Astronauts forced into shorter, less comprehensive shuttle survey
Sunday, May 16, 2010
CAPE CANAVERAL, Fla. -- A snagged cable forced Atlantis' astronauts to resort to a more inconvenient and less comprehensive method of inspecting their space shuttle Saturday as they sped toward a weekend rendezvous with the International Space Station.
Mission Control, meanwhile, was monitoring a piece of space junk that was threatening to come too close to the space station. The debris was projected to pass within six miles of the complex this morning, shortly after the shuttle's scheduled arrival.
Flight director Mike Sarafin said the estimated gap was right at the allowable limit, and noted that even a small error in determining the location and timing of the junk could have dire consequences. Experts did not know how big the object was or where it originated.
Even if the space station has to dodge out of the way, it won't delay this morning's scheduled docking by Atlantis.
The condensed safety survey of Atlantis also will not interfere with the docking, Sarafin said.
The inspection is a standard -- and essential -- procedure the day after liftoff. A 100-foot boom is used to survey the heat shield on both wings and the nose in a hunt for launch damage. On Saturday morning, however, the astronauts could not tilt the bundle of laser sensors and TV camera on the end of the pole.
It turns out a cable was pinched by the camera at the end of the boom. The astronauts didn't think they could free it.
The six astronauts used cameras and binoculars to beam down close-up pictures. The cable was dented where it was being squished, Ham reported.
Finally, after several hours, Mission Control had the astronauts use the backup set of lasers and camera hard-mounted to the boom, which left out some potential problem areas. They were limited to the daytime side of Earth because of the digital camera equipment.
The crew focused on the most vulnerable areas -- the heat shield on the wings and nose. It was unlikely they would get everything they needed from the left wing.
Sarafin said he expects to get all the necessary images one way or another, either from extra zoom-in photos taken by the space station crew during Atlantis' final approach Sunday or following the linkup.
It's possible the astronauts could free the cable during one of the three planned spacewalks for the mission, if deemed necessary. Sarafin said it was too soon to know whether the equipment was put in wrong or whether the cable was shaken out of position during liftoff.
Day-after-launch and day-before landing shuttle inspections were put in place following the 2003 Columbia disaster. Columbia shattered during re-entry because of a hole in the left wing; it was left there by insulating foam that broke off the fuel tank during liftoff.
Only a few small pieces of foam were spotted coming off Atlantis' tank Friday. Nonetheless, the wings and nose still needed to be checked.
This is Atlantis' last planned flight after a quarter-century of service. It's hauling fresh batteries and a new Russian compartment to the space station. Three spacewalks are planned to plug in the batteries and other equipment.
Only two more shuttle flights remain, by Discovery and Endeavour. NASA is ending the program so it can focus on presidential-ordered trips to asteroids and Mars.