alb@alice.UUCP (Adam L. Buchsbaum) (07/14/85)
NASA said today that technicians believed yesterday's abort to be due to a faulty actuator on a hydrogen cutoff valve. The actuator will be removed Sunday for extensive testing, and NASA officials will meet Monday to decide how to proceed -- whether to set another launch date or move the Challenger off the pad and delay its mission indefinitely. Timing becomes critical now. Columbia is scheduled to arrive at the Cape on Sunday, marking the first time all four shuttle have been at the space centre. Atlantis is due to be moved into the VAB this week for mating with SRB's and ET and then moved to the launch pad for a flight readiness test firing (lasting 20 seconds) on 30 July. If Challenger's launch is set for later this month, that firing will be delayed, thereby postponing Atlantis' maiden mission, now set for mid-September. Discovery is due to launch on 24 August; its mission will be to deploy three communications satellites and attempt to rescue to the stranded Syncom satellite. The launch window for that mission is only four days wide. Columbia's next launch, its first after its recently completed overhaul, is set for December.