(TNND) — American astronauts Suni Williams and Butch Wilmore are coming back to Earth after what was meant to be a weeklong mission turned into nine months aboard the International Space Station.

Williams and Wilmore took off in June on a Boeing Starliner capsule and will splash down Tuesday in a SpaceX capsule off the Florida coast.

President Donald Trump blamed his predecessor for the astronauts’ long stay in space and took credit for their return.

“This began when I asked Elon Musk to go up and get the abandoned Astronauts, because the Biden Administration was incapable of doing so,” Trump said Monday in a social media post. “They shamefully forgot about the Astronauts, because they considered it to be a very embarrassing event for them – Another thing I inherited from that failed group of incompetents. Elon and I have taken on the project, sending up the SpaceX Dragon, which has successfully docked and, hopefully, while there is always danger involved in such a mission, they will soon be on their way home ..."

Is this a win for the administration after Williams and Wilmore were stuck in space for longer than expected?

“This is a win for the administration because ... the government is doing what government does best, which is solve problems,” said Peter Loge, the director of the School of Media and Public Affairs at George Washington University. “And this is a win for government. This is a win for federal agencies. This is a win for civil servants. It’s a win for scientists.”

Loge said the astronauts’ delayed return shouldn’t be a political issue.

“This isn't about politics or personalities,” Loge said. “This is about science.”

Williams and Wilmore launched last June as the first crewed flight test aboard Boeing’s Starliner spacecraft bound for the space station.

The Boeing craft launched and docked at the space station successfully.

“But on the way to the station after reaching orbit, they noticed a couple of things,” David Alexander, the director of the Rice Space Institute, said Tuesday. “One was a helium leak, which is not too uncommon. But the other thing was that some of the thrusters were malfunctioning.”

Alexander said NASA wanted to figure out why the thrusters malfunctioned and if those were of concern.

NASA decided to keep Williams, Wilmore and the Boeing capsule at the space station to analyze the problems before their return.

The thrusters that were malfunctioning were on the service module, which couldn’t return to Earth for examination.

“It basically gets jettisoned and burns up in the atmosphere, which means that there would be no opportunity to analyze the problem,” Alexander said.

Boeing said in August that its tests confirmed 27 of 28 thrusters were healthy and back to full operational capability.

And Boeing said it was confident in its spacecraft’s ability to return Williams and Wilmore safely.

But the decision was made to return the Boeing capsule unmanned in September and fold Williams and Wilmore into the upcoming SpaceX Crew-9 mission.

“That was NASA putting the astronaut safety ahead of everything else, which is the right thing for them to do,” Alexander said.

The unmanned Boeing craft safely returned to Earth.

And SpaceX sent two crew members, not the typical four, up in late September for the Crew-9 mission so Williams and Wilmore would have seats back home.

NASA’s shuttle program ended in 2011. NASA relied on the Russians to ferry American astronauts to the space station before contracting with SpaceX and Boeing to provide those services.

Contracting with both Boeing and SpaceX offered NASA redundancy, Alexander said.

“Your Uber app doesn't work, you jump to a taxi,” he said.

So, that’s what NASA did to bring Williams and Wilmore home.

But Alexander said mission cadence is important for NASA.

That’s why Williams and Wilmore were left up another six months to team with NASA astronaut Nick Hague and Russia’s Aleksandr Gorbunov to form the Crew-9 team.

“If everything had gone to plan, Crew-9 would have been four astronauts,” Alexander said. “And they would have gone up and spent their six months, and came back, and Crew-10 would have replaced them.”

Crew-10 just arrived to relieve Williams, Wilmore, Hague and Gorbunov.

“And so, we're back in cadence again,” Alexander said.

Astronaut time is very expensive on the space station, he said.

And a lot of planning goes into each mission.

Alexander dismissed the idea that politics played a part in Williams and Wilmore staying in space longer than they otherwise would have.

“This was the most efficient way of taking advantage of those folks and their skill set while maintaining NASA's plans,” he said. “This is them spending the taxpayers’ money to do all these things ... and they've been planning for years, and to keep that going and with minimal disruption.”

Williams and Wilmore are experienced astronauts, with about 500 days of space flight between them, Alexander said.

“I'm sure they kind of wanted to stick to the mission” of just a week, so they could return to their families, Alexander said.

“But they’re seasoned professionals,” he continued. “They know the ropes up there. They know what to do. They know how to do it. And they get on with it.”