NASA Insignia
Imagine the Universe!

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).


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

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


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
March 1972 - May 1974
Prognoz Series
April 1972 - January 1994
October 1972 - April 1974
April 1975
October 1975 - April 1982
Helios 2
January 1976 - December 1979
June 1977 - June 1979
August 1977 - May 1981
Pioneer Venus
May 1978 - October 1992
August 1978 - May 1997


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

Artist concept of a DMSP satellite in orbit

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
August 1962 - Present
Prognoz Series
April 1972 - January 1994
Solar Max
February 1980 - December 1989
February 1987 - November 1991
April 1987 - March 2001
July 1988 - March 1989
December 1989 - November 1998


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

Artist concept of the CGRO satellite

An artist's conception of CGRO. (Credit: NASA)

August 1962 - Present
March 1987 - July 2001
July 1990 - February 1992
October 1990 - June 2009
April 1991 - June 2000
July 1992 - July 1993
Mars Observer
September 1992 - August 1993
November 1994 - Present
December 1995 - January 2012
February 1996 - February 2001


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

Artist concept of INTEGRAL

An artist's conception of INTEGRAL. (Credit: ESA. Illustration by D. Ducros)

October 2000 - March 2007
October 2002 - Present
November 2004 - Present
Fermi (GLAST)
June 2008 - Present