dietz@SLB-DOLL.CSNET (Paul Dietz) (12/14/85)
>| The following items are more important: >| (1) Cheaper transport to low earth orbit >Better is the enemy of good enough. I think we've spent enough effort >on getting to LEO and we need to spend some effort on other things >now. If we continue to work on cheaper Earth-to-LEO we won't have time >or money for the rest. We have Arianne, USSR boosters, private >boosters, for bulk materials that are expendable if the rocket fails. >We have STS for irreplacable things like trained humans and expensive >or one of a kind equipment. If somebody happens to make a new way to >get to orbit, fine, but let's not spend our money on it now. (I'm not >very practical, I might be wrong.) I disagree. The shuttle and all other launchers are unacceptably expensive. As my previous message said, there appear to be many new airbreathing engine ideas that could get us to orbit much more cheaply. >Whatever happened to the Interim Upper Stage that was in the works >about 5 years ago but didn't get funding? You mean the booster used to lift the TDRS to GEO? It's not reusable. I've had a change of heart about reusable OTV's. Their main use would be lifting satellites to GEO, and that can be done more cheaply with a tether-type launcher in low orbit and an expendable apogee kick motor on the satellite. Satellite repair is a second-order market, and is not likely to be large for some time to come. Asteroid visits would need a different vehicle, as would moon landings, and so cannot justify an OTV. > (5) A GEO space station > Wait until after LEO station done, then see if GEO station needed, or > remote-control from LEO will be totally sufficient. Remote control from LEO?! You mean remote control from the ground, don't you? Comet rendevous is not likely to be done soon, because there is no market for it, and because for most comets the delta-v is prohibitive, making any resource recovery uneconomical. >| The first missions to Mars will probably establish bases on or near >| Phobos and/or Deimos. These moons are likely to contain water >| and carbon compounds, and could be processed into air, food and fuel. >I think a remote-controlled local-servo rover on Mars such as HPM >designed ten years ago is still the next thing to do on Mars, before >sending people there. You can get an awful lot of science done by >robotics. Really, why send people except as a publicity stunt?? While remote controlled robots will work fine on the moon, they will have severe problems on Mars because of communication lag. I don't believe AI will advance sufficiently in the near term to allow much autonomous operation. I agree, however, that dropping people to the Martian surface is not likely to be economical for some time.