Comments on: NEOShield international asteroid threat-reduction group forming now

By: Jared

Jared — Wed, 01 Feb 2012 01:26:00 +0000

Actually, the proposed technique is to use what’s called a “gravitational tug.” You send the spacecraft up to the asteroid years before the impact. Then you simply park your spacecraft next to the asteroid. The mutual gravity will cause the asteroid to tug on the space craft and vice versa. You just leave your ion drive on (very low force, but can run for years, at least in theory) and maintain your distance from the asteroid. The thrust from the ion drive is enough to very slightly deflect the asteroid. If you can do this several years before impact, a ridiculously small deflection will result in a “miss” back on Earth. Effectively, the gravity between the spacecraft and the asteroid acts as a very weak rubber band between the two, and you just use your engines to tug the asteroid into a slightly different orbit.

By the way, you don’t go straight out and then stop. You pick a trajectory that lets you creep up on the asteroid slowly in nearly the same orbit and would likely need a gravitational assist from Earth along the way. A japanese mission called Hayabusa actually managed to go out to an asteroid, land, collect samples, and return to Earth a couple of years ago. Quite an achievement.

By: Yakuzagang5

Yakuzagang5 — Fri, 27 Jan 2012 22:34:00 +0000

Adding to my previous comment, with a degree that small, it could (possibly) be as simple as slamming the thing into the asteroid and burning remaining fuel in some direction.

By: Yakuzagang5

Yakuzagang5 — Fri, 27 Jan 2012 22:31:00 +0000

Yeah, not sure how they plan on doing that, but given the expected warning time of greater than 5 years, I assume it would give enough time to get out there. But yeah, doing a complete 180 and catching up to the asteroid would be incredibly difficult, considering how far away it will be, it would have to be automated somehow. I don’t really understand either how they would be able to tug it out of the way either, although again, if you move something over 5 years away moving multiple miles per second just 0.0001 degrees, the course would be altered considerably. It would only need to be nudged enough to veer it a few thousands mile off course over the span of around a billion or more miles.

Doing a little math from school (wow), over the course of 950 million miles, it would only need to be forced 0.00000526 degrees off course to miss Earth.

By: Yakuzagang5

Yakuzagang5 — Fri, 27 Jan 2012 22:18:00 +0000

”
upon impact of asteroids from space”

As opposed to impact of asteroids from Russia?

By: Pointing Out the Obvious

Pointing Out the Obvious — Fri, 27 Jan 2012 21:23:00 +0000

Um…yeah?? Do you have any idea how much more knowledge and talent these people have in this area than, say, your typical slashgear.com reader? ;)

By: jezza

jezza — Fri, 27 Jan 2012 21:02:00 +0000

actually its not

By: Frederic

Frederic — Fri, 27 Jan 2012 20:45:00 +0000

Intercepting (matching speed and path with an asteroid) will require a huge amount of fuel. This is because a threat asteroid will almost certainly be detected on its inward journey. You have to boost the spacecraft pretty fast to get out there in time, then kill all that speed by reverse thrusting.

Then what? Shoot a harpoon into the asteroid and tug it off course? Do these folks have any idea what it would take to deflect a ten-billion ton asteroid even a tiny bit?

By: Tyler Thierolf

Tyler Thierolf — Fri, 27 Jan 2012 20:38:00 +0000

I could stay awake, just to hear you breathingggggg!

By: x x

x x — Fri, 27 Jan 2012 20:25:00 +0000

Seriously, This is the stupidest idea I have heard of in a long time.