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.

History
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 on board STS-107, who was killed in the Columbia disaster with the rest of the crew.

Alternate and back-up (not flown) Payload Specialists
This section needs to be completed Wubbo Ockels, Michael Lampton Robert W. Phillips Robert Thirsk George W. Simon, Diane K. Prinz Ulf Merbold Joseph M. Prahl, Albert Sacco Jean-Jacques Favier David H. Matthiesen, R. Glynn Holt Pedro Duque, Luca Urbani Paul Ronney Paul Ronney Alexander W. Dunlap, Chiaki Mukai
 * STS-9
 * STS-40
 * STS-41-G
 * STS-51-F
 * STS-61-A
 * STS-50
 * STS-65
 * STS-73
 * STS-78
 * STS-83
 * STS-94
 * STS-90

Payload Specialists who trained later as Mission Specialists
All were international astronauts.
 * Marc Garneau - flew on STS-77, STS-97
 * Mamoru Mohri - flew on STS-99
 * Steven MacLean - flew on STS-115
 * Hans Schlegel - flew on STS-122
 * Umberto Guidoni - flew on STS-100
 * Robert Thirsk - flew on Soyuz TMA-15
 * Bjarni Tryggvason - retired in June 2008 without flying again