Senate GOP aides and aeronautical insiders floated retired Air Force Lt. Gen. Steven Kwast as the heir apparent to Isaacman.

Billionaire entrepreneur Jared Isaacman, who has close ties to Elon Musk, was President Trump's pick to serve as NASA administrator.

The White House is planning to withdraw the nomination of Jared Isaacman to be the administrator of the National Aeronautics and Space Administration, a White House official confirmed to POLITICO. The sudden move comes days before the Senate was slated to vote on his nomination to lead NASA.