Jared Isaacman is leading a series of SpaceX missions called the Polaris Program.
Patrick T. Fallon/AFP/Getty Images
- The billionaire Jared Isaacman said his Polaris missions with SpaceX are "a question mark" now.
- Donald Trump nominated Isaacman for NASA Administrator months after he did SpaceX's first spacewalk.
- Space experts doubt Isaacman will fly during his NASA term, due to job demands and safety risks.
SpaceX and its go-to billionaire-turned-private-astronaut seem to be going their separate ways...