Precourt flew his first space mission as a mission specialist aboard Columbia on STS-55, which launched from Kennedy Space Center, Florida, on April 26, 1993. Nearly 90 experiments were conducted during this German-sponsored Spacelab D-2 mission to investigate life sciences, materials sciences, physics, robotics, astronomy and the Earth and its atmosphere. STS-55 also flew the Shuttle Amateur Radio Experiment (SAREX) making contact with students in 14 schools around the world. After 160 orbits of the earth in 240 flight hours, the 10-day mission concluded with a landing on Runway 22 at Edwards Air Force Base, California, on May 6, 1993.
On his second flight (June 27 to July 7, 1995), Precourt was the pilot on the seven-member crew (up) and eight-member crew (down) of Space Shuttle mission STS-71. This was the first Space Shuttle mission to dock with the Russian Space Station Mir, and involved an exchange of crews. The Atlantis Space Shuttle was modified to carry a docking system compatible with the Russian Mir Space Station. It also carried a Spacehab module in the payload bay in which the crew performed various life sciences experiments and data collections. Mission duration was 235 hours, 23 minutes.
Most recently, he served as crew commander of a seven-member international crew on STS-84 (May 15-24, 1997). This was NASA's sixth Shuttle mission to rendezvous and dock with the Russian Space Station Mir. In completing this 9-day mission, Precourt traveled 3.6 million miles in 144 orbits of the Earth logging a total of 221 hours and 20 minutes in space.
Manned seven crew. Carried German Spacelab-D2. Payloads: Spacelab D-2 with long module, unique support structure (USS), and Reaction Kinetics in Glass Melts (RKGM) getaway special, Shuttle Amateur Radio Experiment (SAREX) II.
Mir Expedition EO-19. Transferred Budarin, Solovyov to Mir, returned Soyuz TM-21 crew to Earth. After undocking from Mir on July 4, Atlantis spent several days on orbit, carrying out medical research work with the Spacelab-Mir module in the cargo bay. Payloads: Shuttle/Mir Mission 1, Spacelab-Mir, IMAX camera, Shuttle Amateur Radio Experiment (SAREX).
Atlantis blasted off on a night launch to Mir, docking with the station on May 17 at 02:33 GMT. Jerry Linenger, who had begun his stay on Mir in mid-January aboard STS-81, would return aboard STS-84. Michael Foale would be left at the station for his stint as the American crew member of Mir. The crew transfered to Mir 466 kg of water, 383 kg of U.S. science equipment, 1,251 kg of Russian equipment and supplies, and 178 kg of miscellaneous material. Returned to Earth aboard Atlantis were 406 kg of U.S. science material, 531 kg of Russian logistics material, 14 kg of ESA material and 171 kg of miscellaneous material. Atlantis undocked from Mir at 01:04 GMT on May 22. After passing up its first landing opportunity due to clouds over the landing site, the Shuttle fired its OMS engines on the deorbit burn at 12:33 GMT on May 24. Atlantis landed at 13:27 GMT at Kennedy Space Center's runway 33.
The final shuttle-Mir mission, STS-91 recovered NASA astronaut Andy Thomas from the Mir station and took Russian space chief and ex-cosmonaut Valeri Ryumin to Mir for an inspection tour of the ageing station. This was the first test of the super lightweight Aluminium-Lithium alloy external tank, designed to increase shuttle payload to the Mir / International Space Station orbit by 4,000 kg. At 22:15 GMT Discovery entered an initial 74 x 324 km x 51.6 deg orbit, with the OMS-2 burn three quarters of an hour later circulising the chase orbit. Discovery docked with the SO module on Mir at 17:00 GMT on June 4. NASA equipment was retrieved from the station, and Discovery undocked at 16:01 GMT on June 8, and landed on Runway 15 at Kennedy Space Center at 18:00 GMT on June 12.