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NASA Proposes Manned Asteroid Mission
eldavojohn writes "NASA has proposed a manned asteroid mission to a near earth object. They mention this being viewed as a "gap-filler" to keep the public's attention between a lunar exploration & manned mars mission. The article also cites these goals as in line with the Constellation Program. From the article, 'Furthermore, a human venture to a space rock may well accelerate precursor robotic surveys of asteroids, Schweickart observed. "Early unmanned visits to asteroids ... it's the same pattern as we did with the Moon and we're doing right now with Mars. It's all pretty logical," he told SPACE.com.'"
It would take more than a "little shove" - unless you don't mind smiting your enemies a couple of hundred years hence.
...following the principles of Heisenburger's Uncertain Cat...
It is quite obvious that this is the result from someone sending us a message from the future telling us to start this program. It only makes sense that an asteroid in our future will be heading towards us. Next we'll have to gather up the best men on the planet to take this bitch down. By starting this program now, we're saving ourselves for the future. It's all pretty logical.
Power is anything but cheap, especially in space.
A decent ion engine, such as the one which powered Deep Space 1, required most of the spacecraft's 2.4 kW of power, and that was to get a 500kg craft around.
Ion drive thrust increases with power input. So, in order to move an asteroid about within our lifetimes you're probably going to need several football fields of panels, not to mention either a large number of actual engines, or a new breed of them. (And try getting all that to the asteroid in the first place).
The whole benefit of ion engines is that you require less fuel on your spacecraft due to higher isp. If you can figure out how to use materials on the asteroid for chemical rockets, do it.. if you don't, you're still going to be pushing that mass with an ion engine anyway.
I just found the box to change my sig. Um.... [timeless witticism].
Exactly... some rough math gives me that an asteroid about a tenth the size of Ceres would be about 10^20 kg, or 10^17 metric-tons. In order to move that from the moons orbit to LEO (I'm working on a similar problem right now) in 2 decades would require about 10^12 Newtons, which would require 10^13 kW, which would require a similar order of magnitude of solar array area with a good estimate of future capabilities (Solar array efficience is improving only incrementally.) This, with the prices scaling linearly (which they wouldn't, you'd start having economies of scale), would cost 10^13 million dollars. Note, these are very rough order of magnitude numbers scaled from a ~4 month journey to the moon with ~30 m-T, ~100 m^2 of solar arrays for ~100 kW of power. These things tend to scale linearly (solar array area to power, power to thrust, thrust to time, etc.)