NASA may need more astronauts for space station, moon missions, report says

NASA astronaut Mark Vande Hei seen during a spacewalk conducted in 2017.
NASA astronaut Mark Vande Hei seen during a spacewalk conducted in 2017. (Image credit: NASA)

NASA may need more astronauts to meet its human spaceflight goals over the coming years, according to a new report from the agency's investigative office.

Currently, NASA only flies astronauts to the International Space Station aboard SpaceX's Crew Dragon capsules and Russia's Soyuz vehicles. But the agency's ambitious Artemis program to return humans to the moon is set to change that, with the program's first crewed mission targeting 2024. That flight is meant to be the first stage in developing a long-term lunar exploration program that supports future human exploration of Mars

As a result, NASA is looking at sending more astronauts off-Earth — perhaps more than the agency can expect to have available, according to a report from the Office of Investigator General released on Tuesday (Jan. 11) that evaluates how NASA manages its astronauts.

"After reaching its peak of nearly 150 astronauts in 2000, the size of the corps has diminished with the end of space shuttle missions in 2011 and now stands at 44, one of the smallest cadres of astronauts in the past 20 years," officials wrote in the report. "As NASA enters a new era of human space flight, including returning to the moon and eventually landing humans on Mars, effective management of its astronaut corps — the people who fly its space flight missions — is critical to the agency’s success."

Related: How to become an astronaut

While flying on missions to space missions is perhaps the highlight of a NASA astronaut's duties, NASA also assigns astronauts roles like capsule communicators who relay information from mission control to space, as well as training new astronauts and speaking with the public about NASA's work.

Right now, NASA has the smallest astronaut corps since the crew slipped below 40 people in the 1970s. The current size of the corps is in part due to a surge in retirements — about 10 a year, according to the report — around 2011 when the agency grounded its fleet of space shuttles and flight opportunities starkly decreased.

The potential shortage is even more complicated because astronauts are not interchangeable, as the report noted. NASA assigns individual astronauts to specific flights based on criteria ranging from flight experience to their training with the specific vehicle to how their specific expertise fits in with the rest of the crew. Those requirements will become more complicated to meet as NASA astronauts fly on more different types of vehicles to more destinations, the report warned.

"With a corps aligned to a single mission, as it is now with the ISS [International Space Station], the Astronaut Office is in a position to quickly reassign astronauts because all 44 have been selected and initially trained for the same mission," officials wrote in the report. "However, as the agency undertakes new missions with new requirements and new vehicles, fewer astronauts will be trained and available for each mission."

The agency uses a formula to guide how many astronauts it will bring into each new class of astronaut candidates. The newest class of 10 was announced in December 2021 and just began the agency's general two-year training program; the class prior, which "graduated" in January 2020 added 11 astronauts to the corps.

NASA's 10 new astronaut candidates, plus two representing the United Arab Emirates who will train alongside them, arrived at NASA's Johnson Space Center on Jan. 10, 2022.  (Image credit: NASA)

After becoming a full-fledged astronaut, training for a space station mission requires an additional 18 to 24 months. The first two astronauts to fly from the most recent graduated class are currently in space, Raja Chari and Kayla Barron. This lengthy training time means that the latest recruits likely won't begin to fly until perhaps late 2025, so the agency needs to think now about its crew requirements for later in the decade.

Artemis missions are expected to require about the same period of specialized training as space station missions, the report noted. But while NASA has selected a group of 18 astronauts from which to pull Artemis crewmembers, it has not assigned any seats yet, nor has the agency developed the training program for its moon missions; the report warned that the agency may be running low on time for that process.

"While the Astronaut Office estimates training for the Artemis 3 and successor missions will require approximately two years, even with the projected delays to Artemis 2 and 3 launches the agency could be overestimating the time available to develop and implement the necessary training framework and regimen across key Artemis systems," the report noted.

Overall, the report conveys concern that NASA's astronaut corps will join the list of constraints on future missions along with factors like budgets, spacesuit supply and rocket manufacturing. "If not addressed," the report states of its astronaut recommendations, "these factors could potentially result in disruptive crew reorganizations, extended training periods, or mission delays."

In addition to flagging concerns about astronaut quantity and training schedules, the report also suggested that the agency beef up its information management system for data including astronaut demographics and skills to help facilitate the assignment process.

For example, as NASA pushes to diversify its representation in space, the agency needs accurate demographic information about its astronauts, the report noted. Similarly, as missions head to planetary surfaces instead of low Earth orbit, tracking which astronauts have backgrounds in geology — currently just four astronauts — will be important, according to the report.

As part of the report procedure, the Office of Inspector General provided a draft of the document to Kathy Lueders, NASA's associate administrator for space operations for comment. Lueders wrote that the agency concurred with all four of the report's recommendations and intends to execute them by November. NASA declined to provide additional comments about the report to

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Meghan Bartels
Senior Writer

Meghan is a senior writer at and has more than five years' experience as a science journalist based in New York City. She joined in July 2018, with previous writing published in outlets including Newsweek and Audubon. Meghan earned an MA in science journalism from New York University and a BA in classics from Georgetown University, and in her free time she enjoys reading and visiting museums. Follow her on Twitter at @meghanbartels.