STS-91

STS-91 was the final Space Shuttle mission to the Mir space station. It was flown by Space Shuttle Discovery, and launched from Kennedy Space Center, Florida, on 2 June 1998.

Crew

Mission highlights

STS-91 marked the final Shuttle/Mir Docking Mission. This Phase 1 Program was a precursor to the International Space Station maintaining a continuous American presence in space and developing the procedures and hardware required for an international partnership in space.

The mission was the first to use the super lightweight external tank (SLWT) which was the same size, at 154 feet (47 m) long and 27 feet (8.2 m) in diameter, as the external tank used on previous launches, but 7,500 pounds (3,400 kg) lighter. The tank was made of an aluminum lithium alloy and the tank's structural design had also been improved making it 30 percent stronger and 5 percent less dense. The walls of the redesigned hydrogen tank were machined in an orthogonal waffle-like pattern, providing more strength and stability than the previous design. These improvements would later provide additional payload capacity to the International Space Station.