How to build non-asparagus heavy lifter

[Toxicterror]

I'm trying to build a lifter for the Bobcat Ind. HOME systems, but i fail with the last "stage to orbit".

I always run out of fuel between 60km and 80km and adding more tanks or more engines doesnt really help or change anything.

Has anyone some tips what i could change?

Craftfile:

http://www.file-upload.net/download-7741328/Mun-Home.craft.html

[Elsig]

More is not always better! You got too many engines and too much fuel. Once your boosters are empty and ditched that one mainsail (or is it skipper?) engine does not have enough power to lift the two orange fuel tanks AND your load.

I always use asparagus now, but here's one of my very first heavy lifters before I knew what asparagus was. I got this into my 300k orbit and docked with my space station.

[capi3101]

I do have a heavy lifter design - it's two jumbo tanks with a mainsail and eight radials, with a set of eight double-stacked jumbos with mainsails and eight 24-77s around it, with another set of eight double-stacked jumbos with mainsails surrounding that. Light the whole thing at once and has fuel lines running from the outer tanks to the inner ones. It's rated for 130 tonnes. I've heard my design described as "onion staging", in that I "peel off" rings of boosters at a time. Ugly, strutted all to heck and if you leave the third stage at full throttle at separation the stack pancakes, but it gets the job done.

In your case, I'm a bit lost because I'm not familiar with the parts in the mod you're using. Which stages correspond to your payload? What's its mass by itself?

[jwenting]

this will get the top orange tank (full), with the crew capsule and nuclear engines into a 100km orbit with fuel to spare on the 3rd stage (the second orange tank down).

Skipper on the 3rd stage, 1 Mainsail on the 2nd, 6 Mainsails on the 1st stage. 2 NERVAs on the 4th stage.

Plenty for a return trip to Duna, and possibly Eve or even further (I've only tried it to Duna so far).

It's a further development, heavier version, of this, which can get one Kerbal to Duna orbit and back BARELY.

[zanzibar196]

Pretty much all heavy lifters use asparagus style to get the job done. Good luck trying to do it without...

[Toxicterror]

thanks for the answers

the two part-addons are bobcat's HOME and KSPX (pretty much all parts already existing, just in other forms. like the 2m LV-N as i used there).

got the HOME to the mun, but not sure if i built an asparagus for it or if i changed it after the success ^^ craft-file is asparagus-style now

but seems like there is no way to have a "slim" rocket which can launch up about 20 tons, is there?

[Johnno]

Depends what you mean by heavy lifting. I routinely lift 124 tons without asparagus, my personal best is 177 tons without asparagus (without trying even, I was testing a launcher and ended up having the third stage in orbit nearly half full with no payload).

As for design process I simply build a core using rockomax fueltanks and mainsails (sometimes skippers on last stage), strut tanks to eachother etc, then copy it out with x6 symmetry, strut the rest to eachother and core, winglets and launch towers/stabilizers. Turn off gimbal on outer engines of the first stage through action groups and it's good to go. My heaviest launchers usually need extra reinforcing with girders and struts between stages.

As for a 'slim' 20 ton launcher, how do you define slim? Assuming you're getting 15% payload to start mass you're looking at roughly 133 ton starting mass. Minus payload, divided by 36 tons (for jumbo tanks) you're looking at 3 jumbo tanks with mass leftover for two mainsails. So payload - decoupler - jumbo tank - mainsail - decoupler - jumbo tank x2 - mainsail. Alternatively a skipper on second stage, slightly better delta-V. Should just about get you to orbit. Rather quick design though so could use refining. Engines overheat easier on jumbo tanks though so you might want to use X200-32 tanks, make sure to strut everything together.

[foamyesque]

Pretty much all heavy lifters use asparagus style to get the job done. Good luck trying to do it without...

Challenge accepted.

OP: I like a Mainsail -> Skipper -> Poodle stack. Just clone it as many times as you need to lift your payload.

[Flixxbeatz]

Well if you have a computer powerful enough then you can build yourself a non-asparagus booster as large as you wanted it to.

[Festivefire]

this asparagus is required talk thats been on the forums lately is frankly a load of crap. I never ever ever use asparagus, i find it tedious, and i can easily send a 120 ton base module to the mun.

[Flixxbeatz]

this asparagus is required talk thats been on the forums lately is frankly a load of crap. I never ever ever use asparagus, i find it tedious, and i can easily send a 120 ton base module to the mun.

It's not required (since we've got our own preferences), but most people use it for efficiency and extra OOMPH.

[sal_vager]

Asparagus used to provide a much bigger boost, but it doesn't seem as good these days, craft don't fly quite like they used to in 0.13 to 0.17

It does get kinda boring though, and I have gone back to good old fashioned staged craft, with each stage lifting the ones above it, very much in the Saturn V style.

I don't worry about any slight loss in deltaV as it just presents new and interesting design challenges, plus it saves on yellow tubing

[Evrion]

I've just done some testing on Asparagus staging vs. Disposable Fuel Tanks, a method I have been using.

To define the terms as I'm using them:

Asparagus staging - 7 Engines, all firing off of 7 tanks, fuel lines set up to use up the outer 2 tanks first, which are then dropped along with their engines. then the next two, and so on 'til there is one tank and one enigne.

Disposable Fuel Tanks - Fewer engines, same number of tanks and same staging as Asparagus. Outer tanks do not have engines and therefore fuel burns slower, ascent takes longer. Outer tanks are dropped as they are used up.

In my small scale test, (Small payload, second smallest large radius tanks, 1 mailsail or 7 mainsails) Disposable was WAY better, but asparagus got kinda burny, so air resistance probably played a large role. In my large scale (realistic) test, the results were much closer:

Asparagus:

261,488m

Disposable Tank (A):

192,342m

Disposable Tank (:

288,071

All payloads are 72.1 tons.

Asparagus method used 7 orange tanks plus 7 of the smallest large radius tanks so I could have 7 mainsails on full throttle.

Disposable Tank (A) used the same fuel tanks, but 4 mainsails, 3 going full throttle using up 6 tanks, 3 dropped when empty. Then dropping engines and tanks to start up and burn through the last fuel tank with the extra engine. (Stage 1 - 3 engines up, one off, 7 tanks, Stage 2 - drop 3 tanks, Stage 3-drop 3 tanks and 3 engines, start up last engine)

Disposable Tank ( is the same as (A) except that I added a set of fuel lines to the last fuel tank so I could do an Asparagus like thing to have the last of the 4 engines also throttled up the whole way. This amounts to a mix of disposable tank with asparagus. (Stage 1 - 4 engines up, 7 tanks, Stage 2- Drop 3 tanks, stage 3 drop 3 tanks 3 engines)

Conclusion: Asparagus is good, but it may be possible to do better by dropping some of the engines.

[Festivefire]

I just use straight fuel cross feed and drop all my liquid boosters at the same time, not asparagus style, because it leads to extra design time, and alot of times it causes an unstable roll in the craft.

[redteddy23]

I'm trying to build a lifter for the Bobcat Ind. HOME systems, but i fail with the last "stage to orbit".

I always run out of fuel between 60km and 80km and adding more tanks or more engines doesnt really help or change anything.

I like the design a lot it's quite pretty just not enough oomph on the final orbit stage like you said. I took your design and had a look I'm not sure I can keep the aesthetics while giving it enough power but I did do a mun mission while putting it on my falcon 9 style launch system which uses cross feed from the side boosters to the middle but isn't exactly asparagus.

Each main booster has 8 LV-T30s and 1 LV-T45 in the middle and 2 orange tanks. The side 2 feed to the middle and once the middle is gone one skipper and the X200-32 tank push it into a 100km orbit. With MechJeb I started to circularize at 10km because a big double tank draining will raise the center of mass right up to the payload and make it difficult to control towards the end of the burn and you want the engine not having to make any sharp turns while its a bit unstable. This leaves enough fuel to start the munar injection and help the atomic rocket along. Here's the album http://imgur.com/a/PxW7R/all

I also reduced the number of those overpowered radial HOME engines to 2 as you don't need 3.34Gs of thrust to land on the Mun

Edited June 23, 2013 by redteddy23

[DChurchill]

Define heavy. This one clocks in at just over 600 tons.

[Geschosskopf]

One thing about lifting stuff.... If you have the Ferram Aerospace mod, you'll find you only need about 2800-3000 delta-V to reach LKO, which pretty much eliminates any need whatsoever for asparagus staging. If the core stack won't quite do it, a couple of moderate boosters should do the trick.

NOTE, however, that all this is only possible if your rocket is nicely streamlined, has its center of lift as far towards the bottom as you can get it, and you've got plentiful RCS, usually as far out towards both ends as you can put them, with 1 or 2 big tanks of mono. FAR-friendly rockets are long and skinny, so have such huge moments of inertia that they're almost impossible to maneuver without lots of RCS going. On the plus side, however, once you get to LKO and ditch the long, skinny rocket, the need for constant RCS at least goes away. The other part of the flip-side of FAR is that if your rocket ain't streamlined, it ain't flying. This means nosecones or tanks, fairings on lumpy payloads and pretty much everything has to be in-line with the core. Try to avoid exposed landers hanging off the sides or T-shaped things like you see a lot of station-builders use.

[bsalis]

How to build non-asparagus heavy lifter?

Easy. With MOAR. Lots MOAR.... mainsails, SRBs, and struts. MOAR the better.

350 tons to LKO (usually)

[GusTurbo]

Following the principles of the Saturn V makes a pretty effective non-asparagus lifter.

Javascript is disabled. View full album

[Clouds]

2.5 Jumbo tanks and a Mainsail will achieve SSTO with a bit of payload, so just strapping a sufficient number of those stacks to your orbiter will do the job. It's not efficient, but it's simple to set up if it doesn't need more than one layer of radial symmetry.

[arq]

People have such a negative view of asparagus staging, and not for much of a reason. It's a much simpler way to design a rocket and can save you a little on part-count. Besides, anything with boosters might as well be asparagus-staged, and most people use boosters on the bottom level anyway. You're just throwing away dv by not adding the fuel lines. When you start looking at 400t+ payloads, a vertical lifter starts becoming less and less feasible because of the height limit of the VAB.

Still, if you insist on not, your bottom stage looks a little long (by my reckoning). You could try splitting it into two stages and maybe making it a touch longer?

[Flixxbeatz]

People have such a negative view of asparagus staging, and not for much of a reason. It's a much simpler way to design a rocket and can save you a little on part-count.

But it's each and everyone's preference to go asparagus or not anyway.

[foamyesque]

People have such a negative view of asparagus staging, and not for much of a reason. It's a much simpler way to design a rocket and can save you a little on part-count. Besides, anything with boosters might as well be asparagus-staged, and most people use boosters on the bottom level anyway. You're just throwing away dv by not adding the fuel lines. When you start looking at 400t+ payloads, a vertical lifter starts becoming less and less feasible because of the height limit of the VAB.

The reason people tend to look down on asparagus is because it is 1. easy mode for dV and 2. only doable because of magic fuel lines.

NASA would sell their soul for KSP's plumbers.

[ASnogarD]

I like none conventional designs myself, have a affair with tri symmetry designs like this one...

(older picture... I got rid of the strut connections, added a 2nd stage under the payload but still inside the tri stacks)

Unfortunately this design barely gets my 40 ton 'bus' into orbit , I have to circlise the orbit with the payload engines which isnt really a problem if I get my gravity turn done properly... a nice flat arc out to orbit at a good speed ensures my orbit fixing burn is not too demanding on the nukes limited thrust.

I have been playing about with the lifter design to try make it more powerful for heavier loads but without adding rings of boosters and / or engines + fuel stacks I cant do much more... extra fuel on top just makes the ascent much slower and in the end eats up all the extra fuel without really gaining anything... cluster engines instead of mainsails spare the juice but slow the ascent down so much that the fuel saved is used to reach the same heights the mainsails managed... effectively same result just slower.

[rkman]

adding more tanks or more engines doesnt really help or change anything.

Has anyone some tips what i could change?

More stages, optimize staging: once delta-V is about right, don't add more fuel and engines, but instead move fuel and thrust from one stage to another.

That thing looks like it is intended to be (almost) SSTO. The final stage is a huge engine on a tiny bit of fuel (and a sizable payload), it's not going to get very far.

Btw how much mass are you trying to get to LKO?