Three NASA astronauts, Matthew Dominick, Michael Barratt, and Jeanette Epps, and one Roscosmos cosmonaut, Alexander Grebenkin, were assigned to the mission.

The crew outfitted the Crew-8 capsule to accommodate two extra astronauts if an emergency occurred prior to Crew-9 docking on 29 September 2024.

[10] The first launch attempt, the day prior was scrubbed at T−03:25:38 due to elevated winds in offshore areas of the flight path.

[18] The Boeing Crew Flight Test mission docked with the ISS on June 6, 2024 after experiencing anomalies with its thrusters.

The return of Crew-8 was delayed for several additional weeks due to poor weather conditions in the splashdown zones surrounding Florida caused by Hurricane Milton and several other storms.

After a completing 3,760 orbits and traveling nearly 100 million miles (160 million kilometers), Endeavour began its entry back into the Earth's atmosphere and splashed down in the Gulf of Mexico, near Pensacola, Florida on 25 October 2024 at 07:29:02 UTC (3:29:02 am EDT, local time at the landing site).

After that check-up, NASA flew all of the crew members to the Ascension Sacred Heart Pensacola by helicopter for additional evaluation.