Workers attach a cable from the hoist to the GLAST spacecraft to lift it into the mobile service tower.

At pad 17-B at Cape Canaveral Air Force Station, workers attach a cable from the hoist to the GLAST spacecraft to lift it into the mobile service tower. GLAST is a powerful space observatory that will explore the Universe's ultimate frontier, where nature harnesses forces and energies far beyond anything possible on Earth; probe some of science's deepest questions, such as what our Universe is made of, and search for new laws of physics; explain how black holes accelerate jets of material to nearly light speed; and help crack the mystery of stupendously powerful explosions known as gamma-ray bursts. The launch date is targeted no earlier than June 3. Photo credit: NASA/Kim Shiflett