Astronauts may need to take the unprecedented step of temporarily abandoning the International Space Station if last week's Russian launch accident prevents new crews from flying there this fall.
Until officials figure out what caused Russia's Soyuz rocket to crash, there will be no way to launch any more astronauts before the current residents have to leave in mid November. The rocket was carrying an unmanned cargo ship.
"We have plenty of options," NASA's space station program manager, Mike Suffredini, assured reporters Monday. "We'll focus on crew safety."
Abandoning the space station, even for a short period, would be an unpleasant last resort for the world's five space agencies that have spent decades working on the project. Astronauts have been living aboard the space station since 2000, and the goal is to keep it going until 2020.
Suffredini said flight controllers could keep a deserted space station operating indefinitely, as long as all major systems are working properly. The risk to the station goes up if no one is on board to fix equipment breakdowns.
Six astronauts are living on the orbiting complex. Three are due to leave next month; the other three are supposed to check out in mid November.
Russia's Soyuz spacecraft have been the sole means of getting full-time station residents up and down for two years. The rocket has been extremely reliable over the decades. Russian space officials have set up an investigation team and until it comes up with a cause for last week's accident and a repair plan, the launch and landing schedules remain in question.