NASA Explorer Program Missions
Name(s)
Launch Date
Mission
S 45A
May 25, 1961
Ionosphere research, failed to achieve orbit
EPE-A (S 3, Energetic Particle Explorer-A)
August 16, 1961
Energetic particle research
S 55A
August 25, 1961
Micrometeoroid research
EPE-B (Energetic Particle Explorer-B)
October 2, 1962
Energetic particle research
EPE-C (Energetic Particle Explorer-C)
October 27, 1962
Energetic particle research
S 55B
December 16, 1962
Micrometeoroid research
AE-A (Atmosphere Explorer-A)
April 3, 1963
Atmospheric research
IMP-A (IMP 1, Interplanetary Monitoring Platform-A)
November 27, 1963
Magnetospheric research
AD-A (Atmospheric Density-A)
December 19, 1963
Atmospheric density measurements
IE-A (S 48, TOPSI, Ionosphere Explorer-A)
August 25, 1964
Ionosphere research
IMP-B (IMP 2, Interplanetary Monitoring Platform-B)
October 4, 1964
Magnetospheric research
BE-B (S 66, Beacon Explorer-B)
October 10, 1964
Ionospheric and geodetic research
S 55C (Explorer 23)
November 6, 1964
Micrometeoric research
AD-B (Atmospheric Density-B)
November 21, 1964
Atmospheric density measurements
Injun 4 (IE-B, Ionosphere Explorer-B)
November 21, 1964
Ionospheric research
EPE-D (Energetic Particle Explorer-D)
December 21, 1964
High energy particle observations
BE-C (Beacon Explorer-C)
April 29, 1965
Magnetospheric research
IMP-C (IMP 3, Interplanetary Monitoring Platform-C)
May 29, 1965
Magnetospheric research
GEOS 1 (GEOS-A)
November 6, 1965
Geodetic earth monitoring
SOLRAD 8 (SE-A)
November 19, 1965
Solar radiation monitoring (Cover for covert ELINT mission)
DME A
November 29, 1965
Ionospheric research
AE-B (Atmosphere Explorer-B)
May 25, 1966
Atmospheric research
IMP-D (AIMP 1, Anchored IMP 1, Interplanetary Monitoring Platform-D)
July 1, 1966
Magnetospheric research
IMP-F (IMP 4, Interplanetary Monitoring Platform-F)
May 24, 1967
Magnetospheric research
IMP-E (AIMP-E, AIMP 2, Anchored IMP 2, Interplanetary Monitoring Platform-E)
July 19, 1967
Magnetospheric research
GEOS 2 (GEOS-B)
January 11, 1968
Geodetic earth monitoring
Solrad 9 (SE B)
March 5, 1968
Solar radiation monitoring (Cover for covert ELINT mission)
RAE-A (RAE 1, Radio Astronomy Explorer-A)
July 4, 1968
Radio astronomy
AD-C (Atmospheric Density-C)
August 8, 1968
Atmospheric density measurements
Injun 5 (Injun C, IE-C, Ionosphere Explorer-C)
August 8, 1968
Magnetospheric Research
IMP-G (IMP 5, Interplanetary Monitoring Platform-G)
June 21, 1969
Magnetospheric research
SAS-A (Small Astronomy Satellite-A, SAS 1)
December 12, 1970
X-Ray Astronomy
IMP-H (IMP 6, Interplanetary Monitoring Platform-H)
March 13, 1971
Magnetospheric research
Solrad 10 (SE-C, SOLRAD-C)
July 8, 1971
Solar radiation monitoring (Cover for covert ELINT mission)
SSS-A (S-Cubed A)
November 15, 1971
Magnetospheric research
Meteoroid Technology Satellite (MTS, METEC)[2]
August 13, 1972
Micrometeoroids research
IMP-I (IMP 7, Interplanetary Monitoring Platform-I)
September 23, 1972
Magnetospheric research
SAS-B (Small Astronomy Satellite-B, SAS 2)
November 15, 1972
X-Ray Astronomy
RAE-B (RAE 2, Radio Astronomy Explorer-B)
June 10, 1973
Radio astronomy
IMP J (IMP 8, Interplanetary Monitoring Platform-J)
October 26, 1973
Magnetospheric research
AE-C (Atmosphere Explorer-C)
December 16, 1973
Atmospheric research
Hawkeye 1, Injun 6 (IE-D, Ionosphere Explorer-D)
June 3, 1974
Magnetospheric research
SAS-C (Small Astronomy Satellite-C, SAS 3)
May 7, 1975
X-Ray Astronomy
AE-D (Atmosphere Explorer-D)
October 6, 1975
Atmospheric research
AE-E (Atmosphere Explorer-E)
November 20, 1975
Atmospheric research
ISEE 1 & 2 (International Sun-Earth Explorer-A & B)
October 22, 1977
Magnetospheric research
IUE
January 26, 1978
Ultraviolet astronomy
HCMM (AEM-A, Applications Explorer Mission-A, Heat Capacity Mapping Mission)
April 26, 1978
Thermal mapping of the earth
ISEE 3 (International Sun-Earth Explorer-C, ICE)
August 12, 1978
Magnetospheric research
SAGE (AEM-B, Applications Explorer Mission-B, Stratospheric Aerosol and Gas Experiment)
February 18, 1979
Stratospheric aerosol and ozone data
MAGSAT (AEM-C, Applications Explorer Mission-C, Magnetic Field Satellite)
October 30, 1979
Mapped the near surface magnetic field of the Earth
DE 1 (DE-A, Dynamics Explorer-A)
August 3, 1981
Magnetospheric research
DE 2 (DE-B, Dynamics Explorer-B)
August 3, 1981
Magnetospheric research
SME (Solar Mesosphere Explorer)
October 6, 1981
Atmospheric research
AMTPE/CCE (Active Magnetospheric Particle Tracer Explorers/Charge Composition Explorer)
August 16, 1984
Magnetospheric research
COBE
November 18, 1989
Microwave astronomy
EUVE
June 7, 1992
Ultraviolet astronomy
SAMPEX
July 3, 1992
Magnetospheric research
RXTE
December 30, 1995
X-ray astronomy
FAST
August 21, 1996
Auroral phenomena
ACE
August 25, 1997
Solar/interplanetary/interstellar particle research
SNOE
February 26, 1998
Atmospheric research
TRACE
April 2, 1998
Solar observatory
SWAS
December 6, 1998
Submillimeter astronomy
WIRE
March 5, 1999
Infrared astronomy, primary mission failed due to loss of coolant
TERRIERS
May 18, 1999
Atmospheric research, satellite failed shortly after achieving orbit
FUSE
June 23, 1999
Ultraviolet astronomy
IMAGE
March 25, 2000
Magnetospheric research
HETE-2
October 9, 2000
UV, X-Ray, and gamma ray astronomy
WMAP
June 30, 2001
Microwave astronomy
RHESSI
February 5, 2002
X-ray and gamma ray solar flare imaging
CHIPSat
January 13, 2003
Ultraviolet spectroscopy and astronomy
GALEX
April 28, 2003
Ultraviolet astronomy
SWIFT
November 20, 2004
Gamma ray astronomy
THEMIS A
February 17, 2007
Magnetospheric research
THEMIS B (ARTEMIS P1)
February 17, 2007
Magnetospheric research
THEMIS C (ARTEMIS P2)
February 17, 2007
Magnetospheric research
THEMIS D
February 17, 2007
Magnetospheric research
THEMIS E
February 17, 2007
Magnetospheric research
AIM
April 25, 2007
Noctilucent cloud observation
IBEX
October 19, 2008
Mapping the boundary between the Solar System and interstellar space.
WISE
December 14, 2009
Infrared astronomy
NuSTAR
June 13, 2012
High-energy x-ray astronomy
IRIS
June 27, 2013
Solar UV astronomy