The failure of a Russian spaceship, which crashed back to Earth shortly after its launch last week, could lead to the International Space Station being unmanned for the first time since 2001. Russian engineers are trying to determine why the unmanned ship crashed, but they only have a short time to fix the problem if they want to relieve the six astronauts currently on the space station: All are scheduled to rotate home by November, Space.com reports, and NASA won’t allow any astronauts on a Soyuz rocket until the problem has been solved and several unmanned launches have been successful.
While those six astronauts won’t be affected much by the crash itself—they have enough supplies—three are due to return home next month, and the other three by mid-November, and several factors prevent them from extending their stays. Russia’s space agency originally planned to launch a manned mission Sept. 22, but that has now been postponed until late October or early November due to the failed launch, CNN adds. Even if the delay prevents a new crew from reaching the station, NASA officials say they will be able to operate it from the ground and “remain on orbit indefinitely.”