Rocket Falling from gravity turn?

[Bearsh]

Hello all! This post is here for a problem i've had for a long time, Sometimes in the proccess of the gravity turn after a while the rocket starts falling back down due to the gravity turn, Why is this happening? How can i fix it??

Thanks in advance!

[biohazard15]

It seems that your gravity turn is too sharp and\or your rocket has insufficient TWR.

[Streetwind]

Moar Boosters!!!

No, seriously, you need more thrust. You're falling back down because you don't accumulate the necessary forward momentum by the time your upwards momentum runs out.

[KvickFlygarn87]

Either more boosters or point upwards when this happens.

[Seret]

Have you dropped a stage just before your gravity turn? It sounds like the stage you've got firing has insufficient TWR. This is not uncommon for upper stages, I find the Skipper engine often needs to be augmented slightly with radial engines to get the TWR up high enough. A mod such as Kerbal Engineer or Mechjeb is needed to display the TWR of your stages while still in the VAB (or you could do it by pen and paper...).

[Superfluous J]

If by "falling" you mean that the nose goes down and you can't bring it back up, you may have dropped engines that had thrust vectoring (Gimbaling) and now have engines with none, and you can't control your craft.

[FREEFALL1984]

Yeah your T/W is too low, after starting the gravity turn you should be able to slowly "follow" the prograde marker down the navball towards the horizon and the prograde marker should never drop below the horizon during launch, if you find you're having to burn towards the sky to keep the prograde marker above the horizon while still in the atmosphere then you're asking too much of your lifter and you might find that removing the fuel from the payload before launch helps a little although whether you are left with enough fuel to transfer any excess from your lifter to your payload once in orbit is a different matter. it's often a useful technique with big lifters and interplanetary tugs.

If the issue is that the rockets orientation is flipping and then suddenly aiming groundwards then you may have too much drag on the payload, the only way I can think to fix this is to never point too far from the prograde marker in order to keep the center of thrust behind the center of drag so start the gravity turn early, (about 5000m) and turn very slowly

Edited April 24, 2014 by FREEFALL1984