Two of the mission’s four-member crew will venture out of their Crew Dragon capsule in Earth’s orbit for a tethered spacewalk, marking the first major test of SpaceX’s new spacesuits.

The capsule lacks an airlock and will completely depressurize for the spacewalk, requiring all four crew members to rely on their suits for survival.

The mission, scheduled for launch at 3:38 a.m. ET (0738 GMT) on Aug. 27 from NASA’s Kennedy Space Center in Florida, is expected to last six days, with the spacewalk planned for the third day.

Here’s a look at the profile of the astronauts:

Jared Isaacman

Isaacman, the billionaire CEO of payments processing firm Shift4 Payments and a seasoned pilot, is commanding the Polaris Dawn mission and will be one of the two members — along with Sarah Gillis — performing the spacewalk outside the capsule.

He is bankrolling the mission under his Polaris program, although he declined to disclose the total expenditure, estimated to be in the hundreds of millions of dollars.

The mission will be his second foray into space, following his leadership of the first all-civilian Inspiration4 mission to orbit Earth in 2021, organized and primarily funded by him in partnership with SpaceX.

After Polaris Dawn, Isaacman has two more missions planned under the Polaris program – another flight on Crew Dragon followed by a flight on Starship, SpaceX’s next-generation rocket under development. He has not announced crewmates or dates for those flights.

Sarah Gillis

Gillis has trained astronauts and now is becoming one herself. She graduated from the University of Colorado Boulder with an engineering degree, began as an intern at SpaceX in 2015 and is now the company’s senior space operations engineer. Her responsibilities include training astronauts on safety and flight operations.

Gillis, Polaris Dawn’s mission specialist, has trained NASA astronauts for several operations, including International Space Stations Dragon missions Demo-2 and Crew-1 and Inspiration4 mission in 2021.

Scott Poteet

Poteet, the mission pilot for Polaris Dawn, had a 20-year career in the U.S. Air Force, with more than 3,200 flight hours in various aircraft including the F-16 fighter jet.

Poteet’s involvement in the private space sector began when he served as Mission Director for the Inspiration4 mission.

Poteet was the vice president of strategy at Isaacman’s Shift4 company until 2022, according to his LinkedIn. Until 2020, he was a business development director at defense contractor Draken International, founded by Isaacman, before he sold a majority stake in the firm to Blackstone in 2019.

Anna Menon

Menon is a mission specialist and medical officer for the program and is a lead space operations engineer at SpaceX, where she manages the development of crew operations, ensuring that procedures and protocols are in place for astronauts during their missions.

The former NASA biomedical flight controller will be responsible for the crew’s health and well-being during the Polaris Dawn mission, monitoring their physiological responses and providing medical care if needed.

She holds a Master of Science degree in biomedical engineering from Duke University.

Menon is married to Anil Menon, a former SpaceX flight surgeon who is currently a NASA astronaut-in-training.

—Akash Sriram, Reuters