Approaching a quarter century in orbit, the International Space Station is nearer its end than its beginning. What comes next? Sean Blair finds out
All through the 21st century it has been above us, growing larger with the passing years. As the sunlight catches it, the sprawling structure becomes the brightest star of dusk or dawn.
The International Space Station’s first segment was launched 25 years ago, on 20 November 1998. Since then, 15 further modules have been added to the initial foundation of Russia’s Zarya FGB block and the ISS has grown into a 400-tonne behemoth. At 109 metres across, it is longer than a football pitch. Continuously occupied since 2 November 2000, more than 260 people from 21 countries have lived and worked on the Space Station. But it was originally designed for just 15 years in orbit. It can’t last forever. So what happens next?
The ageing station has generated negative headlines in recent years – micro-fractures triggering air leaks; a thruster misfiring that spun the ISS out of control; a greater number of space debris near-misses; coolant leaks from Soyuz and Progress craft, and a communications dropout this July – amid ongoing diplomatic strife between Russia and other ISS partners the US, the European Space Agency (ESA), Canada and Japan since Moscow’s invasion of Ukraine.
But the severity of reported malfunctions is often overstated. As has been the case throughout the station’s life, its international nature is a source of resilience. For instance, when NASA communications suffered a power cut in July, Moscow mission control stepped in. When Russian supply ships experienced coolant leaks – a Soyuz capsule in December 2022, then a Progress freighter in February – the US Dragon and Cygnus spacecraft remained available.
Countdown to a fiery finish
All but one of the international partners have signed on to keep the ISS flying until early 2031, with Russia’s Roscosmos committing to 2028 so far (despite previous protesting). In practice, Roscosmos will be needed until the ISS’s disposal, which is planned to take the form of a controlled deorbit. Depending on the solar-cycle-influenced density of the atmosphere, the ISS’s altitude will be allowed to decay from the end of 2026 onwards so that, as seen from Earth, the ISS ‘star’ will grow brighter still.
Once it reaches as
