Behnken's wife wife, NASA astronaut Megan McArthur, will be among four crew members expected to fly to space in the same, refurbished, capsule next spring.
With all eyes on Tropical Storm Isaias, which was bearing down on Florida's east coast, NASA on Saturday declared "conditions are "Go" for Sunday's return.
The undocking, coast and splashdown phase are all meant to be performed entirely via automation, with the control systems SpaceX designed for Crew Dragon managing the entire process, including burns to control the capsule's travel away from the Station and its controlled descent through the atmosphere.
"It's been a great two months, and we appreciate all you've done as a crew to help us prove out Dragon on its maiden flight", Hurley told the remaining USA station crew member Chris Cassidy, as Crew Dragon autonomously eased away from its docking port to begin the 21-hour journey home.
This will be SpaceX's first splashdown with astronauts on board, ending a two-month test flight that began May 30 at NASA's Kennedy Space Center - the first launch of a crew from the U.S. in almost a decade. "We could stay up here longer".More news: Lions QB Matthew Stafford placed on COVID-19/reserve list
A SpaceX recovery ship staffed by engineers, medical personnel and fast-response support crews with jet skis and other gear will be stationed nearby to recover the capsule.
"It's been a great two months, and we appreciate all you've done as a crew to help us prove out Dragon on its maiden flight", Hurley told Cassidy, the station's commander, via a radio link.
From here, Endeavour is scheduled to remain in free flight for over twelve hours, following which - weather permitting -Bob, Doug, and Endeavour will begin their final preparations for their return to Earth.
"As you can imagine, even if you made a decision to go deep sea fishing one day, and you've lived on Earth your whole life, people get seasick. We're going to do it from space and end up in the water", he added. "So there's a pretty good likelihood that we may see breakfast twice on that particular day".
"Folks didn't feel well - that's the way it is with a water landing", he said.
Asked later what that "appropriate hardware" was, Hurley said it was bags like sickness bags on airliners, along with towels.More news: Wisconsin's governor makes face coverings mandatory in indoor spaces
Along with SpaceX, NASA also has a contract with Boeing to eventually fly people to the space station, and the agency is making plans to allow private individuals to launch to the station for tourist flights.
A successful unpiloted test flight was carried out past year, helping clear the way for Hurley and Behnken to blast off atop a SpaceX Falcon 9 rocket on May 30.
Why it matters: Behnken and Hurley's return will mark the end of SpaceX's first crewed mission to the station - and the first mission in which American astronauts launched from US soil in nine years.
NASA managers say the Crew Dragon has chalked up a near flawless flight, setting the stage for re-entry and splashdown. "My son is six years old and I can tell from the videos that I get and from talking to him on the phone that he's changed a lot", Behnken said.
The aerospace company's first operational flight is expected to take place in September, where a second Crew Dragon spacecraft will carry four astronauts to the space station.More news: Muslims mark start of Eid al-Adha in age of coronavirus