(CNN) — SpaceX has launched a crew of astronauts who will take over duties on the International Space Station from NASA’s Sunni Williams and Butch Wilmore — allowing the duo to return home from the International Space Station after a days-long journey turned into a nine-month, politically c harged trip. The Crew-10 mission, part of a routine staff rotation jointly operated by NASA and SpaceX, took off at 7:03 p.m. ET Friday from Kennedy Space Center in Florida. A SpaceX Dragon capsule, riding atop one of the company’s Falcon 9 rockets, carried the four Crew-10 astronauts — NASA’s Anne McClain and Nichole Ayers, Takuya Onishi of the Japan Aerospace Exploration Agency, and Roscosmos cosmonaut Kirill Peskov — to orbit. The four crew members are expected to dock with the space station around 11:30 p.m. ET Saturday. They will spend a few days undergoing a “handover” period with Williams, Wilmore, and their fellow Crew-9 astronauts, NASA’s Nick Hague and Roscosmos’ Aleksandr Gorbunov. The Crew-9 Dragon capsule has been docked at the space station since September. If all goes according to plan, Williams, Wilmore, Hague and Gorbunov will climb aboard the Crew-9 spacecraft and head back to Earth on March 19. NASA had slated Williams, Wilmore and the other Crew-9 astronauts to return as soon as Sunday. However, their departure hinges on the safe arrival of the relief crew — and SpaceX called off an attempt to launch the Crew-10 mission on Wednesday due to issues with the company’s launchpad ground systems. The new date is closer in line to a late March departure time that NASA gave the astronauts in December before SpaceX opted to swap the Dragon capsule it used to fly Crew-10 in an attempt to accelerate Williams and Wilmore’s return. Launch attempts are routinely called off because of technical issues, but the slight delay in getting Crew-10 off the ground has reignited conversations of Williams and Wilmore being “stuck” or “stranded” in space — descriptors the two astronauts have rejected. “That’s been the narrative from day one: stranded, abandoned, stuck — and I get it, we both get it,” Wilmore told CNN’s Anderson Cooper in February. “Help us change the narrative, let’s change it to: prepared and committed despite what you’ve been hearing. That’s what we prefer.” After the hand-off of duties to Crew-10 astronauts is complete, the Crew-9 astronauts can board their capsule and undock — and that milestone will kick off the final stretch of Williams and Wilmore’s fraught journey. While their stay in space has become increasingly politicized, with SpaceX CEO Elon Musk and President Donald Trump asserting the Biden administration abandoned the duo in space, Williams and Wilmore have known since at least last summer they would return home with Crew-9 as part of a routine staffing rotation. Acting NASA administrator Janet Petro said during Friday’s launch webcast that she spoke to Williams and Wilmore and their crewmates last week. She said they suspect the four astronauts will have “mixed emotions.” “Every time you get to go to space — which is what all astronauts want to do — you never know it might be your last time, because you might not be selected for another mission,” Petro said. “So I bet they have mixed emotions leaving their colleagues up there at the space station. I’m sure they’re anxious to get home and put their feet on Earth and spend time with their family — but I think that they have enjoyed their time and space.” From Starliner to Crew Dragon Williams and Wilmore began their trip to the International Space Station in June when they piloted the inaugural crewed test flight of Boeing’s Starliner capsule. But multiple problems with the vehicle cropped up en route to the station, including propulsion issues and helium leaks. Those challenges prompted NASA to extend Williams and Wilmore’s stay on the space station as mission teams assessed the issues. Ultimately, NASA decided last summer that it would be too risky to return Williams and Wilmore home aboard the Boeing vehicle. The space agency announced in August it would instead fold Williams and Wilmore into the official space station staff — making them part of the routine crew rotation — which set them up to return home with SpaceX’s Crew-9 mission. Agency officials made that decision in lieu of flying a separate mission outside the regular space station schedule, which could have cost millions of dollars. Steve Stich, the program manager for NASA’s Commercial Crew Program, told reporters in August it “just didn’t make sense to go ahead and accelerate a (SpaceX) flight to return Butch and Suni earlier.” He added that NASA “never considered that option” — referring to the idea of flying a separate SpaceX mission dedicated to retrieving Williams and Wilmore rather than returning them aboard a routine, prescheduled flight. In his latest posts about the matter on X, however, Musk has said SpaceX could have brought Williams and Wilmore home months ago, but the offer was denied for “political reasons.” A former senior NASA official, however, told CNN that SpaceX never communicated such an offer to agency leadership — and NASA likely would not have entertained the idea regardless. If Musk had made the offer to someone outside NASA leadership, the source noted, “I’m sure they would have responded and said, ‘Well, that would cost us several $100 million extra that we don’t have for a new Dragon capsule and Falcon 9.’” Musk has since said that the offer was not made to NASA but was taken directly to the Biden White House, which “refused to allow it.” It’s unclear why such a deal would be discussed with the White House, which does not typically have any involvement in NASA crew assignments or space station staffing matters. A former White House staffer did not respond to a request for comment. Williams and Wilmore react For their part, Williams and Wilmore have repeatedly said they enjoy their time in space. “This is my happy place,” Williams said in September. “I love being up here in space. It’s just fun. You know, every day you do something that’s work, quote, unquote, you can do it upside down. You can do it sideways, so it adds a little different perspective.” The duo has also sought to dispel accusations that the Biden administration left them behind. While acknowledging that there have been difficult parts to the mission, Williams and Wilmore have repeatedly sought to express they were well-prepared to extend their stay in space and were not abandoned. “We have plenty of clothes. We are well-fed,” Wilmore said in January. Williams added, “It’s just a great team and — no, it doesn’t feel like we’re castaways. “Eventually we want to go home,” she added, “because we left our families a little while ago, but we have a lot to do while we’re up here.” Still, Wilmore added fuel to speculation about Musk’s claims regarding an offer to return the astronauts early during a March 4 news conference conducted from the International Space Station. “I can only say that Mr. Musk, what he says is absolutely factual,” Wilmore said. However, he added, “We have no information on (a deal SpaceX may have offered), though, whatsoever. What was offered, what was not offered, who was offered to, how that process went — that’s information that we simply don’t have.” How Crew-9 is bringing Williams and Wilmore home The SpaceX capsule that will serve as Williams and Wilmore’s ride home from the space station launched in September, with Crew-9’s Hague and Gorbunov flying a SpaceX Dragon with two empty seats for Williams and Wilmore. The four astronauts have since been engaged in typical station activity — conducting spacewalks, carrying out science experiments and keeping up with routine space station maintenance. Williams even took over as commander of the space station. The timing of Williams and Wilmore’s return trip has always been contingent on the successful launch of the Crew-10 mission. NASA has maintained the two crews needed to undergo a handover period because it’s essential to space station operations. Allowing Crew-9 to return before Crew-10 would also have left only one US astronaut on board the space station — NASA’s Don Pettit, who arrived on a Russian Soyuz spacecraft in September. NASA and Russia’s Roscosmos space agency jointly operate the orbiting laboratory with the European Space Agency, Japan Aerospace Exploration Agency and Canadian Space Agency. NASA aims to keep at least four astronauts from the United States or partner space agencies on board the space station at all times. With a possible government shutdown looming, NASA spokesperson Steve Siceloff told CNN that the Crew-10 mission would not be impacted because it’s deemed “mission critical.” “You may see some changes to the broadcast channel if a shutdown does happen,” he said, referring to NASA TV. “It wouldn’t be a situation where there’s no signal but you would just probably see less of it,” he added. ...read more read less