Cape Canaveral (AP): NASA's two stuck astronauts headed back to Earth with SpaceX on Tuesday to close out a dramatic marathon mission that began with a bungled Boeing test flight more than nine months ago.

Butch Wilmore and Suni Williams bid farewell to the International Space Station — their home since last spring — departing aboard a SpaceX capsule alongside two other astronauts.

The capsule undocked in the wee hours and aimed for a splashdown off the Florida coast by early evening, weather permitting.

The two expected to be gone just a week or so after launching on Boeing's new Starliner crew capsule on June 5. So many problems cropped up on the way to the space station that NASA eventually sent Starliner back empty and transferred the test pilots to SpaceX, pushing their homecoming into February. Then SpaceX capsule issues added another month's delay.

Sunday's arrival of their relief crew meant Wilmore and Williams could finally leave. NASA cut them loose a little early, given the iffy weather forecast later this week.

They checked out with NASA's Nick Hague and Russia's Alexander Gorbunov, who arrived in their own SpaceX capsule last fall with two empty seats reserved for the Starliner duo.

“We'll miss you, but have a great journey home,” NASA's Anne McClain called out from the space station as the capsule pulled away 260 miles (418 kilometers) above the Pacific.

Their plight captured the world's attention, giving new meaning to the phrase “stuck at work”.

While other astronauts had logged longer spaceflights over the decades, none had to deal with so much uncertainty or see the length of their mission expand by so much.

Wilmore and Williams quickly transitioned from guests to full-fledged station crew members, conducting experiments, fixing equipment and even spacewalking together.

With 62 hours over nine spacewalks, Williams set a new record: the most time spent spacewalking over a career among female astronauts.

Both had lived on the orbiting lab before and knew the ropes, and brushed up on their station training before rocketing away. Williams became the station's commander three months into their stay and held the post until earlier this month.

Their mission took an unexpected twist in late January when President Donald Trump asked SpaceX founder Elon Musk to accelerate the astronauts' return and blamed the delay on the Biden administration.

The replacement crew's brand new SpaceX capsule still wasn't ready to fly, so SpaceX subbed it with a used one, hurrying things along by at least a few weeks.

Even in the middle of the political storm, Wilmore and Williams continued to maintain an even keel at public appearances from orbit, casting no blame and insisting they supported NASA's decisions from the start.

NASA hired SpaceX and Boeing after the shuttle program ended, in order to have two competing US companies for transporting astronauts to and from the space station until it's abandoned in 2030 and steered to a fiery reentry.

By then, it will have been up there more than three decades; the plan is to replace it with privately run stations so NASA can focus on moon and Mars expeditions.

Both retired Navy captains, Wilmore and Williams stressed they didn't mind spending more time in space — a prolonged deployment reminiscent of their military days. But they acknowledged it was tough on their families.

Wilmore, 62, missed most of his younger daughter's senior year of high school; his older daughter is in college. Williams, 59, had to settle for internet calls from space to her mother. They'll have to wait until they're off the SpaceX recovery ship and flown to Houston before the long-awaited reunion with their loved ones.