Amount of fuel from Class E Asteroid

[Montag]

Is it practical to capture and bring a class E asteroid to a 100 km orbit for refueling purposes? How much fuel do you get from asteroids?

Edited September 29, 2015 by Montag

[SpaceplaneAddict]

Possibly. ISRU's also provide free funds in career mode because they make free fuel. Plus, Class E asteroids, huge, so big, many fuel, much wow.

[SpeedDaemon]

Well, one way to see if it's economical would be to send a craft that mines the ore for the fuel it uses to get it into orbit. If you're left with a worthwhile amount of ore once you have it where you want it, then, yes, it's worth it.

[SlithyTove]

Absolutely practical. To put it in perspective, here is my latest class E hauler completing a contract to throw a class E out of the solar system.

The "craft" with the asteroid attached weighed 3300 tons and it needed around 3000 delta V to get it out of the system. I had mined less than 1/3 of the ore available when the contract completed. You could supply a lot of missions with normal sized craft with that kind of fuel reserve. If it hadn't suffered a kraken attack after mission completion it could have then visited Eeloo, retuned to Kerbin, and still supplied a few big Jool missions.

[Kobymaru]

I'm gonna be rude for a bit and piggyback on the question:

My Install has a mod which apparently makes it possible that an Asteroid is made out of Water (Ice, I guess) instead of Ore. Had that once, and was kinda disappointed because I designed my craft with the expectation of free fuel. (Still "mined" it to make it lighter and could complete the mission).

So is there something that I can do if my 'Roid is made of water instead of Ice? Can I turn that into fuel somehow? Is there any way to tell before I get in physics range? Or do I actually have to send a reconnaissance probe?

[Specialist290]

Which mod specifically are you using, Kobymaru? It might be worth finding the appropriate mod project thread here on the forums and seeing if there's anything in the documentation that might help you out.

[Kobymaru]

Which mod specifically are you using, Kobymaru? It might be worth finding the appropriate mod project thread here on the forums and seeing if there's anything in the documentation that might help you out.

Well that's the question, isn't it? I'm not sure, but I think it's UKS that's responsible for that. Here's my mod-list:

[Specialist290]

Yeah, that would be the most likely culprit here (by way of the Community Resource Pack that comes bundled with it) from that particular mod list. Unfortunately it doesn't appear that anyone's thought to make a "water rocket" that's compatible with that particular resource system, though it would undoubtedly make for an interesting project for a modder so inclined to make one.

[Laie]

Is it practical to capture and bring a class E asteroid to a 100 km orbit for refueling purposes? How much fuel do you get from asteroids?

Typically, 80-90% of an asteroids' mass can be harvested as fuel. For a class E, that's 2000t plus X.

Some of that will certainly be consumed until you have maneuvered it into LKO. Depending on circumstances, patience and skill, that may be anything from 10-50%. Still, the remainder should allow for a thorough exploration of the whole solar system.

Is it practical? Your call. Redirecting a huge asteroid is a bit of work even if you know exactly what you're doing, and the first attempt is usually quite a learning experience. Arguably the same effort could launch a great many supply missions. So the main question is if you feel like doing it.

[KerikBalm]

Its most efficient if its coming in near equatorial, and you intercept it far enough out that you can nudge it to get a gravity capture by Mun.

After that, nudge its perapsis down to slowly aerobrake it... and then you should have several hundred tons of Ore in LKO