NASA Renegades

[Darrell]

Interesting article about some NASA upstarts wanting to go with the Jupiter Direct launch system instead of the Ares system NASA has been planning to replace the shuttle. Found over at Insty:

http://www.origin.popularmechanics.com/ ... 98615.html

There's a good image you can enlarge to see the two different spacecraft, in both ISS and lunar configurations.

[Draven]

I disagree with using either, we need to get rid of the shuttle junk.

[Rich]

We are always going to have groups proposing that their ideas are better, and sometimes they are.

What we need is a system that will put as much tonnage as possible into orbit and beyond, and be as simple as possible to operate. Whether or not the return vehicle has wings or not is a question of lesser importance.

IMHO, the shuttle has performed admirably, considering it was a very limited production run of the vehicle, essentially every one a prototype, and was used by a culture that ensured it would never become the quick turnaround vehicle it was sold to the public and Congress as being.

Both shuttle accidents occurred because the shuttle rode alongside the main fuel tank instead of on top of it. A classic design flaw that allowed both accidents to happen. Most of the new design proposals feature stacked components because of those shuttle experiences, but the shuttle itself is still a very versatile vehicle.

I would not be adverse to building some.more shuttles, designed to ride atop an engine/fuel tank cluster rather than beside it.

[Draven]

well, one accident occured becuase of the SRBs, which NASA always intended to replace with throttleable liquid fuelled ones.

And now they wanna use em as a launch vehicle

[Rich]

Draven: well, one accident occured becuase of the SRBs, which NASA always intended to replace with throttleable liquid fuelled ones.

IIRC, that was due to a faulty "O" ring, and may have been survivable if the explosion had occurred under the tail of the shuttle instead of right underneath the belly.

The other accident was the chunk of ice that damaged the tile at the wing/fuselage juncture of the shuttle. It never would have happened if the shuttle had been on top of the engine tank cluster as the chunk of ice would have had nothing to hit.

<edited to get my facts straight>

[Kommander]

Honestly for what NASA does they have a very good accident rate, and that is part of the problem. If the pioneers in the aeronautics industry had been as afraid of accidents as NASA we would still be flying biplanes. They would be very safe biplanes, but still just biplanes. NASA needs to realize that what they do, strapping some guys to a "craft" and launching them into FUCKING SPACE, is inherently unsafe and need to accept the fact that people are going to die. Once they do that we can begin to move forwards again.

[Precision]

Honestly for what NASA does they have a very good accident rate, and that is part of the problem. If the pioneers in the aeronautics industry had been as afraid of accidents as NASA we would still be flying biplanes. They would be very safe biplanes, but still just biplanes. NASA needs to realize that what they do, strapping some guys to a "craft" and launching them into FUCKING SPACE, is inherently unsafe and need to accept the fact that people are going to die. Once they do that we can begin to move forwards again.

NASA isn't the problem with accepting the odds. We the people and the whiny want to cut money from the NASA budget congress weasels are the problem there. NASA only genuflects to that because if they don't, they get no money.

[mekender]

Draven: well, one accident occured becuase of the SRBs, which NASA always intended to replace with throttleable liquid fuelled ones.

IIRC, that was due to a faulty "O" ring, and may have been survivable if the explosion had occurred under the tail of the shuttle instead of right underneath the belly.

The other accident was the chunk of ice that damaged the tile at the wing/fuselage juncture of the shuttle. It never would have happened if the shuttle had been on top of the engine tank cluster as the chunk of ice would have had nothing to hit.

<edited to get my facts straight>

ok Challenger was due to an o ring that was not designed to operate at the temperatures that they launched at... the rubber became brittle at the sub freezing temps and caused a burn through... that thrust caused the SRB to swing sideways and into the fuel tank... from there it was all over but the clean up...

Columbia was due to a foam insulation that was used as a coating on the fuel tank... a peice about 6 feet wide hit the wing of the orbiter and caused a hole that breeched into the wheel well... on re-entry, the heat caused the tire to pop and then caused the explosive bolts that drop the wheels into place to fire off (note, there is no system for retracting the wheels while in flight)... with one wheel down and the orbiter moving at close to 8000MPH, there was nothing else that could be done...

please note, challenger was not destroyed by an explosion, it came apart because of high aerodynamic stresses as it started to tumble during launch...

neither incident was the fault of the type of system that is used for launch, but a flaw in manufacturing of one of the components...

[Rich]

Challenger disintegrated because the liquid hydrogen exploded after the SRB "O" ring failed. The explosion was at a right angle to the direction of flight. Several crew members evidently survived the initial breakup and died when the shuttle remains hit the ocean. If the shuttle had been on top of the stack, the explosion would have been along the axis of flight, and the shuttle may have survived in good enough shape to attempt ditching or even trying to land at Patrick AFB. Or, it may not have survived an explosion along that axis either.

Columbia would have survived if it had been perched atop the stack because the foam (I said ice, but as Mekender correctly pointed out, it was a fairly large piece of foam) piece would have had nothing to hit, and the launch would probably have proceeded normally.

Please note, while the type of system didn't directly cause either accident, it allowed one to happen and may have acerbated the other.

[mekender]

according to the challenger incident review, the disintegration of the orbiter would have subjected the crew to about a 20g shock... enough to black them out but that many if not all of them probably survived and regained consciousness during the 2+ minute free fall back to the ocean... though it does say that the over 200g shock of the impact with the ocean would have most definitely been fatal...

as for the survival possibilities of a different axis, i dunno... i mean you are talking about tremendous stresses and speeds involved... i suspect that any deviation of more than a degree or two from the flight axis would be enough to rip the wings right off... at conventional airplane speeds, sure... but at speeds of several times mach, i dont think so...

as to columbia, i have to say i saw it first hand... i was on the ground in TX sticking flags next to debris for several days... there wasnt much left... the launch would have been totally fine had the procedures for securing the foam been more like they are now... the flip side of the argument is that any object collision could have caused the same thing...

in all, you are talking about 2 fatal incidents over a course of 125 launches... the design was that such that it would have 1 incident for every 50 launches so its not far from its mark... actually it is quite remarkable when you consider that you are talking about strapping humans to the top of some 6 million pounds of thrust that is created by some of the most volatile compounds known to man...

someone above said something about replacing the SRBs with a liquid... that was considered for a while... but the solids were lighter, cheaper and gave a more consistent thrust... as far as i know the plan is to continue using solids for every one of the design plans that has been proposed...

realistically the biggest problem with NASA is that congress weasels and senators always have better things to do with the money than fund a space program... im sure NASA could come up with much better designs and programs and use much better technology... but they rarely get the budget to do so...