Payload Specialist

A payload specialist (PS) is an individual selected and trained by commercial or research organizations for flights of a specific payload on a NASA Space Shuttle mission. People assigned as payload specialists included individuals selected by the research community, a company or consortium flying a commercial payload aboard the spacecraft, and non-NASA astronauts designated by international partners.

The term refers to both the individual and to the position on the Shuttle crew.

Payload specialists were generally selected for a single specific mission and were chosen outside the standard NASA astronaut selection process. They were not required to be United States citizens, but had to be approved by NASA and undergo rigorous training. In contrast, a Space Shuttle mission specialist was selected as a NASA astronaut candidate first and then assigned to a mission.

Payload specialists on early missions were technical experts to accompany specific payloads such as a commercial or scientific satellite. On Spacelab and other missions with science components, payload specialists were scientists with expertise in specific experiments. The term also applied to representatives from partner nations who were given the opportunity of a first flight on board of the Space Shuttle (such as Saudi Arabia and Mexico), and to Congressmen and the Teacher in Space program.

Other positions on board Space Shuttle were mission commander, pilot, and mission specialist. Unlike other Shuttle crew, international or scientific payload specialists were generally assigned a back-up who trained alongside the primary payload specialist and would replace him/her in the event of illness or other disability.

Payload specialists were flown from 1983 (STS-9) to 2003 (STS-107). The last flown payload specialist was the first Israeli astronaut, Ilan Ramon, who was killed in the Columbia disaster on mission STS-107 with the rest of the crew.

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