Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site ucbvax.BERKELEY.EDU Path: utzoo!watmath!clyde!burl!ulysses!ucbvax!space From: dietz@SLB-DOLL.CSNET (Paul Dietz) Newsgroups: net.space Subject: Re: Shuttle Articles in Discover Magazine Message-ID: <8512040335.AA22626@s1-b.arpa> Date: Tue, 3-Dec-85 18:41:08 EST Article-I.D.: s1-b.8512040335.AA22626 Posted: Tue Dec 3 18:41:08 1985 Date-Received: Thu, 5-Dec-85 08:03:03 EST Sender: daemon@ucbvax.BERKELEY.EDU Organization: The ARPA Internet Lines: 83 I see no evidence that launching people with a satellite increases the launch reliability. If anything, it decreases reliability, because we've inserted another stage (the low-orbit to high orbit transfer) into the launch process. It is at this stage that three failures have occured (the two PAM failures and the IUS failure with the TDRS satellite). The Ariane launches directly to geosynchronous altitude (admittedly, the Ariane has more stages than the shuttle, and can be criticized on that count). Note also that no shuttle flight has managed to repair or recover a broken satellite that was launched on the same mission. >>At least in the satellite launch business, it makes little sense to >>lift people into orbit along with the cargo. The proper response is >>to make the hardware sufficiently reliable that it doesn't need costly >>human supervision. >This can easily be as costly as sending humans along. *Reliable* hardware >is expensive; that's why Shuttle costs so much, and why Ariane's so cheap. There is a difference between the reliability needed for carrying people and the reliability needed for economic launchers. For example, launching a $100 million satellite on a booster with a 5% chance of catastrophic failure is acceptable; the insurance costs will be a small fraction of launch costs. Launching people in such a booster is clearly unacceptable. The shuttle needs to be much more reliable than expendable boosters, and it costs. The question here is: does it make sense to make the booster more reliable so that you can make the PAM motor less reliable? Not likely, given that the booster costs orders of magnitude more than the PAM motor (assuming that the unmanned system would even HAVE a PAM motor). Also, using the shuttle to launch high-energy upper stages using LH/LOX fuel is causing big headaches. The Centaur upper stage used with Gallileo is having safety problems and may delay that mission for a while. >>Developing the current shuttle was a silly waste of hard-to-get funding. >Not at the time the decision was made. There was a serious danger there >would be no space program as such at all, just a bunch of Atlas and Titan >boosters kicking communications satellites into orbit. The shuttle changed >all that, and instead of no spaceflight we have spaceflight that's so >routine it's not even newsworthy anymore. Now the truth comes out. Could it be that the purpose of the shuttle was not to provide cheap transport into orbit, but rather to allow NASA (aka "the space program") to continue to exist? That putting people into space was taken as given and a justification was invented for doing so? This is not necessarily bad, if the money would otherwise have gone to some worthy cause like propping up the price of butter. But... I suspect that if the shuttle hadn't been developed the aerospace companies would have gone to work improving their expendable boosters, much as the europeans did. As it happened, they didn't, because NASA was supposed to produce a fantastically cheap launcher that would make any such expendable booster uneconomical, and working on the shuttle was a risk-free source of money. --- An aside: an article in Business Week (12/9/85, page 124) talks about the DOD and their shuttle facility at Vandenburg. It contains the paragraph: "Operation of manned space-launch facilities at Vandenburg will add only $400 million to the military's $15 billion space budget next year. But Congress may have to increase that figure considerably in 1987 and beyond because of plans to replace the present space shuttle. The next-generation spacecraft will be designed to take off from an airport rather than from a rocket pad. This will reduce waiting time between launches and cut their cost in half." DOD apparently isn't constrained to justify the shuttle. In fact, there have been reports (in Science last year, for example) that the DOD was concerned about the shuttle's poor reliability and potential for catastrophic failure, and wanted to develop an interim expendable booster (NASA was horrified; I don't know if the idea has died). The military is the biggest customer for low altitude satellites -- weather and spy satellites -- for which the shuttle is suited. This is probably the biggest market for satellite repair the shuttle can service, or, rather, will be once the shuttle is able to reach polar orbit.