Discussion in 'Science' started by chainbolt, Apr 6, 2013.
NASA wants to lasso asteroid, tow it home
Great, let them save the world
Bit in debt though aren't they?
Probably why they are only asking for 100million to start the project off, rather than ~2.5billion. Also probably has something to do with why they are proposing it as a joint venture with roscosmos.
Much like SLS, in the current political/economic climate, it'll be heavily delayed if it ever gets off the ground.
with our current technology i don't see how this is even remotely feasible*
would they take it out of the asteroid belt that is inside our solar system? one would assume that is where it would have to come from. hope they work out how to stop it moving before they work out how to start it moving...
*i'm an engineer not a rocket scientist
How hard could it be? Space shuttles have towballs, right?
But seriously, this is cool.
Average speed of asteroid according to google search 25km/second = 25,000 m/s
Mass of asteroid they want to tow (lets assume C class asteroid - most common type and might have water): say 500 tonnes at density of 1.38 t/m3 (362 m3 in volume)
Momentum = mv = 12,500,000 kg m/s
Kinetic energy = 1/2 mv2 = 156,250,000 kJ
Maybe we can find a really slow moving one...?
It would be a small near earth asteroid, so not from the main asteroid belt between mars and jupiter, that would probably by quite hard at present
It doesn't really require any great leaps in current technology, a fairly modest improvement in the PPU for the thrusters, re-purposing of some existing systems for tracking and discovery etc.
If your genuinely interested take a look http://www.kiss.caltech.edu/study/asteroid/asteroid_final_report.pdf for some details that aren't in most of the news reports.
I'd go so far as to say it will never happen, or at least in any reasonable forseeable future period.
Maybe they can post it on the kickstarter?
so crazy it might actually work!
I can imagine the ultimate aim is not to deflect asteroids but to capture those worth mining.
Maybe a really small slow moving one.
Really anything of interest/trackable is going to be 1000t or much larger, so multiply by a thousand.
sure beats trying to smack something into it as they have done before.
well, i don't think that the 'big wigs' in washington have thought this through with much input from scientists and engineers.
the thought i'm having is how the damn are they going to " catch up" to an asteroid in the first place to even try and " lassoo " it....
Chemical rockets are pretty much useless one were talking those sorts of speeds.
Nuclear explosion propulsion can do it, but would take time to build up speed, however there's this little thing called the no nuclear in space treaty....
having a look now, I wonder if they released the report a day late?
it makes more sense to me to at least do initial mineral processing on the asteroid itself rather than dragging the whole thing to earth, why move stuff you don't need to?
This is why we need an ethically-good Death Star that was petitioned.
there are a few low applied energy ways. Split bits off it and use conservation of momentum to move the bit you want in the direction you want.
You might be able to use the asteroid itself for fuel.
Or if you have lots of time, use gravity of surrounding planets to capture it for you - all you have to do then is some small steering and some speed change to modify the orbit.
Towing it doesn't mean they plan to bring it to a stop - ie your energy calculations are way over the top.
Read the report I linked a few posts up, the 'big wigs' proposal is largely based on it. It was written by scientists and engineers from NASA/JPL/Planetary Society/Various Universities etc...
Your overestimating the relative speed of most NEA's (or greatly underestimating how fast we can go on proven chemical and electric propulsion).
Nuclear explosion propulsion is an impractical pipe dream. There's a treaty preventing nuclear weapons in space, nothing stopping other nuclear devices though.
If you look at the rationale, mineral processing is only one of their target goals and certainly isn't the primary reason for the mission.
Yep, considering that lots of satelites/exploration vehicles use nuclear isotopes to generate power, no problem with that.
Although there would be an almighty shitstorm if a country did try to launch a nuclear propelled vehicle. I can't see it happening any time soon. Even if the engine is only started in orbit, getting the fuel out of the atmosphere is a dangerous business.
I guess you could mine the fuel from asteroids to avoid that though.
if they're happy with you launching kilos of the stuff very recently (last three mars rovers for example) why is there going to be a shitstorm over an alternative propulsion device? All of them were put through the atmosphere, regardless of how they are being used.