Getting to an asteroid

[theShiz]

I have a mission to put an asteroid into orbit of the Mun. What I'm having difficulty doing is planning a route there. I have MechJeb, but can't select an asteroid to have it navigate for me. I put myself on an exit trajectory from Kerbin in the direction of an asteroid only to trapped by Kerbol. What's the best way to get there while needing as little dV as possible?

Edited March 11, 2015 by theShiz

[Mister Dilsby]

Are you 'trapped' by Kerbol, or orbiting it? Meeting an asteroid in Kerbol orbit is exactly the same as meeting a stranded Kerbal in Kerbin orbit. You intercept the target's orbit at the point in space and time where the target will be (or get as close as possible) and reduce your velocity relative to target to zero at that point. I don't use Mechjeb, so i suggest you 'turn off your targeting computer' and use the navball. I find a good technique is to (1) select the asteroid as target (2) drag maneuver nodes until you find the closest intercept you can get (3) as you approach, select Target mode on the navball and use correcting burns to 'push' or 'pull' your directional marker until you moving straight at the target (4) decelerate (still pushing the marker onto the target path) until you are within a few hundred meters and your velocity relative to target is a few meters per second.

[capi3101]

Going to direct you to Claw's tutorial on how to do asteroid rendezvous outside of Kerbin's SOI. The probe he builds for the job is good enough to capture Class A and B asteroids, and it's small enough that if you prefer to do so you could conceivably launch it via spaceplane (though I might recommend swapping out the 909 with an LV-N in that case so you have a little delta-V to spare for making inclination changes.

After you get the rock, I'd suggest hitting the aerobraking calculator site and put your desired apoapsis around Kerbin up by Mun's orbit. If you're lucky, you'll get an encounter and can take it in from there. Again, inclination is going to be a significant factor there.

[theShiz]

I think my problem is that none of the asteroids are inbound / I can't select them. They all say, Unidentified asteroid, last seen XXdays ago.

[Taki117]

I think my problem is that none of the asteroids are inbound / I can't select them. They all say, Unidentified asteroid, last seen XXdays ago.

You need to be actively track it in the tracking station first.

[jackal40]

You need to be actively track it in the tracking station first.

And how does one do that, I can't seem to find anything related to this subject.

[Taki117]

And how does one do that, I can't seem to find anything related to this subject.

First step is to upgrade the tracking station to tier 3 (You may also need to upgrade mission control) This allows unknown objects to be tracked, then make sure that you have the unknown objects selected. Then it's just a matter of picking the right one, the button at the bottom of the tracking station should turn to track (Instead of Fly) that should then allow you to set it as a target.

[jackal40]

First step is to upgrade the tracking station to tier 3 (You may also need to upgrade mission control) This allows unknown objects to be tracked, then make sure that you have the unknown objects selected. Then it's just a matter of picking the right one, the button at the bottom of the tracking station should turn to track (Instead of Fly) that should then allow you to set it as a target.

So that is something that can only be done in career mode, not sandbox?

[Taki117]

So that is something that can only be done in career mode, not sandbox?

IT should also be able to be done in sandbox, you just don't need to upgrade the tracking station.

[jackal40]

IT should also be able to be done in sandbox, you just don't need to upgrade the tracking station.

Then I'm at a loss on how to do this. Trying to select one from the tracking center just gives me the Unknown object, last seen etc. I cannot select it like I can a ship or station. I'll try a burn to a nearby moon (minimus atm) and see if I can get a captures.

[Pecan]

Unidentified asteroids are 'virtual' objects and disappear after a while so they don't interfere with anything else you have going on. When you select one in the Tracking Station look at the buttons at the bottom-left of the screen. One of them is a 'radar dish' for tracking. Click it and the asteroid will be tracked, identified and become 'real'.