Byron Kurt Lichtenberg, Sc. D. (born February 19, 1948) is an American engineer and fighter pilot who flew aboard two NASA Space Shuttle missions as a Payload Specialist. In 1983, he and Ulf Merbold became the first Payload Specialists to fly on the shuttle.

Charles David "Charlie" Walker (born August 29, 1948) is an American engineer who flew on three Space Shuttle missions in 1984 and 1985 as a Payload Specialist for the McDonnell Douglas Corporation. He is the first non-government individual to fly in space.

Paul Desmond Scully-Power, AM, FRAeS (born May 28, 1944) is an Australian-American oceanographer, technology expert and business executive. In 1984, while a civilian employee of the United States Naval Undersea Warfare Center, he flew aboard NASA Space Shuttle mission STS-41-G as a Payload Specialist. He was the first Australian-born person to journey into space, and the first astronaut with a beard.

Colonel Gary Eugene Payton, USAF, (born June 20, 1948) is an American former astronaut. Payton flew on the STS-51-C mission aboard the Space Shuttle Discovery in January 1985 which launched and returned to land at the Kennedy Space Center, in Florida. STS-51C was the first dedicated Space Shuttle Department of Defense mission. Payton traveled over 1.2 million miles in 48 Earth orbits, and logged more than 73 hours in space.

Edwin Jacob "Jake" Garn (born October 12, 1932) is an American astronaut and politician, a member of the Republican Party, who served as a U.S. Senator representing Utah from 1974 to 1993. Garn became the first sitting member of the United States Congress to fly in space when he flew aboard the Space Shuttle Discovery as a Payload Specialist during NASA mission STS-51-D (April 12–19, 1985).

Lodewijk van den Berg born March 24, 1932) was a Dutch American chemical engineer, specializing in crystal growth, who flew on a 1985 Space Shuttle Challenger mission as a Payload Specialist.

Loren Wilber Acton (born March 7, 1936) is an American physicist who flew on Space Shuttle mission STS-51-F as a Payload Specialist for the Lockheed Palo Alto Research Laboratory.

John-David Francis Bartoe (born November 17, 1944 in Abington, Pennsylvania) is an American astrophysicist. He is the Research Manager for the International Space Station (ISS) at NASA's Johnson Space Center. He provides oversight for the Program Manager concerning the research capability, research hardware, and research plans of the ISS. As a civilian employee of the US Navy, he flew aboard Space Shuttle mission STS-51-F as a Payload Specialist.

William Arthur Pailes (Colonel, USAF) (born June 26, 1952) was a USAF astronaut in the Manned Spaceflight Engineer Program during the mid-1980s. He served as a Payload Specialist on STS-51-J Atlantis (October 3–7, 1985).

Clarence William Nelson II (born September 29, 1942) is an American politician serving as the senior United States Senator from Florida, first elected to that seat in 2000. A member of the Democratic Party, he previously served in the Florida House of Representatives from 1972 to 1978 and in the United States House of Representatives from 1979 to 1991. In January 1986, he became the second sitting member of Congress to fly in space when he served as a payload specialist on the Space Shuttle Columbia.

Robert Joseph "Bob" Cenker (born November 5, 1948) is an American aerospace and electrical engineer, aerospace systems consultant, and former astronaut. Cenker worked for 18 years at RCA Astro-Electronics, and its successor company GE Astro Space, on a variety of spacecraft projects. He spent most of his career working on commercial communications satellites, including the Satcom, Spacenet and GStar programs. In January 1986, Cenker was a crew member on the twenty-fourth mission of NASA's Space Shuttle program, the seventh flight of Space Shuttle Columbia, designated as mission STS-61-C. Cenker served as a Payload Specialist, representing RCA Astro-Electronics. This mission was the final flight before the Challenger disaster, which caused the Space Shuttle program to be suspended until 1988, and impacted NASA's Payload Specialist program for even longer. As a result, Cenker's mission was called "The End of Innocence" for the Shuttle program. Following the completion of his Shuttle mission, Cenker returned to work in the commercial aerospace field. Since his flight, he has made numerous public appearances representing NASA and the Shuttle program, in the United States, as well as internationally.

Gregory Bruce Jarvis (August 24, 1944 – January 28, 1986) was an American engineer who died during the destruction of the Space Shuttle Challenger on mission STS-51-L, where he was serving as Payload Specialist for Hughes Aircraft.