Path: utzoo!attcan!uunet!wuarchive!zaphod.mps.ohio-state.edu!samsung!umich!dgsi!gregc From: gregc@cimage.com (Greg Cronau/10000) Newsgroups: sci.space.shuttle Subject: Re: launch rates Message-ID: <1990Oct3.232201.5196@cimage.com> Date: 3 Oct 90 23:22:01 GMT References: <10195.26fde341@pbs.org> <1990Sep25.033816.16652@zoo.toronto.edu> <1990Oct1.191917.24542@cimage.com> <1990Oct2.031535.6556@zoo.toronto.edu> Reply-To: gregc@dgsi.UUCP (Greg Cronau/10000) Organization: Cimage Corp, Ann Arbor, MI Lines: 91 In article <1990Oct2.031535.6556@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: >In article <1990Oct1.191917.24542@cimage.com> gregc@dgsi.UUCP (Greg Cronau/10000) writes: >>... The *FACTS* are that the average number of shuttle launches >>per year is nearly double what the average number of Saturn launches were. > >That is a fact. A thoroughly meaningless one. Ask any statistician what >he thinks of an average as a useful measure of such an uneven distribution. >or see any modern book on data analysis. > > >>I think these discussions should be based on "what is" rather than "what could >>have been". > >Yup. "What is" is that the Saturn V achieved 5/year, briefly, from late >1968 to late 1969. "What is" is that the shuttle has only once exceeded >that rate, and the evidence clearly shows that this overstrained the system. >Now, personally I suspect that the sustainable shuttle launch rate is >higher than that, but if we are to be obsessed with numbers to the exclusion >of thinking about what they mean, we can't consider that. >-- >Imagine life with OS/360 the standard | Henry Spencer at U of Toronto Zoology >operating system. Now think about X. | henry@zoo.toronto.edu utzoo!henry Henry this is really getting ridiculous. You continue to put down my assertions based on a set of data that you contend is meaningless, and then turn around and make your own assertions based on that very same data. 1.) I am not "Obsessed" with numbers. But the space launch question revolves around numbers: maximum thrust, weight, tonnage to LEO, launch turn around time, etc. If you can provide a qualitative vs. quantitative way to evaluate boosters, please, I'd like to hear about it. 2.) You state that the "Saturn V achieved 5[launches]/year, briefly," It did that *once*. You asked me to talk to a statitician about my conclusions, what do you think statiticians call a one-time unrepeatable spike in data? I'll tell you: noise. 3.) You state that: "The evidence clearly shows..." No. Sorry. The evidence shows no such thing. The design flaw in the SRB was aggravated by the cold on the morning of the launch. It was an accident waiting to happen. It would have happened if it had been preceded by 1 or 20 launches in the previous year. I will grant, however, that the evidence does "suggest". 4.) If, however, you would like to use that argument, what about Apollo 13? Memory fails me right now, and I don't have any of my ref books handy, but didn't it occur shortly after that 5/year period you mentioned? It could just as easily be blamed on the hurry up syndrome that you claim caused challenger. Don't get me wrong, I was unhappy to see Saturn pass into history. Few things make me as sad as seeing one of those great birds laying on thier sides corroding into dust. I wish there had been the funds to keep Saturn active in addtion to the shuttle program, but consider this: Saturn, because it is expendable, has an absolute lower limit to it's cost. How often do you think congress would have approved a launch with NASA saying it's going to cost $XXX million and it can't get any cheaper. The shuttle *can* be cheaper, it was promisied and designed that way. It didn't work out that way and I'm not surprised. Do you have any idea how hard it is to estimate what it's going to cost to build and maintian somthing *that's never been built before!!!* There are people that ernestly believe that somthing like that can be accurately estimated, I believe that's a fantasy. But, the shuttle *can* become cheaper. As we learn better ways to do things, the cost will come down and that can be sold to congress. I think we tend to loose perspective about the space program. Getting into space is several orders of magnitude more difficult than getting into the air. It is therefore going to require several orders of magnitude more work, time, money, and experience. While I won't put us at the level of the Wright flyer, I do believe that the shuttle is about the equivalent of a 1910 biplane. We've worked out some problems, but we've barely scratched the surface of the problems/possibiliies. Compare the total number of rocket launches with the total number of airplane flights, How much experience do we *really* have? I know the damned shuttle isn't perfect. It's far from it. I am surprised at how much of a jump it is from it's predecessor though. Few things make that much progress in one evolutionary step. But that's what it should be. A step. A step towards the next, better, design. Even if the shuttle had been built the way it was originally proposed back in the late 60's, I believe it would have been flawed. We just don't know enough. Someone stated in a previous message a few weeks ago: (I paraphrase) "People don't understand how nasty it is to get into space" I have worked with computers, mechanics, and electronics for almost 20 years now and I am still awed at the delicate ballet of barely controlled energys and precision timing that is required to get a rocket into space. Engines that are designed to run for 7 minutes, but not 8, and withstand temperatures just a hair below thier melting temp. Superstructure thrust points that can take 100 lbs of force here, but not 110. Electronics that have to be able to withstand multi-G shocks and keep working. I am amazed when it works and not surprised when it doesn't. Because it is nasty. But we seem to live in a world where something done once is now expected to be routine. The technocrats are expected to serve up thier magic on a regular schedule and are crucified when they don't. End Of Catharthis. gregc@cimage.com