3 [failed]	1958-09-26
Vanguard-2 (SLV4)	1959-02-17	Vanguard-2 Vanguard-2 Vanguard-2
Vanguard-SLV5 [failed]	1959-04-13	Vanguard-SLV5
Vanguard-SLV6 [failed]	1959-06-22
Vanguard-3 (SLV7)	1959-09-18	Vanguard-3 Vanguard-3 Vanguard-3

U.S. Pioneer-series (non-planetary) satellites:

Of the numbered Pioneer satellites, only Pioneer-2 failed but was numbered in sequence. This occurred before it was common practice to delay final numbering until a launch was successful. (Similarly, Explorer-2 and Explorer-5 were numbered even though they failed to reach orbit.) Pioneer satellites that failed to orbit are noted in the listing.

Satellite	Launch Date	Images
		reference	launch covers	postal items
Pioneer-0 (lunar orbit attempt) [failed]	1958-08-17	Pioneer-0/1/2 Pioneer-1	Pioneer (non-planetary)	Pioneer (non-planetary)
Pioneer-1 (lunar orbit attempt)	1958-10-11
Pioneer-2 (lunar orbit attempt) [failed]	1958-11-08
Pioneer-3 (lunar flyby attempt)	1958-12-06	Pioneer-3 Pioneer-3/4 Pioneer-4
Pioneer-4 (solar orbit)	1959-03-03
Pioneer-P1 (lunar orbit attempt) [failed]	1959-09-24
Pioneer-P3 (lunar orbit attempt) [failed]	1959-11-26
Pioneer-5 (P2, like Explorer-6)1	1960-03-11	Pioneer-5 Pioneer-5 Pioneer-5 Pioneer-5
Pioneer-P30 (lunar orbit attempt) [failed]	1960-09-25
Pioneer-P31 (lunar orbit attempt) [failed]	1960-12-15
Pioneer-6 (Pioneer-A)	1965-12-16	Pioneer-6 Pioneer-6 Pioneer-6
Pioneer-7 (Pioneer-B)	1966-08-17	Pioneer-7
Pioneer-8 (Pioneer-C)	1967-12-13	Pioneer-6/7/8/9 Pioneer-6/7/8/9 (not Pioneer-1)
Pioneer-9 (Pioneer-D)	1968-11-08
Pioneer-E [failed]	1969-08-27	Pioneer-E
Later Pioneer-series (planetary) satellites (Pioneer-10 — Pioneer-13)			Pioneer (planetary)	Pioneer (planetary)

¹Both Pioneer-5 and Explorer-6 were "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.

U.S. Orbiting Geophyiscal Observatory (OGO) series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
OGO-1 (OGO-A)	1964-09-05	OGO-1	OGO	OGO
OGO-2 (OGO-C) / POGO-1	1965-10-14	OGO-2
OGO-3 (OGO-B)	1966-06-07	OGO-3
OGO-4 (OGO-D) / POGO-2	1967-07-28
OGO-5 (OGO-E)	1968-03-04
OGO-6 (OGO-F) / POGO-3	1969-06-05	OGO-6
OGO	Unspecified	OGO

U.S. Owl-series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
Owl-1 (Transit-O13)	1967-05-18	Owl Owl-1
Owl-2 (Transit-O14)	1967-09-25

U.S. Pegasus-series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
Pegasus-1	1965-02-16	Pegasus	Pegasus-1 Pegasus-1 Pegasus-1 (10th anniv.)	Pegasus
Pegasus-2	1965-05-25		Pegasus-2 Pegasus-2 Pegasus-2
Pegasus-3	1965-07-30		Pegasus-3 Pegasus-3 Pegasus-3 Pegasus-3

U.S. [Apollo-launched] Particle and Field Sub-satellites (P&FS):

Satellite	Launch Date	Images
		reference	launch covers	postal items
P&FS [Apollo-15 launched]	1971-08-04	P&FS (Apollo-15)	P&FS (Apollo-15)	P&FS P&FS P&FS (Apollo-16)
P&FS [Apollo-16 launched]	1972-04-24	P&FS (Apollo-16)	P&FS (Apollo-16)

U.S. LAser GEOdynamics Satellite (LAGEOS) series:

Satellite	Launch Date	Images
		reference	launch covers	postal items
LAGEOS-1 (LAGEOS-A)	1976-05-04	LAGEOS LAGEOS	LAGEOS-1 LAGEOS-1
LAGEOS-2 (LAGEOS-B) [STS/Columbia-launched]	1992-10-22	LAGEOS-2

U.S. High Energy Transient Explorer (HETE) series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
HETE-1	1996-11-04	HETE-1
HETE-2 / Explorer-79	2000-10-09	HETE-2 (Explorer-79)

U.S. Gravity Probe (GP) series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
GP-A (sub-orbital)	1976-06-18
GP-B	2004-04-20	GP-B GP-B GP-B (prototype)	GP-B GP-B	GP-B GP-B GP-B GP-B GP-B

U.S. Space Electric Rocket Test (SERT) series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
SERT-1	1964-07-20	SERT-1	SERT-1
SERT-2	1970-02-04	SERT-2	SERT-2 SERT-2

U.S. TEst and TRaining (TETR) series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
TETR-1 (TETR-A)	1967-12-13	TETR	Pioneer-8+TETR-1 Pioneer-8+TETR-1 Pioneer-8+TETR-1 (wrong image)
TETR-2 (TETR-B)	1968-11-08		Pioneer-9+TETR-2 Pioneer-9+TETR-2 Pioneer-9+TETR-2
TETR-3 (TETR-C) [failed]	1969-08-27		Pioneer-E+TETR-3
TETR-4 (TETR-D)	1971-09-29		OSO-7+TETR-4 OSO-7+TETR-4 OSO-7+TETR-4

U.S. Beacon series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
Beacon-1 [failed]	1958-10-23
Beacon-2 [failed]	1959-08-14		Beacon-2

U.S. Plasma Interaction eXperiment (PIX) series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
PIX-1	1978-03-05	PIX	Landsat-3+OSCAR-8+PIX-1 Landsat-3+OSCAR-8+PIX-1 Landsat-3+OSCAR-8+PIX-1
PIX-2	1983-01-26		IRAS+PIX-2 IRAS+PIX-2 IRAS+PIX-2 IRAS+PIX-2

U.S. Biological Satellite (Biosatellite or Biosat) series:

Satellite	Launch Date	Images
		reference	launch covers	postal items
Biosatellite-1	1966-12-14		Biosatellite-1
Biosatellite-2	1967-09-07		Biosatellite-2 Biosatellite-2
Biosatellite-3	1969-06-29		Biosatellite-3

U.S. Wake Shield Facility (WSF) series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
WSF-1 [STS/Discovery-launched, failed]	1994-02-03
WSF-2 [STS/Endeavour-launched]	1995-09-07	WSF-2
WSF-3 [STS/Columbia-launched]	1996-11-19

U.S. Starshine-series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
Starshine-1 [STS/Discovery-launched]	1999-05-27	Starshine-1
Starshine-3 (Starshine-OSCAR-43, SO-43)	2001-09-30	Starshine-3
Starshine-2 [STS/Endeavour-launched]	2001-12-05	Starshine-2

Canadian Alouette-series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
Alouette-1 (Alouette-A)	1962-09-28	Alouette-1 Alouette-1	Alouette	Alouette
Alouette-2 (Alouette-B)	1965-11-28

Canadian International Satellite for Ionospheric Studies (ISIS) series:

Satellite	Launch Date	Images
		reference	launch covers	postal items
ISIS-X / Explorer-31 (DME-A)	1965-11-28		ISIS	ISIS
ISIS-1 (ISIS-A)	1969-01-29	ISIS-1
ISIS-2 (ISIS-B)	1971-03-31	ISIS-2
ISIS-C	Canceled

United Kingdom (UK) / Ariel-series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
Ariel-1 / UK-1 (S-51)	1962-04-26	Ariel-1	Ariel	Ariel
Ariel-2 / UK-2 (UK-C, S-52)	1964-03-27	Ariel-2
Ariel-3 / UK-3 (UK-E)	1967-05-05	Ariel-3 Ariel-3 Ariel-3 Ariel-3/4 (not Ariel-5) Ariel-3/4 (not Ariel-5)
Ariel-4 / UK-4	1971-12-11	Ariel-4 Ariel-4 Ariel-3/4 (not Ariel-5) Ariel-3/4 (not Ariel-5)
Ariel-5 / UK-5	1974-10-15	Ariel-5
Ariel-6 / UK-6	1979-06-02	Ariel-6 Ariel-6

Italian San Marco-series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
San Marco-1 (sub-orbital) test rocket (Shotput-6)	1963-04-22	Shotput	San Marco	San Marco
San Marco-2 (sub-orbital) test rocket (Shotput-7)	1963-08-02
San Marco-1 (San Marco-A)	1964-12-15	San Marco-1 San Marco-1
San Marco-2 (San Marco-B)	1967-04-26
San Marco-3 (San Marco-C)	1971-04-24
San Marco-4 (San Marco-C2)	1974-02-18
San Marco-D/M [failed]	1983-07-01
San Marco-5 (San Marco-D/L)	1988-03-25	San Marco-5 San Marco-5

Satellite Italiano Ricerca Industriale Orientata (SIRIO) series:

Satellite	Launch Date	Images
		reference	launch covers	postal items
SIRIO-1 (SIRIO-A)	1977-08-25		SIRIO-1 SIRIO-1 SIRIO-1 (Intelsat-4 image) SIRIO-1	SIRIO-1 SIRIO-1+Intelsat-4
SIRIO-2 (SIRIO-B) [failed]	1982-09-10	SIRIO-2	SIRIO-2+Marecs-B SIRIO-2+Marecs-B SIRIO-2+Marecs-B SIRIO-2+Marecs-B SIRIO-2+Marecs-B

German Aeros-series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
Aeros-1 (Aeros-A)	1972-12-16		Aeros	Aeros
Aeros-2 (Aeros-B)	1974-07-16	Aeros-2

French A-1, FR-1, and D-series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
A-1 / Asterix	1965-11-26	A-1 A-1	A-1	A-1
FR-1 / France-1	1965-12-06	FR-1	FR-1	FR-1
D-1A / Diapason	1966-02-18	D-1 D-1 D-1A D-1A	D-series	D-series
D-1B	Canceled
D-1C / Diademe-1	1967-02-08	D-1C/D
D-1D / Diademe-2	1967-02-15
D-2A / Tournesol	1971-04-15	D-2A D-2A
D-2A / Polaire [failed]	1971-12-06
D-2B / Aura	1975-09-27	D-2B
D-3	Changed to FR-2 or CAS-B and canceled
D-4	Unknown/canceled
D-5A / Pollux, D-5B / Castor [failed]	1973-05-21	D-5A D-5B
D-5A / Pollux, D-5B / Castor	1975-05-17
SIGNE-31 (D-2B type)	1977-06-17	D-2B

¹SIGNE-1 and SIGNE-2 were payloads on Prognoz-2 and (possibly) Prognoz-6 spacecraft, respectively.

French Eole / Cooperative Applications Satellite (CAS) series:

Satellite	Launch Date	Images
		reference	launch covers	postal items
Peole (Preliminary Eole)	1970-12-12	Peole	Eole	Eole
Eole / CAS	1971-08-16	Eole

French/Russian Satellite des Recherches et d'Etudes Technologiques (SRET) / Maliy Avtonomiy Sputnik (MAS) series:

Satellite	Launch Date	Images
		reference	launch covers	postal items
SRET-1 / MAS-1	1972-04-04		Molniya-1-20+SRET-1
SRET-2 / MAS-2	1975-06-05		SRET-2 D-2+D-5B+SRET-2	Explorer-52+SRET-2

European Scientific Research Organization (ESRO) series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
ESRO-2A [failed]	1967-05-29	ESRO-2 ESRO-2A	ESRO	ESRO
ESRO-2 (ESRO-2B) / Iris	1968-05-16	ESRO-2B ESRO-2B
ESRO-1A / Aurorae	1968-10-03	ESRO-1 ESRO-1 ESRO-1A
ESRO-1B / Boreas	1969-10-01
ESRO-TD1A	1972-03-11	ESRO-TD1A ESRO-TD1A
ESRO-4	1972-11-21	ESRO-4 ESRO-4

European Highly Eccentric Orbit Satellite (HEOS) series:

Satellite	Launch Date	Images
		reference	launch covers	postal items
HEOS-1 (HEOS-A)	1968-12-05	HEOS-1 HEOS-1 HEOS-1	HEOS	HEOS
HEOS-2 (HEOS-A2)	1972-01-31

European Space Agency (ESA) Geostationary Earth Orbit Satellite (GEOS) series:

Satellite	Launch Date	Images
		reference	launch covers	postal items
ESA-GEOS-1	1977-04-20	ESA-GEOS-1	ESA-GEOS	ESA-GEOS
ESA-GEOS-2	1978-07-14
ESA-GEOS	Unspecified	ESA-GEOS ESA-GEOS ESA-GEOS

Japanese Ionospheric Sounding Satellite (ISS) / Ume series:

Satellite	Launch Date	Images
		reference	launch covers	postal items
ISS-1 (ISS-A) / Ume-1	1976-02-29	ISS-1	ISS-1
ISS-2 (ISS-B) / Ume-2	1978-02-16		ISS-2

Japanese Exospheric Satellite (EXOS) series:

Satellite	Launch Date	Images
		reference	launch covers	postal items
EXOS-A / Kyokko	1978-02-04
EXOS-B / Jikiken	1978-09-16
EXOS-C / Ohzora	1984-02-14		EXOS-C EXOS-C
EXOS-D / Akebono	1989-02-21	EXOS-D		EXOS-D EXOS-D EXOS-D EXOS-D

Japanese Engineering Test Satellite (ETS) / Kiku series:

Satellite	Launch Date	Images
		reference	launch covers	postal items
ETS-1 / Kiku-1	1975-09-09	ETS-1
ETS-2 / Kiku-2	1977-02-23		ETS-2 ETS-2
ETS-4 / Kiku-3	1981-02-11		ETS-4 ETS-4 ETS-4
ETS-3 / Kiku-4	1982-09-03		ETS-3 ETS-3 ETS-3 ETS-3
ETS-5 / Kiku-5	1987-08-27		ETS-5 ETS-5	ETS-5 ETS-5/6 + others
ETS-6 / Kiku-6	1994-08-28	ETS-6 ETS-6 ETS-6	ETS-6 ETS-6	ETS-5/6 + others
ETS-7 / Kiku-7	1997-11-27	ETS-7	ETS-7+TRMM
ETS-8 / Kiku-8	2006-12-18	ETS-8

Japanese Tansei-series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
Tansei-1 / MS-T1	1971-02-16	Tansei-1	Tansei-1
Tansei-2 / MS-T2	1974-02-16	Tansei-2
Tansei-3 / MS-T3	1977-02-19	Tansei-3	Tansei-3
Tansei-4 / MS-T4	1980-02-17	Tansei-4	Tansei-4 Tansei-4

Other (selected) Japanese scientific/research satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
Ohsumi	1970-02-11	Ohsumi	Ohsumi	Ohsumi Ohsumi
Shinsei	1971-09-28	Shinsei	Shinsei Shinsei
Denpa / REXS	1972-08-19	REXS	Denpa
Taiyo / SRATS	1975-02-24	SRATS
Hakucho / CORSA-B	1979-02-21	Hakucho CORSA-B	Hakucho
MABES / Jindai	1986-08-12	MABES	MABES
EGP / EGS / Ajisai	1986-08-12	EGS	Fuji-1+EGS Fuji-1+EGS Fuji-1+EGS Fuji-1+EGS
DEBUT / Orizuru	1990-02-07	DEBUT	DEBUT
MDS-1 / Tsubasa	2002-02-04	MDS-1	MDS-1

(Selected) Indian scientific/research satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
Aryabhata (Ariabata)	1975-04-20	Aryabhata	Aryabhata	Aryabhata
Bhaskara-1 / SEO-1	1979-06-07	Bhaskara	Bhaskara	Bhaskara
Bhaskara-2 / SEO-2	1981-11-20	Bhaskara-2+Rohini-1B
Rohini-1A [failed]	1979-08-10	Rohini-1	Rohini	Rohini
Rohini-1 (Rohini-1B)	1980-07-18	Rohini-1B Bhaskara-2+Rohini-1B
Rohini-2	1981-05-31
Rohini-3	1983-04-17
SROSS-1 (SROSS-A) [failed]	1987-03-24	SROSS-1
SROSS-2 (SROSS-B) / SRS-2 [failed]	1988-07-13
SROSS-3 (SROSS-C)	1992-05-20
SROSS-C2	1994-05-04

Pakistani Badr-series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
Badr-1 (Badr-A)	1990-07-16	Badr-1 Badr-1	Badr	Badr
Badr-2 (Badr-B)	2001-12-10	Badr-2

Chinese Shi Jian (SJ) series satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
SJ-1 / PRC-2 / China-2	1971-03-03
SJ-2A / PRC-11 / China-11	1981-09-19			SJ-2
SJ-2B / PRC-9 / China-9	1981-09-19
SJ-2C / PRC-10 / China-10	1981-09-19
SJ-4 / Practice-4	1994-02-08		SJ-4 SJ-4 (back)	SJ-4
SJ-6A	2004-09-08		SJ-6A+B SJ-6A+B (back)
SJ-6B	2004-09-08
SJ-7	2005-07-05

(Selected) Swedish scientific/research satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
Viking	1986-02-11	Viking Viking Viking	Viking	Viking
Freja	1992-10-06	Freja Freja	Freja	Freja
Astrid-1	1995-01-24	Astrid-1 Astrid-1
Astrid-2	1998-12-10	Astrid-2
Munin	2000-11-21	Munin	EO-1+SAC-C+Munin
Odin	2001-02-20	Odin

Other (selected) U.S. scientific/research satellites:

Satellite	Launch Date	Images
		reference	launch covers	postal items
ASSET (sub-orbital)	1964-10-27		ASSET
OFO	1970-11-09		OFO
CEP-1	1970-12-11		NOAA-1+CEP-1 NOAA-1+CEP-1 NOAA-1+CEP-1 NOAA-1+CEP-1 NOAA-1+CEP-1 NOAA-1+CEP-1 (insert)
RadCat-2, RadSat (Pi-in-the-Sky)	1972-10-02		RadCat-2+Pi-in-the-Sky
SCATHA / P78-2	1979-01-30		SCATHA
Solwind / P78-1	1979-02-24	Solwind
Hilat / P83-1	1983-06-27	Hilat
LDEF [STS/Challenger-launched]	1984-04-06	LDEF	STS-41C+LDEF (STS/Challenger-launch)	LDEF LDEF (STS/Challenger-launch) LDEF (STS/Columbia-retrieval)
LDEF [STS/Columbia-retrieved]	1990-01-09
NUsat [amateur-built, STS/Challenger-launched]	1985-04-29	NUsat	STS-51B+NUsat (STS/Challenger-launch)
GLOMR [STS/Challenger-attempted-launch]	1985-04-29	GLOMR
GLOMR [STS/Challenger-launched]	1985-10-30
PegSat	1990-04-05		PegSat
CRRES	1990-07-25	CRRES		CRRES
Geotail / GTL	1992-07-24	Geotail	Geotail
Stella	1993-09-26			ARCAD+Stella ARCAD+Stella ARCAD+Stella ARCAD+Stella
Wind	1994-11-01	Wind	Wind
PAMS-STU [STS/Endeavour-launched]	1996-05-19	PAMS-STU (STS/Endeavour-launch)
Equator-S	1997-12-02		Equator-S Equator-S Equator-S Equator-S	Equator-S Equator-S Equator-S
Acrimsat	1999-12-20	Acrimsat ARIMsat	Acrimsat
Genesis / Discovery-5	2001-08-08	Genesis	Genesis Genesis (crash landing)	Genesis Genesis Genesis
Simplesat [STS/Discovery-launched]	2001-08-10	Simplesat
TIMED	2001-12-07	TIMED	Jason-1+TIMED Jason-1+TIMED
GRACE	2002-03-17	GRACE	GRACE
MEPSI [STS/Endeavour-launched]	2002-11-23	MEPSI-1A+B+PLA
Coriolis / WindSat	2003-01-06	Coriolis	Coriolis	Coriolis
ICESat	2003-01-12	ICESat	ICESat ICESat
SORCE	2003-01-25	SORCE	SORCE SORCE
Formosat-3 / COSMIC	2006-04-14

Other (selected) non-U.S. scientific/research satellites:

Satellite	Country	Launch Date	Images
			reference	launch covers	postal items
WRESAT	Australia	1967-11-29	WRESAT
Azur / GRS	Germany	1969-11-07	Azur	Azur	Azur
Dial / Wika	France / Germany	1970-03-10	Dial-Wika	Dial-Wika	Dial-Wika
Prospero	Great Britain	1971-10-28	Prospero
Intasat	Spain	1974-11-15	Intasat	Intasat Intasat+Olympus NOAA-4+Intasat+OSCAR-7 NOAA-4+Intasat+OSCAR-7 NOAA-4+Intasat+OSCAR-7 NOAA-4+Intasat+OSCAR-7 NOAA-4+Intasat+OSCAR-7	Intasat name (ESA-GEOS image)
Firewheel / MPE [failed]	Germany / USA	1980-05-23	Firewheel	MPE
SPAS-1 [STS/Challenger-launched-and-recovered]	Germany / USA	1983-06-22	SPAS-1	STS-7+SPAS-1 (with Challenger)	SPAS-1 (with Challenger) SPAS-1 (with Challenger)
SPAS-1A [STS/Challenger-launched-and-recovered]		1984-02-03
Eureca-1 [STS/Atlantis-launched]	Europe (ESA) / USA	1992-07-31	Eureca Eureca-1 (STS/Atlantis-launch)
Eureca-1 [STS/Endeavour-retrieved]		1993-06-21
Bremsat [STS/Discovery-launched]	Germany	1994-02-03	Bremsat
Cerise, Upm/lb	France / Spain	1995-07-07		Helios-1A+Cerise+Upm/lb
Kwangmyongsong-1 [failed]	China (PRC)	1998-08-30	Kwangmyongsong-1		Kwangmyongsong-1
Oersted	Denmark / USA	1999-02-23	Oersted	Oersted	Oersted
Abrixas, MegSat	Germany / Italy	1999-04-28		Abrixas+MegSat
CHAMP	Germany	2000-07-15	CHAMP
BIRD-1	Germany	2001-10-22	BIRD-1
PROBA	Belgium / India	2001-10-22			MOS+PROBA+Uribyol
SciSat-1	Canada	2003-08-12	SciSat-1	SciSat-1 SciSat-1
DoubleStar-1 / TC-1	China (PRC)	2003-12-30	TC-1	TC-1 TC-1 TC-1 TC-1 TC-1 TC-1	TC-1
FSW-3-2 / recoverable satellite-19	China (PRC)	2004-08-29	FSW-3	FSW-3-2 FSW-3-2 (back)
FSW-3-3 / recoverable satellite-20	China (PRC)	2004-09-27	FSW-3	FSW-3-3 FSW-3-3 (back)
DoubleStar-2 / TC-2	China (PRC)	2004-07-26	TC-1	TC-2 TC-2
CryoSat [failed]	ESA	2005-10-08	CryoSat		CryoSat CryoSat CryoSat
Libertad-1 [amateur-built]	Colombia	2007-04-17	Libertad-1		Libertad-1
Cluster-2 (FM6/Salsa, FM7/Samba)	ESA	2000-07-16	Cluster	Cluster-2	Cluster Cluster
Cluster-2 (FM5/Rumba, FM8/Tango)	ESA	2000-08-09
GOCE	ESA	2009-03-17	GOCE	GOCE GOCE GOCE
Kwangmyongsong-2 [failed]	China (PRC)/Korea	2009-04-05			Kwangmyongsong-2

Links to scientific/research satellite information:

(The links below lead to information sources that are maintained by others. They are not part of this Website.)

• NASA GSFC: Explorer Missions
• NASA Headquarters History Office: Explorer Series of Spacecraft
• JPL library: Explorer program
• JPL library: Pioneer program
• Astronautix.com: Explorer program
• Astronautix.com: Pioneer program
• Krebs: Explorer program
• SNSB: Swedish satellites

Back to Un-Manned Satellite Philately.