A SpaceX capsule carrying a new crew has docked at the International Space Station (ISS), paving the way for astronauts Butch Wilmore and Suni Williams to come home.
The pair were due to be on the ISS for only eight days, but because of technical issues with the experimental spacecraft they arrived on, they have been there for more than nine months.
The astronauts are due to begin their journey back to Earth later this week. Steve Stich, manager of Nasa’s commercial crew programme said he was delighted at the prospect.
Live footage showed the SpaceX Crew Dragon docking with the ISS and opening a hatch. Shortly after 0545 GMT, the astronauts embraced and hugged their counterparts in zero gravity.
The astronauts, along with their ISS workmates, Nasa’s Nick Hague and Roscosmos cosmonaut Aleksandr Gorbunov, will be relieved by four astronauts, from Russia, Japan and two from the US.
There will be a two-day handover after which the old crew are due to begin their journey back to Earth. But there could be a small further delay, as they wait for conditions on Earth to be right for a safe re-entry of the returning capsule, according to Dana Weigel, manager, of the ISS programme.
Ms Weigel explained that the astronauts had begun getting ready for the handover last week.
The astronauts have consistently said that they have been happy to be on board the space station, with Suni Williams describing it as her “happy place”. But Dr Simeon Barber, of the Open University, said there would likely have been a personal cost.
Butch and Suni arrived at the ISS at the beginning of June 2024 to test an experimental spacecraft called Starliner, which was built by the aerospace firm Boeing, a rival to SpaceX.
The mission had been delayed by several years because of technical issues in the spacecraft’s development, and there were problems during its launch and docking on to the ISS. This included issues with some of Starliner’s thrusters, which would be needed to slow the spacecraft for re-entry into the Earth’s atmosphere, and leaks of helium gas in the propulsion system.
Nasa decided that it would not take even a small risk in bringing back Butch and Suni on Starliner, when they had the option of returning them on SpaceX’s Dragon capsule. Nasa decided the best option was to do this during a scheduled crew rotation, even though it would mean keeping the astronauts on the space station for several months.
Boeing has consistently argued that it would have been safe to bring Butch and Suni back on Starliner, and were unhappy about the decision to use a rival’s capsule instead, which will be “embarrassing” for Boeing, according to Dr Barber.
Both President Trump and SpaceX CEO Elon Musk have said that Butch and Suni could have been brought home sooner, most recently in a joint interview with Fox News in February.
President Trump states: “They got left in space.”
When the interviewer, Sean Hannity, elaborates, saying “They were supposed to be there eight days. They’re there almost 300,” Mr Trump responds with one word: “Biden.” Mr Musk follows up asserting: “They were left up there for political reasons.”
The assertion is denied by Nasa’s Steve Stitch.
“We looked at a wide range of options and worked hand-in-hand with SpaceX to look at what was the best thing to do overall and when we laid all that out the best option was to have the one we are embarking upon,” he said.
That decision was supported by Dr Libby Jackson, who is head of space at the Science Museum in London and worked at Europe’s control centre for the ISS.