STS-90 COLUMBIA/NEUROLAB LAUNCH POSTPONED 24 HOURS

The launch of Space Shuttle Columbia on STS-90 with Neurolab has been postponed 24 hours due to difficulty with network signal processor No. 2 on the orbiter. This device formats data and voice communications between the ground and the Space Shuttle. Two network signal processors are required for launch and landing and are also highly desirable for on-orbit mission operations. The unit, which is located in the orbiter's middeck, will be removed and replaced today.

The weather forecast continues to reflect a zero percent chance of not meeting the launch weather criteria on Friday. The planned launch time for Columbia continues to be 2:19 p.m. EDT at the opening of a 2 1/2 hour window.

Launch commentary on NASA Television will begin at 8 a.m. Friday.