How to play without asparagus staging?

[V7 Aerospace]

To be honest, I have never used asparagus, not really ever had a reason to use it. Your everyday standard vertical stack will do the job perfectly.

[maccollo]

28 minutes ago, GoSlash27 said:

Wow, I hadn't seen Honest Jeb's design before. We're both working the same way

 Best,

-Slashy

I use a very similar design, except I don't use fins or RCS. Both are stupidly expensive and reduce the cost effectiveness of solid first stages vs liquid cores. The thud isn't a very good engine, neither in cost effectiveness or performance, but it's not abysmal and it offers very good control authority. If you want to get control authority you might get some additional payload capacity at the same time. Combine this with a poodle upper stage and you'll get launchers that can throw about 1 kg to orbit per 0.75-0.9 funds.

36 tons to LEO, 800 funds per ton.
https://www.youtube.com/watch?v=k1ss2XPGUY0

27 tons to LEO, 750 funds per ton.
https://www.youtube.com/watch?v=2SygZiPl8Os

Edited January 2, 2016 by maccollo

[Temstar]

1 hour ago, GoSlash27 said:

By all means, but you won't be able to. The first stage is solid propellant

http://wikisend.com/download/380030/cheep38.craft

37.6 ton payload
rocket cost $35,600

Looks like $946.81 per ton to me, unless you want to go into those of those "is S-IVB part of the rocket or part of the payload" type argument.

Anyway to nudge this line of conversation back towards asparagus. If it's cheap price per ton to orbit you want you want your craft to be reusable. And just as with the space shuttle if you want reusable and done well you'll probably need to know how to use them fuel lines:



Can't do fancy stuff like this with out fuel lines, so better get some training by playing around with asparagus.

Edited January 2, 2016 by Temstar

[tater]

I've never used asparagus for anything, ever. Since funds have never seemed like an issue to me, I've never been careful about reusable boosters.

[GoSlash27]

Temstar,

It's 38.1t payload and $33,400. The guidance is assumed to be provided by the payload since the booster is disposable. $877/ tonne fully disposable. If you make the upper stage with guidance recoverable as in your design, The price drops to $25,288, or $664/ tonne.

Asparagus staging is not economically competitive in the range where single engines are feasible and SRBs beat the stuffing out of LF&O where they can be used.

 When you get into the scale you're working at, sure. You have no choice *but* to use clustered LF&O, so you might as well use asparagus staging.

If you doubt what we're telling you, just try building an asparagus staged lifter for a 38 tonne payload.

Best,

-Slashy

 

Edited January 2, 2016 by GoSlash27

[Sandworm]

If you are going to avoid asparagus staging as unrealistic or little used in the real world, then I wouldn't read much more about realworld rocketry.  There are plenty of things in KSP that are total fictions.  Top of my list: infinitely throttling engines.  In realworld, those engines that do throttle have very specific modes/limitations, which in turn can affect ISP.  Also, rocket bodies (fuel tanks) can only take so much force.  In combination with non-throttling engines that means doing lots of calculations to ensure your lower stages don't get so light that the rocket accelerates faster than the upper stages can withstand.  But KSP parts can survive 5,8,10 gs without issue.  Asparagus staging isn't exactly OP in comparison.

 

Asparagus staging isn't all that unrealistic.  Shuttle arguably used it in that shuttle dropped a tank and carried on, or at least piped fuel from one body to another.  Some Russian rocket designs (not flown) have considered it viable.  The real issue seems not to be the piping (ie what shuttle did) but that engines/bells designed for one stage of assent (ie liftoff) are rarely ideal for later stages (ie vacuum).  So you want to ditch all the engines anyway.

Edited January 2, 2016 by Sandworm

[Psycho_zs]

Here is my take at not using asparagus:

I am using gradually less powerful (and fuel-hungry) engines in staging, with six boosters and the core they go like this:

1. 2x Kiwi,

2. 2x Reliant,

3. 2x Swivel,

4. 30% thrust Swivel on the core, throttles up after all boosters are done. Flames out when almost reached the orbit, allowing the core booster to be caught by the atmosphere.

5. Terrier on the ship itself

67.5K kerbobucks, 110 tons, Stage Recovery is used for 6 boosters. Fins placed on the first stage to prevent boosters being flip-shredded by the airflow, Kiwi's chewing fuel pretty fast and these boosters are dropped just a bit after max Q.

 

The ship weights 19.5 tons and has 1778m/s dV, carries 4 kerbals. Also 300 units of monoprop, small supplies pack, batteries and probe core packed inside large decoupler.

Ideal for Kerbin orbit rescue missions, or LKO crew and supply runs, with dumping excess resources on the station before reentry. Radial core on the pod to land 4 tourists on Kerbin.

Stuff from mods: One small supplies pack from USI Life support, Kiwis, 4K pod and radial probe core from NecroBones' mods. Everything else is stock.

[Warzouz]

I played science mod game in beta 0.9 and I used a lot of asparagus launchers.

As 1.0, I played in career mode, where cash as importance in early and mid game. There was 2 problems to deal with

• Reducing the cost of a launch to LKO
• Stabilising flight pattern/aspect/attitude (the ship design doesn't change too much)

The answer was rocket SSTO.

• The shape of the ship doesn't change during flight, there is much less risk of flipping
• Faster and easier to fly than rockets or space plane SSTO
• The payload fraction is lower (15 to 19%)
• Need dedicated parts for reentry and control
• The cost to LKO is very low because of recovery (around 350/450 funds per ton, instead of 1000/1500 for a unrecoverable regular rocket)
• Easily scalable (just add engines and fuel to an existing design)
• Need a bit of time for reentry (around 1 minute with)
• Reentry is a bit trickier since 1.0.5, but I didn't test it a lot

Here is my SSTO rocket launcher from 15tons to 600 tons

http://forum.kerbalspaceprogram.com/index.php?/topic/110947-cygnus-recoverable-ssto-rockets-15-to-600-tons/

 

[Musil]

I use a Delta-V design: a main stage with two LF boosters. After launch, and reaching about 100m/s, I throtle down the main engine to about 60%. After booster separation, throtle back up. 

Still haven't found a payload that wont go up with this when it's 3 mainsails... It also makes the launches more fun and, in my mind, more realistic. 

Edited January 4, 2016 by Musil

[Tourist]

I only use asparagus staging where I really have no other choice. Mainly putting "motherships" into orbit, which need to be large but rigid, or for ships which need complicated staging to get off some body other than Kerbin, like Eve. Otherwise I try to put everything in orbit via spaceplanes, and then dock with a mothership or a tug. If a spaceplane can't lift it then I just use the "moar boosters" approach. 

Edited January 4, 2016 by Tourist

[Gojira1000]

I like asparagus for its fiddliness, but I find I don't use it very often any more outside of gargantuan single-launch projects..

[Caelib]

It really boils down to two key principles:

1) build efficient and simple rockets.

2) if you cannot accomplish the dreams of what you want because of principle #1, assemble it in orbit with multiple launches.

Consider how the International Space Station was built and use that for inspiration ... it doesn't have to be a space station, I usually launch a lander and its orbiter separately and dock them in orbit around Kerbin before sending them on their merry way.  The overall launch cost is more, but it's easier and realistic (assuming you know how to rendezvous and dock).  This approach works well for a Mun landing mission ... if you're going somewhere like Duna, consider this approach (this is an amazing accomplishment just meant to give you ideas):

 

Edited January 5, 2016 by Caelib

[Guz]

if you dont mind clipping then my shuttle may be interesting to you

 

[Guest]

On ‎12‎/‎31‎/‎2015 at 9:22 PM, GunnDawg said:

Anyways, lets hear your tips and pointers on building rockets that DO NOT use asparagus staging. I'm talking some SpaceX or Soyuz rocket style designs I guess.

Taking inspiration from real rockets is a good way to start building effective designs.

My own versions of an Atlas Rocket, and a Saturn 1b. Perhaps not beautifully crafted replicas, but as functionally similar as possible.

The best advice I can offer is: build it, test it, and redesign it as many times as are necessary.

[AlextheBodacious]

Trip to the Mun you say? Look no further! If you want standard, rocket-looking yet original rockets, I'm your guy! I use this almost failsafe design to go to the Mun as often as I can. Want pictures?

Get this, and so much more, at this great website

[wumpus]

On 1/2/2016 at 4:10 PM, Sandworm said:

[deleted just a few of the impossible things Kerbals do before breakfast...]

Asparagus staging isn't all that unrealistic.  Shuttle arguably used it in that shuttle dropped a tank and carried on, or at least piped fuel from one body to another.  Some Russian rocket designs (not flown) have considered it viable.  The real issue seems not to be the piping (ie what shuttle did) but that engines/bells designed for one stage of assent (ie liftoff) are rarely ideal for later stages (ie vacuum).  So you want to ditch all the engines anyway.

My understanding is that SpaceX has abandoned the cross-fuel plans for Falcon Heavy.  That wouldn't change anything in the air pressure/vacuum calculations of the various staging, just apparently too complicated to stick in the pumps.  

Note that Falcon Heavy had a weird system where only 1/3 of the engines from each booster would feed one [each] of the other boosters: this may have left the thing carrying empty fuel tanks/dead rockets while the other 2/3 of the fuel tanks emptied.  It didn't look like something you would really want in your rocket.

[Rath]

PSA: Aspargus staging is like this  (o=Booster or core -=Connection   ==Connection with fuel line    *=Decoupled connection) 

             o=o=o=o=o

then this happens.

          o*       o=o=o      *o

All the tanks are still full.

            o*            o       *o

Middle is still full.

 

Onion staging is this:

             o=o=o

  o*            o       *o

Asparagus staging is the feeding of one set of boosters into another set, and then the core stage.

 

Edited January 8, 2016 by Rath

[Dfthu]

I very rarely use them. I would use them more if they were easier to make. 

[NecroBones]

Another diagram that usually makes the rounds:

 

The one in the upper right in the image below is what we would call Onion Staging:

 

[sgt_flyer]

Well, you can use clustering / boosters with no crossfeed too if you don't want to make boosters too tall  - for tank clustering, think Proton 1st stage 

For boosters with no crossfeed (think soyuz, delta / atlas with SRBs, Ariane IV and V, longmarch launchers, where the central core burns at the same time as the boosters, but has more fuel - the key point, is to have spent enough fuel in the core stage at the end of the boosters burn to have a TWR > 1 for the core stage + upperstage & payload above it.

 

[Streetwind]

Early-on in the game, when I have only low-tech parts available, I like to do a lot with a "common booster core" consisting of two FL-T800 tanks (or their equivalent) and a Swivel engine, which I pack into clusters of increasing size that can be stacked inline up to three times.

Obviously, the concept becomes outdated once unlocking 2.5m parts, because they're so much better, but it's especially early on where you're struggling to find good ways to launch decent payloads, or spacecraft with decent dV's. In fact, I find that outside of the early game, it's no challenge whatsoever. So you're getting my earlygame solution here, with nothing but 1.25m parts.

 

Tier 1: The common booster core by itself SSTO's a simple capsule to low Kerbin orbit for 3200 funds (payload not counted). There's plenty of dV margin to pack science instruments, and plenty of TWR margin to pack a little bit more fuel if you need even more dV. For example, I generally use some variation of this to send a Kerbal into polar orbit for EVA reports across all biomes.

Ultimately, adding more fuel and payload (please excuse the nonsensical mass simulator) until TWR becomes uncomfortably low will top out somewhere around 2.5 to 2.6 tons of payload with a 3850 fund booster. Yeah, not nearly as money efficient as some other designs here, but this is using crappy earlygame parts after all! And honestly, at less than 4k funds for the entire booster, who cares? Given a small upper stage and a probe core, this rocket can fly LKO rescue contracts, and even some satellite missions.
 

Tier 2: The classic triple stack, achieved simply by taping two common boosters directly to a center one. There's no side booster detaching, the whole thing is one stage which is added below the previous single common booster core, creating a two-stage booster. It pushes up to 10 tons to LKO, for about 12,350 funds. It needs a tier 2 launchpad, but only a tier 1 VAB. What may not be immediately apparent is that I have replaced the two outer Swivels with Reliants here, which is absolutely necessary to achieve acceptable off-the-pad TWR with maximum payload (and even so it is kinda slow). You will see this happen again in tier 3.  If you're not pushing maximum payload, though, you can leave the Swivels in place... but honestly it barely changes anything. And yes, due to the way copying and attaching parts works, you may want to add a pair of struts to the bottom of the triple-core. It tends to be unstable without.

Tier 3: Tripling the triple! You simply copy the triple stack from tier 2, turn it sideways, and attach three editions of it to the bottom of the tier 2 stack (with Swivels, not the modified one with Reliants). Four additional struts will hold the assembly more securely together. Then, depending on your payload, you can consider replacing some swivels with Reliants on the bottom stage; in this screenshot I have opted for Reliants on the four corners, leaving five Swivels. You can't see it, because I can't zoom out far enough, but there's actually an orange tank on top of this stack... meaning this tier 3 booster pushes 36 tons to LKO for 42,375 funds. It needs a tier 2 VAB and a tier 3 launchpad.

I rarely ever fly this configuration in practice, because for payloads of this weight class you really want a 2.5m stack, and because of the launchpad mass requirement... but sometimes, I fly it with smaller payloads for high dV missions, where the stack won't expend all of its fuel just to get to orbit. Replacing the single Swivel in the upper stage with a Terrier is a solid option. Removing that stage entirely is also an option, and combined with a smaller payload, that may let you scrape by with a tier 2 launchpad.

 

Two notes:

1.) I realize that SRBs are an option. I often use SRBs. But for some reason I simply like the sheer simplicity of just taping copies of the same common core together in symmetry, especially when it works out as well as this one does

2.) I've also had good success with these things in a KScale2 game, where the solar system is twice the size and dV required to orbit is ~33% higher. Gotta downsize the payloads to increase the dV, obviously - or pack an actual second stage on top of a tier 1 booster - but the stack will also reward you with higher TWRs as you do this.

Edited January 9, 2016 by Streetwind