How to go Moho, Dres and the Outer Rim

[johnnyhandsome]

I can get to Mun, Minmus, Eve and Duna.

But I can't get to Moho or Dres. Yeah, they're in a different plane, which is part of the problem, but the big problem is that I can't build a rocket large enough to reach either, let alone the outer planets and moons. What am I doing wrong?

Here's a photo of rocket I often to use, can you offer any suggestions? The brute force way seems to work well, but only to a certain extent. Ideally I'd like to launch 20 tens to Moho, Dres etc. That amount includes a rover and landing system.

[Spartwo]

what are your reservations with nervas?

[Malaugrym]

Imo, the simplest way is build a spacecraft in orbit, refuel, and go on your merry way. Trying to get vehicles from the surface of Kerbin to these targets is rather difficult.

[johnnyhandsome]

Nervas? What do you mean?

[Spartwo]

Nervas? What do you mean?

I don't notice any nuclear engines.If there is any I didn't notice.

EDIT:They are extremely efficient although in exchange for low thrust.they are perfect for inbetween kerbin orbit and orbit around any planet your going to.the optimum TWR would be .20 but don't use more than 2.

Edited May 17, 2013 by Spartwo
V explaining

[johnnyhandsome]

I've never used nuclear engines! Do tell me why I should!

[PDCWolf]

I've never used nuclear engines! Do tell me why I should!

NERVAs have an ISP of 800, being the most efficient engines in vacuum.

[Specialist290]

I've never used nuclear engines! Do tell me why I should!

PDCWolf has already given the basic answer, but if you want to go into the basics of why that's as important as it is, I'd highly advise reading this page.

The long and short of it is: Your rocket's "range" (not the best word to use, as the basic assumptions for travel are different in space than they are here on the ground) is effectively determined by two factors: The efficiency of its engines, and the ratio of its fuel to the total mass of the vehicle. Because of the way the rocket equation works, in order to increase the amount of delta-v (potential change in velocity) from having more fuel by the same measure as you could from having a more efficient engine, you'd need to add tons of fuel... which translates into a heavier payload for your rocket to lift into orbit... which in turn means even more fuel in your ascent stage.

Speaking of ascent stages, you really want to get rid of the vast majority of the fuel on your rocket (and the fuel tanks used to carry them) in that first climb up to Low Kerbin Orbit. There's another page on that website that goes into a bit more detail, but in general you want your first stage to be much, much heavier than the final payload.

You might also want to look into things such as fuel crossfeeding (particularly a concept known as "asparagus staging") and interplanetary phase angles, although there are other people who can and have explained these things much better than I ever could. There's a wealth of information available on these subjects in the Drawing Board, which is stickied to the top of this particular forum (or you could just use the link in my signature).

That said, Moho is an absolute bear of a target to get to. I'm actually in the middle of sending a tanker out to a pair of kerbalnauts I've got in orbit there, and it's even crazier trying to build a craft that can make orbit there and still have plenty of fuel to transfer to my first craft than it was to get them out there in the first place! Ah well, even us people who know what we're doing have our off days...