Anyone capture big asteroids?

[lazarus1024]

So I finally got around to trying out this whole "asteroid" thing even though I've been playing KSP for something like 2 years now and they've been around for months. I went for a big boy and instantly regretted. I mean, it was cool, but my puny little dual NERVA engine "tug" could barely put a dent in its velocity and even doing my best to aim for CoM on it resulted in it spinning quickly.

So I tried the same tug with a class C. Lot of time and effort invested, but I did get a capture on it and parked in Kerbal orbit in a 600km to 4,500km equitorial orbit. Still wobbly/rotate-y, but I managed. Only had to fuel up my tug once to manage the "feat". Of course the rock probably doesn't weigh much more than my tug does (medium rockomax tank with dual NERVAs, MKIII capsule, solar, lights, RCS, docking ports to refuel. Basically it). I plan on building a station off of the thing, for fun. Then probably jettisoning the tug once I've pulled all of the fuel out of it for the station.

Just gotta design the first station module now, launch and attach it.

[Wiseman]

I've tried to capture a few large asteroids, and it has always ended in bitter tears. I hear that building your tug to be a puller, rather than a pusher, is a good way to help with the wobbliness... Of course, when I tried this, my engines were too close to the surface of the asteroid, and poof it went

[Kamuchi]

On my first astroid tug mission I tried to bring back a class E one back to Kerbin, safe to say that I cried for 3 days trying to even nudge it out of it`s orbit

I will give it another try once my moon base is complete by transforming a class A or B into a giant tugboat

[Norcalplanner]

I've captured both D and E size asteroids. The trick is giving your ship a ridiculous amount of fuel, and tons of attitude authority. I seem to recall that my ship had six LVNs feeding off a central 82 ton 3.75m tank with some drop tanks, plus four of the 2.5m SAS wheels. Don't be afraid to use partial throttle for a long time if you're having wobble problems. Also remember to strut things so that your ship's connection to the claw is rock solid.

[BagelRabbit]

I got a Class E, once. It was a lot of fun. Aerobreaking and a load of fuel got it into a 75x220km Kerbin orbit, although it was a bit touch-and-go.

I also had to keep the throttle at 1/2 to 1/3 throughout the burns, as the asteroid was relatively wobbly and didn't like being towed. Luckily, the five LV-Ns did a pretty good job of keeping everything going.

Here's an image of the (rather small for a Class E but still rather formidable) asteroid. Note that there's an eighteen-Kerbal crew on the ship, because why not?

I'm not sure whether I should be more proud of achievements like these, or whether I should be more proud of things like this or this.

[Sirrobert]

A small tip for aiming directly at the center of Mass of an asteroid: AFTER you docked with it, unlock pivot on the claw. Now you can turn the ship indipendant from the asteroid. Target the Asteroid's CoM, point directly at it, and lock pivot again. Now you're perfectly lined up

[Commander Zoom]

Yup! I've now intercepted and captured two class Ds coming in from high out of the ecliptic, and wrangled them into circular polar orbits. Next stop, involving a lot of fuel tankers, is getting them into equatorial orbit (in the same direction), and then into the same orbit... yes, I plan to link 'em up, if the game (and KAS) lets me.

I've also got a class E swinging by in a few weeks. Now that is going to be a monster. Fortunately, it's a much less inclined orbit, and a nice wide arc. Still, I might want to dock an extra fuel tank to the tug before I even send it out there... I have a feeling I'm gonna need it.

Edited October 18, 2014 by Commander Zoom

[cantab]

The biggest I've captured, indeed the biggest I attempted to move, was a 500-ton D class. The tug was quite modest - twin NERVAs and a half-orange tank of fuel. I met the asteroid in solar orbit and only had 100 m/s of delta-V with it clawed (not helped by wasting some in a muck-up earlier), but that sufficed to aerocapture it into Kerbin orbit. Not a neat orbit, but that was deliberate; I probably could have got a much lower inclination if I'd tried. It's the Macbeth 3 mission in my albums.

[Mathman]

I managed to capture a 1500t E class a couple of times. Getting enough fuel there is just a matter of assembling a large enough tug. The problem was the same as reported above stability. Second time around I broke the tug into three parts. an engine section with 7 LV-Ns and almost no structure in front of it other than 2 2.5m gyro reaction units and 4 banks of vernor engines. Squat and well braced. I connected two fuel tankers AFTER securing the engine to the asteroid. The key was to have a grapple on each large tanker to secure them during thrust. Docking the tanker so that it's grapple impacted the same time the dock coupled with the engine took some finesse, but worth the effort. A nice spread out and stable thrust and fuel element with plenty of thrust and reaction control. I was easily able to apply full thrust with no wobble and no breakup of the ship. (About 500m/s delta v and around .25m/s^2 max acceleration for whole asteroid. )

[bitbucket]

I grabbed an 1800-ton class E back in 0.25. It took an 800-ton tug and multiple airbrakes to get it into a 135km orbit. The effort involved in trying to then turn it into a fuel depot with the Karbonite mod ended in explosions and tears, and the experience has put me off the idea of trying such things again.

Edited May 1, 2015 by bitbucket