Just found out about asparagus staging. I still think my old design is better.

[Bluemeriadoc]

I call it the Staged Pendulum Liquid Fuel Tornado Booster Thing. Or just tornado staging. Got this game three weeks ago. Addicted.

Edited January 10, 2014 by Specialist290
IMG tags for the win!

[Tank Buddy]

That doesn't quite look like you have asparagus staging. Asparagus is when you have engines with fuel stacks feed fuel in to the inner stacks one pair at a time. You seem to have a drop-tank method.

Sorry, didn't read the whole message. That is quite the vessel anyways. It looks pretty efficient, or at least interesting.

[sgt_flyer]

This design ensures that your engines are never dead weight, but you end up having to reduce throttle sooner or later (so the gain over classic asparagus is minimal) - 'classic' asparagus staging allows to limit TWR without touching the throttle (as you drop the engines with the empty boosters)

- also, having engines higher than the COM means you can't use gimbals at all (as the gimbal controls need to be reversed in this case, a SAS would mess up big time if you let gimbals active ) - so to overcome the lack of gimbals, you need either a lot of RCS, or lots of torque wheels

[Bluemeriadoc]

Yeah, I have five SAS Modules on top, but together only weigh 1.0. Right, I don't use thrust vectoring; I just go straight up into space, dump the booster, and navigate from there.

[Khobai]

Not really seeing the advantage over asparagus staging. Proper asparagus staging will also decouple unneeded engines to prevent them from becoming dead weight. Asparagus staging can also give you higher TWR to exit the lower atmosphere faster.

[Comrade Jenkens]

I always use linear staging simply because I prefer how it looks. My heavy lifter is a craft quite similar to the lower stages of Mulbin's Munbug.

[Rune]

Not really seeing the advantage over asparagus staging. Proper asparagus staging will also decouple unneeded engines to prevent them from becoming dead weight. Asparagus staging can also give you higher TWR to exit the lower atmosphere faster.

Yup, in fact the need to throttle down means this scheme is less efficient than "the technique commonly know as asparagus", which should be properly called parallel staging with crossfeeding across all stages. Tailoring the relative sizes and T/W of each stage can give you a far more perfect T/W curve over the flight than any other method, at the same time minimizing empty tankage. Hands down the most efficient possible configuration.

Rune. Sorry to rain on your parade.

[Bluemeriadoc]

Not really seeing the advantage over asparagus staging. Proper asparagus staging will also decouple unneeded engines to prevent them from becoming dead weight. Asparagus staging can also give you higher TWR to exit the lower atmosphere faster.

The drag should be way, way lower, n'est-ce pas? Assuming all other things being equal it should get to escape velocity sooner. Guess I should test both. Gonna try out this vegetable theory, see how it goes.

What's all this talk about need to throttle down? Why would I throttle down?

If the asparagus is dropping engines, technically it is the one throttling down, hehe. I keep my 8 engines till the end. Well, almost. In the second to last stage I drop three Rockomax 48-7S helper engines.

I just got a 24.33t ship going 2994 m/s. Now I haven't tried the accepted asparagus way yet, but this seems like a pretty good result.

Edited January 10, 2014 by Bluemeriadoc
Merging sequential posts.

[Bluemeriadoc]

I just got a 24.33t ship going 2994 m/s. Now, I haven't tried asparagus yet, but this result seems pretty good.

[lajoswinkler]

This what I use for tugs. Only smaller.

[Captain Sierra]

Ironically enough, I did something very similar when I first got the demo. lol There must be SOME sense to this method if players with more hours logged tried something like this.

Problem I had with it was control. Then again, mine was demo. no SAS torque system like there is now.

[Bluemeriadoc]

Success!

Escaped sun's gravity and still have a mass of 5.21t. Three unused stages left on my rocket.

[Levelord]

Success!

Escaped sun's gravity and still have a mass of 5.21t. Three unused stages left on my rocket.

That has to be the most inefficient orbital intercept I had ever seen for a craft with a payload that small. :I

[ihtoit]

the idea of Asparagus is to have every engine firing, with the maximum amount of thrust available while minimising the deadweight (tanks!). Linear staging causes upper stage engines to become dead weight since they're not firing until activated by jettisoning the lower stage. Those lower stage engines have not only to lift the fuel above them, they also have to lift engines that are not firing!

I'm currently working on a sort of hybrid system which uses linear upper staging and short-burn solid boosters alongside longer burn liquid boosters in Asparagus configuration to lift ridiculously heavy payloads. So far I'm up to 190 tonnes, I'm hoping to hit 500 to LKO in a single launch.

[tntristan12]

The most ideal configuration would be a single engine (or set of engines) providing thrust while as many tanks that carry as little fuel as possible are jettisoned as they become empty. In a perfect universe you would have massless decouplers jettisoning tank mass at a rate directly proportional to the rate at which the fuel is drained from it such that all tanks are gone the moment the fuel level hits zero. However for practical terms, with the decouplers and structure and fuel lines you'd need, it'd just be easier, cheaper, and more effective to simply go with a traditional multi-stage or fancy asparagus setup.

[Rune]

What's all this talk about need to throttle down? Why would I throttle down?

Reasons for throttling down:

1- Air resistance. Going over terminal speed while in lower atmosphere may decrease gravity losses, but it will increase drag losses more.

2- Every kilogram of engine that makes orbit counts as lost payload. If my aparagus bundle makes orbit on a single LV-909 on the last stage, the payload weight I lose to engines is 0.5mT. If I take six LV-T30's to orbit with me, that's 6.8mT if I recall correctly, so 6.3 mT less payload.

3- Do a proper gravity turn with your ship pointing prograde at all times, and still complete orbital insertion on a single burn. That's more for "pros" that both know their ships well, can pilot, and know the physics of it. But I've managed to squeeze some amazing performance out of designs by doing a very good gravity turn. The only problem is, without mechjeb reliability depends on how good a pilot you are, and how well balanced your rocket is.

The most ideal configuration would be a single engine (or set of engines) providing thrust while as many tanks that carry as little fuel as possible are jettisoned as they become empty. In a perfect universe you would have massless decouplers jettisoning tank mass at a rate directly proportional to the rate at which the fuel is drained from it such that all tanks are gone the moment the fuel level hits zero. However for practical terms, with the decouplers and structure and fuel lines you'd need, it'd just be easier, cheaper, and more effective to simply go with a traditional multi-stage or fancy asparagus setup.

In the ideal case, the rocket would weight nothing and have T/W infinite. In a less perfect world (but still pretty good), the engine would be made of infinite little engines, so you can drop them and engine weight would decrease as well (maintaining a fixed T/W, of course). Because less fuel needs less engine to lift it up.

Rune. This is not an opinion, BTW, this is all demonstrable by math.

Edited January 10, 2014 by Rune

[GoodGameHunter]

That's a fun design. I played around with different configurations of this too but I can't say I got any special efficiency out of it. Well, that's maybe because of my stubbornness to use a recoverable platform. Still, I find the model to be a bit too complicated for no extra benefit from a classic design, except for being fun to play around with. Here's my design (codename Babel) for anyone that wants to download and have fun with it: http://goo.gl/84W0Jq

I'm currently shooting a video of it, will upload in a bit and post the video here.

[Comrade Jenkens]

That has to be the most inefficient orbital intercept I had ever seen for a craft with a payload that small. :I

That's got to be the quickest flight to Jool I've ever seen!!

[Rune]

That has to be the most inefficient orbital intercept I had ever seen for a craft with a payload that small. :I

Let me dig up a (very) old photo... Dang it, can't find it. Must be from 0.18 or thereabouts. Anyhow, my most what? moment in KSP: here I was, just launched my first probe into solar escape trajectory. Either probes were kinda new, or ion engines, and I wanted to see how fast I could get one going. Got the most out of Oberth effect on chemical engines and all that. It gets into kerbol's SoI and... BAM! tuns out the game decides it's going retrograde instead of prograde. A mess of an orbit with high eccentricity at that. Thanks, Kraken! Thankfully Jool was close by, and I managed to squeeze an intercept out of ions. It put the probe on kerbol polar escape trajectory just with the gravity assist. Talk about inefficient trajectories... retrograde encounter with a gas giant and a polar trajectory just to get escape from the solar system!

It's got to be in one of my old save files still flying towards that rendezvous, but I don't wanna fire up the old versions, so I guess you will have to take my word for it, but it was one of those moments in KSP that stuck with me.

Rune. It was a hilarious bug, that's for sure.

[Bluemeriadoc]

Reasons for throttling down:1- Air resistance. Going over terminal speed while in lower atmosphere may decrease gravity losses, but it will increase drag losses more.

I could calculate the intersection of these curves but I don't have the equations for the drag curve or gravity curve for Kerbin.

@ihtoit I can't exactly use my booster engines for landing on Gilly, haha. Of course I'm going to have linear stages on top of my boosters.

@Levelord Haha, yeah I was just trying to escape the sun for a test and I happened to pass near Jool.

[Giggleplex777]

Did you just fly straight up?!

[Bluemeriadoc]

Did you just fly straight up?!

Yeah, of course! I launch at night when going to the outer solar system and launch in the day when going to the inner solar system. I guess sunrise and sunset would be better though, hehe.

@GoodGameHunter Babel - Mk III says "Contains locked or invalid parts", even in sandbox. If it requires mods, I'm not gonna mod until I get through with the career mode. Besides, I want to test an asparagus that uses parts comparable to those I use in my fuel tornado.