A few years ago at the Amsat Colloquium University of Surrey we were privilaged to have astronaut Ron Parise (SK) as a guest speaker. He explained the ignition suquence for the shuttle in a very entertaining way, as best I remember it went like this
As the engines come up to thrust the explosive bolts fire and away she goes. If one of the pyrotchnics fails its no problem the bolt just gets ripped out of the concrete
73 John G7HIA
________________________________ From: Jeff Moore tnetcenter@gmail.com To: amsat-bb@amsat.org Sent: Sunday, 6 June, 2010 20:43:11 Subject: [amsat-bb] Re: Falcon 9 video - moving early?
That sort of thing is actually common practice. The Shuttle, for example, fires the main engines and allows them to get up to thrust and stabilize while the vehicle is still clamped down, then they fire the solid boosters, then they let it go.
Jeff Moore -- KE7ACY BAR - Born Again Rocketeer CN94
----- Original Message ----- From: "Elan Portnoy" elanportnoy@yahoo.com
That's been the case even earlier as well. Listen to any of the countdowns for the Apollo lunar missions. The Saturn V's engines would ignite at about T-9 and take a few seconds to produce full thrust before lift-off at T = 0.
I remember the announcer saying something to the effect of, "T minus 9, ignition sequence has started."
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