Gamma (satellite)

Infobox Space telescope
name = Gamma


caption =
organization = RKA
major_contractors =
alt_names =
nssdc_id =
location = Earth orbit
orbit_type =
height = 375 km
period =
velocity =
accel_gravity =
launch_date = 11 July 1990
launch_location =
launch_vehicle =
mission_length = 2 years
deorbit_date =
wavelength = Gamma ray
mass =
website =
style =
diameter =
area =
focal_length =
instrument_1_name = Gamma-1 telescope
instrument_1_characteristics = 50 MeV to 6 GeV
instrument_2_name = Disk-M telescope
instrument_2_characteristics = 20 keV to 5 MeV
instrument_3_name = Pulsar X-2 telescope
instrument_3_characteristics = 2-25 keV
stats_ref = cite web |url=http://heasarc.gsfc.nasa.gov/docs/heasarc/missions/gamma.html |title=The Gamma Satellite |publisher=NASA |accessdate=2008-03-01]

Gamma was a Soviet gamma ray telescope. It was launched on 11 July 1990 into an orbit around Earth with a height of 375 km and an inclination of 51.6 degrees. It lasted for around 2 years. Onboard the mission were three telescopes, all of which could be pointed at the same source. The project was a joint Soviet-French project.

The Gamma-1 telescope was the main telescope. It consisted of 2 scintillation counters and a gas Cerenkov counter. With an effective area of around convert|0.2|m2|sqft, it operated in the energy range of 50 MeV to 6 GeV. At 100 MeV it initially had an angular resolution of 1.5 degrees, with a field of view of 5 degrees and an energy resolution of 12%. A Telezvezda star tracker increased the pointing position accuracy of the Gamma-1 telescope to 2 arcminutes by tracking stars up to an apparent magnitude of 5 within its 6 by 6 degree field of view. However, due to the failure of power to a spark chamber, for most of the mission the resolution was around 10 degrees.

The Disk-M telescope operated in the energy range 20 keV - 5 MeV. It consisted of Sodium iodide scintillation crystals, and had an angular resolution of 25 arcminutes. However, it stopped working shortly after the mission was launched.

Finally, the Pulsar X-2 telescope had 30 arcminute resolution and a 10 deg x 10 deg field of view, and operated in the energy range 2-25 keV.

The telescope was conceived in 1965, as part of a Cloud Space Station. Work on Gamma began in 1972, and it became a joint venture with France in 1974. However, also in 1974, the MKBS/MOK space station complex (as the Cloud Space Station had evolved into by then) was cancelled. A few years later, in February 1976, the Soviet space program was reconfigured, and on 16 February 1979 production of the telescope was authorized. The telescope was originally planned to be launched in 1984, but technical delays pushed the launch back to 1990.cite web | url=http://www.astronautix.com/craft/gamma.htm | title=Gamma | publisher=Astronautix.com | accessdate=2008-03-02]

Observations included studies of the Vela Pulsar, the Galactic Centre, Cygnus X-1, Hercules X-1 and the Crab Nebula. The telescopes also measured the Sun during peak solar activity.

References

External links

* [http://www.daviddarling.info/encyclopedia/G/Gamma_orbiting_telescope.html Gamma on the Internet Encyclopedia of Science]
* [http://www.astronautix.com/craft/gamma.htm Gamma at Astronautix.com]