Michael Landon Gernhardt is a NASA astronaut and manager of Environmental Physiology Laboratory and principal investigator of the Prebreathe Reduction Program (PRP) at the Lyndon B. Johnson Space Center.

John Mace Grunsfeld is an American physicist and a former NASA astronaut. He is a veteran of five Space Shuttle flights and has served as NASA Chief Scientist. His academic background includes research in high energy astrophysics, cosmic ray physics and the emerging field of exoplanet studies with specific interest in future astronomical instrumentation. After retiring from NASA in 2009, he served as the Deputy Director of the Space Telescope Science Institute in Baltimore, Maryland. In January 2012, he returned to NASA and served as associate administrator of NASA's Science Mission Directorate (SMD). Grunsfeld announced his retirement from NASA in April 2016.

Wendy Barrien Lawrence is a retired United States Navy Captain, former helicopter pilot, an engineer, and a former NASA astronaut. She was the first female graduate of the United States Naval Academy to fly into space and she has also visited the Russian Space Station Mir. She was a mission specialist on STS-114, the first Space Shuttle flight after the Space Shuttle Columbia disaster.

Jerry Michael Linenger is a retired Captain in the United States Navy Medical Corps, and a former NASA astronaut who flew on the Space Shuttle and Space Station Mir.

Richard Michael Linnehan is an American veterinarian and a former NASA astronaut.

Michael López-Alegría is a Spanish-American astronaut; a veteran of three Space Shuttle missions and one International Space Station mission. He is known for having performed ten spacewalks so far in his career, presently holding the second longest all-time EVA duration record and having the third longest spaceflight of any American at the length of 215 days; this time was spent on board the ISS from September 18, 2006 to April 21, 2007.

Scott Edward Parazynski is an American physician and a former NASA astronaut. A veteran of five Space Shuttle flights and seven spacewalks, Parazynski's latest mission was STS-120 in October, 2007 – highlighted by a dramatic, unplanned EVA to repair a live solar array. In May 2016 he was inducted into the US Astronaut Hall of Fame. He retired from NASA in March 2009 to pursue entrepreneurial opportunities in the private sector, and he is currently the CEO of a technology start-up. He is the first person to have both flown in space and summited Mount Everest, the highest point on Earth.

Winston Elliott Scott is a retired United States Navy Captain and former NASA astronaut. He served as a mission specialist on STS-72 in 1996 and STS-87 in 1997 logged a total of 24 days, 14 hours and 34 minutes in space, including three spacewalks totaling 19 hours and 26 minutes. Winston was also a naval pilot and flew helicopters and navy planes.

Steven Lee Smith is an American technology executive and former NASA astronaut, being a veteran of four space flights covering 16 million miles and seven space walks totaling 49 hours and 25 minutes. Smith’s spacewalk time places him in the top ten on the all-time American and World spacewalk duration lists.

Joseph Richard "Joe" Tanner is an American instructor at the University of Colorado Boulder, mechanical engineer, a former naval officer and aviator, and a former NASA astronaut. He was born in Danville, Illinois. He is unusual among astronauts as he did not have a background in flight test nor did he earn any advanced academic degrees. Typically those who did not do military flight test have an M.D. or Ph.D., if not a master's, whereas Tanner's path to becoming an astronaut followed operational military flying and then into NASA for operational jet training before being selected into the NASA Astronaut Corps in 1992, following an unsuccessful application in 1987.

Andrew "Andy" Sydney Withiel Thomas, AO is an Australian-born American aerospace engineer and a NASA astronaut. He became a U.S. citizen in December 1986, hoping to gain entry to NASA's astronaut program. He is married to fellow NASA astronaut Shannon Walker.

Mary Ellen Weber is an American executive, scientist, aviator, speaker, and a former NASA astronaut.