For over a decade, the International Space Station has never seen a day in which it didn’t have occupants. Many thought when it was first permanently crewed, back in November of 2000, that it was a watershed in history — the day after which there would never again not be humans living off the planet. That was certainly the plan, because it was assumed that there would be follow-on programs even after the ISS was decommissioned. But it may have been another false start, because NASA is now contemplating at least temporarily giving up our tentative first foothold in the long climb to eventual space settlement.
As a result of the failure of the upper stage of the Russian Roscosmos Progress flight last month, the agency can no longer rely on the Soyuz crew launcher, because it is essentially the same rocket. Until the Russians have determined what caused the problem and how they will fix it, their rockets cannot be trusted. The implications for the ISS are potentially dire. First, there were plans to deliver a new crew on the Soyuz in a few weeks. These will now obviously be delayed.
Also delayed will be the return to earth of three current crew members, which had been planned about the same time as their replacement would be arriving. This isn’t an immediate issue, other than prolonging their stay in space, with whatever health detriments may accrue. The real problem is that they can’t delay it indefinitely, because the Soyuz capsule only has a limited on-orbit life (seven months), after which it cannot be used to return crew home with confidence. The one they planned to bring back will reach its use-by date in late October. So they’ll have to come home then, leaving only three aboard, reducing or eliminating any science that can be performed there until it reaches a full crew complement again.
The remaining three could in theory stay until January, when their Soyuz also starts to get stale, but there are earthly issues to deal with in terms of their schedule. If they wait that long, they will come down in a brutal Kazakh winter, and if they want to get in before that, the last time they can leave and still come down in daylight is in November, so for safety reasons, if the Russians haven’t figure out the problem and gotten a new expedition up by then, they will abandon the station entirely until they can. NASA believes that it can continue to maintain the facility remotely, at least for a while, but it will be a major psychological setback, particularly now that the station has just completed assembly and was about to start finally doing some serious research, including experiments with potential implications for medical cures.
Ironically, it would also be a setback for the most promising near-term means of reducing or eliminating our reliance on the Russians.
Space Exploration Technologies (SpaceX) is currently scheduled to launch its Dragon capsule to the ISS in late November, with plans for a test docking with the system in early December (almost exactly a year after its first successful flight). If that mission is successful, it will be cleared to start delivering cargo to the station next year, and it will be a major milestone toward using it as a crew delivery vehicle and lifeboat. To deliver crew, conventional wisdom is that it will need a life-support system and a launch abort system, which are in work, but won’t be ready for two or three years, depending on funding availability. It could serve as a lifeboat (and one capable of returning seven instead of three) with the addition of the life-support system only, and it could be a fairly rudimentary one for the short trip back to earth. With these capabilities, America would have its own answer to Soyuz.