It doesn’t take an expert to see that Elon Musk’s pride is as delicate as a Tesla in extremely cold weather. On Thursday, the billionaire displayed his impatience after clashing with an astronaut and ex-SpaceX pilot who called him out for a blatant mistruth.

Danish engineer and astronaut Andreas Mogensen confronted Musk on Friday after the SpaceX founder claimed during a Fox News interview that two astronauts stationed at the International Space Station (ISS) for over six months had been left in orbit due to “political reasons.”

Mogensen, who commanded SpaceX’s Crew-7 mission to the ISS in 2023, replied on social media, calling Musk’s assertion a “lie” and questioned Musk’s consistent complaints about dishonesty in mainstream news.

Musk’s response was to lash out at Mogensen, outright dismissing him. “You are fully retarded,” he stated. He further claimed, “SpaceX could have rescued them several months ago. I OFFERED THIS DIRECTLY to the Biden administration, and they declined. Their return was delayed for political reasons. Idiot.”

Mogensen responded: “You know as well as I do that Butch and Suni are slated to return with Crew-9, as has been the scheme since last September. Even now, there is no rescue mission being launched to bring them home. They are coming back on the Dragon capsule that has been at the ISS since last September.”

NASA’s Suni Williams and Butch Wilmore are expected to return to Earth with Crew-9 in March, following their launch in September for a planned six-month stay at the ISS, which began from Cape Canaveral with two fewer crew members than initially anticipated to accommodate Williams and Wilmore’s return.

Williams and Wilmore arrived at the ISS over six months ago during a two-person test mission for Boeing’s Starliner spacecraft. However, technical complications with Starliner made their planned 10-day return unsafe, necessitating their extended stay until they could safely come back on an alternative mission. Extended missions on the ISS aren’t uncommon; for instance, astronaut Frank Rubio spent over a year there from 2022 to 2023 due to delays caused by damage to the Soyuz MS-22 spacecraft.

In a conversation with CNN’s Anderson Cooper earlier this month, Williams and Wilmore countered the idea that they were abandoned or stranded in space by the U.S. government.

“We don’t feel abandoned, we don’t feel stuck, we don’t feel stranded,” Wilmore stated.

“We anticipated there might be issues with Starliner and discovered some problems, but that wasn’t unexpected,” Williams noted.

Yet, their time on the ISS has become a contentious topic within the political arena. Last month, Musk tweeted: “The @POTUS has asked @SpaceX to expedite the return of the 2 astronauts on the @Space_Station. We will comply. It’s appalling that the Biden administration has kept them there for so long.”

NASA has firmly denied accusations about the Biden administration leaving any astronauts behind. Former NASA Administrator Bill Nelson stated in August that “unequivocally,” political factors “did not influence [the] decision” regarding the delays in Williams and Wilmore’s return from the ISS. According to a February report, NASA emphasized that attempting to return the astronauts on Starliner would have considerably increased the risk to their safety. The delay “ensured a safe return for the crew while minimizing the risks related to the Starliner’s technical challenges,” the agency stated.

Musk’s comments have also raised red flags regarding his potential conflicts of interest, particularly given his influence over government expenditures.

In July, NASA granted SpaceX a contract exceeding $1 billion for the decommissioning of the ISS, set for 2030. Meanwhile, Musk has been actively scrutinizing the federal budget, including NASA’s spending, while simultaneously managing companies that benefit from federal contracts. In the midst of his dispute with Morgensen, Musk suggested that the ISS decommissioning should be expedited to 2027.

“It’s time to initiate preparations for deorbiting the @Space_Station,” he tweeted. “It has fulfilled its purpose and holds little further utility. Let’s focus on Mars.”

Musk added that the ultimate decision rests with the President but recommended proceeding as quickly as possible.