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A payload specialist (PS) was 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.


NASA's payload specialist program has been criticized for giving limited Shuttle flight positions to civilian aerospace engineers such as Greg Jarvis (killed aboard Challenger), politicians such as US Representative Bill Nelson, and other civilians such as Teacher in Space Christa McAuliffe (also killed aboard Challenger). Even the rationale for the Shuttle flight of former Mercury astronaut and US Senator John Glenn was questioned.[1] The concern was that these people had replaced career astronauts in very limited flight opportunities, and some may have flown without understanding the level of danger.

A 1986 post-Challenger article in The Washington Post reviewed the issue, reporting that as far back as 1982, NASA was concerned with finding reasonable justifications for flying civilians on the Shuttle as was directed by the Reagan administration. The article says that "A review of records and interviews with past and present NASA and government officials shows the civilian program's controversial background, with different groups pushing for different approaches."[2] The article concludes with:

Author Tom Wolfe, who chronicled the early days of the space program in The Right Stuff, wrote after the Challenger explosion that support for the citizen program, and therefore McAuliffe's place aboard the ill-fated shuttle, was part of an insiders' battle. NASA civilians, pitting themselves against the professional astronauts, used the program for the "dismantling of Astropower," which Wolfe described as "the political grip the original breed of fighter-pilot test-pilot astronauts had on NASA."[2]

List of all payload specialistsEdit

Until ChallengerEdit

Payload specialist Mission Notes
Ulf Merbold STS-9 first payload specialists, Ulf Merbold was the first international (German) payload specialist
Byron K. Lichtenberg
Charles D. Walker STS-41-D first non government-affiliated payload specialist
Marc Garneau STS-41-G Garneau was the first Canadian in space, Scully-Power the first Australian
Paul Scully-Power
Gary Payton STS-51-C first military payload specialist
Charles D. Walker STS-51-D
Jake Garn then-U.S. Senator, first U.S. legislative branch payload specialist
Lodewijk van den Berg STS-51-B
Taylor Wang
Patrick Baudry STS-51-G two international payload specialists
Sultan bin Salman Al Saud
Loren Acton STS-51-F
John-David F. Bartoe
William A. Pailes STS-51-J
Reinhard Furrer STS-61-A three international payload specialists, most payload specialists on a single flight
Ernst Messerschmid
Wubbo Ockels
Rodolfo Neri Vela STS-61-B first Mexican in space
Charles D. Walker Walker's third and final spaceflight
Robert J. Cenker STS-61-C
Bill Nelson then-U.S. Representative, second and final U.S. legislative branch payload specialist
Gregory Jarvis STS-51-L killed in the Challenger disaster
Christa McAuliffe

Post-Challenger to ColumbiaEdit

Payload specialist Mission Notes
Samuel T. Durrance STS-35 first post-Challenger payload specialists
Ronald A. Parise
F. Drew Gaffney STS-40
Millie Hughes-Fulford
Thomas J. Hennen STS-44
Roberta Bondar STS-42
Ulf Merbold
Byron K. Lichtenberg STS-45
Dirk Frimout first Belgian in space
Lawrence J. DeLucas STS-50
Eugene H. Trinh
Franco Malerba STS-46 first Italian in space
Mamoru Mohri STS-47 first Japanese astronaut on board Space Shuttle
Steve MacLean STS-52
Ulrich Walter STS-55
Hans Schlegel
Martin J. Fettman STS-58
Chiaki Mukai STS-65
Samuel T. Durrance STS-67
Ronald A. Parise
Frederick W. Leslie STS-73
Albert Sacco
Umberto Guidoni STS-75
Jean-Jacques Favier STS-78
Robert Thirsk
Roger K. Crouch STS-83
Gregory T. Linteris
Roger K. Crouch STS-94 mission reflight
Gregory T. Linteris
Bjarni Tryggvason STS-85
Leonid Kadeniuk STS-87 Ukrainian payload specialist
Jay C. Buckey STS-90 final Spacelab mission
James A. Pawelczyk
Chiaki Mukai STS-95
John Glenn final American payload specialist
Ilan Ramon STS-107 first Israeli in space, final payload specialist, killed in the Columbia disaster

Alternate and back-up (not flown) payload specialistsEdit

Other statisticsEdit

Multiple flightsEdit

Flights Payload specialist
3 Charles Walker
2 Ulf Merbold, Byron K. Lichtenberg, Samuel T. Durrance, Ronald A. Parise, Chiaki Mukai, Roger Crouch, Greg Linteris
No. of payload specialists flights Country
36   United States
6   Germany
5   Canada
3   Japan
2   France
2   Italy
1   Saudi Arabia
1   The Netherlands
1   Mexico
1   Belgium
1   Ukraine
1   Israel
Total 60 payload specialist flight opportunities

Payload specialists who trained later as mission specialistsEdit

All were international astronauts.

See alsoEdit


  1. ^ Oberg, James. "NASA hypes "Glenn Mission" Science". Retrieved 4 March 2017.
  2. ^ a b Pincus, Walter. "NASA's Push to Put Citizen in Space Overtook Fully 'Operational' Shuttle". The Washington Post. Retrieved 4 March 2017.
  3. ^ Ramsay, Janis (21 February 2015). "Barrie astronaut continues to keep eye on skies". Barrie Advance. Retrieved 10 January 2019.

External linksEdit