Updated 11:15 p.m. Eastern after post-splashdown briefing.

WASHINGTON — A SpaceX Crew Dragon spacecraft splashed down off the Florida coast March 11, returning four people from the International Space Station after more than five months in space.

The Crew Dragon spacecraft Endurance splashed down at the primary landing location west of Tampa, Florida, at 9:02 p.m. Eastern. The splashdown took place nearly 19 hours after the spacecraft undocked from the station.

The splashdown marked the end of the 157-day Crew-5 mission that started with an Oct. 5 launch on a Falcon 9. NASA astronaut Nicole Mann commanded the mission, with fellow NASA astronaut Josh Cassada serving as pilot. JAXA astronaut Koichi Wakata and Roscosmos cosmonaut Anna Kikina were mission specialists on Crew-5.

Endruance departed the station eight days after the arrival of another Crew Dragon, Endeavour, on the Crew-6 mission. It delivered to the station NASA astronauts Stephen Bowen and Woody Hoburg, Emirati astronaut Sultan Alneyadi and Roscosmos cosmonaut Andrey Fedyaev. They will remain on the station for about six months, when they are relieved by the Crew-7 mission, which will also use the Endurance spacecraft.

SpaceX will conduct two commercial Crew Dragon missions before Crew-7. The Ax-2 mission for Axiom Space is tentatively scheduled for May, going to the ISS for about 10 days. It will feature former NASA astronaut Peggy Whitson as commander and John Shoffner, a customer, as pilot along with Saudi astronauts Rayyanah Barnawi and Ali Alqarni.

Polaris Dawn, a Crew Dragon mission that is part of billionaire Jared Isaacman’s Polaris Program of private astronaut missions, is expected to launch in the summer, Isaacman said Feb. 23. Isaacman will command the mission with Scott “Kidd” Poteet as pilot and SpaceX employees Sarah Gillis and Anna Menon as mission specialists. The five-day mission will not dock with the ISS but instead conduct other tasks, including the first spacewalk from a Crew Dragon.

Upcoming missions

NASA and SpaceX will now turn their attention to the next Dragon cargo mission, SpX-27. That mission, carrying more than 2,700 kilograms of cargo, is scheduled to launch March 14 at 8:30 p.m. Eastern from the Kennedy Space Center.

The next crewed mission to the station is scheduled to be the first crewed test flight of Boeing’s CST-100 Starliner vehicle, with two NASA astronauts on board. At a post-splashdown briefing, Steve Stich, NASA commercial crew program manager, said that mission, the Crew Flight Test (CFT), was scheduled for no earlier than the end of April.

“We really need to step back here in March and take a look at where we’re at and then determine what the next steps are,” he said, noting work was ongoing to complete certification work and final software testing.

The uncrewed Soyuz MS-22 spacecraft is scheduled to undock from the station March 28. That spacecraft, which brought two Russian cosmonauts and one American astronaut to the station in September, suffered a damaged radiator in December that caused it to lose coolant. Roscosmos launched a new, uncrewed Soyuz spacecraft, Soyuz MS-23, in February to replace Soyuz MS-22.

Joel Montalbano, NASA ISS program manager, said at the briefing that while the damaged radiator does not return to Earth, controllers will collect data on the temperature and humidity conditions inside the capsule during its return to Earth.

He said that Russian engineers are investigating the possibility that it, along with a Progress cargo spacecraft that suffered a similar loss of coolant in February, had a manufacturing defect. “Did something change in the production of these vehicles?” he said, calling such a review “exactly what we would do on our side.”

He added NASA still believed that Soyuz MS-23 could safely return crew home from the station in September, according to current station manifests. “We’re confident in that. Confidence is good, but we’re always looking.”

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...