Science: Spacecraft: Propulsion
Going my way?   (+5, -4)  [vote for, against]
Hitch a ride on an asteroid

Asteroids can travel at 45,000kph or more, that speed is a valuable asset that should be used for space travel. Select a suitable asteroid that passes relatively close to Earth, then launch your spacecraft to intercept it. Latch on to the rock and ride it to your destination, say Mars. The only fuel you'd need is getting to and from the rock.
-- simonj, May 07 2008

Asteroid landing planned http://www.guardian...ts.spaceexploration
laughing all the way to pluto and beyond [xenzag, May 08 2008]

Whatever you do, don't use a bungie cord. Sheesh. slingshot_20space
[2 fries shy of a happy meal, May 08 2008]

You'll have to match speed enough that the asteroid's gravety field holds you in orbit, this requiring a good deal of fuel...
-- Voice, May 07 2008


Voice, I think simon means you physically attach yourself to the asteroid.
-- xaviergisz, May 07 2008


I find it dangerous to stand in front of a 1-ton object moving 30 mph. So, this n-ton object moving 45,000 mph is not dangerous, only "valuable"?

(Oh, I know! I know! I'll just "jump" the instant before impact, then I'll be safe!)
-- lurch, May 08 2008


[xaviergisz], Thats even worse: If you're matching speeds anyway, wheres the advantage?
-- Voice, May 08 2008


[x] you've got a couple megatons of asteroid between you and any space-dust... apart from that, dunno.
-- FlyingToaster, May 08 2008


[Voice] & [flying Toaster], the advantage is that instead of burning fuel for 6 months, your only burning fuel for about a week (or however long it takes to rendezvous). Didn't I make that clear?
-- simonj, May 08 2008


How do you think that's going to help? You will still need to burn the same amount of fuel, except you need to burn it a lot faster, which means bigger engines, which are heavier, which means the same amount of fuel won't do it after all - you'll need more.

Unless you're thinking that you don't have to accelerate all the way up to the speed the asteroid is going... in which case, see my prior post.
-- lurch, May 08 2008


It's all about the angle of interception, gravity wells, slingshots... It's technical.
-- simonj, May 08 2008


// It's all about the angle of interception, gravity wells, slingshots... It's technical.//

It also wouldn't make that much of a difference unless your asteroid was *big*... stick with "shield from space-dust and gamma rays" :D
-- FlyingToaster, May 08 2008


To overcome the deceleration problem you could lasso a really long bungee cord (I'd estimate 300km) onto the asteroid and enjoy the ride.
-- xaviergisz, May 08 2008


I don't get it.

//The only fuel you'd need is getting to and from the rock// - as opposed to the doing it without the asteroid, when the only fuel you'd need would be getting to and from the trajectory to Mars. If there's an idea here could someone explain it to me?
-- wagster, May 08 2008


The biggest asteroid (Ceres) is almost 1k km in diameter (so about 1/4 the dia of the moon)... got any figures as to what kind of acceleration you can get off of that ?
-- FlyingToaster, May 08 2008


This wouldn't save you any fuel at all. You'd still have to use exactly the same amount of fuel to accelarate to 45,000 kph to match velocity with the asteroid as you would to accelerate to 45,000 kph to go through space on your own. Once you're up to speed, travelling through space in the same direction at a constant 45,000 kph requires no fuel at all (Newton's first law).
-- hippo, May 08 2008


[Hippo] you wouldn't have to match the ateroid's velocity exactly, you'd just have to 'capture' it as it passes by. All you need to ensure is that the attachment (tether or whatever method is suitable) & the cargo can withstand the acceleration G's. [xaviergisz] is closest to getting the idea with his bungy cord.
-- simonj, May 08 2008


I think the advantage would lie in being able to control the craft much more easily close to Earth, let it take lots of measurements as it circuits the Solar System, then download all that data in high resolution once it comes back again.
-- DrCurry, May 08 2008


"To overcome the deceleration problem you could lasso a really long bungee cord (I'd estimate 300km) onto the asteroid and enjoy the ride."

[link]
-- 2 fries shy of a happy meal, May 08 2008



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