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).
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.
All Gamma-ray missions active during the 1960s
The OSO-1 satellite under construction (Credit: NASA)
- Luna Series
- January 1959 - August 1976
- Explorer 11
- April 1961 - November 1961
- Ranger Program
- August 1961 - March 1965
- OSO Series
- March 1962 - October 1978
- Cosmos Series
- March 1962 - Present
- OGO Series
- September 1964 - March 1972
- ORS Series
- September 1964 - March 1972
- Proton Series
- July 1965 - July 1969
- Vela 5A/B and 6A/B
- May 1969 - June 1979
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.
All Gamma-ray missions active during the 1970s
The COS-B satellite (Credit: ESA)
- Solrad Series
- June 1960 - July 1977
- Mars Program
- October 1960 - March 1974
- Venera Program
- February 1961 - July 1984
- OSO Series
- March 1962 - October 1978
- Cosmos Series
- March 1962 - Present
- IMP Series
- November 1963 - October 2008
- Vela 5A/B and 6A/B
- May 1969 - June 1979
- SAS Series
- December 1970 - April 1979
- Apollo 15 and 16
- August 1971 - January 1973
- TD-1A
- March 1972 - May 1974
- Prognoz Series
- April 1972 - January 1994
- Radsat
- October 1972 - April 1974
- Aryabhata
- April 1975
- COS-B
- October 1975 - April 1982
- Helios 2
- January 1976 - December 1979
- SIGNE 3
- June 1977 - June 1979
- HEAO
- August 1977 - May 1981
- Pioneer Venus
- May 1978 - October 1992
- ISEE-3
- August 1978 - May 1997
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.
All Gamma-ray missions active during the 1980s
An artist's conception of the DMSP Block 5-2 satellites, which includes DSMP-8, DSMP-9, DSMP-10, DSMP-11, DSMP-12, DSMP-13, and DSMP-14. (Credit: USAF)
- Venera Program
- February 1961 - July 1984
- DMSP
- August 1962 - Present
- Prognoz Series
- April 1972 - January 1994
- Solar Max
- February 1980 - December 1989
- Ginga
- February 1987 - November 1991
- Kvant-1
- April 1987 - March 2001
- Phobos
- July 1988 - March 1989
- Granat
- December 1989 - November 1998
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.
All Gamma-ray missions active during the 1990s
An artist's conception of CGRO. (Credit: NASA)
- DMSP
- August 1962 - Present
- SROSS
- March 1987 - July 2001
- Gamma
- July 1990 - February 1992
- Ulysses
- October 1990 - June 2009
- CGRO
- April 1991 - June 2000
- EURECA
- July 1992 - July 1993
- Mars Observer
- September 1992 - August 1993
- Wind
- November 1994 - Present
- RXTE
- December 1995 - January 2012
- NEAR
- February 1996 - February 2001
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. Fermi, launched in 2008, promises to be the premier gamma-ray observatory into the next decade.
All Gamma-ray missions active during the 2000s
An artist's conception of INTEGRAL. (Credit: ESA. Illustration by D. Ducros)
- HETE-2
- October 2000 - March 2007
- INTEGRAL
- October 2002 - Present
- Swift
- November 2004 - Present
- Fermi (GLAST)
- June 2008 - Present