Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/5/84; site ssc-vax.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxj!houxm!vax135!cornell!uw-beaver!ssc-vax!eder From: eder@ssc-vax.UUCP (Dani Eder) Newsgroups: net.columbia Subject: Re: Telling When Launch Will Occur Message-ID: <314@ssc-vax.UUCP> Date: Mon, 7-Jan-85 15:29:21 EST Article-I.D.: ssc-vax.314 Posted: Mon Jan 7 15:29:21 1985 Date-Received: Tue, 8-Jan-85 05:38:53 EST References: <3241@alice.UUCP> Organization: Boeing Aerospace Co., Seattle, WA Lines: 28 > 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