The orbiter Discovery approaches the door of KSC's Vehicle Assembly Building after leaving the Orbiter Processing Facility Bay 2.

The orbiter Discovery approaches the door of KSC's Vehicle Assembly Building after leaving the Orbiter Processing Facility Bay 2. Soon, it will be hoisted upright into a vertical position to be mated with an orange external tank and two white solid rocket boosters. Once mated, the orbiter becomes the Space Shuttle Discovery, slated for launch on STS-91, the ninth and final docking mission with the Russian Space Station Mir. The six-member crew of STS-91 will dock with Mir and pick up Mission Specialist Andrew Thomas, Ph.D., who will have been on Mir about four months, to return him to Earth. STS-91 is scheduled to launch June 2 at about 6:04 p.m. EDT