Bad vibrations may knock years off the space station's life

NASA is investigating whether moving the International Space Station last month caused structural damage that could cut the station's useful life, the agency said Monday.

Russian engineers last month sought to position the station to receive a robotic spacecraft on Feb. 13. The rockets used to change the station's location cut off abruptly rather than gradually, said NASA spokesman Kelly Humphries said.

That caused the station to shake more than it usually does, according to daily reports on the station's condition that are posted on NASA's website.

The extra jostling may have caused damage to the station that could affect its longevity, Humphries said.

"Anytime you impart a vibration to the station it has potential implications" for the station's solar panels and the connections between the station's parts, Humphries said.

The station's longevity is a sore point. NASA has no firm plans to make use of the orbiting laboratory, which costs roughly $100 billion, after 2015. Many of the other 13 nations that helped build and operate the outpost want to keep it going until 2020.

The station was built with extra structural strength, Humphries said, and the current analysis is "just making sure we haven't eaten into that margin."

NASA officials may decide today whether to call off a second attempt to move the station planned for Wednesday or to do it with a different set of rockets than those used in the station's earlier move, Humphries said.

The rockets used in January are on the exterior of a section of the station that serves as a kitchen and dining room. There's also a set of rockets on a robotic cargo pod that is temporarily parked at the station. Those could move the station Wednesday if engineers are still worried that last month's problem could recur.

The rockets on the station are also used to move the station out of the path of any oncoming debris that could puncture its exterior shield. Humphries said he did not know whether such maneuvers would be performed given the current uncertainty over the rockets' performance.

Space shuttle Discovery is scheduled to blast off Feb. 12 to carry new solar panels to the station. Its visit should not be affected by the relocation that went awry, Humphries said.

The station also needs to move in March so it can receive a Russian spacecraft carrying two new residents for the station. That will allow two crewmembers now aboard the station to go home.

Delays in construction mean that the station, which was started in 1998, still isn't finished and has been occupied by skeleton crews of two or three people. The first full crew of six people is scheduled to take up residence in May.

Equipment inside the station also is giving NASA headaches. New equipment for converting urine into drinking water — necessary to maintain a crew of six — failed, according to the daily online reports about the station. Officials hope to fly a replacement part on the upcoming shuttle flight.