It’s unclear how serious Musk’s threat was. But the capsule, developed with the help of government contracts, is an important part of keeping the space station running. NASA also relies heavily on SpaceX for other programs including launching science missions and, later this decade, returning astronauts to the surface of the moon.
SpaceX is the only U.S. company capable right now of transporting crews to and from the space station, using its four-person Dragon capsules.
Starliner remains grounded as NASA decides whether to go with another test flight with cargo, rather than a crew.
Cargo versions of the Dragon capsule are also used to ferry food and other supplies to the orbiting lab.
Russia’s Soyuz capsules are the only other means of getting crews to the space station right now.
The Soyuz capsules hold three people at a time. For now, each Soyuz launch carries two Russians and one NASA astronaut, and each SpaceX launch has one Russian on board under a barter system. That way, in an emergency requiring a capsule to return, there is always someone from the U.S. and Russian on board.
With its first crew launch for NASA in 2020 — the first orbital flight of a crew by a private company — SpaceX enabled NASA to reduce its reliance on Russia for crew transport. The Russian flights had been costing the U.S. tens of millions of dollars per seat, for years.
NASA has also used Russian spacecraft for cargo, along with U.S. contractor Northrup Grumman.
The company has used its rockets to launch several science missions for NASA as well as military equipment.
