President Donald Trump appointed Transportation Secretary Sean Duffy as NASA’s interim administrator.

Trump had been searching for a replacement for billionaire commercial astronaut Jared Isaacman, whose nomination was pulled after revelations over his past Democratic support. The withdrawal reportedly played a significant role in the fallout between Trump and erstwhile ally Elon Musk. As he searches for a permanent replacement, the president announced that Duffy would be taking on the position.

“I am pleased to announce that I am directing our GREAT Secretary of Transportation, Sean Duffy, to be Interim Administrator of NASA. Sean is doing a TREMENDOUS job in handling our Country’s Transportation Affairs, including creating a state-of-the-art Air Traffic Control systems, while at the same time rebuilding our roads and bridges, making them efficient, and beautiful, again,” Trump announced in a post on Truth Social.

“He will be a fantastic leader of the ever more important Space Agency, even if only for a short period of time. Congratulations, and thank you, Sean!” he added.

Duffy thanked Trump for the appointment in a post on X.

“Honored to accept this mission. Time to take over space. Let’s launch,” he said with a satellite, rocket, and American flag emoji.

Duffy has been a reliable Trump ally and more visible than most transportation secretaries due to the administration’s battles with blue states over transportation matters. His handling of several crises, including January’s deadly midair collision over the Potomac between a passenger jet and a military helicopter, has also kept him in the spotlight.

Retired Air Force Lt. Gen. Steven Kwast, a MAGA faithful, is a favorite to be Trump’s permanent NASA administrator. The celebrated former combat pilot has emerged as a major champion of Space Force and Trump’s ambitious Golden Dome missile defense project. Kwast is a favorite of many Trump allies.

“I have worked for years with Kwast. He was the brilliant head of the Air University. He is probably the most forward-looking Air Force General I’ve ever worked with, and he would be an extraordinary leader at NASA,” former House Speaker Newt Gingrich told the Washington Examiner last month.

INSIDE TRUMP’S DECISION TO YANK NASA NOMINEE AND HIS PLANS FOR A REPLACEMENT

Isaacman drew the ire of Trump and his allies after his past support for Democrats was revealed, in part by reporting from the Washington Examiner. His removal was a major source of contention between Musk and Trump.

“The Administrator of NASA will help lead humanity into space and execute President Trump’s bold mission of planting the American flag on the planet Mars,” White House spokeswoman Liz Huston said in a statement. “It’s essential that the next leader of NASA is in complete alignment with President Trump’s America First agenda and a replacement will be announced directly by President Trump soon.”