Astronauts living aboard the International Space Station were surprised by the unexpectedly strong vibrations that rattled their orbiting lab last month, but don?t believe the event damaged their $100 billion outpost.
Space station commander Michael Fincke of NASA said the Jan. 14 vibrations shook objects loose from the walls during a scheduled engine burn, but it did not immediately spark concerns over the health of the spacecraft.
?We were definitely surprised,? Fincke told SPACE.com Thursday via a video link. ?It?s not usual during a reboost to see anything come off the walls.?
Video from a camera inside the space station showed equipment doors and other objects shaking back and forth.
The vibrations on Jan. 14 occurred during what was expected to be a routine Russian thruster firing to boost the space station into a higher orbit. During the two-minute, 22-second maneuver, sensors aboard the space station picked up vibrations that exceeded acceptable limits.
Michael Suffredini, NASA?s space station program manager, said Tuesday that a subsequent analysis has shown that the vibrations did not shorten the orbiting lab?s 15-year design lifetime. Space station flight controllers, however, did cancel another planned thruster firing slated for Wednesday pending more study.
?Fortunately, the results of the analysis so far shows that we haven?t hurt the space station,? Fincke said. ?But we certainly could have, so we?re definitely going to be very careful next time.?
Fincke described the engine burn as the strongest thrust he and his two crewmates had felt since they launched into space last fall aboard a Russian Soyuz rocket and NASA space shuttle. Whenever Fincke let go of a handhold in the station, the rest of the ship would noticeably move around him as he floated in weightlessness.
?At the time it was quite amazing,? Fincke said. ?Then the harmonic vibrations started to kick in and we saw things shaking off the walls. That was surprising, but it didn?t last very long.?
The astronauts then had to fly through the space station?s cabin collecting loose items and reattaching them to the outpost?s walls, he added.
Shuttle Discovery?s delay
With the vibration event behind them, the space station crew is preparing the orbiting lab for the arrival of a new Russian cargo ship and the space shuttle Discovery later this month. The unmanned cargo ship Progress 32 is slated to launch early next week and dock at the station on Feb. 13. But the planned Feb. 12 launch of Discovery has been delayed at least one week as engineers evaluate a fuel flow control valve concern.
For space station flight engineer Sandra Magnus, also of NASA, Discovery?s delay means a longer stay in orbit. Magnus arrived at the orbiting lab last November and will return home aboard Discovery.
?Of course, with shuttle schedules you never really want to get your heart set on a specific date because it?s a very flexible program," Magnus told SPACE.com. ?Another week is fine, they?ll make the right decision when to launch the shuttle and I?ll go home whenever it arrives.?
Discovery is now slated to launch no earlier than Feb. 19 to deliver the last set of U.S. solar arrays and Magnus?s replacement, Japanese astronaut Koichi Wakata.
Earlier this week, Magnus raided the space station?s pantry to put together some special treats during Sunday?s Super Bowl showdown between the Pittsburgh Steelers and Arizona Cardinals. Fincke, a Pittsburgh, Pa.-native who grew up in Emsworth, is a vocal Steelers fan who beamed down video messages of support to spur his team on during the NFL playoffs and their Super Bowl win.
?We really didn?t have a party, but Sandy did. She put together some really amazing dips and other Super Bowl treats that we normally would have on the ground,? Fincke said. ?It made the day even more special.?
- New Video - Shaky Space Station
- Video - Space Station Acrobatics
- NASA Weighs Excessive Vibrations on Space Station