NASA's rollercoaster escape for Ares I

[josh_simonson]

Well, if you're going to count passive passenger miles, such as for the STS in orbit (where it's basically parked), we have to count that as well. So my car is moving at 1000m/h with the earth's rotation, and 67000m/h with the earth around the sun - I submit that my oldest car has traveled about 9,500,243,000 miles with no casualties.

 

[vulture2]

(discussing whether there are any contingencies that would require use of the roller coaster)<br /><br /> />>Prop tanks loaded pressurized for flight and we loose ground powere and it can not be restored quickly.<br /><br />If there's no power to extend the vent swingarm, how do we extend the crew access swingarm? <br />(Note that tanks are leak before burst, so it is hard to see how an explosion could occur.)

 

[halman]

mrmorris,<br /><br />I am guilty of using analogy in my argument, which I know is a poor way to argue. However, I am trying to illustrate a concept of preventability, in that NASA was aware that foam strikes were causing potentially catastrophic damage to the TPS, yet choose to fly rather than grounding the fleet until a fix could be found. If that decision was influenced by political factors, then it was an even more criminal choice. To knowingly operate a vehicle as complex as the Space Shuttle when basic parameters are being violated is sheer stupidity. Seeing as the loss of the shuttle was a result of this choice of actions, which was corrected by making changes to the External Tank, not to the orbiter, I believe that the Columbia accident should not be used in judging the safety of the vehicle. I can make any aircraft crash, any car wreck, by operating it far enough outside parameters. That does not mean that the vehicle is inherently unsafe, and needs to be redesigned.<br /><br />So, if the Challanger loss was entirely preventable, and should never have happened, and had nothing to do with operations under normal conditions, it should be excluded in judging the safety of the shuttle. The same holds true for the loss of Columbia. Therefore, under normal operating conditions, the shuttle has not experienced any fatalaties.<br /><br />The reason that autombiles are so dangerous is because of the people who operate them. You are not very likely to die in a wreck resulting from the engine blowing up, or the tie rods breaking. But your chances of being seriously injured or killed are considerable every time you get into a car, either as a result of your own actions, or of someone elses. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[halman]

shuttle_guy,<br /><br />I remember hearing that the second O-ring had been breached on one occaision, but it was after the SRB's had seperated, and did not exhibit the signs that the motor was at full thrust at the time of the breach. As I understand it, the last few seconds of the burn, the internal pressure drops somewhat due uneven propellant consumption.<br /><br />Okay, be pedantic! By lift off, I meant the first few minutes of the flight. Techinically, I should have said ascent.<br /><br />In spite of tile loss and damage to RCC panels on almost every flight, the orbiters usually come home. MMOD damage does not reflect on the safety of the vehicle, in my opinion, it is an inherent risk of traveling 17,000 miles per hour.<br /><br />Few people seem to remember that we only flew capsules for a few years, and there were not that many flights period. So we cannot say that we have a large body of data on capsule safety resulting from our own space program. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[mrmorris]

Halman:<br /><br />It's not worth my time to make another post about the flaws in your argument. You get full marks for spreading some sand on the floor and doing the old soft shoe rather than simply replying 'Yeah -- what I posted didn't really make sense. What I *should* have typed was... X"<br /><br />Mind you -- I'd have more respect for your future posts if you'd done the latter.

 

[vulture2]

Shuttle_guy - I hope I haven't given the impression that I am a nihilist on this issue. I am 100% in favor of having a fast gound egress route. <br /><br />I simply think it should be available every day and from all major levels. It makes little sense to have a fire escape that is available only on one day and one level, let alone a fire escape so hazardous it is not even used during exercises. Emergencies can happen anytime, particularly with a rocket that is always loaded, and the lives of ground employees are not less valuable than those of astronauts. I feel the high-speed elevator concept (with emergency power) also makes sense because it is the only one that is bidirectional, and some contingencies require a rescue crew to go in before the injured person(s) can be taken out.