Readers Carl Ehrlich and David Ashford assert that spaceplanes are the correct choice for space transportation (AW&ST April 12, p. 8), in a classic case of solutions looking for problems.rnOne first has to examine the requirements before the best choice can be made. If the mission is crew transport with safety as the primary driver, space-planes can never compete cost-wise with capsules. They do not have the complexity of spaceplanes in the areas of windward outer mold line penetrations,rnflight controls, software and thermal protection, to name a few. So what is the acceptable safety requirement baseline? If it is the NASA Human Rating Requirements document, then it is already game-over for an affordable spaceplane.
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