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Gamma-ray Astronomy Satellites & Missions

We present the many satellites which have detected electromagnetic radiation with energy greater than 100 keV by the decade in which the satellite was launched. You will see, as you go through the 1960s, 70s, 80s, and 90s, that the sensitivity increase in the detectors has developed greatly during the over 30 years of gamma-ray astronomy. In addition, our ability to localize the incident gamma-rays has developed enormously -- allowing us to obtain high-quality images of many fascinating celestial objects.

NOTE: We include here only missions which detected non-solar gamma-rays (intentionally or not).

OSO 3
OSO 3
(Credit: NASA)

1960s

The first dedicated gamma-ray astronomy mission was, in fact, the first high-energy astrophysics satellite as well. Explorer-XI was launched in 1961. The instrument package weighed 30 pounds, was 20 inches high and 10 inches in diameter. The experimenters believed that they detected 22 cosmic gamma rays. Their next detector, on Orbiting Solar Observatory -3, may be more accurately described as having proof of the discovery of cosmic gamma radiation, since it found a galactic plane anisotropy of high-energy gammas, much later to be confirmed with SAS-2 and COS-B. However, a totally unexpected but very important contributor to the origins of gamma ray astronomy in the 1960s and 1970s were the Vela satellites. Intended to watch for countries violating an international treaty banning atmospheric testing of nuclear weapons, they instead gave us the first hints at the odd phenomena of gamma-ray bursts.

OSO 6 August 1969 - January 1972
Vela 5A May 1969 - June 1979
Vela 5B May 1969 - June 1979
OSO 5 January 1969 - July 1975
OGO 5 March 1968 - June 1971
OSO 4 October 1967 - December 1971
Cosmos 163 June 1967
ORS 4 April 1967 - June 1968
OSO 3 March 1967 - November 1969
Cosmos 135 December 1966
Luna 12 October 1966
OGO 3 June 1966 - February 1972
Luna 10 March - April 1966
Proton 2 November 1965 - February 1966
ORS 3 July - November 1965
Proton 1 July - October 1965
Cosmos 60 March 1965
OGO 1 September 1964 - November 1971
Ranger 5 October 1962
OSO 1 March 1962 - April 1963
Ranger 3 January 1962
Explorer 11 April - September 1961

COS B
COS B
(Credit: NASA)

1970s

The SAS-2 satellite in 1972 discovered a diffuse gamma-ray background, and the COS-B (1975 - 1982) satellite produced the first detailed map of the sky at gamma-ray wavelengths. A number of pulsars were discovered to also emit pulses at these wavelengths. The gamma-ray sky was found to be dominated by diffuse emission from the galactic plane, which at the highest energies (E > 100 MeV) is the decay of neutral pions generated in the collision of cosmic rays with interstellar gas.

HEAO-3 September 1979 - May 1981
Cosmos 1106 June 1979
Prognoz 7 October 1978 - June 1979
Venera 12 September 1978 - April 1980
Venera 11 September 1978 - February 1980
ISEE-3 August 1978 - 1982
Pioneer Venus May 1978 - October 1992
Prognoz 6 September 1977 - March 1978
HEAO-1 August 1977 - January 1979
SIGNE 3 June 1977 - June 1979
Cosmos 914 May - June 1977
Cosmos 856 September - October 1976
Solrad 11B March - December 1976
Solrad 11A March 1976 - July 1977
Helios 2 January 1976 - 1981
COS-B October 1975 - April 1982
OSO 8 June 1975 - September 1978
Aryabhata April 1975
Mars 5 July 1973 - March 1974
Mars 4 July 1973 - February 1974
SAS 2 November 1972 - June 1973
IMP 7 September 1972 - October 1978
Radsat October 1972 - May 1973
Prognoz 2 June - December 1972
Apollo 16 April 1972
TD-1A March 1972 - 1973
Cosmos 461 December 1971
OSO 7 September 1971 - July 1974
Apollo 15 July - August 1971
IMP 6 March 1971 - September 1972
Vela 6A/B April 1970 - 1979

DMSP
DMSP
(Credit: NASA)

1980s

The decade of the 1980s saw a few missions occur which continued to gather data on gamma-ray burst distributions in the sky, gamma-ray emission from known X-ray sources, and so on. Much of this decade, however, went into the development of new technologies, technologies that would be needed to take gamma-ray astronomy to the next level of sensitivity and understanding.

Granat December 1989 - November 1998
Phobos 2 July 1988 - March 1989
Phobos 1 July - September 1988
DMSP 9 February 1988 - April 1992
DMSP 8 June 1987 - August 1994
Kvant May 1987 - mid 1990's
Ginga February 1987 - November 1991
Prognoz 9 July 1983 - March 1984
Venera 14 November 1981 - March 1983
Venera 13 October 1981 - March 1983
Solar Max February 1980 - December 1989

Impression of CGRO
CGRO
(Credit: NASA)

1990s

With the launch of the Compton Gamma-Ray Observatory (CGRO) in April 1991, the field of gamma-ray astronomy at long last had its flagship. The satellite carried four major experiments which greatly improved the spatial and temporal resolution of gamma-ray observations. The CGRO ceased operation in June 2000, and was de-orbited by NASA. However, scientists are still studying its data to improve our understanding of the high-energy processes in our Universe.

DMSP 15 December 1999 -
DMSP 14 April 1997 -
NEAR February 1996 - February 2001
RXTE December 1995 -
DMSP 13 March 1995 -
Wind November 1994 -
DMSP 12 August 1994 -
Mars Observer September 1992 - August 1993
EURECA August 1992 - July 1993
SROSS 3 May - July 1992
DMSP 11 November 1991 -
CGRO April 1991 - June 2000
DMSP 10 December 1990 - September 1994
Ulysses October 1990 -
Gamma July 1990 - 1992
LEGRI April 1997 - February 2002

INTEGRAL
INTEGRAL
(Credit: NASA)

2000s

The initial years of the 21st century see the a new fleet of gamma-ray instruments and observatories. With the result from Beppo-SAX and other observatories that gamma-ray bursts are at extra-galactic distances, Swift was poised to determine the nature of GRBs by performing rapid follow-up observations in X-ray and UV wavelengths. GLAST, set for launch in mid-decade, promises to be the premier gamma-ray observatory into the next decade.

HETE-2 October 2000 -
INTEGRAL October 2002 -
Swift November 2004 -
GLAST June 2008 -

If words seem to be missing from the articles, please read this.

Imagine the Universe! is a service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA's Goddard Space Flight Center.

The Imagine Team
Project Leader: Dr. Barbara Mattson
Curator: Meredith Gibb
Responsible NASA Official: Phil Newman
All material on this site has been created and updated between 1997-2014.
This page last updated: Wednesday, 18-Jun-2008 14:55:37 EDT