The role of Elon Musk's SpaceX in an ambitious new U.S. missile defense system is in question following the dramatic feud last week between the billionaire entrepreneur and President Donald Trump, according to three people familiar with the project.

Musk's Department of Government Efficiency, or DOGE, installed a Starlink Wi-Fi terminal at the White House in March – despite warnings from security officials that doing so could open the administration to potential data leak and espionage risks.