Puller Rocket

[RedRockets]

I have recently had the idea for a 'Puller Rocket' where the payload is under the boost stages and thus you can benefit from the tensile strength of the parts and not their stiffness or compressible strength.

A little research on Robert Goddard (father of modern rocketry) will show his first liquid fueled rockets had this same layout with the motor in-front of the tanks. It was reportedly very unstable, the heavy tanks wanted to pitch above the smaller and lighter motor.

I think this could be a great design challenge to all the kerbalnauts out there designing more ambitious designs than this or those interested in the historical progress of rocketry and manned rocket flight.

I think I now know why von Braun didn\'t follow in his direct footsteps.

RRs

http://kerbalspaceprogram.com/forum/index.php?topic=3622.msg39342#msg39342

Pics of my first and only attempt not very successful keeps pitching around its center of gravity

[Tim_Barrett]

Wouldn\'t getting fuel to the top of the rocket become an issue?

[RedRockets]

oh yeah that\'a serious concern. if you look at Goddard\'s first rocket the tanks have abnormally long fuel lines runnig up to the motor at the top.

And he love struts before it was cool!!

[Edvardo Perez]

Hey guys. I know I'm way late to the game on this post but I can't find any other puller rocket discussions.

You can actually have fuel drain from the bottom up using the fuel lines. I run them inside the stage separators on what I've termed the "gangles." It's a great way to reduce weight as you ascend since you can dump empty fuel canisters off the bottom of the stack without dropping any engines. The gangles don't experience compression forces and can be strung to improbable lengths. A few control surfaces and disabling the engine gimbal till the gangles reach a shorter length are all it takes to make it stable. More gangles tends to make for a more stable rocket too. I've found personally that I can build much larger rockets in the puller configuration than the pusher. My current design, excluding all stages above the main engines, is the equivalent of 20.25 of the large orange fuel tanks. I'm still experimenting with engine configuration.

[DesertWolf]

Hey guys. I know I'm way late to the game on this post but I can't find any other puller rocket discussions.

You can actually have fuel drain from the bottom up using the fuel lines. I run them inside the stage separators on what I've termed the "gangles." It's a great way to reduce weight as you ascend since you can dump empty fuel canisters off the bottom of the stack without dropping any engines. The gangles don't experience compression forces and can be strung to improbable lengths. A few control surfaces and disabling the engine gimbal till the gangles reach a shorter length are all it takes to make it stable. More gangles tends to make for a more stable rocket too. I've found personally that I can build much larger rockets in the puller configuration than the pusher. My current design, excluding all stages above the main engines, is the equivalent of 20.25 of the large orange fuel tanks. I'm still experimenting with engine configuration.

Hi Edvardo, here is my best puller rocket design: http://kerbalspaceprogram.com/puller-rocket/. Managed to tug 27 tons to 75km orbit. The full weight to payload ratio is 7.4:1It was originally designed for a challengewhich is why you will find some limitations on the craft file. Feel free to experiment with it.

Challenge: http://forum.kerbalspaceprogram.com/showthread.php/41141-10-Engines-Challenge-%28aka-efficient-staging-design-challenge%29

I prefer putting engines on the inside of the rocket, the design is more stable with me.

Edited July 21, 2013 by DesertWolf
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