NASA may be forced to evacuate the International Space Station unless its Russian partners can find a quick fix to a problem with their primary launch system.

That was the blunt message Monday from Mike Suffredini, the Houston-based manager of the large, orbiting laboratory.

"We're going to do what's safest for the crew and the space station," Suffredini said.

The Russians have formed an investigative team to determine the cause of a rocket problem that led to the loss of an unmanned Progress space capsule last week.

The Soyuz space capsule, the only means NASA currently has to ferry astronauts to the space station, relies on similar launch technology.

Suffredini said if the Russian rocket issue isn't resolved by Nov. 16, the space station will have to be evacuated temporarily.

There's currently a full complement of six astronauts aboard the station, which has two Soyuz capsules already docked there for return trips. Three - Expedition 28 commander Andrey Borisenko, Alexander Samokutyaev and Ron Garan - likely will come home in mid-September in one of those capsules.

A replacement crew had been scheduled to launch aboard a Soyuz next month, but that is now on hold until the investigation into and recovery from the Progress accident is complete.

The space station can operate normally with just three crew members, but their maintenance work leaves little time for scientific research.

The remaining three astronauts aboard the station - Expedition 29 commander Mike Fossum, Sergei Volkov and Satoshi Furukawa - will have to come home in mid-November because their Soyuz capsule is rated to stay on orbit for only six months and will be near the end of that time frame.

Mid-November target

That means if a replacement crew is to arrive before Fossum and his colleagues depart, the Russians have to identify, implement and test a fix to the launch system before mid-November.

It's entirely possible that will happen, said Jim Oberg, former mission control operator, NBC News consultant and Russian space program expert.

"I think the technical solution to this probably will be evident pretty quickly, then isolated to a component, and isolated to a production batch," Oberg said.

Under this scenario the revamped launch system could be tried in a Progress flight in October as well as three planned launches of commercial Soyuz spacecraft carrying cargo rather than passengers. If these launches go well, NASA probably will press ahead with a November crew launch.

Workforce challenge

The launch problem, as well as issues other Progress capsules have had trying to dock with the space station, highlight a bigger problem that NASA faces in regard to its Russian partner, Oberg said.

"In the Russian press, dozens of experts point to the recent failures as a reasonable consequence of a severe workforce challenge that's been 20 years in the making," Oberg said.

The workforce that designed and built the original Soyuz and Progress vehicles several decades ago has moved on, Oberg said, and the younger replacements are low-paid. It's not surprising that production line issues are cropping up, he said.

The new challenges with getting crew to the International Space Station, which has been inhabited for 11 years, come just a month after NASA retired the space shuttle.

The space agency is counting on private companies such as SpaceX and Boeing to develop alternative capsules, but those technologies may not be ready until 2015 or beyond.

Remote control

If NASA has to evacuate the space station it can still operate the facility remotely to keep it running smoothly, Suffredini said. But there are risks.

"It would be bad because the chance for loss of station goes up quite a bit when there is no crew onboard," said Leroy Chiao, a former astronaut who commanded ISS Expedition 10 in 2004 and 2005.

The risk comes from potential failures with station systems that could cause the station to lose attitude control, throwing off the ability of Houston and Moscow to send commands to the station antennas.

Under such a scenario the station's solar arrays could point away from the sun, and it would slowly power down and die, losing altitude and entering Earth's atmosphere.

eric.berger@chron.com