Crew-2 astronauts
The four Crew-2 astronauts will depart the space station Nov. 7, four days before their replacements on the Crew-3 mission arrive. Credit: NASA

WASHINGTON — The four Crew-2 astronauts currently on the International Space Station will return to Earth ahead of the delayed launch of their replacements, NASA announced late Nov. 5.

NASA said that the Crew Dragon spacecraft Endeavour will undock from the station at 1:05 p.m. Eastern Nov. 7. The spacecraft will splash down off the Florida coast at 7:14 a.m. Eastern Nov. 8.

The spacecraft will return to Earth the four members of the Crew-2 mission to the station: NASA astronauts Shane Kimbrough and Megan McArthur, ESA astronaut Thomas Pesquet and JAXA astronaut Aki Hoshide. Under the current schedule, the four will splash down after spending 199 days in space.

NASA elected to bring Crew-2 home before the launch of another Crew Dragon spacecraft, Endurance, on the Crew-3 mission. That launch, previously scheduled for Oct. 31, was postponed first to Nov. 3 by poor weather in abort landing zones in the Atlantic, and then to no earlier than Nov. 6 because of a “minor medical issue” with one of the four astronauts. Unfavorable weather again pushed the launch back to no earlier than Nov. 8.

With Crew-2 returning home first, NASA has rescheduled the Crew-3 launch for no earlier than Nov. 10 at 9:03 p.m. Eastern. If the spacecraft does launch at that time, it would dock with the station at about 7:10 p.m. Eastern Nov. 11.

In statements earlier in the week, NASA hinted that it was considering bringing Crew-2 back before launching Crew-3. The agency prefers a “direct” handover, when the new crew arrives before the old crew departs, rather than this “indirect” handover when the old crew leaves before the new crew arrives.

A direct handover allows the outgoing crew to brief the incoming one. “A lot of that handover time that we’re scheduled with the next crew is just showing little things on living in space,” said Kimbrough during a Nov. 5 media event. “It’s the little things that we don’t get trained on, like eating and going to the bathroom and sleeping and those kinds of little tidbits that we would pass along to the next crew.”

Kimbrough added that, if his crew left before Crew-3 arrived, that Mark Vande Hei, who flew to the station on a Soyuz spacecraft in April and will remain there until next March, will brief the new crew.

When Endeavor undocks, it will fly around the station, performing a photo reconnaissance of the exterior. “We don’t have that many opportunities to see the station from outside,” said Pesquet at the media event, noting that exterior cameras have limited views of parts of the station. That will include looking at some specific areas, like docking ports and equipment on the station’s truss.

“We’ll back off from the station and then go around it, and while we’re going around it we’ll try to take as many pictures as we can,” he said. “It’s not going to be easy from the Dragon because it’s not designed for that, but we’ll try to get the best results for the people on the ground.”

During their 18-hour return to Earth, the Crew-2 astronauts will not be able to use the toilet on the Crew Dragon because of a leak in the capsule’s waste management system. “Of course, that’s suboptimal,” said McArthur. “We are prepared to manage that in the time that we’re on board Dragon on the way home. Spaceflight is full of lots of little challenges. This is just one more that we’ll encounter.”

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...