alb@brunix.UUCP (Adam Buchsbaum) (03/03/85)
The mission of the space shuttle Challenger has been scrubbed because officials are worried that a timing problem in the TDRS-A satellite, now in orbit, will be duplicated in TDRS-B, now in Challenger's cargo bay. The problem is in the satellite's encryption mechanism, used to code signals sent to and from military shuttle flights. A Canadian communications satellite, also in Challenger's bay, will be moved to Discovery's bay, for a hybrid mission including that satellite and a Navy communications satellite that was scheduled to launch aboard the Discovery on 22 March. That date may move to early April. The retrieval of the LDEF (Long Duration Exposure Facility), which was left in orbit last April and was due to be retrieved by the Discovery crew, will probably be put off until a later mission. NASA will announce this week which crew, the Challenger's or the Discovery's, will fly the Discovery mission, and whether or not Senator Jake Garn will have to wait for another flight. It will also announce the new launch date. Challenger will be moved back to the VAB, where it will await another mission, probably Spacelab-2 in late April.