VSE: LAST CHANCE TO KILL NEGATIVITY?

[spacefire]

I thin 65 seconds is damn good-because it involves booster separation. The Space Shuttle RTLS only provides for the failure of ONE engine during flight. IMO that's a pretty 'happy' scenario.<br /><br /><font color="purple">"The RTLS abort mode is designed to allow the return of the orbiter, crew, and payload to the launch site, Kennedy Space Center, approximately 25 minutes after lift-off. The RTLS profile is designed to accommodate the loss of thrust from one space shuttle main engine between liftoff and approximately four minutes 20 seconds, at which time not enough main propulsion system propellant remains to return to the launch site."</font>/safety_wrapper> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[wdobner]

<i>This is getting ridiculous. The Apollo managers and engineers at the time concluded that reaching the moon "before this decade is out" was only possible using the very simple Apollo architecture and even then just barely. That's the reason von Braun dropped his earlier plans - but maybe you want to pretend that you know better than NASA's finest... </i><br /><br />I agree, I apologize for bringing it up. Von Braun remained a staunch supporter of the Earth Orbiting Rendezvous approach to a moonshot, which would have closely mimicked the space station approach he initially proposed. Unfortunately we wound up with the Lunar Orbit Rendezvous, which did little to extend the state of the art or secure anything like a permanent place in space.<br /><br /><i>Not going to happen. As you already pointed out in your post NASA's RLV programs failed for various reasons and I'm absolutely certain that they wouldn't do any better if they were given yet another chance. </i><br /><br />Apollo failed to keep us on the moon on a permanent basis, yet it's getting a second chance for virtually no reason other than us now pursuing a wasteful lunar program which provides us with no long term benefits. <br /><br /><i>These programs failed in every way imaginable. They were both management/bureaucratic failures and engineering failures. We don't have the technology for SSTO spaceplanes and we won't have it any time soon. Scramjets don't help that much, something the NASP people realized too late. It would never have worked no matter how much money NASA had spent/wasted on this ill-concieved project. </i><br /><br />What technologies do we lack. Carbon-Carbon materials can take the heat projected on nearly all parts of the craft during acent and decent. A more advanced tile system would provide a more robust thermal protection system than the shuttle ever had, all while possibly being lighter. They'd also have the benefit of active cooling using the LH or even just hydrocarbon fuel heading in

 

[spacefire]

what happens to the Shuttle if:<br />an SRB explodes;<br />an SSME explodes;<br />the ET explodes (or catches fire or somehow it sops feeding the SSMEs)<br /><br />catastrophe. the Shuttle really sucks. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[JonClarke]

Name one booster that does not experience catastrophe in the event of a strap on booster explosion, a main engine explosion, or a propellant leak and fire.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[darkenfast]

This is where a capsule with an escape tower (as will be on the new CEV) comes in VERY handy. Neither the SRB or the upper stage will detonate like an explosive (nor did the Challenger's). It certainly looks like it, but the burn rate is a lot slower. Challenger was destroyed by aerodynamic forces when it was pushed sideways against a supersonic airflow. The SAIC safety and reliability study on the ATK launcher proposal looks at this scenario and concludes that a capsule with an escape tower should survive. At higher altitudes, after the tower is jettisoned, a rupture of the second stage should also be survivable by a well-built capsule.

 

[JonClarke]

Exactly.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[centsworth_II]

So "furturistic" comic book spacecraft, however cool they may look, are NOT necessarily the best in real life! Especially with the current know how and budget. <div class="Discussion_UserSignature"> </div>

 

[spacefire]

<font color="yellow">This is where a capsule with an escape tower (as will be on the new CEV) comes in VERY handy. Neither the SRB or the upper stage will detonate like an explosive (nor did the Challenger's).</font><br />This proves my point exactly. oyu NEED an abort motor on the orbiter to take you away from the booster. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[spacefire]

<font color="yellow">Challenger was destroyed by aerodynamic forces when it was pushed sideways against a supersonic airflow</font><br />just out of curiosity and not to prove a point, can our shuttle experts tell what would happen to the orbiter in the following scenarios:<br />1) All 3 SSMEs stop working while the SRBs are still firing<br />2)One SRB booster stops firing<br />3)Fire in the ET<br />4)One SSME somehow catches fire<br /> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[spacefire]

<font color="yellow">The Orbiter rides out the SRB burn then separates from the ET to ditch. </font><br />can it hold together with the change in pitch -i.e. the orbiter, instead of supplying some of the thrust-becomes only a source of drag. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[darkenfast]

"This proves my point exactly. oyu NEED an abort motor on the orbiter to take you away from the booster."<br /><br />Assuming for the sake of discussion that the CEV capsule weighs about 15,000 lbs, and the tower about 10,000. How much would an abort motor weigh have to weigh to perform the same function as the tower pulling the entire orbiter away? Even an escape capsule (the pressure hull ejected out of the fuselage) was rejected as being way too heavy. The shuttle's caught in a weight trap, due to it's conflicting requirements as a crew-carrying cargo spacecraft with a big wing and tail. All they can do is fix what they can, which they are doing, and fly the program out to 2010.

 

[skyspider]

Will somebody explain why a stupid replacement for foam isn't a viable alternative? Why not enclose the tank in a dry nitrogen or helium plastic "bubble" a few inches thick .. internal standoffs of inflatable sections.. ? When the shuttle fires, the bubble goes poof and the bird flies. Foam is only there to keep ice from forming.. something a few inches of dry helium should be able to accomplish. After booster start, its no longer needed, so why carry it into the sky?