dietz@loki.cs.cornell.edu (Paul F. Dietz) (06/14/88)
In article <18206@cornell.UUCP> dietz@loki (Paul F. Dietz) writes: > Frank et. al. estimate a density of about 3e-12 cometesimals per > cubic kilometer. Travelling at 20 km/sec, the flux of comets > near the earth would be something like 6e-11 per square kilometer > per second. A ten square kilometer powersat would be hit once > every fifty years, on average. Correction: 3e-11 per km^3, and 10 km/sec, not 20. So the powersat is hit once every ten years, on average, if the cometesimals exist. Paul F. Dietz dietz@gvax.cs.cornell.edu
palmer@tybalt.caltech.edu (David Palmer) (06/15/88)
In article <18262@cornell.UUCP> dietz@loki (Paul F. Dietz) writes: >In article <18206@cornell.UUCP> dietz@loki (Paul F. Dietz) writes: > >> Frank et. al. estimate a density of about 3e-12 cometesimals per >> cubic kilometer. Travelling at 20 km/sec, the flux of comets >> near the earth would be something like 6e-11 per square kilometer >> per second. A ten square kilometer powersat would be hit once >> every fifty years, on average. > >Correction: 3e-11 per km^3, and 10 km/sec, not 20. So the powersat >is hit once every ten years, on average, if the cometesimals exist. > > Paul F. Dietz > dietz@gvax.cs.cornell.edu Comet strikes need not be fatal if the powersat is designed reasonably. A 10 meter snowball would merely make a 10 meter hole in whatever it hit, plus whatever damage the fragments do, if the structure is sufficiently flimsy. There is no reason to make the structure rigid enough that the comet delivers the bulk of its energy to the rest of the structure. David Palmer palmer@tybalt.caltech.edu ...rutgers!cit-vax!tybalt.caltech.edu!palmer "In retrospect, no one should have been surprised by the discovery that Harvard Business School was being supported by a consortium of large Japanese companies." -- 1993, The Year In Review