Tanner performed two spacewalks as a member of the STS-82 crew to service the Hubble Space Telescope (HST) in February, 1997. The STS-82 crew of seven launched aboard Space Shuttle "Discovery" on February 11 and returned to a night landing at Kennedy Space Center on February 21. During the flight the crew completed a total of 5 spacewalks to improve the science capability of the telescope and replace aging support equipment, restoring HST to near perfect working condition. The crew boosted HST's orbit by 8 nautical miles (15 km) before releasing it to once again study the Universe. Tanner's two space walks totaled 14 hours and 01 minutes. The flight orbited the earth 150 times covering 4.1 million miles (6,600,000 km) in 9 days, 23 hours, 37 minutes.