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Orion PDR slides to mid 2009
"Derek Lyons" wrote in message ... "Alan Erskine" wrote: They're having all sorts of problems; is this kind of thing unusual in a major program? I mean, to have this many problems this early (booster, CM etc)... It's not unusual at all - the capsule programs of the 60's had it just as bad, as did the Shuttle. The difference it that because of the 'net the problems are visible to thousands of armchair engineers very nearly in real time. The difference was with Apollo, von Braun didn't believe the initial weight estimates for the CSM and LEM. So he put in generous performance margins in the design of the Saturn V. That didn't happen with Ares I and Orion, which is why mass budgets are so tight on both programs. In other words, today's NASA management thought there wouldn't be problems when they set the initial mass/payload requirements for Orion/Ares I. Jeff -- A clever person solves a problem. A wise person avoids it. -- Einstein |
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Orion PDR slides to mid 2009
"Alain Fournier" wrote in message ... There is also the difference that in the sixties, those building space ships were considered the cutting edge of engineering. Problems were considered normal. Nowadays, people expect engineers to be able to re-solve the problems that were already solved in the fifties and sixties without much difficulty. Today management expects that as well. I don't believe Ares I's original requirements had as much performance margin as von Braun quietly slipped into the Saturn V. von Braun did this specifically because he did not believe the initial mass estimates for the CSM and LM (i.e. he believed they would both grow in order to solve problems with the initial designs). He was right. Jeff -- A clever person solves a problem. A wise person avoids it. -- Einstein |
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Orion PDR slides to mid 2009
Jeff Findley wrote:
"Alain Fournier" wrote in message ... There is also the difference that in the sixties, those building space ships were considered the cutting edge of engineering. Problems were considered normal. Nowadays, people expect engineers to be able to re-solve the problems that were already solved in the fifties and sixties without much difficulty. Today management expects that as well. I don't believe Ares I's original requirements had as much performance margin as von Braun quietly slipped into the Saturn V. von Braun did this specifically because he did not believe the initial mass estimates for the CSM and LM (i.e. he believed they would both grow in order to solve problems with the initial designs). He was right. I recall he had to be convinced that hydrogen in the upper stages was a good idea. They ran some quick performance simulations on a computer (that must have been a trick back in those days) and he was convinced. |
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Orion PDR slides to mid 2009
"Jeff Findley" writes:
I don't believe Ares I's original requirements had as much performance margin as von Braun quietly slipped into the Saturn V. von Braun did this specifically because he did not believe the initial mass estimates for the CSM and LM (i.e. he believed they would both grow in order to solve problems with the initial designs). He was right. I'm quite sure he did that also because he didn't knew exactly how much he would be able to squeeze out of the Saturn V and so was very conservative with the design. Jochem -- "A designer knows he has arrived at perfection not when there is no longer anything to add, but when there is no longer anything to take away." - Antoine de Saint-Exupery |
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Orion PDR slides to mid 2009
In sci.space.history Jeff Findley wrote:
That didn't happen with Ares I and Orion, which is why mass budgets are so tight on both programs. In other words, today's NASA management thought there wouldn't be problems when they set the initial mass/payload requirements for Orion/Ares I. Is it they didn't think there would be problems, or was it that to add-in the extra margin to cover problems would have even more clearly called into question the whole Ares I and (not)being a "just shuffle shuttle components" at the beginning? rick jones -- The computing industry isn't as much a game of "Follow The Leader" as it is one of "Ring Around the Rosy" or perhaps "Duck Duck Goose." - Rick Jones these opinions are mine, all mine; HP might not want them anyway... feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH... |
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Orion PDR slides to mid 2009
"Jeff Findley" wrote:
"Derek Lyons" wrote in message ... "Alan Erskine" wrote: They're having all sorts of problems; is this kind of thing unusual in a major program? I mean, to have this many problems this early (booster, CM etc)... It's not unusual at all - the capsule programs of the 60's had it just as bad, as did the Shuttle. The difference it that because of the 'net the problems are visible to thousands of armchair engineers very nearly in real time. The difference was with Apollo, von Braun didn't believe the initial weight estimates for the CSM and LEM. So he put in generous performance margins in the design of the Saturn V. Von Braun's actions have no bearing whatsoever of the question of whether or not such problems are unusual. D. -- Touch-twice life. Eat. Drink. Laugh. http://derekl1963.livejournal.com/ -Resolved: To be more temperate in my postings. Oct 5th, 2004 JDL |
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Orion PDR slides to mid 2009
Derek Lyons wrote: Von Braun's actions have no bearing whatsoever of the question of whether or not such problems are unusual. Since building manned spacecraft shares a lot in common with building high performance aircraft, when's the last time you heard of a aircraft coming in significantly _under_ the planned weight? :-) Pat |
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Orion PDR slides to mid 2009
Pat Flannery wrote:
Derek Lyons wrote: Von Braun's actions have no bearing whatsoever of the question of whether or not such problems are unusual. Since building manned spacecraft shares a lot in common with building high performance aircraft, when's the last time you heard of a aircraft coming in significantly _under_ the planned weight? :-) Or [combat] ships and submarines. D. -- Touch-twice life. Eat. Drink. Laugh. http://derekl1963.livejournal.com/ -Resolved: To be more temperate in my postings. Oct 5th, 2004 JDL |
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Orion PDR slides to mid 2009
On 1 Sep, 20:26, "Alan Erskine" wrote:
"Alain Fournier" wrote in message ... There is also the difference that in the sixties, those building space ships were considered the cutting edge of engineering. Problems were considered normal. Nowadays, people expect engineers to be able to re-solve the problems that were already solved in the fifties and sixties without much difficulty. Then why can't they? *Why do such problems keep happening? NASA hasn't developed an all new launcher since the Space Shuttle in the 70s. The engineers who made that happen have retired. The performance problems with Ares 1 are also having a knock on effect with Orion. Not so much Orion being overweight, as Ares 1 under performing. |
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Orion PDR slides to mid 2009
On Mon, 01 Sep 2008 19:26:18 GMT, "Alan Erskine"
wrote: "Alain Fournier" wrote in message ... There is also the difference that in the sixties, those building space ships were considered the cutting edge of engineering. Problems were considered normal. Nowadays, people expect engineers to be able to re-solve the problems that were already solved in the fifties and sixties without much difficulty. Then why can't they? Why do such problems keep happening? Because they're different problems. They just look the same. New materials, new designs, new problems. I mean, there's not that much difference, practically, between a 707 and a 747-400, except for the materials, aerodynamics, structure, propulsion, performance, avionics, cabin electronics, and a bunch of other things. Mary "Even the external lighting is different" -- Mary Shafer Retired aerospace research engineer We didn't just do weird stuff at Dryden, we wrote reports about it. or Visit my blog at http://thedigitalknitter.blogspot.com/ |
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