Comment Here's why you would bother with this mission: (Score 1) 202
Ugh. If it's one thing I can't stand about slashdot is that all you people are CS majors or some such... Why I bother at all boggles the mind!
Okay, so here's the WHY of it. Asteroid composition is a very interesting subject because it seriously affects whatever technique you decide to use to divert a threatening asteroid. What you are looking for when studying asteroids is their porosity. Asteroids are not like they are portrayed on TV or in the movies, i.e. they are not solid chunks of rock. Instead, they can range from solid pieces of stainless steel (frigthening!) to loose aggregations of rubble (flying gravel piles) which are very porous. Porous materials are very good at absorbing energy and hence are much more difficult to deflect.
So, if one were to use a nuke on an asteroid that was porous, it would do a lot less to the porous asteroid than one that was solid through and through. So the purpose of these missions would be to scout out and start to get a better idea of what the distirbution (statistically speaking) of the porosity of the asteroids that are floating around out there. Their idea is to do this cheaply with ion propulsion. If you've got a lot of time to spend, ion propulsion is ideal to get around the inner solar system without spending a lot of mass on fuel.
If you have any more questions, I suggest you look at some papers by Ahrens or Holsapple. Also check out http://neo.jpl.nasa.gov.
-banjo
Okay, so here's the WHY of it. Asteroid composition is a very interesting subject because it seriously affects whatever technique you decide to use to divert a threatening asteroid. What you are looking for when studying asteroids is their porosity. Asteroids are not like they are portrayed on TV or in the movies, i.e. they are not solid chunks of rock. Instead, they can range from solid pieces of stainless steel (frigthening!) to loose aggregations of rubble (flying gravel piles) which are very porous. Porous materials are very good at absorbing energy and hence are much more difficult to deflect.
So, if one were to use a nuke on an asteroid that was porous, it would do a lot less to the porous asteroid than one that was solid through and through. So the purpose of these missions would be to scout out and start to get a better idea of what the distirbution (statistically speaking) of the porosity of the asteroids that are floating around out there. Their idea is to do this cheaply with ion propulsion. If you've got a lot of time to spend, ion propulsion is ideal to get around the inner solar system without spending a lot of mass on fuel.
If you have any more questions, I suggest you look at some papers by Ahrens or Holsapple. Also check out http://neo.jpl.nasa.gov.
-banjo
