New SLS vs Asparagus

[No one]

I have never had a problem with money since I spend a lot of time making upper stages light as possible. What I found to be expensive were the gravioli sensors. I went to Duna-Ike and took numerous sensors since I planned on covering as many biomes and science as possible without transmitting. Just consider: Ike High, Low and Surface and Duna High, Low and Surface PLUS duplicates for the high value stuff (in other words I run some stuff twice). Just consider that there are FIFTEEN Mun biomes (I never knew there was a Northern Basin) and I may have missed some.

It's not about having problems, it's just about trying to make things as cheap as possible because you can. If I wanted I'm sure I'd be able to afford the SLS-asparagus monstrosities I used in .235, but spending funds feels morally wrong. The liquid SLS parts are way more expensive than getting the same thrust would be with rockomax.

[UmbralRaptor]

This again?

In real life, asparagus staging is not used because fuel pumps are hard while high TWRs and mass ratios are easy. In KSP it's the opposite. Drag has nothing to do with it, and realistic aerodynamics would at most hurt flying pancakes. (Anything up to a full 4 stage/single layer setup would be fine. Possibly multiple layers.) It's worth noting that in real life, a large number of rockets (eg: Titan IIIE/34D/IV, R-7 family, Ariane 5) use horizontal staging as a major component, and a few (STS, Energia) used it exclusively.

Costs aren't so much rough on asparagus staging in general as on terribly inefficient/overbuilt designs. You know, the ones that get 5% payload fractions when with a better layout they would be getting 15%.

As for the ARM parts, use them or don't. They're more rocket than is strictly needed for a lot of career mode, but money's not that hard to get either.

The great thing about 0.24 is that it gave SRBs something that they're clearly better at (cost).

[Jouni]

I am pretty sure you can build non-asparagus Eve lifter too. Asparagus is just more efficient and therefore lighter (and cheaper) than non-asparagus lifter.

If you don't take funds into account or if you compare different staged designs, asparagus is still the most efficient one. It just can't compare with SSTO technology when it comes up to funds.

I had plans for an Eve lander without fuel lines in April. I no longer have the plans, but the difference to traditional asparagus-staged landers was huge.

On Kerbin, asparagus staging only gives a few percentage points higher payload fraction, so it's no longer worth the trouble. When simple two-stage rockets already have payload fractions around 14-15%, and adding a couple of boosters increases that to 16-17%, such efficiency concerns no longer feel that relevant.

[Russoft]

SLS is too prohibitively expensive to use in career. It's much cheaper just to make an asparapancake out of mainsails.

I disagree. I've used SLS parts just fine in career. Of course, I try to recover as much as possible to keep the launch economical.

[merendel]

I'm surprised that you don't get overheating issues with so many solids strapped in tight. I'd been using this...

The SLS SRBs are very forgiving on the heat when attached to eachother. I have a radial SRB assembly that consists of 1 booster on the decoupler, struts top and botom of that main booster holding it to the craft solidly, and 3 additional boosters attached to that central booster. Even at full thrust I've never had that pack get hot enough to explode. Normaly the are only 25% full on the overheat bar when they run outa fuel. Pulling the same stunt with the small SRB's still creates fun explosions though. For my heavier lifters I can strap as many of those to the ship as needed and ride the SRB's up to 8-9km before kicking them off and lighting the liquid engiens.

[Torquemadus]

I'm surprised that you don't get overheating issues with so many solids strapped in tight.

I'm surprised you didn't add moar boosters!

[hugix]

I never liked asparagus stagin. One thing KSP forgets is the weight of the fuel & oxidizer. Lets say you got a 4 way asparagus rocket. With the East & west booster fueling the north and south booster. what you would get in the real world is a big, big spin. As fuel flows anti clockwise the rocket will follow the path of the fuel. KSP doesn't simulate the momentum of the fuel. but in real life. It would be a disaster.

[Eric S]

I never liked asparagus stagin. One thing KSP forgets is the weight of the fuel & oxidizer. Lets say you got a 4 way asparagus rocket. With the East & west booster fueling the north and south booster. what you would get in the real world is a big, big spin. As fuel flows anti clockwise the rocket will follow the path of the fuel. KSP doesn't simulate the momentum of the fuel. but in real life. It would be a disaster.

Not quite. The force of the fuel entering the fuel line would be balanced by the force of the fuel exiting the fuel line, except for the brief period of time when the fuel line is either filling up or emptying. Note that the fuel lines would probably fill up before the launch clamps are released, which would dampen that portion of the force.

As has been mentioned before, the reasons that asparagus staging isn't currently being used in real life boil down to two things. The first is that we don't have the highly reliable high throughput turbo fuel pumps that the kerbals do. Seriously, baring human error, those seem to be the most common reason for launch failure, and asparagus staging would place an even greater dependence on them.

Second, since kerbal engines have a lower TWR and fuel tanks have a higher dry mass than their real world counterparts, the benefits of asparagus staging are greater in the kerbin universe.

[Kerbart]

I never liked asparagus stagin. One thing KSP forgets is the weight of the fuel & oxidizer. Lets say you got a 4 way asparagus rocket. With the East & west booster fueling the north and south booster. what you would get in the real world is a big, big spin. As fuel flows anti clockwise the rocket will follow the path of the fuel. KSP doesn't simulate the momentum of the fuel. but in real life. It would be a disaster.

Most of the fuel would be burnt before you start to turn, so the weight isn't really an issue. At any rate, weight would be a different vector (pointing down) than the direction in which the fuel flows.

I can imagine though that moving all that mass around would matter, but you were talking about weight.

Yes. I'm nitpicking. But c'mon, we're talking about physics here. And rockets. Understanding the difference between weight and mass is important.