Anthony replied to me: > That table includes additional costs for entering Earth orbit, and > realistically that cost is pretty variable. It requires a 3.7 kps burn > to take a comet in a 30 AU circular orbit and get it onto an elliptical > orbit with aphelion at 1 AU. It takes an 11.8 kps burn to take that > comet and recircularize its orbit at 1 AU, in fairly deep space. To > instead enter low Earth orbit takes anywhere from 8.4 to 23 kps, > depending on your thrust; at your designed thrust, expect to take nearer > the maximum cost. Stopping in far earth orbit can probably be managed > for a bit less than the deep space cost.
Hello Anthony, the idea is to get the rock into a useful position for an Earth-based society -- if it was about bases in the outer system, they wouldn't expend that much delta-V. That might be the Sun-Earth or Earth-Moon L4 or L5 points, or a wide orbit around Earth, but just passing through is not enough. Saving a few kps here or there won't help much, either. If the mass driver engine from VXi is used, only a small part of the original rock will arrive. By contrast, the fusion rocket from Vehicles should be able to deliver more than 80% of an ice or ice/rock mudball to Earth, e.g. to supply water and reaction mass to orbital industries. Regards, Onno _______________________________________________ GurpsNet-L mailing list <[email protected]> http://mail.sjgames.com/mailman/listinfo/gurpsnet-l
