January 26, 2004

NEO Missions

Jeff Foust has an interesting article today on the feasibility of missions to near-Earth-objects (mostly asteroids). He summarizes the justifications for studying these bodies as fear (of another dinosaur-killer), greed (for their mineral riches), and curiosity (because they're there). These objects are also fairly "inexpensive" in terms of delta-v:

While there are a number of good reasons for visiting NEOs, what makes the case for such missions -- human in particular -- so compelling is the accessibility of these bodies. The proximity of these objects and their small size sharply reduce the delta-v -- the change in velocity -- and thus the amount of propellant needed to reach them. In many cases, the total delta-v for a NEO mission is less than a mission to the Moon. At a September 2002 conference on mitigating asteroid impact hazards in Arlington, Virginia, Durda described an example of a mission to one NEO, 1991 VG. A round-trip mission lasting just 60 days would require a total delta-v of 6.1 kilometers per second, approximately the same as a one-way mission to the Moon. Extending the mission duration to 90 days decreased the delta-v to 4.9 km/sec. These factors put manned NEO missions almost entirely within the capacities and experience of human spaceflight today.

This last item reminded me of a science fiction story "gimmick" that I thought up about 15 years ago. As far as I know it hasn't been used in a story yet (and I haven't put it in a story yet, either!) The idea would be to use an asteroid or comet as a launching platform to the outer planets. I am too weak on orbital mechanics to work it out, but essentially the explorer craft would "lasso" an asteroid and then hitch a ride until it reached a good "jumping off" point to match
orbits with Mars, Jupiter, or some other destination. Do any of my technically-inclined readers think this idea has any merit?

Posted by JohnL at January 26, 2004 09:21 PM
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