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Does a solid-fuel Ares 1 make sense?
Ares 1 or the 'Stick' is based on the shuttle SRB. The grandfather of
manned space flight, Von Braun, was of the opinion that solid rockets should not be used for personnel because they cannot be turned off when ignited and they have a higher failure rate than liquid fuelled equivalents. Of course the SRB has only failed once in STS operation, but that was enough to cause the Challenger catastrophe. So, does the use of the SRB for Ares make sense or not? Or are we waiting on an accident in the future? |
#2
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Does a solid-fuel Ares 1 make sense?
Stephen Horgan wrote:
Ares 1 or the 'Stick' is based on the shuttle SRB. The grandfather of manned space flight, Von Braun, was of the opinion that solid rockets should not be used for personnel because they cannot be turned off when ignited and they have a higher failure rate than liquid fuelled equivalents. Of course the SRB has only failed once in STS operation, but that was enough to cause the Challenger catastrophe. So, does the use of the SRB for Ares make sense or not? Or are we waiting on an accident in the future? There are two components to this question. I don't claim to be competent to address the technical part fully. However, solid rockets may have improved since the days of von Braun. As well, the Challenger catastrophe was due to a failure of the O-rings, one that related to a specific design issue. As we know, there were people who were *consciously aware* of a serious elevated risk of an accident in cold weather, and who *consciously chose* not to take steps to avoid that risk by advising NASA against a launch in cold weather until the flaw was corrected - for _trivial_ reasons of avoiding embarassment and protecting corporate profits. Thus, the Challenger disaster had specific causes that don't necessarily imply that all solid rocket boosters are inherently unsafe. It may be now that if solid rocket boosters are used in a conscientious and ethical manner, they may have a role in space flight. This brings up the non-technical component. People die in industrial accidents all the time. Being a test pilot is a hazardous occupation, and so is being a race-car driver. At least in the days of the Apollo program, being an astronaut was glamorous - because astronauts were regarded as brave people, taking risks. Therefore, some have asked - and it is not unreasonable to ask - whether or not it is justified to spend inordinate sums to make astronauts "safe". Are their lives worth so much more than anyone else's? My take on *this*, though, is that that's asking the wrong question. For one thing, a Saturn V booster happens to be a very expensive beastie. Making sure it doesn't blow up on the launch pad, therefore, is going to cost a *lot* of money. Observing from statistics that we usually spend, on average, not more than $2 million on a precaution that saves one life, and attempting to place that as a ceiling on the space program, would simply lead to the rockets blowing up every time, hence no space program. In the case of launching space probes and satellites, we can simply weigh dollars and cents against dollars and cents. The financial losses involved in a launch failure times the probability of a launch failure, plus the cost of a launch given a certain level of safety precautions... is the quantity to minimize by a wise choice of safety precautions. We want astronauts to effectively carry out tasks when they are in space. This means that being an astronaut cannot be an occupation appealing only to reckless daredevils; such people aren't suited to do the job. But the main issue is this: We quite properly resist explicitly and directly putting a "dollar figure" on human life. We expect that everything that can be done, unless it is utterly ridiculous and absurdly excessive, and can be seen to be so, to address any avoidable risk to human life will be done. Anything else would leave someone *morally to blame* should an accident occur. The continued existence of a space program rests on the goodwill of the American taxpayer. (Of course, that statement, although seemingly axiomatic based on past experience, is in itself debatable. And decisions made by private persons with respect to their own lives, and freedom of contract and all that, would allow the existence of a different yardstick in the event of privately-funded manned space activities.) And that good will cannot be abused. The safety record of the Apollo program, along with the conscientious spirit it inspired, is the goal to emulate. A program to send someone to Mars is *long* overdue. If we waited much longer, particularly thanks to ideas like Bob Zubrin's, the first man to land on Mars might well have been Chinese... or even North Korean. (If one can take his price tag seriously, it's a pity Canada didn't accept the offer of the Turks and Caicos Islands to join our country. They have a nice downrange to the East, just like Florida, and they're much closer to the Equator than any part of Canada, therefore being a much more suitable place to launch rockets from with ecliptic-related tasks.) But just as there might have been worries, had the program been started under Bill Clinton, that it was all a plot to distract us from Monica, despite a generally magnificent response to the terrorist attack of September 11, 2001, the administration of George W. Bush has not managed to entirely escape controversy. (Some wag might, of course, ask how _that_ is supposed to be a scathing criticism of _any_ U.S. President, but I digress.) The effort to explore space must be carefully shielded from the corrosive winds of cynicism. Despite what some revisionist historians may claim, John F. Kennedy was very nearly universally beloved during his tenure as President, not just after his shocking assassination. Today, politics seems to be played more roughly than in the halcyon days of my youth - back then, the party of the liberals would not have thought to get so far ahead of public opinion as to openly embrace legalizing abortion, or, sadly, even legalizing homosexual acts between consenting adults. Back then, instead, one could point to real injustice suffered by black people *that was still being actively contributed to by the actions of some governments*. And, back then, the party of the liberals recognized that the Soviet Union was no 'workers paradise', but a cruel hoax played on those who looked for a better way than the injustices and union-busting of the Depression. In other words, since then, the Democrats have steadily been losing respectability, and the Republicans have been gaining it - but we are left without a political party with which we can be *fully satisfied*. One that isn't led by people who will let political correctness get ahead of national security - but that is led by people we can trust to have their hearts in the right place. If the American people could have a President they could *love*, then were he to suggest bold new initiatives in space, all thoughts of a base partisan motive would be banished, and we could proceed on this bold adventure with our hearts properly singing. John Savard |
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Does a solid-fuel Ares 1 make sense?
Stephen Horgan wrote:
So, does the use of the SRB for Ares make sense or not? No. Or are we waiting on an accident in the future? Yes. It's a perfect example of a rocket on steroids, huge bulging head, skinny legs. Just the impression we need to give to the world. America - high on steroids, totally irrational. http://cosmic.lifeform.org |
#4
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Does a solid-fuel Ares 1 make sense?
On 7 Sep 2006 01:09:51 -0700, "Stephen Horgan"
wrote: Of course the SRB has only failed once in STS operation, but that was enough to cause the Challenger catastrophe. And part of the liquid propulsion system (the External Tank) caused the Columbia accident. Call it a wash. So, does the use of the SRB for Ares make sense or not? Off the shelf, 4 segment SRB possibly, if only minimal changes are necessary. The 5-segment booster now planned makes no sense whatsoever. It's pork for Utah, plain and simple. When Ares 5 jumped to 5-segments and dumped the SSME, NASA should have cut its losses and switched to one of the EELVs. Brian |
#5
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Does a solid-fuel Ares 1 make sense?
Brian Thorn wrote in
: On 7 Sep 2006 01:09:51 -0700, "Stephen Horgan" wrote: Of course the SRB has only failed once in STS operation, but that was enough to cause the Challenger catastrophe. And part of the liquid propulsion system (the External Tank) caused the Columbia accident. Call it a wash. So, does the use of the SRB for Ares make sense or not? Off the shelf, 4 segment SRB possibly, if only minimal changes are necessary. The 5-segment booster now planned makes no sense whatsoever. It's pork for Utah, plain and simple. When Ares 5 jumped to 5-segments and dumped the SSME, NASA should have cut its losses and switched to one of the EELVs. Hmm? Ares 5 was always 5-segment. Did you mean Ares 1? -- JRF Reply-to address spam-proofed - to reply by E-mail, check "Organization" (I am not assimilated) and think one step ahead of IBM. |
#6
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Does a solid-fuel Ares 1 make sense?
On Thu, 07 Sep 2006 01:09:51 -0700, Stephen Horgan wrote:
Ares 1 or the 'Stick' is based on the shuttle SRB. The grandfather of manned space flight, Von Braun, was of the opinion that solid rockets should not be used for personnel because they cannot be turned off when ignited and they have a higher failure rate than liquid fuelled equivalents. Of course the SRB has only failed once in STS operation, but that was enough to cause the Challenger catastrophe. So, does the use of the SRB for Ares make sense or not? Or are we waiting on an accident in the future? Solid rockets on manned vehicles only make sense if you like holding your breath for two minutes. -- Craig Fink Courtesy E-Mail Welcome @ |
#7
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Does a solid-fuel Ares 1 make sense?
"Stephen Horgan" wrote in message ups.com... Ares 1 or the 'Stick' is based on the shuttle SRB. The grandfather of manned space flight, Von Braun, was of the opinion that solid rockets should not be used for personnel because they cannot be turned off when ignited and they have a higher failure rate than liquid fuelled equivalents. Of course the SRB has only failed once in STS operation, but that was enough to cause the Challenger catastrophe. Actually, you can install thurst termination systems on the SRB. The ones installed on the shuttle unzipper the casing along the length. Unfortunately this event would be extremely violent. So some here do say that you can "turn off" the thrust of a large SRB, but I have no idea if the CEV designers will design the CEV such that it could survive thrust termination. The obvious way to do this would be to first fire the escape tower, and then the thurst termination system. Unfortunately, the Titan program showed us that there are failure modes of large, segmented boosters that give little to no warning before the things violently destroy themselves, so the above wouldn't necessarily help in all cases. So, does the use of the SRB for Ares make sense or not? Or are we waiting on an accident in the future? Possibly. Of greater significance is the fact that it will be a 5-segment SRB instead of the 4-segment shuttle SRB that we have a lot of experience with. Adding that fifth segment (with it's new fuel cross section and thrust versus time curve) essentially makes it a new SRB. Also, Aries I requires a roll control package for the SRB, and an all new upper stage which uses an engine that while based on the venerable J-2 used on the Saturns, was never fully developed. In other words, we have zero flight experience with the upper stage and its engine. Put all this together and the "safe, simple, soon" claims of ATK are clearly marketing intended to hide the fact that this design has serious "image problems" when it comes to safety, complexity (with its 5th segment and upper stage this thing is a bit too long and slender which could cause design challenges), and schedules. Then there is the whole philosophy of keeping as much shuttle infrastructure around as possible for Aries V. This added overhead won't make Aries I inexpensive at the low flight rates expected. EELV's are looking better to me every day. Jeff -- "They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety" - B. Franklin, Bartlett's Familiar Quotations (1919) |
#8
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Does a solid-fuel Ares 1 make sense?
"Brian Thorn" wrote in message ... On 7 Sep 2006 01:09:51 -0700, "Stephen Horgan" wrote: Of course the SRB has only failed once in STS operation, but that was enough to cause the Challenger catastrophe. And part of the liquid propulsion system (the External Tank) caused the Columbia accident. Call it a wash. True, but that one is easy to avoid. Stick your sensitive payloads above the tanks with SOFI, just like Saturn V and the proposed Aries designs. So, does the use of the SRB for Ares make sense or not? Off the shelf, 4 segment SRB possibly, if only minimal changes are necessary. New roll control package, redesign of the top of the SRB to support payloads on the top rather than the side, elimination of the SRB separation motors, etc. The 5-segment booster now planned makes no sense whatsoever. It's pork for Utah, plain and simple. When Ares 5 jumped to 5-segments and dumped the SSME, NASA should have cut its losses and switched to one of the EELVs. Agreed. Also, while the planned J-2X is based off the venerable J-2, and follow-on development done previously, it's not a flight proven engine. I would have felt better if NASA had picked an engine being flown today, not one where they pretty much have to scour storage facilities and museums for hardware to examine. :-P But all of that is beside the point. Aries I/V are designed to keep the shuttle infrastructure intact. As such, it's going to be yet another NASA only, high fixed cost, low flight rate vehicle that has little to no chance of being economical and little to no chance of anyone outside of NASA ever using it. That's not a recipe that will help the US launch industry in any way, shape, or form. Jeff -- "They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety" - B. Franklin, Bartlett's Familiar Quotations (1919) |
#9
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Does a solid-fuel Ares 1 make sense?
"Craig Fink" wrote in message news On Thu, 07 Sep 2006 01:09:51 -0700, Stephen Horgan wrote: Ares 1 or the 'Stick' is based on the shuttle SRB. The grandfather of manned space flight, Von Braun, was of the opinion that solid rockets should not be used for personnel because they cannot be turned off when ignited and they have a higher failure rate than liquid fuelled equivalents. Of course the SRB has only failed once in STS operation, but that was enough to cause the Challenger catastrophe. So, does the use of the SRB for Ares make sense or not? Or are we waiting on an accident in the future? Solid rockets on manned vehicles only make sense if you like holding your breath for two minutes. Yep. As the Titan showed, they can fail extremely quickly and destructively. Not exactly a case I'd want to face if I was trying to design a launch escape system for the CEV. I wouldn't exactly want to trust a multi billion dollar lunar lander and TLI stage to two 5-segment versions of them. There is zero flight experience with 5 segment SRB's. If they were so "safe, simple, and soon", you'd think we would have seen them developed instead of the current Al-Li ET to increase payloads for ISS missions. Jeff -- "They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety" - B. Franklin, Bartlett's Familiar Quotations (1919) |
#10
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Does a solid-fuel Ares 1 make sense?
On Thu, 07 Sep 2006 21:25:33 -0500, "Jorge R. Frank"
wrote: Off the shelf, 4 segment SRB possibly, if only minimal changes are necessary. The 5-segment booster now planned makes no sense whatsoever. It's pork for Utah, plain and simple. When Ares 5 jumped to 5-segments and dumped the SSME, NASA should have cut its losses and switched to one of the EELVs. Hmm? Ares 5 was always 5-segment. Did you mean Ares 1? Whoops! Yes. Brian |
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