01 · THE LAST EIGHTEEN MONTHS
How the station comes down
NASA's plan fixes four moments. The deorbit vehicle (the craft that pushes the station down) docks eighteen months before the end. The last crew leaves at six months. Four days before the end, a series of burns begins.
Source · NASA · June 2024
02 · WHAT YOU ASSUME
The station is not worn out
That falling line is a schedule, not a diagnosis. NASA drew every step of it on the ground, years before the first engine fires. The station is old, and it does leak, but nothing on board sets the year it stops.
What most people think
The station is ending because it is falling apart. Cracks and leaks have run it out of life.
What the data shows
NASA picked SpaceX to build the craft that will push the station down. Its delivery date, not its hardware, sets the year.
NASA selected SpaceX in June 2024 to build the US Deorbit Vehicle, a single award worth up to $843 million.
Source · NASA · 26 June 2024
03 · THE DATES THAT MATTER
Six moments, one of them decisive
NASA bought the ending before anything on board gave way. And the 2030 date itself came from an agreement: five space agencies signed up to run the station that long, and Russia, one of the five, through at least 2028.
- 2 Nov 2000
Continuous presence begins. The first three residents move in.
- 26 Jun 2024
NASA buys the deorbit vehicle. SpaceX, single award, up to $843 million.
- 17 Jun 2026
Auditors name the window. GAO: within a year, decide what replaces it.
- 2027
The decision year. Nothing on the station forces this date.
- 1 May 2029
Vehicle delivery required. Contract date. The clock behind everything.
- 2030
Station operations end. Russia's commitment runs through at least 2028.
Both dated decisions, in 2024 and 2026, were made on the ground, years before the station's last day.
Source · GAO-26-107805 · 17 June 2026
04 · WHY SO EARLY
Why the choice lands in 2027
The timeline put a decision in 2027 and an ending in 2030. The gap between them is lead time. Think of booking a wedding hall: the hall needs a long lead time, so its calendar fixes your date.
The burn needs a vehicle. The vehicle must already be docked about eighteen months before the final burn.
The vehicle needs a rocket. It weighs over 30,000 kg, so the heavier rocket is bought at least three years ahead.
So the choice comes first. Count back from 2030, then add certifying a replacement station and buying extra flights: 2027.
Source · NASA and SpaceX · 17 July 2024
05 · THE FUEL BILL
Bringing it down is the cheap option
So lead time picks the year. But why bring the station down at all? Every choice costs fuel, and engineers write that bill as delta-v: the speed change a manoeuvre needs, in metres per second. Bigger number, bigger tank.
Deorbiting costs about 57 m/s of speed change. Holding the orbit for a century costs 120 to 140. Long-term storage costs about 760.
Source · NASA · 2024
06 · WHAT INDIA SPENT
India's answer, priced in rupees
Dropping it in the ocean is the cheapest option, and NASA bought it. Three months later, India's Cabinet answered differently: it expanded Gaganyaan, India's human spaceflight programme, and added the first module of its own station.
India's Cabinet approved the expansion on 18 September 2024, taking Gaganyaan from 9,000 crore rupees to 20,100 crore.
Source · SpaceNews, ISRO · 18 September 2024
07 · THE GAP NOBODY OWNS
What happens if nothing is ready
India is building upward while NASA plans downward, and the two calendars nearly touch, at almost the same height above Earth. The GAO, the US government's auditor, asked NASA to write down how it will judge whether a commercial replacement is ready, including its assumptions and risks. That means the test does not exist yet.
Steve Hoeser, an engineer writing in The Space Review, goes further. He argues NASA has no power written into law to certify a station it does not own, that is, to declare it safe for crew. Think of a driving licence from an office that was never given the power to test anyone, so the licence means nothing.
Source · GAO-26-107805, The Space Review · 17 June 2026
Auditors want a written test for a replacement station. NASA may not even have the legal power to declare one safe for crew.
08 · WHERE INDIA WILL BE
Same band of sky, different decade
So the replacement has no test, and maybe no examiner. The station works between 370 and 460 km. India's first crewed flight is planned for 400 km, inside that band. Same strip of sky, one arriving as the other leaves.
The station flies at about 415 km. India's first crewed mission is planned for 400 km. The station's last crew departs from about 330 km.
Source · ISRO (Nov 2022), NASA, Spaceflight Now · 2022–2024