Fermi Gamma-ray Space Telescope

Observatory Status

Fermi Observations for MW 735

Mission week 735 starts with a continuation of the symmetric +/- 50 deg. rocking profile from the previous week. At 00:51 on day of year 181 (2022-06-30) there is a 10 minute freeze observation during which an updated symmetric +/- 50 deg. profile is loaded. This profile continues for the rest of the week. Note that positive rock angles are south, and negative angles are north.

» More Timeline Info

The Fermi Gamma-ray Space Telescope was launched from Kennedy Space Center on June 11, 2008. The observatory checkout phase completed on August 11, 2008, after which Fermi began science operations. A general Fermi mission overview and related media resources can be found here.

The Fermi spacecraft supports two gamma-ray instruments; the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM). The LAT is a wide-field gamma-ray telescope (20 MeV - 300 GeV). For more details on the instrument hardware, see the home pages of the GBM and the LAT. Some information about the LAT's Anti-Coincidence Detector (ACD) is available here.

From the start of science operations in August 2008 the adopted default observation mode for the LAT was a survey mode, continuously scanning the sky to provide all-sky coverage every two orbits. Other survey strategies` and inertial pointed Target of Opportunity (ToO) observations motivated by the scientific community were also employed.

On March 16 2018, the spacecraft suffered a mechanical failure and can no longer move one of its solar arrays. As a result of that anomaly, a new sky survey strategy has been implemented. Alternative survey strategies and pointed ToO observations will not be done for the forseeable future. Please see this page for further details of the new sky survey strategy.

For the results of LAT and GBM observations, see:

More information on Fermi Observations: