Solar-observing spacecraft

Below are checklists of Solar-observing spacecraft, including launch dates and images of the spacecraft. 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.

Note: Solar-observing spacecraft (such as Explorer-81 / HESSI / RHESSI / SMEX-6, Explorer-91 / IBEX / SMEX-10, and Explorer-94 / IRIS / SMEX-12) that are part of a larger mostly non-solar-observing series (in these examples they are part of the long Explorer-series) are listed only as part of that larger series. In other words, in such cases their entries are not repeated in this page.

Spacecraft series covered:

USA SOLar RADiation (SolRad)¹ / GRAB / GREB series satellites:

Satellite	Launch Date	Images
		reference	launch covers	other postal items
SolRad-1 / GRAB-1	1960-06-22	SolRad-1 SolRad SolRad-1 (+ Transit-2A)	SolRad	SolRad
SolRad-2 / GRAB-(2) [failed]	1960-11-30
SolRad-3 / GRAB-2	1961-06-29	SolRad-3 (+ Injun-1) SolRad-3 (+ Transit-4A+Injun-1) SolRad-3 (+ Transit-4A+Injun-1)
SolRad-4A / GRAB-(3a) [failed]	1962-01-24
SolRad-4B / GRAB-(3b) [failed]	1962-04-26
SolRad-5 / GRAB	Never launched
SolRad-6 (carried by Poppy-2A) [partial failure]	1963-06-15
SolRad-7A (carried by Poppy-3A)	1964-01-11
SolRad-7B (carried by Poppy-4A)	1965-03-09
SolRad-8 / Explorer-30 (SE-A)	1965-11-19	Explorer-30
SolRad-9 / Explorer-37 (SE-B)	1968-03-05	Explorer-37 Explorer-37
SolRad-10 / Explorer-44 (SE-C)	1971-07-09	Explorer-44
SolRad-11A, SolRad-11B	1976-03-14	SolRad-11A+11B
SolRad-11C	Never launched

¹The SolRad satellites' primary mission was to locate Russian radar sites. Their secondary mission, to conduct solar radiation studies, did provide some scientific data, but the fundamental reason for including the secondary mission was to hide the true nature of these satellites.

West German Helios-series satellites:

Satellite	Launch Date	Images
		reference	launch covers	other postal items
Helios-1 (Helios-A)	1974-12-10	Helios Helios-1 Helios (patch)	(West German) Helios	(West German) Helios
Helios-2 (Helios-B)	1976-01-15

USA Orbiting Solar Observatory (OSO) series satellites:

Satellite	Launch Date	Images
		reference	launch covers	other postal items
OSO-1 (OSO-A)	1962-03-07	OSO-1	OSO	OSO
OSO-2 (OSO-B)	1965-02-03
OSO-C [failed]	1965-08-25
OSO-3 (OSO-E)	1967-03-08	OSO-3 (newspaper article)
OSO-4 (OSO-D)	1967-10-18
OSO-5 (OSO-F)	1969-01-22	"OSO-5"
OSO-6 (OSO-G)	1969-08-09	"OSO-6" OSO-6 (mis-labeled "OSO-7")
OSO-7 (OSO-H)	1971-09-29	OSO-7
OSO-8 (OSO-I)	1975-06-21	OSO-8 OSO-8 OSO-8 "OSO-8" OSO-8 (newspaper articles)
AOSO	Canceled	AOSO AOSO AOSO AOSO (mis-labeled "OSO-1")		AOSO

Japanese Solar-series satellites:

Satellite	Launch Date	Images
		reference	launch covers	other postal items
Solar-A / Yohkoh	1991-08-30	Solar-A	Solar	Solar
Solar-B / Hinode	2006-09-22	Solar-B

USA Solar Maximum Mission (SMM) satellite:

Satellite	Launch Date	Images
		reference	launch covers	other postal items
SMM [rocket-launched]	1980-02-14	SMM SMM (patch, with STS-41C/Challenger) SMM (patch, with STS-41C/Challenger)	SMM (rocket-launched)	SMM
SMM [STS-41C/Challenger-repaired and re-deployed]	1984-04-08/12		SMM (repaired)

Russian Comprehensive ORbital Near-earth Observations of the Active Sun (CORONAS / KORONAS) series spacecraft:

Satellite	Launch Date	Images
		reference	launch covers	other postal items
KORONAS-I	1994-03-02	KORONAS-I	KORONAS / CORONAS	KORONAS / CORONAS
KORONAS-F	2001-07-13	KORONAS-F
KORONAS-Foton	2009-01-30	KORONAS-Foton

Other (selected) USA solar-observing spacecraft:

Satellite	Launch Date	Images
		reference	launch covers	other postal items
Solwind / P78-1	1979-02-24	Solwind	Solwind	Solwind
P80-2	Canceled	P80-2
Ulysses [STS-41/Discovery-deployed]	1990-10-06	Ulysses Ulysses Ulysses (patch) Ulysses (patch) Ulysses (patch) Ulysses (patch, with STS-41/Discovery)	Ulysses	Ulysses
Wind	1994-11-01	Wind	Wind	Wind
Genesis / Discovery-5	2001-08-08	Genesis	Genesis	Genesis
SORCE	2003-01-25	SORCE SORCE SORCE SORCE	SORCE	SORCE
STEREO-A, STEREO-B	2006-10-26	STEREO STEREO (patch)	STEREO	STEREO
SDO	2010-02-11	SDO	SDO	SDO
DSCOVR / Triana / "GoreSat"	2015-02-11	Triana DSCOVR DSCOVR (patch) DSCOVR (patch)	DSCOVR	DSCOVR
PSP / SPP	2018-08-12	PSP PSP (patch)	PSP	PSP
SWFO-L1	2024-?	SWFO-L1

Other (selected) non-USA solar-observing spacecraft:

Satellite	Country	Launch Date	Images
			reference	launch covers	other postal items
SOHO	Europe (ESA)-USA (NASA)	1995-12-02	SOHO (early-version) SOHO (early-version) SOHO SOHO SOHO SOHO SOHO (patch)	SOHO	SOHO
Picard	France (CNES)	2010-06-15	Picard Picard	Picard	Picard
Solar Orbiter	Europe (ESA)-USA (NASA)	2020-02-10	Solar Orbiter Solar Orbiter (patch)	Solar Orbiter	Solar Orbiter
ASO-S / Kuafu	ChinaPR	2022-10-08	ASO-S

Back to Un-manned Satellite Philately.