[Request] Asteroid Catching (Stock!)

[Keramane]

I've watched videos on youtube of people soaring after asteroids or doing the docking with auto-plots and such likely from MechJeb. I would LOVE to see someone give a comprehensive tutorial on how to set orbit, match the approaching asteroid and peg it. I can get CLOSE to the right trajectory (my best being 14km) but after that, I can't close the last gap. Docking has you set into a similar orbit, but asteroids are on a 1 shot pass-by, so I can't inch in over continuous orbits. How does one come by and snatch an asteroid properly? (Pictures/Videos help when alongside text; the latter does more of course)

[goldenpeach]

I would like such a tutorial too, I've searched a lot on this forums for a tutorial and tried a lot of these tutorial but I haven't been able to get anywhere close to an asteroid.

I'm starting to be desperate enough to let the asteroid escape kerbin and dock with it in solar orbit(please, tell me that they still can be tracked after they leaved kerb in(if it's true)).

EDIT: I've started such a mission because I have the feeling that if I don't grab an asteroid soon I will snap out(I've the most powerfull rocket I ever built, way more powerfull than anything I ever imagined building in KSP, it will relax me and make jeb proud).

EDIT2: I've find out that I had way too much power(more than 11 000 000 newtons) and way too much fuel. It worth it.

Edited April 4, 2014 by goldenpeach

[Dizzle]

I would also like a tutorial.

[Superfluous J]

I've almost got my process down so I can nab an asteroid every time. I do use KER for extra info but could do it without. Maybe I'll do an all-stock run and throw it on YouTube.

I was going to actually record something today. I may try to get it recorded tonight and then do a voice-over.

[Slouch]

I managed to dock with an asteroid on my first try but it was really, really inefficient. A tutorial on how to do it well (without 3 massive burns that it took me, after i got to orbit, 15 min, 8 min and 7 min plus the rendezvous maneuvers) would be great.

[Superfluous J]

You may not like my method then. Not counting the burn(s) to get into orbit it has 5 distinct burns, each with a clear and specific goal. Depending on your ship, it could take that long to do all those burns. It's tailored more for ease of understanding though than efficiency, though I don't think it's dV-wasteful. Or at least, when I waste dV it's to greatly shorten the time it would take to do something.

I've been using a fairly small ship with a half-orange tank and 4 lv-n engines, and the burns tend to take 1-3 minutes each.

Edited April 4, 2014 by 5thHorseman

[DonLorenzo]

I made this video. It's about an hour and covers everything from launch, asteroid intercept and redirect. It's not strictly in the tutorial format, but I do explain what I do and why. And it's full stock.

[Dizzle]

I made this video. It's about an hour and covers everything from launch, asteroid intercept and redirect. It's not strictly in the tutorial format, but I do explain what I do and why. And it's full stock.

Thanks for that, and I'll be sure to check out your other vids. I think the most useful thing I learned from that was to put way less trust in the maneuver nodes, which makes me a little more confident with my current situation.

Edit: Thanks again. I had a class D on an impact trajectory with Kerbin and no idea what I was doing, not to mention a poorly thought-out craft in orbit with no RCS.

Edited April 4, 2014 by Dizzle

[Superfluous J]

I've recorded about 30-40 minutes of step-by-step from 0 to rendezvous. I'm not well versed in what to do once you've caught the darn things (I'm like a dog chasing a car) however I got from LKO to within grabbing distance of an asteroid out at Kerbin's SOI boundary with about 2000 dV, and I think that's pretty good. It could be done with less, but I don't think much less.

I have to encode, edit, and post it and that may not happen until tonight. In the meantime I suggest you watch DonLorenzo's video which I haven't seen but I'm sure is good, because I watch all of his videos and they're all good. Seriously. Watch this man's videos. He's a baws.

[DonLorenzo]

Thanks for that, and I'll be sure to check out your other vids. I think the most useful thing I learned from that was to put way less trust in the maneuver nodes, which makes me a little more confident with my current situation.

Edit: Thanks again. I had a class D on an impact trajectory with Kerbin and no idea what I was doing, not to mention a poorly thought-out craft in orbit with no RCS.

http://i.imgur.com/alIYhKn.png

Awesome! Glad you liked it. That link you posted goes to the main forum page btw, that's probably not the intention. Which is funny since in the quote window here it does show an imgur link. Oh well, must be black magic at work again

[Dizzle]

I had that problem at first as well. I've found that for some reason middle-clicking a spoiler or otherwise opening in a new tab redirects to the forum, but left-clicking unhides it.

[CaptainKipard]

I've recorded about 30-40 minutes of step-by-step from 0 to rendezvous. I'm not well versed in what to do once you've caught the darn things

That's the easy part. You just burn radially.

[Superfluous J]

That's the easy part. You just burn radially.

Well that will get it to miss Kerbin (or hit it, which I've done on multiple occasions) but I'm talking how to (efficiently) get it into an orbit around Kerbin, Mun, Minmus, Laythe, or whatnot. I know it's all just burning but I have a feeling that I'd need a bit more oomph to do it, and I would like that to be a part of any tutorial involving moving rocks around.

I'm encoding my video now. It says 20 minutes left and then the upload will probably take an hour or so.

EDIT: I have to re-encode. My video editor took a dump and I have to start over.

Edited April 4, 2014 by 5thHorseman

[CaptainKipard]

I'm pretty sure the only thing you can do is burn at the periapsis, how else would you close the orbit?

[goldenpeach]

Well that will get it to miss Kerbin (or hit it, which I've done on multiple occasions) but I'm talking how to (efficiently) get it into an orbit around Kerbin, Mun, Minmus, Laythe, or whatnot. I know it's all just burning but I have a feeling that I'd need a bit more oomph to do it, and I would like that to be a part of any tutorial involving moving rocks around.

I'm encoding my video now. It says 20 minutes left and then the upload will probably take an hour or so.

EDIT: I have to re-encode. My video editor took a dump and I have to start over.

I can't wait for that video!

For now, I will just make more and more powerful rockets until it make jeb scary!

[Superfluous J]

I'm pretty sure the only thing you can do is burn at the periapsis, how else would you close the orbit?

Aerobrake?

And I'm not talking specifically "How do I get to Mun from a wonky orbit." I'm talking more "How do I get a ship with enough fuel in it to the asteroid so I can then get that asteroid from its wonky orbit to Mun, and then how do I get that huge thing to do what I want?"

It's like lifting off of Eve. "Just do it like you'd lift off of Kerbin, only more" is technically correct but doesn't really help anybody having a problem with it.

Update on the video: I decided to take a full pass on it and add a lot of text comments to make clearer what I was doing, and correct some verbal mistakes (calling North South, or Left Right, that kind of thing). It's encoding now and - like before - should hopefully be up in an hour or so.

EDIT: GAAAAH. Now I know why Squad says "Soon." My video looks perfect in the editor but then random parts of it are completely black in the finished video. And every attempt takes about a half hour to render. I'm working on it.

Edited April 4, 2014 by 5thHorseman

[goldenpeach]

Wow, at least I know which problem I will encounter if I make a video

(I plan to do one with KSP but I'm lazy(and I procrastinate a lot)).

On which channel will it be posted?

Edited April 4, 2014 by goldenpeach
Fixed an horrible typo.

[Superfluous J]

It's been posted to my

playlist on my channel, which is pretty sparse on content but this video will surely help

Here's the vid, so fresh YouTube doesn't offer it at 1080p yet. Give it a bit of time. 720 usually looks fine but I wouldn't bother with 360:

[CaptainKipard]

Very nice! Informative, good format...

It's different from what I would have tried to do. My idea was to try and rendezvous with it at it's periapsis, I just wasn't sure how to time it correctly, short of attempting...... MATHEMATICS! (the horror...)

[Superfluous J]

Very nice! Informative, good format...

Thank you

It's different from what I would have tried to do. My idea was to try and rendezvous with it at it's periapsis, I just wasn't sure how to time it correctly, short of attempting...... MATHEMATICS! (the horror...)

You can do that in a similar way to what I did. Get your periapsis near (or right on, really) its periapsis, wait for it to enter Kerbin's SOI and then burn at your periapsis until your encounter markers match up. The problem there is you've got a TON of dV to scrub to bring the orbit down.

It shouldn't be too hard though to slow it down just enough so it's captured by Kerbin, and then you can burn at apoapsis to slow it down to do an aerobrake or somesuch.

One problem with that, you need to do everything quickly as you scream past periapsis. My method, I could take several in-game days and pay almost no dV penalty.

[SpenSpaceCorp]

The trick (for me at least) is in the launch: you want to line up with the asteroid's hyperbolic trajectory as best as you can and in the correct direction. After orbit has been established, match the inclination, and burn somewhere around where the periapse of the asteroid is closest to your orbit (use maneuver nodes to tweak what angle will be optimal.

The second trick is in the timing of the burn - you want to match up with it as close as possible as you expand your orbit outwards towards the asteroid's path.

[Arcamean]

I'm not well versed in what to do once you've caught the darn things (I'm like a dog chasing a car)

Oh I love it... favorite quote thus far in the year.