A faulty navigation system forced a delay in Saturday's scheduled launch of the space shuttle Columbia. NASA hopes to try again Wednesday morning. "This business takes a lot of patience," observed launch director Robert Sieck.
Congress is scheduled to debate funding for the controversial space station this week. Embarrassed by recent disclosures that flawed parts could have destroyed a spacecraft during launch, NASA very much wanted to have Columbia on the job in space today.
It isn't, because of erratic readings from a device called an inertial measurement unit (IMU), one of three carried on the shuttle.
During launch, the IMUs precisely measure the acceleration and movement of the shuttle in reference to a known starting point _ the launch pad _ to fix the shuttle's location. When in space, the shuttle uses stars to establish its location.
The shuttle carries two backup IMUs, and only one is needed to fly. NASA insists on having all three available, however, "because if you have only two, it's not easy to know which one is right and which one is wrong," shuttle program director Robert Crippen said.
During the delay, the faulty IMU will be repaired or replaced. NASA also will replace about 2,400 jellyfish and 30 rats _ the subjects of experiments on the effects of weightlessness. New animals of the exactly correct age and weight will be substituted.