Staging

[KvickFlygarn87]

Are onion and asparagus the only lifter staging setups, or have I seriously missed something?

[Guest Capt_wheelchair]

Vertical staging is technically more efficient, but you need actually good radial engines to pull it off, and a way to balance them.

[KvickFlygarn87]

What's vertical staging?

[Daishi]

Decoupling spent stages from underneath you, I'd presume.

This guy seems to have done something new - http://forum.kerbalspaceprogram.com/threads/39850-Vertical-Asparagus-Stack-Experiment

[KvickFlygarn87]

that's amazing! It's such an obvious solution, but yet so often overlook

[Guest Capt_wheelchair]

i struggle to explain it, and i don't fully understand the semantics of having balanced engines pulling the rocket rather than pushing, so there will be some efficiency loss there, but i'll try explain it

like, instead of normal asparagus, where you have to drop two tanks at a time, you drop one at a time, as they empty meaning you are at optimal weight as you go.

it can be made even more efficient by using small tanks over large ones, dropping them even quicker.

i'll try draw a picture of what i mean, but i struggle because it only got explained to me once, months ago, and i cant show the math to prove it, but it is more efficient by a considerable amount.

[Guest Capt_wheelchair]

http://imgur.com/uPZHcBH&6TkwXFY

sorry for by terrible paint-fu

here's a shot of a more practical version, i just use 2X asparagus for lifting because unlimited resources man.

but these lander/interplanetary stages it makes a bit of a difference in economy, even if you have to use 2 NERVAS

http://imgur.com/fzbbBdo

Edited October 12, 2013 by Capt_wheelchair
image didn't show up, changed to URL, added some shi-

[Vector]

One of the things that makes asparagus work well is that it drops engines in addition to tanks. If you drop only the empty tanks, then your TWR increases over time, and high TWR usually means you're hauling more engine than necessary.

[Tex_NL]

This 'reverse staging' works in theory but in practice you'll run into a few difficulties. Most notably you'll run into two minor flaws in the game itself: engine gimballing and wobble.

Engines placed in front of the CoG should have their gimbal reversed. In KSP this does not happen (yet). As a result your nose will be pushed in the opposite direction of which you want it to go.

Since the connections between parts is not solid parts will start pulling away from each other. The connections closest to the top will be under the most stress and probably break.

[Tex_NL]

One of the things that makes asparagus work well is that it drops engines in addition to tanks. If you drop only the empty tanks, then your TWR increases over time, and high TWR usually means you're hauling more engine than necessary.

Don't forget, in Capt_wheelchairs idea you won't be carrying those engines in the first place. Engines you don't carry don't weigh you down. On the other hand you won't get any thrust from them either.

[Guest Capt_wheelchair]

yeah, i don't use it for lifting stages purely because i have never got it to work properly, mainly because of tex_nl's point about he engine gimbal. but for landers/return stages it works a treat, so long as the scale doesn't get too big so wobble becomes an issue.

I struggle to work out the optimal amount of engines because i cannot into math.

but yeah, if you did work out the ideal amount, you could also jettison them as you go, if it works out more efficient to do so.