Trump nominates Sean Duffy as interim NASA chief after rejecting candidate linked to Elon Musk

President Donald Trump on Wednesday nominated Transportation Secretary Sean Duffy as acting NASA administrator after withdrawing the nomination of well-known businessman Jared Isaacman, linked to Elon Musk, CEO of SpaceX.

The president's decision comes amid growing public conflict between Trump and Musk, once political allies. In a message posted on Truth Social, the president praised Duffy's performance at the helm of the Department of Transportation and assured that he is qualified to lead the space agency at this key stage.

"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. 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!"

Isaacman, whose nomination appeared to have consensus within the Trump administration, was finally ruled out days before the Senate confirmation vote.

Trump justified the decision under a "thorough review of prior associations" and later explained that he found it problematic that the nominee was a "blue blooded Democrat," citing Issacman's history of donating to Democratic politicians.

The president, moreover, also said he felt it was wrong for a "very close friend of Elon, who was in the space business," to assume control of an agency with close contractual ties to SpaceX.

Isaacman, after being rejected for the position, publicly defined himself as a "right-leaning moderate" and pointed out that his ties to Musk have always been exclusively professional, not friendly. He also said he had declared all of his political contributions prior to being nominated and that had not previously posed a problem.

Duffy's nomination comes at a key time for NASA as it prepares to return to the Moon and take the first steps toward a future manned mission to Mars. Duffy himself celebrated his appointment on 'X.'.

"Honored to accept this mission. Time to take over space. Let’s launch," he said.

The agency, for now, is still formally headed by Janet Petro, acting administrator since the start of Trump's second term, but her continuity has not been officially confirmed, and her status within the administration remains in doubt.

With this move, Duffy becomes another of the top Trump Administration officials serving in two or more roles. Currently, Secretary of State Marco Rubio also serves as acting National Security Advisor and temporary director of the National Archives.