What's roughly the Delta-V requirement to get from LKO to an avg. asteroid and back?

[CaptRobau]

In case you didn't read the thread title: 'What's roughly the Delta-V requirement to get from LKO to an average asteroid and back?'

Thanks in advance.

[cantab]

It is very variable depending on the asteroid's trajectory. 3000 m/s is ample, 2000 should be fine. If you're selective with your asteroids and fly well you might manage it in 1000. If you go for a solar orbit intercept then since most asteroids are on Kerbin flyby trajectories, most of your delta-v is spent getting there and matching speeds and it only takes a small amount if any to course correct to a Kerbin landing trajectory.

[merendel]

It depends alot on what your trying to do with the asteroid as well. Are you just going to get a sample off it or do you plan to capture it? It also depends on how you plan to intercept it and where its orbit is comeing in from.

For example if an asteroid comes in very slow relitive to kerbin and passes through the LKO orbit you might be able to get away with 1k dv to intercept it. Launch into the plane of the expected orbit and match your PE with the asteroids. Raise your AP to phase your orbit such that you'll meet up at PE then burn to meet up. It will take 950dv at a minimum to match speeds as the asteroid will be comeing in with at least that much relitive velocity (thats the dV to escape kerbin from LKO), It will be some amount more than this depending on how fast relitive to kerbin it was going. If you only want to get a sample and not capture the thing a couple hundred more dV to slow down so you dont escape and aerobreak back down and your golden.

Going for a solar intercept takes a bit more as your not only haveing to fling yourself out of the kerbin system but also need to turn around to match velocities with the asteroid. Figure around 2k to meet up with the rock plus enough to do whatever you want to the asteroid. Agian if its just a sample you only need enough to direct yourself into an aerobreaking intercept with kerbin. if you want to change the asteroids orbit you'll need more, potentialy alot more if its a big rock or needs a radical change in its orbit. One advantage of the solar intercept is that due to the distance it takes a comparitivly small burn to make significant changes to its orbit. Particularly useful if its going to come in on a retrograde orbit or come in just inside the SOI. If your intercepting a small A or B you dont need a ton of fuel. If you go after an E class monster you can go up with a giant fuel tank with a rocket on the back that has 9k dV and find its only worth a hundred or so once attached to the 2000 ton rock.