4 Astronauts Returning To Earth, 4 Others ISS-Bound This Week: NASA

The SpaceX Crew-2 is bound to return to Earth Monday instead of Sunday. Crew-3's launch, on the other hand, is so far still set for Wednesday.

There's a slight adjustment to the Space X Crew-2's departure from the International Space Station (ISS), setting them for a return to Earth "no earlier than 10:33 p.m. EST" Monday, NASA announced Sunday. The change was made after a "planned weather review," which found that the winds were "unfavorable" for a recovery in the splashdown zone at the Gulf of Mexico.

For the return to Earth, the Crew Dragon Endeavor, which will be carrying European Space Agency's Thomas Pesquet, Japan Aerospace Exploration Agency's Aki Hoshide, NASA's Shane Kimbrough and Megan McArthur, as well as about 530 pounds of scientific investigations and hardware, is set to undock from the orbiting laboratory at 2:05 p.m. and splash down at one of the targeted landing zones off the coast of Florida.

"NASA and SpaceX closely coordinate with the U.S. Coast Guard to establish a safety zone around the expected splashdown location to ensure safety for the public and for those involved in the recovery operations, as well as the crew aboard the returning spacecraft," NASA noted.

Crew-3 Launch

As for the launch of the NASA SpaceX Crew-3 mission, which had been originally set for Oct. 31 but was delayed several times, the latest change set it for a launch "no earlier than 9:03 p.m." Wednesday at the Kennedy Space Center in Florida. Should things go according to plan, the Crew Dragon is expected to dock to the ISS at 7:10 p.m. Thursday.

Originally, the plan was to have the SpaceX Crew-2 astronauts and other Expedition 66 members greet the arriving Crew-3 members for a short handover period before the Crew-2 members' departure for Earth. However, the changes and delays, from weather concerns to a medical issue with one of the Crew-3 members, meant that Crew-2 will have to leave the ISS before the new crew arrives.

So far, the weather appears to be favorable for the launch to push through Wednesday.

"Following Crew-2's return to Earth, Falcon 9 will launch Dragon's third long-duration crew mission to the Space Station as soon as Wednesday, November 10; weather forecast is 80% favorable for liftoff," SpaceX noted in a tweet.

The missions are a part of NASA's Commercial Crew Program, which aims to provide "safe, reliable, and cost-effective transportation to and from the International Space Station" via its partnerships with the private industry.