The Fermi Gamma-ray Space Telescope is a satellite observatory for photon energies from 8 keV to over 300 GeV. Launched on 11 June, 2008, it circles Earth every 96 minutes in a 26° inclination orbit at an altitude of 535 km.
Fermi carries two scientific instruments, pictured at left: the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM). Some important performance characteristics are shown below.
The observatory typically operates in a survey mode, allowing a scan of the entire gamma-ray sky every two orbits.
More about the instruments can be found at NASA's Fermi Web site, http://www.nasa.gov/mission_pages/GLAST/spacecraft/index.html
More about Fermi observation modes can be found at the Fermi Science Support Center site, http://fermi.gsfc.nasa.gov/ssc/observations/types/
|Large Area Telescope||Gamma-ray Burst Monitor|
|Pair-production instrument||NaI and BGO scintillators|
|Energy range: 20 MeV to > 300 GeV||Energy range: 8 keV to 40 MeV|
|Field of view: 2.4 steradians||Field of view: 9.5 steradians|
|Single photon angular resolution: <1° at 1 GeV||Gamma-ray burst localization: typical 3°|
|Timing accuracy: 1 microsecond||Timing accuracy: 2 microseconds|
|LAT Web site:
|GBM Web site:
NASA's Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy and with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.