While U.S. President Donald Trump and Elon Musk were arguing on social media on Thursday, the world's richest man threatened to dismantle a space capsule used to transport astronauts and supplies to the International Space Station.
After Trump threatened to terminate government contracts awarded to Musk's SpaceX rocket company and its Starlink satellite internet services, Musk responded via the social network X that SpaceX "will start dismantling its Dragon spacecraft immediately."
It is unclear how serious Musk's threat is. But the capsule, developed with the help of government contracts, plays a prominent role in keeping the space station operational. NASA also heavily relies on SpaceX for other programs, including launching scientific missions and, later in this decade, returning astronauts to the surface of the Moon.
Currently, SpaceX is the only company in the United States capable of transporting crews to and from the space station, using its four-seat Dragon capsules.
Boeing's Starliner capsule has transported astronauts only once. Last year's test flight went so wrong that the two NASA astronauts had to return to Earth aboard SpaceX in March, over nine months after being sent in June.
The Starliner remains grounded as NASA considers whether to use it on another test flight with cargo, instead of crew.
SpaceX also uses a Dragon capsule for its own private missions. The next of these will take place next week on a charter trip by Axiom Space, a Houston-based company.
Cargo versions of the Dragon capsule are also used to transport food and other supplies to the orbiting laboratory.
Russia's Soyuz capsules are the only other means of transporting crews to the space station at the moment.
Soyuz capsules have the capacity to carry three people at a time. For now, each Soyuz launch carries two Russians and one NASA astronaut, and each SpaceX launch has a Russian on board under a barter system. This way, in an emergency requiring the return of a capsule, there is always someone from the United States and Russia on board.
By conducting its first crewed launch for NASA in 2020 —the first crewed orbital flight by a private company—, SpaceX allowed NASA to reduce its dependence on Russia for crew transportation. Russian flights had been costing the United States 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 NASA scientific missions, as well as military equipment.
Last year, SpaceX also won a NASA contract to help deorbit the space station when it is no longer usable.
SpaceX's Starship megarocket is what NASA has chosen to transport astronauts from lunar orbit to the lunar surface, at least for the first two moon landing missions. Starship conducted its ninth test flight last week from Texas, but went out of control and disintegrated.