Musk's statement comes as the US space agency, NASA, is going through a period of uncertainty. Budget worries, job cuts, and the prospect of SpaceX customer, Jared Isaacman, being its administrator weigh heavily on the agency. Therefore, the possibility of an axe falling on a flagship program such as the ISS will be unwelcome.
NASA's international partners, such as the European Space Agency (ESA), expect the ISS to remain in orbit until 2030 or beyond. Russia has committed to keeping the ISS going until 2028. The Register asked ESA for its thoughts on the matter, and a spokesperson said, "The International Space Station is a project involving various international partners. As such, all matters regarding the ISS are discussed together with all space agencies involved."
An early end to the ISS also has commercial implications. Several private companies have plans for stations in Low Earth Orbit, but even the most optimistic timeline won't result in a standalone station before 2028. Unless, of course, SpaceX manages to get some Starships into orbit to replicate some of the utility of the ISS.
The ISS is hitting its stride in terms of utilization. The station typically has at least seven crew members on board; the number fluctuates during crew rotations using the three-person Soyuz and four-person Crew Dragon spacecraft. There are, therefore, resources available for research as well as maintaining the outpost itself. As such, an earlier-than-planned ditching would be a waste.
Taken at face value, Musk's desire to get to Mars appears to be the driving factor. His company, SpaceX, already has lucrative contracts to keep the ISS supplied with crew and cargo. An early end to the ISS would mean no further contracts. Yet it would also free up resources to fund a human mission to Mars.
However, ESA's comments that the fate of the ISS is something upon which all international partners must agree, as well as the need to get US lawmakers to give the plan the green light, indicates that just tweeting something does not necessarily make it policy.
