What's asparagus got to do with space flight?

[DualDesertEagle]

I just thought about a mission I could fly and as I thought about the necessary asparagus staging I realized that I had never thought about where exactly that name came from.

 

So we all know how to set up and use asparagus staging correctly, aswell as that it gives us more dV for the same cluster of boosters than if we let them all burn for the same duration. But does anyone of u guys know why it's called asparagus staging and not like "cake-slice staging" or something a little more scientific, like "symmetrical staging"?

It's not that I don't like the term (even tho I don't like asparagus that much), I'm just curious about its origin.

 

EDIT: The perfect term, in MY humble opinion, would still be "pair staging".

Edited August 18, 2017 by DualDesertEagle

[HebaruSan]

[RCgothic]

An asparagus has leaves overlapping in a spiral pattern.

For an asparagus staged rocket with a large number of stages, the stages usual end of dropping off in a spiral pattern.

[Ten Key]

Best reference I can find is an orbital mechanics textbook published in 1998. 

 

Quote

This staging plan, which could be scaled up to a large number of boosters, comes from a proposed booster design described in a book on orbital mechanics by Tom Logsdon. In the original proposal, a cluster of identical cores would each crossfeed to a neighboring core, with the last pair crossfeeding to the center. Thus, as the rocket ascends, the first pair of cores provide fuel to all the engines, then drop away. The second pair then fuels all remaining engines, and so on. (Pairs are used to maintain symmetric mass distribution.) An engineer named Ed Keith is attributed as the creator, having called the design an "asparagus-stalk booster" from a large cluster's resemblance to a bundle of asparagus. (Logsdon, Tom (1998), Orbital Mechanics - Theory and Applications).^[7]

https://en.wikipedia.org/wiki/Modular_rocket

[kerbiloid]

Strange. Unlikely they eat asparagus in a spiral.
For me this design looks like peeling an orange.

[DualDesertEagle]

So in other words the same term still applies when all boosters placed around the rocket are ditched at the same time rather than dropping pair after pair? I'm a little confused now 

[Chakat Firepaw]

Dropping them as complete rings is sometimes called "onion staging".

[Just Jim]

On 8/18/2017 at 6:43 PM, HebaruSan said:

Actually, looking at this picture, it all makes sense to me now where the name came from.  

[wumpus]

The following is something I posted a couple of years ago (presumably after reading the book and getting an idea of the timescale of how long rocket science theory has been understood and how tricky it is to put into practice).

While the name "asparagus staging" apparently barely predates KSP, the idea has been around a long time:

Quote

Before continuing it should be pointed out that all staging is not of the tandem type.  The British use wrap-around staging on many of their missiles today.  The Martin Company has investigated lateral staging, where all stages would fire at the same time.  High performance is the expected result.  At all times propellant would be pumped from one of the outer to the inner stages; and when the outer ones emptied, they would drop off.  Not only would higher thrust-to-weight ratios result, but all stages would be ignited before take off.  Professor Crocco of Italy presented a similar plan to the Fourth Congress of the International Astronautical Federation, in 1953.

And obviously it is harder than it looks like in KSP.  The book I am quoting is from 1958 (presumably hastily published after the Sputnik launch).  It is a nifty book I found in my parents old collection: being from 1958 it starts *everything* from first principles, without launching into extremely specialized engineering.  I've looked through some fairly well stocked used bookstores for other Kerbal-type books on rocket science, but haven't seen anything close.

http://www.amazon.com/Space-Flight-Early-thoughts-projections/dp/B0000CK2Z4/ref=sr_1_1?ie=UTF8&qid=1451578393&sr=8-1&keywords=space+flight+by+carsbie+adams

[Vanamonde]

Jokes aside, somebody once thought that the columns of boosters looked like a bundle of asparagus stalks, and the name stuck. It doesn't have anything to do with the pattern in which they are discarded. 

[magnemoe]

12 hours ago, Vanamonde said:

Jokes aside, somebody once thought that the columns of boosters looked like a bundle of asparagus stalks, and the name stuck. It doesn't have anything to do with the pattern in which they are discarded. 

Idea and name is far older than KSP.
If became dominant in old ksp for an number of reasons. low twr for boost stages, weak joints so building long rockets was an challenge. Far better to build wide, simple drag model had no penalty for short and wide rockets. Piping in KSP is simplified so no issue pumping fuel trough 5 stages. 
Mostly fallen out of favor now, some Eve accent crafts uses it, with the SLS parts even 2 stage crossfeed is more than usual needed, long first stages helped by stacks of SRB tend to be cheaper and work better. 
 

 

[wumpus]

On 8/21/2017 at 6:32 AM, magnemoe said:

If became dominant in old ksp for an number of reasons. low twr for boost stages, weak joints so building long rockets was an challenge. Far better to build wide, simple drag model had no penalty for short and wide rockets. Piping in KSP is simplified so no issue pumping fuel trough 5 stages. 
Mostly fallen out of favor now, some Eve accent crafts uses it, with the SLS parts even 2 stage crossfeed is more than usual needed, long first stages helped by stacks of SRB tend to be cheaper and work better. 

Probably the biggest reason that asparagus staging is no longer popular (or at least why I don't use it, SSTO craft are another favorite alternative) is that it is generally cheaper and more efficient to simply grab a larger part.  In reality, it costs huge amounts of money to design a new rocket or even a larger fuel tank.  Of course, building something like a Falcon Heavy or Delta Heavy out of their "base" rockets is also wildly more expensive than you would think (it sounds like Musk was shocked at the time and effort), but still cheaper than custom designing new engines, fuel tanks and custom plumbing.

In KSP "asparagus staging" pretty much came to mean horizontal staging of identical engine/fuel tank combos, all dropped in pairs.  This was pretty much due to both the original aero model (as noted above, it didn't care if things were horizontal or properly vertically occluded) and the souposphere. A TWR of 2.0 was ideal for the souposphere during the entire ascent, so identical stages were almost universally employed.  After looking deeper into it, I was pretty sure a "nautilus staging" with exponentially decreasing masses (more fuel even with the same engines, but changing engines too) would be better far better in terms of delta-v (although possibly not for Kerbin's old souposphere or even current Eve (which is where you would want these tricks anyway).

There are still many lessons you can learn from cross-feeding stages in KSP that don't employ traditional asparagus.  Drop tanks are typically a great idea (empty fuel tanks in KSP are far heavier than in real life, mostly to compensate for Kerbin's lower orbital velocity) even if they don't have engines on them.  A favorite trick of mine is to put a drop tank above the payload and pump that tank empty and stage it (in at least vacuum, you don't want to hit it).  I'll admit that the cost and mass of a terrier engine makes that less needed.

[StrandedonEarth]

10 hours ago, wumpus said:

There are still many lessons you can learn from cross-feeding stages in KSP that don't employ traditional asparagus.  Drop tanks are typically a great idea (empty fuel tanks in KSP are far heavier than in real life, mostly to compensate for Kerbin's lower orbital velocity) even if they don't have engines on them.  A favorite trick of mine is to put a drop tank above the payload and pump that tank empty and stage it (in at least vacuum, you don't want to hit it).  I'll admit that the cost and mass of a terrier engine makes that less needed.

Another little trick is to put properly sized cross-fed fuel tanks on the top of your SRB's, to be dropped with the SRB.

[DualDesertEagle]

On 23.8.2017 at 3:38 AM, StrandedonEarth said:

Another little trick is to put properly sized cross-fed fuel tanks on the top of your SRB's, to be dropped with the SRB.

Which is probably tricky to do...

[wumpus]

5 hours ago, DualDesertEagle said:

Which is probably tricky to do...

Even without Kerbal Engineer, the SRB parts should say how long they burn, and the engines should say what their fuel flow is.  Multiply the numbers together and you have the fuel you need.  Put enough fuel tanks to supply that on the SRBs and you will have the right amount of fuel and oxidizer.

And this method means that there's absolutely no reason to throttle your liquid engine while the SRB is carrying you to orbit, so the fuel rate should be right (I think that is true for 1.0.2, if you can still launch with terriers (inefficiently) it might not be.  Don't expect any information you see on the fora to be accurate for 1.0.2).

[DualDesertEagle]

34 minutes ago, wumpus said:

Don't expect any information you see on the fora to be accurate for 1.0.2).

Never did and never will, and hopefully I won't have to use 1.0.2 for much longer coz the next big spending of money after I got my long desired dirt jump bike is gonna be a more powerful computer. And once I have that I'm actually willing to rebuy the whole game just for the sake of finally being compatible with all the stuff on the forum. For example, most of the challenges are just not possible for me since I can't even make vessels that meet all their requirements. 

[StrandedonEarth]

Bah. I wanted to drop in the meme about "This Asparagus Recipe Looks Complicated" posted by @Red Iron Crown a couple of years ago, but the image link is no longer valid... Google didn't seem to find it.. His last activity was a week ago... Like hey, where'd he go?