With a last-minute repair job complete, NASA managers on Wednesday cleared the shuttle Discovery and its five crew members for blastoff Monday on a mission to launch a $100-million satellite.
The countdown for the flight--the third in the wake of the Challenger explosion and the first of seven missions planned for 1989--is to begin Friday at 12:01 a.m. EST, with launching to be attempted at 8:07 a.m. Monday.
The ship’s crew--commander Michael Coats, co-pilot John Blaha and James Bagian, Robert Springer and James Buchli--plans to fly to the space center on Friday for final launching preparations.
Engineers readying Discovery for liftoff faced dismal weather Wednesday, with rain and cloud cover, but a high pressure system is expected to sweep across central Florida on Saturday, bringing favorable conditions.
The decision to attempt a launching on Monday was made after engineers completed the replacement of a computer assembly in Discovery’s engine compartment that failed Sunday, forcing a two-day delay in launching activity.
The goal of the five-day mission is deployment of a $100-million NASA Tracking and Data Relay Satellite identical to one carried aloft by Discovery last Sept. 29 in the first post-Challenger flight.
The satellites are part of a world-spanning communications network designed to allow mission controllers to stay in contact with shuttle crews and other satellites over at least 85% of each orbit, letting the National Aeronautics and Space Administration shut down costly ground stations.