The Microgravity Sciences Mission (MSL-1), STS-83, was the first space shuttle mission devoted largely to combustion science, with over 150 on-board fires planned for the 16-day flight.

The STS-83 mission was cut short due to concerns over performance of one of the three power-generating fuel cells, with the crew returning to earth after only 4 days in space.

NASA re-flew the mission three months later as STS-94, which became the first mission in the history of manned space flight in which the same crew flew together again in space; it was also NASA's fastest turn-around of the shuttle to date.

STS-94 became a phenomenally successful spacelab flight. Greg Linteris the combustion science Payload Specialist on the flights, will share his experiences on the missions.