Tugboat can save earth.
In the November 10, 2005, Nature, NASA astronauts Edward T. Lu and Stanley G. Love describe how an efficient "tugboat" mission could deflect a potential 200-meter (660-foot) asteroid on course for Earth. Instead of physically attaching itself to the rough, loose surface of a low-gravity asteroid, the spacecraft could simply hover in the direction of towing, angling thrusters outward so their exhaust misses the body. Gravity acts as the towline. By applying continuous weak thrust with a nuclear-electric ion engine as the asteroid rotates, the tugboat can pull the asteroid into a nonthreatening orbit without carrying large quantities of propellant. "This gravitational-tractor-beam solution is a wonderfully elegant solution, and it is well matched in capability to the most likely asteroid size we would have to deflect on a realistic time scale," says Daniel D. Durda (Southwest Research Institute, Colorado).
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|Title Annotation:||astro news briefs|
|Publication:||Sky & Telescope|
|Article Type:||Brief article|
|Date:||Feb 1, 2006|
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