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Do you still use Asparagus?

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For an interplanetary ship, this is valid. For a launcher less so. I don't need more delta-V per se but more payload to orbit. If I've got an asparagus lifter built for a 40 ton payload, and I try and slap a 400 ton payload and more asparagus boosters with it, I'll end up with 1/5th of the TWR on my core stage. Since said core stage actually has the lion's share of the delta-V, chances are I won't make orbit.

By contrast, if I've got a serially staged lifter built for a 40 ton payload, and I want to lift a 400 ton payload, I can gang ten of those lifters together and I'll have exactly the same TWR at all points in my launch.

If it's something like 45 rather than 40 tons then sure, adding a couple of boosters to the asparagus lifter will work. But adding a couple of boosters to the non-asparagus lifter will equally work.

Asparagus doesn't scale well, sure, but creating the first lifter is easier.

Let's say I want to get something into orbit:

I make a lifter which doesn't make it.

If I'm using normal staging, I then have to make another stage which is bigger than the current stage by exactly the right amount. Too much and it's hard to build the next stage, too little and that stage doesn't add much.

If I'm using Asparagus, I can just add another stage which is the exact same as the last one.

Though actually since Career Mode was implemented I've generally been using SRBs for the first stage, and then asparagus (if necessary).

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I didn't use asparagus previously, so the fact that I still don't use it shouldn't come as a news flash.

Asparagus is a supposedly "efficient" staging method that saves fuel (which is cheap) by throwing away lots of engines and empty fuel tanks (which are very expensive). My strategy is based on the use of expendable solids and recoverable fly-back stages.

http://i.imgur.com/1FuiVzW.jpg

http://i.imgur.com/gFoAFGD.jpg

http://i.imgur.com/RRXFgkr.jpg

Asparagus staging is *very* efficient. Not just in terms of fuel, but in terms of payload fraction, which translates to dramatically smaller launchers with lower price tags for the same payload.

It is not, however, more efficient than turbojet/rocket hybrid or RAPIER SSTO lifters. I could probably build a jet asparagus booster even smaller and lighter than my SSTO, but why stage when you don't need to?

Best,

-Slashy

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Asparagus doesn't scale well, sure, but creating the first lifter is easier.

Let's say I want to get something into orbit:

I make a lifter which doesn't make it.

If I'm using normal staging, I then have to make another stage which is bigger than the current stage by exactly the right amount. Too much and it's hard to build the next stage, too little and that stage doesn't add much.

If I'm using Asparagus, I can just add another stage which is the exact same as the last one.

Fair point. My "cores" may be simple low-part-count things but designing them took me a while.

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Asparagus doesn't scale well, sure, but creating the first lifter is easier.

My standard "two vertical stages + two boosters" is about as easy:

  1. You start with an upper stage that's a bit smaller than the payload (maybe 80% of it or so). To make the ascent easy enough, the TWR should be initially at least 0.7. This stage will give you over 1500 m/s of delta-v.
  2. Next you build the lower stage, which should have around 3x more fuel than the upper stage. This stage should also have powerful enough engines that the initial TWR is around 0.7-0.9.
  3. Finally you add the boosters. Their job is to assist the lower stage, until its TWR gets above 1.0. Choose large enough engines to get the initial TWR to 1.1-1.4, and add enough fuel that the boosters last until the lower stage can continue under its own power. One easy way to accomplish this is to take the lower stage, remove 1/3 of the fuel, and use two of these shortened lower stages as boosters. This way, you'll probably get 2000-2500 m/s of delta-v before dropping the boosters, and almost 1000 m/s from the remaining fuel in the lower stage.

The actual rockets I built (when I still played without FAR) usually deviated from this general pattern, because it was more fun to optimize the rockets to use different engines as efficiently as possible.

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I'll use it to some extent, but not much, and never the overly elaborate "pancake" shaped rockets. Usually only a single staged is "asparagused." ie, when I have two or three liquid boosters on the side of a powerful rocket, I'll tie them into the central rocket.

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Rarely. With career mode I've mostly just been using SRBs instead. Plus with stiffer joints it's easier to just build taller now.

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I would use it if ksp didnt delete everything. Losing 200k worth of parts every launch because the game decides to keep the 500 credit decoupler but delete all of my nicely designed parts with parachutes and stuff has definitely changed my uses for Asparagus.

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Yes and no - I use a short asparagus first stage but then linear separation for the remaining stages. Because the first stage usually requires the most power strapping a few liquid boosters on the outside does help a lot but once I'm out of the atmosphere there is no need for so much thrust so a single engine stack works just fine

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I'm also in the "never for launch, but sometimes to take off of heavy planets" group. For ultra high fuel consumption interplanetary work (e.g. to haul a Jool 5 mission out to Jool), I prefer to attach with 6x symmetry and decouple manually.

As for the bonus, "stalks of asparagus" or "asparagus-staged rockets" is the plural, but if we want to talk about multiple individual plants in the genus Asparagus, that would be asparagi.

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I used to use it for almost anything. But, since I started using NEAR, I just don't really have a need to. I generally make a 2-3 stage rocket, and maybe attach 1 stage of liquid or solid fuel boosters to the outside. When I start asparagus staging, then my lifter stages end up with more than enough delta V, and cost more than they need to. I'm sure I'll need to do it when I finally get around to doing an Eve landing/return.

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rarely use it, Eve is the only planet I use it ( again to keep weight down/dv up )

MOAR BOOSTERS, I usually add SRB's to a liquid core and haven't had a problem lifting anything even on carrier mode.

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Asparagus is still really useful, especially for shifting really heavy stuff into orbit; but since I installed FAR I don't really use it anymore, as it makes the rocket too wide, and therefore induces too much drag, even if you put nose cones on it. Twisted Candle and Bamboo staging = OP :P

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Asparagus flowchart.

1. Multiple stages? If not, no asparagus.

2. Should there be drop tanks? If not, no asparagus.

3. Does it need engines on the drop tanks? If yes, asparagus.

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I like to keep my space program as realistic as possible, so I only use fuel crossfeed if it is from an external tank without engines.

It's funny if you think about it, actually. When you first play the game, you build big serial staged rockets to launch small payloads. As you progress, your rockets get smaller and smaller thanks to asparagus staging, and ultimately you reach the peak of LV efficiency. And it's all downhill from there: you realize that asparagus is unrealistic and you return to building serial staged rockets like you did when you began (albeit more efficient).

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I used asparagus on my latest launch: two outboard turbojets with fuel, one inboard. The jets got me stupidly high (200km). I refilled the inboard tanks from the outboard tanks during the launch -- by hand rather than with fuel lines, to save a few bucks. I fired the inboard rockets to get apoapsis above the atmosphere, then separated the fuel pods, and swore at the fact I'd forgotten to refill my inboard rocket-fuel tanks before decoupling. Idjit!

But anyway, that's an asparagus SSTO design to launch a big plane to orbit.

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I always tried to build rockety rockets, the larger parts made that easier, but I will still use it to lift my interplanetary ships that should have been built in orbit instead - maybe I should install the bare minimum needed of an orbital construction mod next time ... :P

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I'm a bit of a novice, so pardon the question. I see some talk of part efficiency in this thread. What is the advantage that people are trying to attain by going for part efficiency? More parts can mean more weight/drag/cost, but not necessarily. So that's why that being stressed confuses me. Is it a matter of pride, or a challenge type thing? Or is there something I'm missing?

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I'm a bit of a novice, so pardon the question. I see some talk of part efficiency in this thread. What is the advantage that people are trying to attain by going for part efficiency? More parts can mean more weight/drag/cost, but not necessarily. So that's why that being stressed confuses me. Is it a matter of pride, or a challenge type thing? Or is there something I'm missing?

More parts means lower performance of the game itself, generally speaking.

Asparagus staging is very mass efficient but not overly part-count efficient.

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I'm a bit of a novice, so pardon the question. I see some talk of part efficiency in this thread. What is the advantage that people are trying to attain by going for part efficiency? More parts can mean more weight/drag/cost, but not necessarily. So that's why that being stressed confuses me. Is it a matter of pride, or a challenge type thing? Or is there something I'm missing?

Using less parts means that the rocket is faster and easier to build, the game runs faster, and you're less likely to make random mistakes when building the rocket. Essentially, part count is the only real efficiency metric in the game, as the cost/recovery model in the career mode is still so bad.

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I used to use asparagus staging, but far less since Career Mode came out. Now, if I'm using liquid-fuelled boosters instead of SRBs, I have the boosters feed into the core stage (is that called Onion Staging?). I try not to use more than 4 LF boosters for cost reasons, opting to use a more powerful core stage instead.

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I used to use asparagus staging, but far less since Career Mode came out. Now, if I'm using liquid-fuelled boosters instead of SRBs, I have the boosters feed into the core stage (is that called Onion Staging?). I try not to use more than 4 LF boosters for cost reasons, opting to use a more powerful core stage instead.

Yes, that's onion staging. Onion is when the entire outer ring of boosters gets jettisoned at once. Asparagus is when only part of the ring gets jettisoned.

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I'm more an in-situ resourcing kinda guy (EPL and Karbonite)

So by the time I need such large launchers I have the industry to fabricate in orbit of the mun or minimus

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I try to go for more realistic staging, the most asparaguslike my rockets get are two boosters feeding into the middle booster.

For a mission I'm planning, I am considering asparagussed ion stages though.

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Ever since I learned how to assemble my unnecessarily large craft in orbit, I haven't used it that often. I typically use a central LF stage and however many SRB's are needed. Every once in a while I'll strap a few LF boosters on, but that's it. I recently tried launching 190 tonnes of fuel into orbit, and I had no choice but to use asparagus. It took me at least 20 tries to get that thing into orbit.

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I usually use srb's around a liquid core with an upper stage. For the heavyer stuff I use more srb's (up to 8) and a bigger liquid rocket as a core. If that is still not enough I may go for 2 big liquid booster around a liquid core. There aren't many payload's in my programm that require even bigger launchers.

I only used asparagus in sandbox mode.

The biggest launcher I ever used was a nasa-sized liquid core and 6 boster with mainsails around that. It had an asparagus setup. The payload was the engine section of my jool 5 ship (which ended up as a 600t monstrosity in low kerbin orbit). As I reached jool I realized that it it still had like 8000 delta-v left.... since that day I use the delta-v map and reduce my safety margin :D

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