Operation: Bothersome Boulder

[TerLoki]

I have not done many interplanetary missions outside of small one-way probes and landers. I also haven't many crazy "for the heck of it" missions like trying to make a spaceplane land on the Mun, or planting a flag on Jool. But when I heard that one of fun easter eggs in the game had been removed before the ARM pack, I knew what had to be done. So with a surplus of asteroids of appropriate size around Kerbin, I set out to save the Magic Boulder.

Of course this would be no easy task, the mission required intercepting an asteroid, stabilizing its orbit until a transfer window opened, sending it to Duna, and finally putting the whole thing into the correct orbit around Ike. Of all my asteroid tugs, only one was both up to the task and reliable enough to see it through.

First stage and fairing separation on the ADA 3. This tug was initially designed to catch a class D asteroid, so it's definitely capable of tackling our rock of choice: A class B coming in on a orbit set to intercept the Mun.

Captured. Even with nearly half of the orange tank depleted the ADA 3's four LV-909's had around 3km/s of dV.

Munar flyby. To maximize the Oberth effect our space rock has will need to be in a low Kerbin orbit, luckily a quick gravity assist was all it took to change orbits from Kerbin escape to LKO with a periapsis of 125km.

Not wanting to take any chances on running out of gas, and with the orange tank depleted, a tanker was sent up in the form of an old Titan asteroid tug to refuel the ADA 3. This is probably the smoothest that I've ever gotten one of my Antares series rockets has ever run.

Refueling in progress. Fun fact: Asteroids make great fuel lines. Also, docking something that massive at 5m/s is a... Well, "fun" experience.

Arrival at Duna. Luckily enough the craft was on course for an Ike encounter right after its Duna periapsis.

After a few maneuvers to capture, change planes, and circularize into a low orbit the propulsion module separates and the mission is complete. Long live the boulder!

Proof that that is in fact Ike. The orbital characteristics are 15x15km at an inclination of 80 degrees. Details on the boulder and its orbital characteristics were taken from Scott Manley's video series.

Edit:

Persistence files:

Stock The Magic Boulder with no mod parts (hopefully). Features the boulder in Ike orbit with a stock probe-based docking adapter, complete with green lights.

Mod The Magic boulder with the modcraft Advanced Docking Adapter (ADA). Features the boulder in Ike orbit with a docking adapter complete with RCS and MechJeb control.

Needed Mods:

MechJeb 2, KSO (Phase II or later), RLA Stockalike

Edited April 25, 2014 by TerLoki

[NERVAfan]

Awesome!!!

[Geschosskopf]

All of Kerbaldom thanks you for your generosity in pulling the Magic Boulder back from Oblivion. Great job.

You know, you should post the code snippet from your save file with the boulder in place. Then folks could patch it into their own saves. I'm sure those too lazy to go to this trouble themselves would thank you profusely.

[Spica]

Ideally, if you want to be as accurate as possible, find the smallest asteroid you can. The magic boulder was in fact QUITE small (about 3.5m diameter).

Anyways, THANK YOU, you've saved the magic boulder. Now all we need is a munolith mod.

[Tw1]

Well done!

Might I suggest adding the craft's save file details, so people who want their own magic boulder substitute can get one?

Edit: Derp. Mr Geschosskopf has already suggested such.

[Specialist290]

Nicely done! I especially like the attention to detail involved in getting the asteroid into the proper orbit.

[TerLoki]

Thanks guys! I'll have to see about getting a stock adapter up to the boulder so I can share the save, as it is I'm using KSO and Mechjeb, but once that's done I'll gladly go digging in the code and grab it.

Edit: It may take a couple of days to get that up and going. I had to reinstall KSP and, though I did manage to keep a save file, it was a save before I got the boulder to Duna. Currently it's sitting over Kerbin. I just tried to redo the mission, but something went a bit wonky and I ran out of fuel. I'll give it another try though, I won't give up on the magic boulder yet.

Ideally, if you want to be as accurate as possible, find the smallest asteroid you can. The magic boulder was in fact QUITE small (about 3.5m diameter).

Well I never went to the boulder myself, but from the images I saw a class B is roughly the right size, though I'll admit it was a bit hard to tell scale without using the same craft as in the vids. For reference though, the ADA unit sans propulsion module is about the size of a Mk. 1 pod plus a fuel tank and LV-N.

Edited April 21, 2014 by TerLoki

[TerLoki]

So, time for an update. I'm not really sure what to say here because while I've definitely made progress (the stock adapter is docked to the asteroid, the tug is refueled, and the whole assembly is about 10 minutes from Duna transfer burn in my current save) I've also hit a bit for a brick wall. See, for some reason that totally mystifies me, the assembly of asteroid and tug refuses to rotate at all, to the point where the ADA unit's decoupler attachment to the propulsion module is bent at around 15 degrees by RCS whenever I try to turn it, yet the thing still stubbornly refuses to move. I thought it might be the stock adapter's SAS unit, but the problem still occurs whether it's on or off. What's more, and this is the really baffling part, the Kraken seems to have picked this moment to surface on my computer since merely trying to turn a class B asteroid has somehow generated enough force to deorbit it. I don't know what kind of phantom voodoo forces are at work here, but I get the feeling I'm in over my head. The only thing I can think of is ditching the stock adapter at this point.

[TerLoki]

I did it! (Again!)

I'm not sure what the problem was, but this attempt worked like a charm. Now I don't know what part of each file to copy, so I'll be posting two whole persistence files instead. Details will be up in the first post.

[CatastrophicFailure]

So, time for an update. I'm not really sure what to say here because while I've definitely made progress (the stock adapter is docked to the asteroid, the tug is refueled, and the whole assembly is about 10 minutes from Duna transfer burn in my current save) I've also hit a bit for a brick wall. See, for some reason that totally mystifies me, the assembly of asteroid and tug refuses to rotate at all, to the point where the ADA unit's decoupler attachment to the propulsion module is bent at around 15 degrees by RCS whenever I try to turn it, yet the thing still stubbornly refuses to move. I thought it might be the stock adapter's SAS unit, but the problem still occurs whether it's on or off. What's more, and this is the really baffling part, the Kraken seems to have picked this moment to surface on my computer since merely trying to turn a class B asteroid has somehow generated enough force to deorbit it. I don't know what kind of phantom voodoo forces are at work here, but I get the feeling I'm in over my head. The only thing I can think of is ditching the stock adapter at this point.

Be most cautious. I never went to the Magic Boulder myself but I've heard enough about it. You are meddling with some very VERY powerful juju here. The Boulder could both summon the Kraken at will AND direct it. If it was gone, perhaps it WANTED to be gone. Erecting a graven image in its place may attract attention that is... Unpleasant.

[TerLoki]

Well I got it in orbit without incident this time. I think the boulder was just telling me to go to sleep, it was around 1am when all that happened.

[RenevB]

I have done a very similar mission after I captured my first asteroid (in sandbox) and hugely overestimated the delta-v and fuel requirements to capture an A-class. I knew about the Magic Boulder, but had heard only recently that it wasn't there any more. Long story short, I flew it over and now it's been in an appropriate orbit for quite some game-time.

I can't seem to post an actual image of this Steam screenshot I made of the Boulder once I decoupled the claw, so you'll have to click the link to see it.