Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!usc!elroy.jpl.nasa.gov!zardoz.cpd.com!dhw68k!ofa123!Wales.Larrison From: Wales.Larrison@ofa123.fidonet.org (Wales Larrison) Newsgroups: sci.space Subject: Re: Reliability and Insurance (1 of 3) Message-ID: <1564.27401C37@ofa123.fidonet.org> Date: 13 Nov 90 03:38:38 GMT Organization: One For All Lines: 67 Allen, you raised some interesting questions... >Of course, the government usually doesn't buy insurance for the >payloads it puts into orbit. Actually they do. There are differing ways of getting launch insurance (or more properly, assurance). One way is placing a bet with a broker on the probability of success, which is the normal commercial insurance method. This the government does not do. However, another form of insurance is "self-insurance" where the payload originator typically buys an additional satellite. Government program managers for programs with greater than 1 satellite constellation will typically buy an additional satellite and keep it on the ground in storage against a possible launch failure. This was done for DSCS, DSP, Fleetsatcom, TDRSS, GPS, and other government programs. Some commercial firms, Intelsat, for example, have elected to also do this due to large block buys of satellites. Another way of launch "assurance" is to very intensively control and monitor the launch operations. This is what is done for some classified programs which launch one of a kind superbly expensive satellites, and is the current way of doing things on Shuttle launches. >First of all, let's look at the cost of doing the same thing with >the Shuttle compared to the HLV: > >Item HLV Shuttle >Payload $22.5 B $22.5 B >Insurance[1] $ 1.125B $ 1.125B >Launch cost[2] $ 0.150 $ 3.5 B >EVA[3] $ 0.0 $ 0.002B >Engineering[4] $ 0.0 $ 2.25 B > -------- --------- > $23.775B $29.377 > [...Notes left out..] Hmmm... interesting point. However, I think you've been very optimistic about the HLV, and very pessimistic about the Shuttle. Let me do a sensitivity analysis, and play at being optimistic about the shuttle, and pessimistic about the HLV. The difference in cost given here is driven by three two factors: 1) an assumption the long-term reliability of the two systems - a yet undeveloped, "paper" HLV will have the reliability of the Shuttle, 2) the difference in assumed launch costs, and 3) the difference for engineering costs for assembly in orbit. 1). Reliability - the shuttle is, I believe, currently 44/45 (.978). Looking at the equivalent past history of ELVs, the Scout failed 11 of the first 49 launches (1960-66, r=.78), Delta had 3 of the first 43 fail (1960-1966, r=.93), and Atlas had 9 of the first 42 spacelaunches fail (1962-1977, r=.79) [Sorry, couldn't quickly find the data for the Titan program history]. Since each system is now showing reliabilities in the range of .94-.98, I would conclude the shuttle system is going through a common trend in space launchers, known as "infant mortality" where design flaws are found and fixed, and the system reliability increases. Rather than throw in some mathmatical mumbo-jumbo trying to project an increased reliability for the shuttle, I think we can say the Shuttle system reliability should increase with time, if the pattern found in historical launch programs is followed. (cont) -- Wales Larrison Internet: Wales.Larrison@ofa123.fidonet.org Compuserve: >internet:Wales.Larrison@ofa123.fidonet.org --------------------------------------------------------------------------