SPACE : Shuttle Launch Date Moved Up

NASA today advanced the date for the second launch attempt of Discovery with its Hubble Space Telescope payload, saying the shuttle will be ready for liftoff Tuesday.

Launch team members and payload managers decided to move up the launch by a day after a new auxiliary power unit in the shuttle passed a crucial test. Liftoff originally was scheduled for Wednesday, 15 days after the first attempt was scrubbed because of a faulty power unit.

Technicians successfully fired up the new auxiliary power unit for about five minutes early today.

The 88-pound power unit, installed over the weekend, is one of three that pressurize the shuttle’s hydraulic system, which is used to move wing and rudder surfaces and in the ship’s braking and steering systems. Each power unit must work before a shuttle can be launched.