brt@whuts.UUCP (B Reytblat) (02/05/86)
In the wake of the loss of USS Challenger, the old argument that reusable launch vehicles are inherently more expensive then the expendable ones has been heard again. The following info, paraphrased from Aviation Leek 2/3/86, is intended as substantiating evidence (but not conclusive) against such an argument. The Titan 34D-7 expendable launch vehicle is under development by Martin Marietta for the US Air Force. USAF will procure 10 of them for 2.09 billion dollars, presumably over the next 2-4 years. This comes out to 209 million per launch, at the rated capacity of 10,000 lb to geosynch for H/W alone. More for actually flying the thing (fuel, servicing and control). Further analysis [ mine....!whuts!brt ]: 1. This is roughly the same order as the STS/IUS, taking subsidy into account. Actual STS/IUS cost per flight is on the order of 250 million (before gvt. subsidy) all inclusive. Neither costs include initial development, as it has already been accounted for in years past. 2. However, STS per launch costs include vehicle construction and maintenance, amortized over N flights (i don't know what N is). At the end of that schedule, we still have a flying vehicle, worth 1-2 billion dollars. THIS IS WHY STS WINS. 3. 34D-7 is probably less capable than STS for low orbit because of restriction on the size of the payload (STS payload bay is larger). 4. 34D-7 does not get us any closer to permanent manned presence in space. 5. Current version of 34D, of which several vehicles are in the USAF inventory, is less capable in terms of $/lb. 34D-7 will not fly until 1988. Conclusion: Although expendable launch vehicles are roughly equivalent to STS for a short term, onezie-twozie program, reusable launch vehicles, even as inefficient as STS, are still preferable for long term presence in space. My personal commitment to the manned space program stands. Ben Reytblat AT&T-BL ...!whuts!brt "... And so it goes ... "