Posted on 02/03/2003 8:22:36 AM PST by Preech1
According to NASA's own websites, the shuttle has 25 minutes to abort a launch before the shuttle enters orbit. Had NASA considered the damage to the wing to be a danger to the crew, they could possibly have saved the lives of the 7 astronauts and we would today be speaking of that dramatic event rather than mourning their deaths.
I am in no way blaming NASA for the deaths of these crew members, but instead I am trying to answer the MANY posters who have said the crew was doomed from the start.
While it is true that the crew was doomed once they attained orbit, there was a 25 minute window after launch in which the shuttle could have aborted the mission.
Here's how I see it. The main reason for the break-up appears to be structural failure due to the combined factors of a damaged wing and the heat and stress of re-entry. Had the shuttle aborted the flight at launch, there would still have been a risk with the damaged wing, but speed and re-entry heating would not have factored in. It would have been a bumpy landing to be sure, but they would have landed.
I only write this article to suggest that NASA consider this possibility in future flights. We can do nothing about the past.
May the souls of the Columbia Rest in Peace.
Why do you persist in all this speculation and finger pointing? On the one hand you act like you have this smoking gun. In the other you admit there was probably nothing that could have realistically been done. What's the point of it all?
Duh. No sh*t, Sherlock. We're not idiots. Uuuuuuuuuuggggggggghhhhh!!!!!!!! I need my medication.
Here's a link to your article: http://spaceflightnow.com/shuttle/sts107/030203analysis/
Abort profiles deal with launch emergencies which occur during ascent. The two types of aborts are the intact and the contingency aborts. An intact abort is a plan to return the orbiter to a preplanned landing site while the contingency abort is used if an intact abort procedure is no longer possible. In the event of a contingency abort the astronauts attempt to land the orbiter wherever they can and if a safe landing is impossible, the crewmembers bail out of the stricken craft and use their parachutes. The contingency abort was examined thoroughly after the Challenger accident and was thought to be survivable. Both of these abort modes assume the orbiter remains in a functioning or flyable condition; the Challenger accident was a catastrophic failure which falls into a non- survivable category.
There are four basic intact shuttle abort modes. They are based upon time of flight of emergency occurrence, energy available, and location of the orbiter. The intact abort mode cannot be initiated until after the SRBs have separated from the rest of the shuttle. The earliest intact abort is the return to launch site (RTLS). If a main engine fails in the first four minutes of flight the orbiter will not reach orbit and the crew must return the shuttle back to KSC. After the SRBs separate the two remaining SSMEs continue to operate to burn as much of the remaining ET propellant as possible. With as little of the fuel remaining in the ET as possible the shuttle executes a powered pitch around maneuver (PPA) where the orbiter and the ET rotate 180_ 6; so that the craft is headed back to KSC. The orbiter is now on top of the ET at this time and the remaining SSMEs are still operating. When the fuel runs out and MECO occurs the ET can be jettisoned safely. It cannot be done so until all of the fuel from the ET has been used because the propellant sloshing around in the ET may cause it to collide with the orbiter. Once the ET has separated the orbiter glides to landing at KSC. This maneuver has never been tried; the aerodynamics involved in rotating a vehicle as large as the orbiter with the ET attached while the SSMEs are still operating could be prohibitive. The RTLS cannot be used after four minutes and thirty seconds into the flight.
If a shuttle main engine fails between 4 minutes 30 seconds and six minutes after launch, the orbiter has enough energy to fly across the Atlantic and land in Morocco, Senegal, Gambia, or Spain depending upon the mission's planned inclination. This is called a Trans Atlantic Landing (TAL). After initiating the TAL the orbiter continues to climb using up all the ET fuel by the operating SSMEs until reaching MECO. The velocity and altitude at this time are far below those required to achieve orbit. The entire vehicle is rolled so the orbiter is on top of the ET and the big tank is jettisoned. The orbiter then lands at the appropriate airfield. The TAL is considered safer than the RTLS and if there is a choice at the four minute mark, the NASA controllers and the astronauts would probably choose the TAL. The TAL is possible at five minutes and thirty seconds into the launch even if two SSMEs are lost.
Six minutes after launch the third option or abort once around (AOA) becomes feasible if one SSME fails. After the ET's propellant burns out and MECO occurs there is enough velocity to achieve a very low orbit through the Earth's upper atmosphere. These orbits decay extremely rapidly, but permit the orbiter to land in California. The astronauts activate the OMS thrusters to sustain a temporary orbit prior to attempting a landing. At seven minutes into the launch the AOA is feasible even if two SSMEs fail.
The final option, abort to orbit (ATO), occurs at six minutes and thirty seconds after launch if one SSME fails. When the ET runs out of propellant and MECO occurs the velocity required for orbit falls short of that required to orbit normally. In this case the velocity differential is so small that it can be compensated by OMS thruster burns. ATO is possible after seven minutes into the flight if two SSMEs fail. In this case the remaining operable SSME is throttled up to 109% at seven minutes or 104% at seven minutes thirty seconds into the flight to achieve ATO.
Of these four intact abort mode only the ATO has been used; the other modes are practiced constantly by the astronauts in the simulators, but have not been necessary in actual flight. Extreme emergencies such as three SSME failure, ruptured ET, or malfunctioning SRB may not be survivable because the SRBs and the ET must be jettisoned before the astronauts can bring the orbiter back to Earth. After Challenger many people conjectured about jettisoning the orbiter away from a malfunctioning stack; the experts say that the survivability factor in such an attempt is little or none.
If they had not gotten complacent over tile damage on takeoff they may have proceduralized the "abort" if any damage was seen on takeoff. I can't believe how many are slaying the messenger when they know NOTHING about the subject!
Did you bother to read the link?
I think it's called "Groupthink."
And you don't?
All the more reason!
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