If he succeeds, his startup, Vast Space LLC, will be well-positioned to win a lucrative contract from NASA next year—potentially worth billions of dollars—to replace the International Space Station. If it’s a bust, McCaleb says, he’s fully prepared to lose $1 billion of his fortune. McCaleb controls billions partly via two foundations, which reported a total of $3.3 billion in assets at the end of 2023, funded by his own donations.