The Space Shuttle Columbia completes the STS-55 Spacelab D-2 mission 6 May with a landing at NASA's Ames-Dryden Flight Research Facility (later redesignated the Dryden Flight Research Center), Edwards, California, at 7:30 a.m. (PDT). The landing was scheduled for the Kennedy Space Center, Florida, but was diverted to Dryden during the final hours of flight because of unacceptable weather at the Florida facility. The STS-55 mission began with the launch from Kennedy at 7:50 a.m. (PDT), 26 April. Aboard Columbia were commander Steve Nagel; pilot Tom Henricks; mission specialists Jerry Ross, Charles Precourt, and Bernard Harris; and payload specialists Hans Schlegel and Ulrich Walter, both from Germany. During Columbia's flight the NASA space shuttle fleet logged more than one year of combined flight time in space, including the time of all previous orbiters and Columbia on this flight. That mark was reached at 7:01:42 (PDT) on 5 May, and with Columbia's landing the total flight time had reached 365 days, 23 hours, and 28 minutes.