Elon Musk’s hostilities with Sean Duffy reignited Tuesday, with the billionaire accusing the U.S. Transport Secretary of “trying to kill NASA” and attacking him with crude comments online.
It comes after Duffy told CNBC Monday that Musk’s rocket company was falling “behind” the administration’s timeline for getting humans back on the moon, and that he would now be opening up the government contract to others – including the Jeff Bezos-owned Blue Origin.
“We’re not going to wait for one company,” Duffy, who is also the Acting Administrator for NASA, said.
“We’re going to push this forward and win the second space race against the Chinese. Get back to the moon, set up a camp, a base and from there we’re gonna figure out how we can get to Mars,” he addded.
The SpaceX boss posted a series of posts on his social media platform X in response to remarks made by Duffy, including a GIF of a famous exchange in which an anchor asked a guest, “Why are you gay?”
As well as his offensive GIF post, Musk continued his tirade Tuesday, dubbing the transport secretary “Sean Dummy,” and claiming he was “trying to kill NASA.”
“The person responsible for America’s space program can’t have a 2 digit IQ,” he wrote in a separate post.

Beef between the two men has been stewing for a long time, and this week’s back-and-forth forms part of a wider feud over the NASA leadership and previous tensions between Musk and the Trump administration.
The tech billionaire had been a strong advocate for Jared Isaacman to lead the space agency, though the president ultimately pulled his nomination after a “thorough review of previous associations.”
While not specifying what those associations were at the time, reports soon suggested that Isaacman had donated to the Democrats. Duffy instead was named as the acting administrator – a role he has expressed interest in keeping.

Others speculated that Trump’s withdrawal of Isaacman’s nomination was due to the explosive falling out between the president and Musk in June, in which both men attacked each other on social media.
Isaacman himself claimed that his nomination was pulled as “there were some people who had some axes to grind.”
Duffy also claimed that Musk’s Department of Government efficiency had attempted to fire many “safety critical” positions within the Transport Department, including air traffic controllers.
Musk called the claims a “lie.”

Responding to another X user Tuesday, who suggested it was “silly” to imagine another company getting humans back to the moon quicker than SpaceX, Musk responded: “They won’t.”
“SpaceX is moving like lightning compared to the rest of the space industry. Moreover, Starship will end up doing the whole Moon mission. Mark my words.”
Duffy responded lightly: “Love the passion. The race to the Moon is ON. Great companies shouldn’t be afraid of a challenge. When our innovators compete with each other, America wins!”