NASA Astronaut Corps
NASA unit selecting and training astronauts for U.S. and international missions.
The NASA Astronaut Corps is the branch of the U.S. space agency responsible for choosing, training, and supplying crew members for American and international space missions. Its home is the Johnson Space Center in Houston, Texas.
The agency picked its first American astronaut candidates in 1959 for Project Mercury, which aimed to send people into orbit in single-person capsules. The military was asked to supply names of test pilots who met certain standards. After a tough selection process, NASA introduced the "Mercury Seven" as its first astronauts. Since then, 22 more groups have been chosen, expanding the corps to include civilians, scientists, doctors, engineers, and teachers. By the 2009 class, 61% of all selected astronauts had come from military service. Candidates come from a wide range of backgrounds, and out of thousands of applicants, only a few are picked for the demanding training program. Including the original seven, 339 candidates have been selected so far.
The corps is headquartered at the Johnson Space Center, though members may work elsewhere depending on mission needs—for instance, training at Star City, Russia, for Soyuz flights. The Chief of the Astronaut Office is the top leadership role for active astronauts. This person heads the corps and advises the NASA Administrator on training and operations. Deke Slayton became the first Chief Astronaut in 1962; the current one is Scott Tingle.
New civilian astronauts are paid according to the federal General Schedule, from grades GS-11 to GS-14, based on their education and experience. They can be promoted up to GS-15. As of 2023, those at the Johnson Space Center earn between $79,766 (GS-11 step 1) and $183,500 (GS-15 step 6 and above). Starting with the 2024 candidate class, astronaut candidates will be moved to an "Administratively Determined" pay scale instead. Military astronauts are assigned to the Johnson Space Center but stay on active duty for pay, benefits, and leave.
There is no age limit for the corps. Candidates have ranged from 26 to 46 years old, with an average age of 34. They must be U.S. citizens. Qualifications fall into three areas: education, work experience, and medical. Candidates need a master’s degree in engineering, biological science, physical science, or mathematics from an accredited school, plus two to three years of related professional experience (or graduat
- Founded
- 1959
- Headquarters
- Johnson Space Center, Houston, Texas
- First Astronauts
- Mercury Seven (1959)
- Total Selected
- 339 candidates as of 2009
- Active Astronauts (2026)
- 34
- Management Astronauts (2026)
- 10
- Military Background
- 61% of astronauts selected by NASA have come from military service
Lore & Background
As of August 2026, the corps has 34 active astronauts (15 women, 19 men) and 10 management astronauts. The highest number of active astronauts was 149 in 2000. Astronaut candidates (ASCANs) undergo training at Johnson Space Center. Only three candidates have resigned before completing training: Brian O'Leary and Anthony Llewellyn (1967 group) and Robb Kulin (2017 group). One candidate, Stephen Thorne, died in an airplane accident. Three astronauts were killed in the Apollo 1 ground test accident, fourteen in Space Shuttle missions STS-51-L and STS-107, and others in T-38 crashes and other incidents. Two members were involuntarily dismissed: Lisa Nowak and William Oefelein.
Reader's Guide
The NASA Astronaut Corps has been central to U.S. human spaceflight since 1959, selecting and training astronauts for missions from Project Mercury to the International Space Station. Its evolution from exclusively military test pilots to a diverse pool including civilians, scientists, and teachers reflects broader societal changes. The corps has suffered tragic losses—three in Apollo 1, fourteen in shuttle accidents, and several in training—but has continued to produce astronauts who have orbited Earth, walked on the Moon, and lived on the ISS. The corps' organization, with a Chief Astronaut advising the NASA Administrator, ensures consistent training and operations. Its selection process, requiring advanced degrees and rigorous medical standards, maintains a highly qualified workforce. The corps' legacy includes pioneering space exploration and inspiring generations, while its current size (34 active astronauts in 2026) indicates a shift toward smaller, more specialized crews for future missions.
Did You Know?
- The first American astronaut candidates were selected in 1959 for Project Mercury, resulting in the 'Mercury Seven.'
- As of the 2009 Astronaut Class, 61% of astronauts selected by NASA have come from military service.
- Three astronaut candidates have resigned before completing training: Brian O'Leary, Anthony Llewellyn, and Robb Kulin.
- The highest number of active astronauts at one time was 149 in 2000.
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