Spacecraft very difficult to control while getting into orbit

[notasurgeon]

This is my third attempt at making a lander capable of landing on Tylo (best attempt so far: impact at 400 m/s). I have high hopes for this one and it's currently in route, but it has FAR more trouble orienting itself to prograde once the boosters come off at the end of the ascent stage than any of my previous rockets have. I added some RCS in the hopes that it would help, but I think that the ship is simply so massive that even those can't do much. The first two Tylo ships were almost as heavy, but neither had anywhere near this difficulty orienting itself for the circularizing burn. Any ideas?

Edit: Mods required, mechjeb, protractor, and engineer redux.

Edited October 14, 2012 by notasurgeon

[42undead2]

I will see what i can help with. Posting results later.

Edit: Wait, what mods were you using? It's says that there is parts that i don't have.

Edited October 14, 2012 by 42undead2

[notasurgeon]

Success! My interplanetary stage was way too big, apparently. When I decelerated to do my course adjustments as I entered Jool's SoI, two of my NERVAs broke off and I had to eject about 5,000 dV of fuel and just use the lander stage. Now I'm sitting on the surface of Tylo with 2,700 dV remaining in the lander.

Next goal, miniaturization!

[Vanamonde]

No ladders?

[notasurgeon]

I forgot to add one

[notasurgeon]

I will see what i can help with. Posting results later.

Edit: Wait, what mods were you using? It's says that there is parts that i don't have.

Ah, sorry I should have posted a stock version. Protractor, Mechjeb, and Engineer redux.

[EndlessWaves]

Now I'm sitting on the surface of Tylo with 2,700 dV remaining in the lander.

Try getting back up to your parking orbit with that, it'll give you some idea of how much DeltaV you need to get down.

[notasurgeon]

After wasting all that fuel and having so much left over on the last attempt I started over with a smaller capsule, a substantially smaller transfer stage, and a bunch of asparagus-staged aerospikes with boosters to get off Kerbin. I think my biggest problem was that I had plenty of fuel (I think I got there with over 6,000 dV left with Tylo II), but most of it was getting wasted fighting gravity and not enough was actually being used to slow me down. Shrinking the landers and adding thrust to them had a major payoff.

Tylo I - 326 parts. Arrived with tons of fuel left, but failed to land due to insufficient thrust-to-weight ratio.

Tylo II - 328 parts. Arrived with even more fuel, but still wasted most of it fighting gravity and crashed into the surface killing all aboard.

Tylo III - 397 parts. Arrived with so much fuel that a glitch forced me to abandon about 2 2m tanks worth in space, yet still landed successfully.

Tylo IV - 145 parts. Significant improvement, and I can launch this one without my computer slowing to 0.5 FPS. With some minor modifications I think this one might easily be able to return from Duna.