Acting NASA director Sean Duffy and billionaire Elon Musk had an online spat on October 21 over who will lead the US space agency.

The development comes a day after Mr. Duffy invited companies to join a moon landing mission, directly competing with billionaire Musk’s SpaceX .

The controversy involved a report that acting Administrator Duffy wanted to merge NASA , the National Aeronautics and Space Administration, into the Department of Transportation. Duffy himself is currently the Secretary of Transportation, and a report in The Wall Street Journal suggested such a move could secure Duffy’s position at NASA.

Commenting on this information, billionaire Musk wrote on social network X: “The person responsible for the US space program cannot have a double-digit IQ.”

A day earlier, Mr. Duffy spoke on Fox News’ “Fox & Friends” program, saying that SpaceX’s Starship spacecraft development was behind schedule in its mission to return humans to the moon under NASA’s Artemis program .

The SpaceX Super Heavy rocket carrying the Starship spacecraft during its 11th test flight at the company’s launch pad in Starbase, Texas, USA, October 13, 2025.

PHOTO: REUTERS

As a result, the acting NASA administrator said the agency would invite other companies to compete for the mission, which has been awarded to SpaceX in 2021.

Reuters news agency quoted NASA spokeswoman Bethany Stevens as saying that Mr. Duffy is focused on helping the US beat China in the race to the moon.

Billionaire Musk and SpaceX have not yet responded to requests for comment.

“I love the passion. The race to the moon is ON,” Duffy wrote on X on October 21 in response to a post by Musk pledging that Starship would “eventually take over the entire lunar mission.” He stressed that “big companies shouldn’t be afraid of challenges.”