eder@ssc-vax.UUCP (Dani Eder) (01/07/85)
> Discovery was rolled to the pad today, in preparation for the > 23 January military launch. The Pentagon will only say that > the launch time will be between 1315 and 1615 EST, and the > public will know more specifically only ''when the engines > ignite.'' When might a sightseer be able to predict the launch time? Well, normally about 2 hours before launch, the crew enters the orbiter. You might catch the astronaut convoy driving out to the pad. The External Tank normally begins chilldown at T-5 hr, and is filled over a number of hours. There will be vapors around the tank once it begins to be filled. The support crew leaves at T-30 min. Their trucks might be observed leaving the pad area. At T-9 min the automatic sequencer is started. Beyond this point there is a five minute hold capability. At T-7 min the crew access arm begins retracting. At T-3 min the Space Shuttle Main Engines are gimballed to start position. At T-2 min 30 sec the External Tank vent arm is retracted. Beyond this point there is only a two minute hold capability, and the count would have to be recycled to T-9 min. At T-18 sec the SRB nozzles are swiveled. Of course, at T-3.46 sec the Main Engines are started. Happy Observing. Dani Eder / Boeing Aerospace Co., Advanced Space Transportation Organization "Tommorrow, you can be anywhere" / uw-beaver!ssc-vax!eder / (206)773-4545
droms@CS-Arthur (Ralph E Droms) (01/09/85)
Regarding "leaking" the launch date ... I just took one of the Space Center bus tours and, during the tour, the guide mentioned that the next flight would be on January 23rd (pause two beats), uh, or thereabouts. And there was a big sign on one of the access roads: Next Shuttle flight in 28 days!! (Yeah, I know the launch DATE has never been a "secret", just the time. But everyone on the bus had a good chuckle anyway.) -- Ralph Droms purdue!droms Purdue University droms@purdue.arpa