Against a popcorn-clouded blue sky, Space Shuttle Discovery, atop the mobile launcher platform and crawler transporter, ends its five-hour trek from the Vehicle Assembly Building as it crosses through the gate at Launch Pad 39B. Earlier in the week, the Shuttle was rolled back to the VAB from the pad to repair hail damage on the external tank's foam insulation. The 4.2-mile trek takes about five hours at the 1-mph speed of the crawler. Mission STS-96, the 94th launch in the Space Shuttle Program, is scheduled for liftoff May 27 at 6:48 a.m. EDT STS-96 is a logistics and resupply mission for the International Space Station, carrying such payloads as a Russian crane, the Strela; a U.S.-built crane; the Spacehab Oceaneering Space System Box (SHOSS), a logistics items carrier; and STARSHINE, a student-shared experiment