12 years ago
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if a space shuttle will not take off what are the possible solutions?

if a space shuttle will not take off what are the possible solutions?
Top 2 Answers
12 years ago
kirchwey
Favorite Answer
The shuttle is a very complex system so the possibilities are almost innumerable. Thousands of variables are continuously checked up to liftoff time, and any one of them being out of bounds can call a halt to the countdown. Some faults may be judged allowable, others may be quickly resolved, and others may scrub the launch for the day. On the shuttle itself, to name a few variables, temperatures, pressures, actuator motion speeds and ranges, and instrumentation signal voltages are monitored. Systems checked (again, to name a few) include main engines (SSMEs), orbital maneuvering system (OMS), reaction control system (RCS), propellant tanks and pumps, solid rocket boosters (SRBs), auxiliary power units (APUs), aerosurfaces, flight computers, navigation instruments and other avionics. Redundant computers and instrumentation must agree and redundant actuators must all work. Weather must be OK and the launch zone must be clear of traffic. Conditions must be good at a number of alternate abort landing sites. If delays or "holds" put the time beyond the launch window the flight is scrubbed for the day. At a few seconds before liftoff, the three SSMEs are started. If any of them is performing even slightly abnormally, the SRBs do not ignite and the launch is scrubbed. Otherwise, finally, the SRBs are ignited and "we have liftoff." I could go on, but I hope this much gives you the idea.
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12 years ago
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Take off at the next window. Usually to catch up to the ISS or launch a satellite in the cargo bay, there are "windows" or time slots for several days to launch. The most common problems in launching the shuttle are sensors reporting malfunctions and weather. Often times, the sensors themselves are the culprit, but you can't risk it so you go out and check on the situation. Weather at the Cape or at alternate landing sites around the world may be bad. A sandstorm in North Africa or cloud cover over the Indian Ocean may make an emergency landing there treacherous, so the launch is "scrubbed" (even though there hasn't been an emergency landing of the shuttle in its entire life).
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