Chinese Researchers Propose Asteroid Deflection Mission

wisebabo writes "Researchers in China have proposed sending a solar sail-driven probe to hit the asteroid Apophis to make sure it has no chance of going through a 'keyhole' near earth in 2029. If it goes through the keyhole, then it will hit the earth seven years later. The reason why they need to use a solar sail is because they want the very small probe (~10kg) to hit the asteroid in the opposite direction, a retrograde orbit which would otherwise require an insane amount of fuel (after being put on an escape trajectory, it would need to first cancel out the earth's orbital momentum and then basically speed up to a likewise high velocity in the opposite direction). They are doing this to hit the asteroid at a very high impact speed. While Apophis may not literally be capable of wiping us out (it 'only' weighs 46 million kilograms), it might be able to wreck our civilization." Read on for the rest of wisebabo's thoughts. wisebabo continues, "Rather than putting the fate of our species into the hands of an untried technology (no solar sail has yet imparted substantial delta-V to its spacecraft) may I suggest an alternative? By using Jupiter as a gravity assist, we could send a much heavier probe to hit it at comparable speeds. For example, the Juno spacecraft, recently launched to the gas giant weighs almost 8000kgs. Jupiter could sling a spacecraft around so as to completely cancel its orbital momentum (with no fuel expenditure!). Then it will fall directly towards the sun and, if guided correctly, could hit Apophis broadside. Considering it will be falling from a height of several hundred million miles, it would pack quite a wallop. Admittedly, the impact will be on the side rather than head-on, but that should be okay since all we have to do is assure that Apophis doesn't pass through the keyhole, which is only 600m wide. Don't get me wrong, I hope solar sails become widely used for the (slow, cheap) transport of cargoes in the solar system. It's just that I wouldn't base the defense of earth on them."

Comments

Apophis

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While Apophis may not literally be capable of wiping us out (it 'only' weighs 46 million kilograms), it might be able to wreck our civilization."

Don't worry. Teal'c will take care of Apophis.

Pretzels

[Anonymous Coward]

Well I hear lots of organizations and governments have made plans to deflect an asteroid with a missile should one threaten to hit Earth. I think it wouldn't be a bad think to practice a little on asteroids that are passing close but not threatening us. I think we'd want to be ready for when a real danger shows up.

Re:Chinese

[Nidi62]

It's probably because, at least until recently, the US would be the country that would be best able to absorb the brunt of the costs associated with a mission such as this. Also, US-affiliated technology would have to play some sort of role regardless. But really, should a scenario like this actually occur, I would expect that most countries would contribute in some way.