Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.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 (2 of 3) Message-ID: <1565.27401C39@ofa123.fidonet.org> Date: 13 Nov 90 03:40:15 GMT Organization: One For All Lines: 69 However, this does pose some interesting questions. If, as you say, the Delta HLV design is 7 Deltas strapped together, does this not imply the reliability to be .98^7 = .86? Also, looking at the historical data shows that a significant design change to a launcher typically results in a pattern of failure for a few years (shown in Delta and Scout upgrades, and in the little bit of data I have on Titan history). How do we avoid the "infant morality" for a major design change to a HLV? For discussion sakes, lets say .90 for the new, untested HLV, and .98 from the shuttle. 2) The difference in launch costs. I will accept the Shuttle is never get the economies of scale per individual launch available in a HLV. So the price of an individual shuttle launch will be always higher ($/lb) than a HLV. However, if we can increase the shuttle annual flight rate from 4 to the planned 12, then the cost is reduced by $2.3 B. Similarly, your HLV costs can be claimed as very opimistic. If, LLNL is going to pay for a Space Station to completely recover the development and financing costs for a HLV, and there is no long- term recurring market, I think the cost could be increased. Any problems with early system reliability, delivery schedule, government funding lines (leading to program stretch-out), technical problems with the LLNL station, or the HLV delivery schedules would increase its launch costs. Again, for discussion purposes, let us propose increasing the HLV cost by 30% (at least!) for these considerations, and showing the shuttle costs at a 12 per year flight rate. $0.195B vs $1.170B. 3) Engineering for assembly in orbit. I would assume the provisions needed to assemble something on orbit are the connections be simple and very easy to do/undo via EVA. However, aren't these the same connections needed if the Space Station can be maintained on orbit by EVA? For example, if one of the LLNL modules were to be damaged beyond repair by orbital debris, it would necessarily have to have these EVA dis-assembly provisions, so the module could be unhooked and a new one hooked in. I would rate this as a wash, between the two. Combining all this, gives a set of revised numbers... Item HLV Shuttle Payload $22.5 B $22.5 B Insurance $ 2.250 $ 0.450 Launch cost $ 0.195 $ 1.175 EVA $ 0.0 $ 0.002 Engineering $ 0.0 $ 0.0 Same between the two -------- --------- 24.945 24.017 Which has now reversed.... I would say the most sensitive part of this calculation is reliability since Shuttle total costs come out cheaper is HLV reliability is .94 or less (shuttle at .98). Based upon the historical patterns for launch vehicle development, this might be a reasonable bet. Anyway, I think we've beat this subject to death. Can we agree to disagree on this? My opinion is that we need a HLV capability, and I think it would make sense to apply such to any Space Station program - after a good test period (10-20 flights). I'm just not as hard over on killing our current programs in favor of untested new programs - without a much better examination of what this entails. But I support activities to examine this option. (cont) -- Wales Larrison Internet: Wales.Larrison@ofa123.fidonet.org Compuserve: >internet:Wales.Larrison@ofa123.fidonet.org --------------------------------------------------------------------------