Donald Trump has assigned Transport Secretary Sean Duffy a second job as interim caretaker of NASA after the president dumped his original choice to lead the space agency. Duffy has been locked in a war of words this year with Trump’s former space buddy,

President Trump had pulled the nomination of a close associate of Elon Musk to lead the agency in May. The decision fueled a public breakdown of their alliance.

Trump withdrew Musk-ally and billionaire Jared Isaacman’s nomination for the NASA administrator role in May and has since labeled him a “blue blooded Democrat.”