ADRENALINE...
FROM THE GROUND UP

The official "The Cape"
Web Site can be found here.

(Anything I've used from the TV show is
owned and copywritten by MTM Enterprises, Inc.)



6th Episode: "Family Values"
Aired week of Oct 21, 1996
and week of Mar 3, 1997

RILES SOFTENS UP WHEN HE SPENDS TIME WITH A SON THAT HE'S NEVER KNOWN.

Plot: (pasted from the official "The Cape" Web Site)

text not available



Photos from "Family Values" coming soon!



Shuttle Questions:

How do the Shuttle Engines and Solid Rocket Boosters get ignited?
The spark-throwing devices that can be seen on NASA TV throwing sparks into the Space Shuttle Main Engine (SSME) nozzles are not igniting the engines. The sparklers are actually burning off any stray hydrogen that may have leaked from the SSMEs prior to ignition. They have nothing to do with the actual ignition of the SSMEs or SRBs.

The three SSMEs are started by the Orbiter’s onboard computers at approximately 6.6 seconds prior to liftoff. The Orbiter’s computers tell the SSME controllers (additional computers in control of each SSME) to start a very complex ignition sequence. The controllers open several liquid propellant valves to allow propellant to 'fall' into internal combustion chambers. The controller than turns on several spark ignitors (spark plugs) in each engine which ignite the propellant mixtures in internal combustion chambers. These combustion gases then drive propellant pumps (turbopumps) which continue to feed the overall combustion process. Additional combustion occurs in the 'main' combustion chamber and then the gases escape from the nozzle producing the thrust. It is a very convoluted process with lots of feedback paths for liquid and gaseous propellants. The hard part to believe is that it is just as complicated and delicate a process to get the SSME’s shut down safely at the end of their 8 1/2 minute burn time.

The SRBs also ignite under the control of the Orbiter computers. The SRBs are filled with solid propellant that has a hollowed-out cylindrical cavity from the top to the nozzle (similar to a pencil without its lead). There is a smaller solid rocket motor at the top of the SRB which is ignited by the computer with a pyrotechnic device just prior to liftoff. This small motor sends a flame down the length of the larger booster’s inner cavity and ignites the whole interior propellant. The gases then pressurize the inside of the booster and escape from the nozzle. The Orbiter computers then fracture bolts (with more pyrotechnic devices) which hold the boosters on the pad and....the Shuttle hurtles off the launch pad.

This question was answered by Frank Markle, former Booster Officer in Mission Control, Houston in charge of Space Shuttle launch propulsion systems during ascent.

Text pasted from the official STS-79 Web Site, under the Ask Mission Control Center Questions section.



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This page was written by Kurt Leucht (kleucht@nyx.net)
Last Revised: Sunday October 31, 1996

Disclaimer: This document in no way represents Nyx or the University of Denver. All opinions and erorrs are mine alone.