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Comment by akreal | Hacker News Reader

Redirect it. Double Asteroid Redirection Test mission is going to test soon if this would work in practice:

https://en.m.wikipedia.org/wiki/Double_Asteroid_Redirection_...

I’ve got no experience with this stuff. Is it possible to model asteroid redirection in KSP or something similar?

One oddball idea I wonder about is turning suitable asteroids into something like an O’Neil cylinder. They offer lots of mass that you don’t need to haul up and could be resourceful. Seems the mass would help with radiation hazards. Gravity could be simulated by spinning them through traditional means. I’m talking about hollowing them out.

>Is it possible to model asteroid redirection in KSP or something similar?

Yes, you can do it in KSP.

There is even a KSP tutorial for asteroid redirection. Stock game is designed with task in mind.

Thanks that's interesting. The article says 0.5mm/s of change is enough to miss the earth, but how much time ahead do we need to find the asteroid? (Assuming we launch the day we find the asteroid, which is politically-wise unlikely but well)

So with an end-stage interaction where you're not considering keyhole effects, you very roughly you need to accumulate an Earth diameter of position change. So Earth diameter is ~13000km, so that works out 26 billion seconds or 825 years.

So in real terms, we'd probably wanna do a but more delta V than that. At 1cm/s, you're down to 41 years for example.

Doesn't this assume the asteroid is dead center targeting earth?

Good point! Assuming that the asteroid sees Earth as a disk that it can hit anywhere uniformly at random and also that I can still do calculus in my head, looks like the expected radius away from the circumference is only 1/3 R?

The Daily Tribune: "thank the heavens! Earth saved by Wikipedia article"

https://www.nasa.gov/planetarydefense/dart linked from the Wikipedia article

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