So I just accepted this contract...

[Deustodo]

And now I have no idea how to properly do it. I mainly accepted this because of the description: "The Last Class E asteroid that passed Kerbin nearly wiped out our species, capture one and get rid of it." So I come here, to the forums of ksp to ask for help.

As I understand right now, it can be any Class E asteroid, so my primary plan is to grab one from Dres, which will be fair easier than getting one passing by Kerbin, slowing it down to a stable orbit, etc etc. Considering a Class E has about 550 tons of mass, I wonder how big I need to make a spacecraft to have enough delta V to make it out of Kerbol Orbit. I'm using module fuel tanks, so I can turn the big 3.75 m wide fuel tanks into pure liquid fuel, and I'll only use the nuclear engines.

So I ask the forums, how the hell do I do this? without cheating (using hyper edit or infinite fuel) of course.

[Terwin]

ISRU

Mine that thing down to the bone as a fuel depot and send the husk out of the system.

Either that or just attach a drill+ISRU and plenty of electrical power and let the engine burn whatever is produced until it leaves the system.

No need to have much fuel by the time you have docked with the asteroid, just be able to make fuel out of it(and at the same time reduce the mass you need to push)

[gtmattz]

ISRU

Mine that thing down to the bone as a fuel depot and send the husk out of the system.

As I was reading the contract this is what came to my mind as well. Now this might be something I will try in sandbox just for the sake of doing it!

[GluttonyReaper]

I would recommend using a gravity slingshot of Jool, it should save you some dV.

[katateochi]

With the ISRU option (which for this I think is about the only option) you can encounter a bug with craft that have multiple engines. If you are converting ore to fuel while running the engines, one of the engines can end up running at a significantly reduced thrust. So you can't burn while converting, you just have to alternate (which isn't really a problem for this sort of thing).

And be prepared for a very long burn that you probably won't be able to use physics time warp on!

[problemecium]

My suggestion: Put it on an escape trajectory, then as soon as you get the completion message, turn around and put it back. Trololololol...

[BurningLegion]

Based on the tools that I know exist, I have a few ideas.

If I were designing a ship to do this, I'd make a probe ship with an ISRU, two drills, a small ore tank, a 2.5m reaction wheel, three XL Solar panels spaced evenly, an orange tank, 8 delta wings radiating from the tank's rear, an LV-N, as many struts as it takes to make a stable ship, RCS, and whatever launch vehicle is necessary to get it to the class E. Once contact with the class E is achieved, I'd move it into solar orbit, orient prograde to the sun, and start burning while mining more LF. The sun's power, combined with atomic energy, will keep the ISRU and drills working even as far out as Eeloo while the delta wings radiate enough heat to allow for as long a burn as necessary under maximum thrust and the struts allow the use of physics warp to have to stare at it for only a fourth of the time.

That said, I'm definitely a brute force person in KSP and I've never intercepted an asteroid before. A gravity assist from Jool, or even sundiving to slingshot toward interstellar space may be more preferable (Especially since solar panels work a lot better closer to the sun).

[Vanamonde]

How-to question moved to the how-to section.

[Deustodo]

I went with the ISRU route, lauched a rocket and intercepted a Class E asteroid passing by kerbin, 1550 tons the god damn thing. Turned my 4.000 delta v into a miserable 91. Now I'm (slowly) mining the ore out of it, which is about 1166 tons of right now. the dry mass of the Asteroid is about 198 tons, I think I can make this giant piece of rock fly across space and into oblivion.

[Champ]

i thought it was impossible to put a ship on an escape trajectory out of the sun (Sun's SOI has no limit). Am i wrong ?

[MarvinKitFox]

i thought it was impossible to put a ship on an escape trajectory out of the sun (Sun's SOI has no limit). Am i wrong ?

yes.

An escape trajectory is quite possible. It will only take infinity+1 seconds to actually achieve that escape.

What make a trajectory an "escape" trajectory is when it possesses sufficient velocity to fall out to infinity and still have some velocity left over.

[tomf]

For my heavy asteroid moving purposes I am planning on using the Rhino. Sure it will take more fuel but there is more than enough if you mine the asteroid and the more you mine the lighter and easier it gets. With the LVN you won't significantly deplete the asteroid before you have more fuel than you need.

The mining I can use warp to get through and most importantly I won't have to sit through massive burn times.