At 07:51 AM 2/11/02 -0600, XXX wrote: > "If the governing requirements are to provide longer dwell and=20 > synoptic imagery for battlefield use, then physics allows two=20 > possible solutions: multiply the number of satellites in low orbit > or maintain a constellation of a few vehicles but raise their orbits=20 > significantly." >
Just an addendum: The problem with fewer-birds-higher-up is that the optics need to be bigger. Optics are limited by what you can loft in your launch vehicles. E.g., The hubble telescope (which faces away from earth :-) mirror was limited by the space shuttles' cargo bay. Perhaps there are clever (unfolding?) designs which would increase resolution by using mirror segments separated by long struts, but light-gathering ability depends on mirror area. Maybe that's not important for terrestrial targets. Folding designs might require active stabilization of the mirror-segments. That is not impossible.
