Update, Aug. 2, 11:54 a.m. PT: Crew Dragon.
Splashdown in the Gulf of Mexico is on schedule for 11:48 a.m. PT. There will be about an hour of excitement prior to that moment as Crew Dragon deorbits and re-enters Earth's atmosphere.
NASA and SpaceX are planning on a water landing off the coast of Pensacola, Florida, on Sunday while continuing to monitor any impact from Hurricane Isaias.
This will be the first crew recovery at sea of NASA astronauts since 1975 at the end of the Apollo moon exploration era, the space agency tweeted on Sunday.
A post-splashdown news conference is set for 1:30 p.m. PT on NASA TV.
The reentry process is dramatic. "Crew Dragon will be traveling at orbital velocity prior to reentry, moving at approximately 17,500 miles per hour. The maximum temperature it will experience on reentry is approximately 3,500 degrees Fahrenheit," said NASA in a statement on July 24.
A SpaceX recovery vessel will meet Crew Dragon (which the astronauts named Endeavour) to collect the spacecraft and parachutes from the water. Endeavour will be hoisted onto the ship and Behnken and Hurley will be greeted by a medical team.
There's a lot riding on a safe, uneventful return for Crew Dragon. "This is SpaceX's final test flight and is providing data on the performance of the Falcon 9 rocket, Crew Dragon spacecraft and ground systems, as well as in-orbit, docking, splashdown and recovery operations," NASA said in a release.
If Crew Dragon passes these final tests, then SpaceX will be able to provide regular,. And it would end NASA's reliance on Russian spacecraft for the first time since the shuttle era.