[v1.2]KSP - Silisko Edition

[Kryten]

The thrust to weight ratios on most of the engines are very good.

LV-T300: 122

Large Bertha: 203

For comparison:

NK-33(N-1 engine): 137

Just to point out, the NK-33 has the high T/W ratio of any engine that isn\'t just a lab curiosity, by a significant margin-if the ratios of these engines are higher than that, you can\'t really call them \'low\'.

[NovaSilisko]

Might need an update due to x3 changing gimballing again. At least the upper stage engine got very restless on my rocket, gimballing madly back and forth, almost tearing everything apart (when using ASAS)

That\'s ASAS\'s problem. I\'ve reinstated the normal SAS due to how flawed ASAS is in its current state.

[Tiberion]

I wasn\'t talking about the thrust to weight ratios of the engines (which isn\'t irrelevant, but not the whole idea here)

I was talking about the lifting power of the rockets you can build when you consider the required fuel tanks. We aren\'t nasa, we don\'t scratch build the exact tank we need, we have to put pieces together, and when the pieces are added up, you end up with a rock who can\'t clear the atmosphere unless you build very specific ships.

The attached is the basic 2m launcher I use, it can barely clear atmosphere, requiring you to use the 1m section to finalize orbit, and it can only burn part way to the Mun.

An extra tank or a 2nd stage doesn\'t change how far it gets. The tanks burn out too fast or are too heavy, so when you try to add to flight time, you lose acceleration and are back where you started.

Sure, you can set off 15 boosters or a giant cluster of 8 1m engines, but that is horrible engineering.

That\'s ASAS\'s problem. I\'ve reinstated the normal SAS due to how flawed ASAS is in its current state.

Actually Harv just turned down his gimbalrange in x3, the rocket there in my screenshot oversteers like you wouldn\'t believe with just gimbals.

Edit: Attached .craft file.

[Kryten]

The problem is that first stage-it\'s simply too big for those engines; my heavy-lifter is around that size, and puts quite a bit of weight into orbit-But needs the biggest 2m engine to even get of the ground, and 6 RT-20s to do it efficiently.

[Tiberion]

heh, if you make the 1st stage smaller, it just burns out faster leaving you are 35k. The big engine does worse because it burns faster.

[Kryten]

That\'s about right for a first stage.

[Tiberion]

Sure, but my whole point, way back there, is that the balance is punishing making a staged rocket, when you add the 2nd stage to finish orbit, it reduces the performance of Stage 1 severely, so even stage two fails - you don\'t actually gain anything.

[NovaSilisko]

Yes, and having decouplers that weigh 0.8 vs 0.05 helps to encourage staging immensely, right?

You can get much higher with a stack of 4 LFTs and a main engine, then a stage and a single tank + small engine than 5 tanks and a main engine alone.

[Kryten]

I think a big problem with that rocket is the second stage-it seems as large (or even smaller) than the 3rd-so it probably is going to fail.

Try to make sure that each stage is appreciably bigger than the previous one.

[NovaSilisko]

Eh? You mean 'stages get bigger as you go up the stack'?

I doughnut understand.

[Kryten]

No, I\'m thinking in terms of the game-building top downwards.

[Tiberion]

the 1m LFEs aren\'t for a launching stage, their part of the Munar package (for injection + retroburn) - Its supposed to be an Munar explorer rather than just 'Hey a got a pod here, time to go home' - I\'ve done that easily, you don\'t need 2m parts at all.

I\'ve tried dozens of combinations of 2M packages to get it into orbit, if its possible its beyond me.

[Kryten]

:-\ So you\'re complaining that you can\'t make it SSTO?

[Tiberion]

Uh.. no?

I said that adding a 2nd stage doesn\'t improve performance. I\'ve tried moving one of the half-tanks up as a new stage with one of the smaller 2m engines... same result. Stage one burns so fast you\'re still deep in the atmosphere, so stage 2 still only just reaches 'space'

[frenchie16]

I have had no trouble really with 2m rockets. In my experience, the first stage (plus boosters) gets me to perhaps around 40km, but with enough speed that my apogee is above the atmosphere, so I just wait until then before burning the second stage to enter orbit. Occasionally I need to use just a bit of the second stage\'s fuel to raise my apogee, but it generally works fine. Not sure what the fuss is about.

On the other hand, you can reach orbit with an RCS-only vehicle entirely too easily with that new service module.

[Kryten]

I haven\'t made any huge rockets in a while, so I recreated one from a previous version, complete with TMI/Slowdown stage and Lander/Return stage.

Here it is on the pad;

And here it is in orbit, boosted horizontally solely by its evidentially-not-useless second stage.

First stage apogee-88KM

Looking it this, it seems you need;

-Relatively large first stage, but too large-diminishing returns (and make sure it has enough thrust)

-Smaller second stage-but still quite big

-relatively small later stages.

[NovaSilisko]

With the upcoming version, this rocket got me to the mun with more than enough fuel for multiple orbital adjustments, and a full return trip.

And that was with pretty poor piloting.

[Tiberion]

that is a tiny payload though, you don\'t even need 2m parts for that tiny payload.

Kryten: I dunno how you did that.

Same rocket launching my payload (which is slightly bigger, but that THAT much) a 2 tank 1st stage gets to 20k without boosters and 35k with 6 boosters.

If I swap the 4x engines for Bertha, it gets to 40k.

To further clarify; I don\'t think the engines are underpowered, they feel about right as far as acceleration and how much they can lift.. its just that they burn too quickly, Bertha eats a BIG 2M tank in 35 seconds, which is fine with no payload because you accelerate up and out on 2 tanks pretty easy.

When carrying something though, at 1:10 in you are barely half-way up out of the atmosphere. And as soon as you start adding tanks, the weight factor kills performance and you\'re bogged down.

I haven\'t played that much with large 1m rockets to know if they feel right, but I think that just a small bump in efficiency would make things play a little better. Maybe just the 2m stuff needs it, I dunno.

You won\'t always need to discourage using 2m parts for light stuff, that\'ll come when the 'cost' factor gets added in later.

[zuff]

Nova I beg you to make lunar legs that fit inside the 2m payload fairings.

Looking at the rocket you just posted some legs would be perfect on your lunar lander.

I think someone made legs that jut out a bit then they go straight down. That\'s the style that would work well with your pack.

[Tiberion]

The lander pegs are in Slugs\' assorted hardware pack - they.. are somewhat prone to toppling over if you aren\'t landing perfectly, but they do work.

[zuff]

The lander pegs are in Slugs\' assorted hardware pack - they.. are somewhat prone to toppling over if you aren\'t landing perfectly, but they do work.

Yeah but I know Nova could make some for his pack that fit his style better.

[NovaSilisko]

Enough. A multitude of pages in this thread have been devoted to Tiberion arguing about this pack. No more.

Expected changelog for 0.7:

Added 2m RCS tank

Added new SRB

Decreased weight of quad coupler

Retweak of most engine efficiency values

Changed RCS a tad

Lander engine can now be gimballed

Re-added SAS module

Winglets made a bit more effective

[Tiberion]

Free advertising, buddy.

I\'m not the only one who said anything either. So Meh, whatever.

[icefire]

Made this video to show my friend how to launch a rocket I gave him, but figured I would share it here as well.

made entirely with this mod packs parts of course

[NovaSilisko]

I added another 2m engine. Double nozzle, gimbal enabled. Slightly more efficient than the big one, but with less thrust overall.