The commissioning and first light of the Fermi Large Area Telescope

The Fermi Gamma-ray Space Telescope (FGST) is a new generation high-energy gamma-ray observatory designed to explore the sky with unprecedented sensitivity and resolution. Successfully launched from the Cape Canaveral Air Force Station 11 on June 11, 2008, Fermi entered the routine science data taking phase—which will continue over the next 5–10 years—after a commissioning period of two months. aper presents the highlights from the initial on-orbit verification of the Large Area Telescope, the main instrument onboard Fermi.