Is Asparagus obsolete with SLS?

[Soda Popinski]

I've only been getting back into KSP after a few months of hiatus, and have been focusing on finishing my ongoing Jool mission. In other words, I've not been doing a lot of launches.

I played around with the asteroid redirect briefly, and found it pretty easy to throw together a 3 stage rocket using the new NASA SLS parts (no SRB) to intercept an asteroid out at about the orbit of the Mun, and get an orbital capture.

What kind of payloads can we get into LKO with the SLS rockets? I usually used an Asparagus lifter to get 60 to 80t to LKO. Will a simpler SLS system do the job? Are Asparagi systems obsolete? Or is this a way to make a SUPER ASPARAGUS?!

[KerikBalm]

Not obsolete, just simplified.

I still make designs with side boosters feeding into the core stage, most I've done is 4 asparagus staged radial boosters

[sickboy]

you can sure use the new 3.5M parts to make even bigger asparagus, why not

[Vonar]

I suppose you could do something with 4 external boosters pumping fuel in a asparagus style launch system. I haven't had a chance to test out the KSP version of the SLS to see how close the stock SLS is in capabilities to the rl SLS. Irl the SLS is supposed to be able to launch 130 Tons into LEO. If it is comparable I don't really see a need for Asparagus, after all how often do you need to launch 130 ton payloads in KSP?

[FITorion]

no... we'll just asparagus the SLS parts...

so... obsolete for getting the old payloads to orbit... not obsolete for the new larger payloads we'll be building now that we have more power.

[The Destroyer]

No, definitley not. I asparagus SLS parts due to my massive payloads

[mellojoe]

Most of my missions use a very simple setup, single core plus two boosters with crossfeeding into the core. Rarely have I gone more than that. With this simple one-layer asparagus, not only do I get decent payloads to orbit, but also I don't get mind-numbing part lag. And it feels more real.

[Jouni]

Asparagus staging is just a way to trade part count for fuel efficiency. It was never really necessary, but people just assumed that it was the correct way to do things, because it led to the highest payload fractions.

A simple rocket with 14 orange tanks and 7 Mainsails in the lower stage, and 7 orange tanks and 7 Skippers in the upper stage, can lift over 100 tonnes to LKO. A similar design with the new SLS parts could probably lift around 350 tonnes.

[Soda Popinski]

Asparagus staging is just a way to trade part count for fuel efficiency. It was never really necessary, but people just assumed that it was the correct way to do things, because it led to the highest payload fractions.

A simple rocket with 14 orange tanks and 7 Mainsails in the lower stage, and 7 orange tanks and 7 Skippers in the upper stage, can lift over 100 tonnes to LKO. A similar design with the new SLS parts could probably lift around 350 tonnes.

I suppose "simple rocket" is relative.

I busted out my old Excel sheet where I have calcs for various Asparagi based lifters using Jumbos & Mainsails. I took my "simple" 4 stage 6 part asparagus lifter (60t) - replaced the Jumbo/Mainsails with the new SLS cluster rockets. According to Excel, I've got a delta-V of 5020 m/s to lift 145t of payload.

Going the opposite way, for simplification, I tried a 3 stage linear rocket, 1st stage SLS cluster (KS-25x4), 2nd stage KR-2L, 3rd stage Skipper. 5029 m/s to lift 47t.

Wow. Now all I have to do is research and build them. Now I need to figure out a mission to lift 145t. I've usually just done on orbit assembly of 60t - 70t parts.

[Jouni]

The core of my "simple" rocket is a two-stage rocket with a Mainsail and two orange tanks as the lower stage, and a Skipper and an orange tank as the upper stage. With 7 parts, it can lift 15 tonnes to LKO, if you don't mind that the upper stage remains in orbit. If you need more payload capacity, you can attach 2, 3, 4, or 6 similar rockets radially, allowing you to lift 45, 60, 75, or 105 tonnes with 19, 25, 31, or 43 parts. (You may need some struts to secure the lower stages.)

A modular rocket like that was one of the design patterns I tried when I decided to stop using asparagus staging in lifters. Ultimately I chose to use the more traditional "two boosters and a two-stage core" design, which can be built in many different sizes.

[BMBender]

Make a jool diver. SLS asparagus works great for it. Pretty easy to make one under 300 parts

[Darth_Kerb]

It's asparagus-season in europe btw. Get your pale faces off of the monitor, go to a restaurant and have some asparagus. Avoid eating opposing shoots of asparagus at once because you care for "balance". And don't tell your friends that the center shoot is still full while you ate all the surrounding shoots. It's not cool. Oh, and dont cut off the tip of the central asparagus shoot saying you "decoupled the capsule". It's a vegetable, get over it!

Edited May 3, 2014 by Darth_Kerb

[Vanamonde]

Asparagus isn't obsolete. It just got bigger.

[NecroBones]

Not obsolete at all. My Eve-lander ship was huge, and needed asparagus boosters, even with the SLS parts. The interplanetary stages were in the center, and I did 4 pairs of asparagus boosters around it. Total mass on the launchpad was around 2800 tons.

[Zylark]

Hmmm, so far in my 0.23.5 career, I've just used the good old 1+6 asparagus with Skipper-powered Jumbo-tanks and an outer layer of 12 SRBs. Gotten everything I've needed into orbit. Then again, I don't launch really big stuff to orbit, as I much rather assemble stuff over several launches than having it all in one huge launch. Keeping it modular makes for greater flexibility.

But I suppose I could make a lifter with SLS parts that got the same lift-capability as my current asparagus, whilst at the same time slashing the parts-count by some 60-80%. So yeah, for medium weight launchers (40-60t), asparagus is probably a bit overly complicated these days. Only reason I use it I guess, is because I know exactly how it performs so I never get into any situations where there either is too little fuel to complete the launch, or I'm left with way too much fuel slushing about in the lifter.

Fuel launched into orbit and not put to good use, is waste of precious virtual resources...

[Linear]

"Hyper'sparagus"

[Jouni]

Not obsolete at all. My Eve-lander ship was huge, and needed asparagus boosters, even with the SLS parts. The interplanetary stages were in the center, and I did 4 pairs of asparagus boosters around it. Total mass on the launchpad was around 2800 tons.

Eve landers can often launch on their own, or with the help of a few SRBs. That's how I launched my 1600-tonne lander, and it had enough fuel left to reach Eve orbit before refueling. Now I just need five refueling trips from Gilly to fill it with about 40 orange tanks worth of fuel.

No pictures yet, except from the development version:

That's my only ship using asparagus in 0.23.5.

[Xavven]

Eve landers can often launch on their own, or with the help of a few SRBs. That's how I launched my 1600-tonne lander, and it had enough fuel left to reach Eve orbit before refueling. Now I just need five refueling trips from Gilly to fill it with about 40 orange tanks worth of fuel.

My first Eve return lander used this strategy, but I found that launching and transferring orange tanks for refueling took more effort than designing a transfer stage and lifter right underneath my lander with the SLS parts. Now doing that with stock 0.23.0 parts -- that was a challenge.

But on the topic of Eve, Eve landers still absolutely need asparagus staging. Without it, you can you lose more than 1000 dV with the next-best onion staging model. Making up for it in lower stages is hard to do without going way over 100 tons and still getting near-sea-level capability.

[syfyguy64]

The Asparagus staging looks more aerodynamic now, at least.

Here is my SLS like design, and Apollo lander.

Proof that it acts as the Apollo did.

Edited May 3, 2014 by syfyguy64

[Red Iron Crown]

Asparagus isn't obsolete. It just got bigger.

My thoughts exactly. Bigger parts just means bigger payloads on top of bigger asparagus rockets. There will never be parts so powerful that asparagus becomes obsolete. That would require changing the game mechanics, via better aerodynamics or flow-limited fuel lines.

[Seret]

I suppose "simple rocket" is relative.

Indeed. Pretty sure I've never launched anything with seven mainsails, although five was pretty standard.

Edited May 3, 2014 by Seret

[TimePeriod]

What's the point of launching such massive payloads? Is it not the point of trying to find the optimised launch rocket with a given payload?

[Red Iron Crown]

What's the point of launching such massive payloads? Is it not the point of trying to find the optimised launch rocket with a given payload?

Some people like making big stations, ships and things of that ilk. The stock attachment options are somewhat lacking in structural rigidity for some applications, so it's sometimes better to do one big launch rather than a few smaller ones with orbital assembly.

Not everyone's into optimization, either, sometimes it's fun to see how big you can build something and still have it work.

[goldenpeach]

Will the new SLS parts be available in the 0.24 or are they made only for the ARM patch(like the asteroid)?

[Jouni]

But on the topic of Eve, Eve landers still absolutely need asparagus staging. Without it, you can you lose more than 1000 dV with the next-best onion staging model. Making up for it in lower stages is hard to do without going way over 100 tons and still getting near-sea-level capability.

Asparagus staging is only needed, if you want to make the lander as small as possible. Before I started building my current giant lander, I had planned a simple four-stage lander that had around 11300 m/s of delta-v with the three-kerbal command pod. Even my current design is not fully asparagus: it has around 11800 m/s with three groups of six boosters each. Full asparagus with nine booster pairs would have given 12300 m/s, but it wasn't worth the effort.