The STS-82 mission was the second in a series of planned servicing missions to the orbiting Hubble Space Telescope ("HST"), which had been placed in orbit on 24 April 1990 by Discovery during STS-31. The first servicing mission was done by Space Shuttle Endeavour on STS-61. Work performed by Discovery's crew significantly upgraded the scientific capabilities of the HST and helped to keep the telescope functioning smoothly until the next scheduled servicing missions, which were STS-103 in 1999 and STS-109 in 2002.[1]

On the third day of the mission, Discovery's seven-member crew conducted the first of four spacewalks (also called Extra-vehicular Activities or "EVAs") to remove two older instruments and install two new astronomy instruments, as well as perform other servicing tasks. The two older instruments being replaced were the Goddard High Resolution Spectrograph and the Faint Object Spectrograph, exchanged for the Space Telescope Imaging Spectrograph (STIS) and the Near Infrared Camera and Multi-Object Spectrometer (NICMOS), respectively.