Orange exhaust for Mainsail and Skipper

[Temstar]

Before we start, let's have a look at two pictures:

Here we have the Saturn V burning its first stage. The first stage is powered by five F-1 engines burning kerosene and liquid oxygen. The presence of carbon in kerosene results in the blindingly bright orange exhaust that turns into a sooty smoke trail. F-1 have a sea level Isp of 263s with a thrust to weight ratio of 94.1.

Here we have the space shuttle orbiter firing its engines. The three SSMEs are cryogenic engines burning liquid hydrogen and liquid oxygen, resulting in a nearly invisible clear exhaust. The SSME have a sea level Isp of 363s due to much more energetic fuel but has a lower thrust to weight ratio of 73.1.

Currently in KSP almost all of our liquid fuelled engines use the same blue SSME-like exhaust. Now I understand that we don't really want to separate liquid fuelled engines into three types (the other one is hypergolic fuel) and have triple the amount of fuel tanks we already have in game dedicated to each type, that's just too much trouble for very little gain. I'm happy enough with the generic "LiquidFuel" and "Oxidizer" for bipropellants. However as a compromise we should at least modify the exhaust so that the lower Isp higher thrust engines give off the orange "hydrocarbon" exhaust while the high Isp low thrust engines better tuned for upper stage retains the clear "cryogenic" exhaust. Solids aside, the orange exhaust in fact is already in the game:

Back in 0.17 days the aerospike had an unique orange exhaust that gave it a lot of character. I propose that this exhaust effect is reinstated for the big Mainsail and Skipper engines, suitably upsized to fit their nozzles of course. The result will be:

Cryogenic exhaust: (current blue exhaust)

LV-T30

LV-T45

Poodle

LV-909

Aerospike

LV-N (exhaust is pure hydrogen)

Hydrocarbon exhaust: (orange exhaust)

Mainsail

Skipper

Rockomax 24-77

Rockomax 46-7S (funnily enough these two already have a miniaturised version of the turbulent orange exhaust)

LV-1, LV-1R and Rockomax Mark 55 are clearly hypergolic fuelled engines owning to their low Isp and their form factor encouraging deep space usage. Hypergolic fuelled engines produce a clear exhaust very similar to cryogenic engines:

So it's probably fine to leave them be. Although in the future if we could fine tune the colour so it stands out a little bit from the cryogenic engines would be good.

This way I feel that it gives new player an intuitive feedback on roughly what the roles of the engines are, before they can make sense of Isp and TWR.

Edited September 9, 2013 by Temstar

[Rage097]

Seems a bit odd to do at this point, and will probably lead to many double takes from veteran players. ("Launch! Wait wat...I thought...Oh that's right, they updated that") But other than that I don't see the problem with changing the exhaust color. I'd expect it to be on the bottom of the priority list for the devs, though.

[wasmic]

Nice ideas, I fully agree with you. One thing, though - we already have hypergolics. It's called monopropellant in the game, though. So, adding normal engines running off of monoprop, and adding cryogenic fuel might not be so drastic after all.

[spectrhz]

From what I know, the current engine sounds, exhaust colors, and explosions are just placeholder effects. I could be wrong but that's what I remember hearing.

[Giggleplex777]

I think Aerozine 50 makes the clear exhaust.

Regular hypergolic fuel (UDMH + N2O4) has red-ish exhaust.

Then again, in space, the exhaust is pretty hard to see anyways so this wouldn't really matter.

Also, I believe that the more efficient engines are Methane(Kethane?)-LOX fueled except for the LV-N.

Edited September 9, 2013 by Giggleplex777

[Rulare]

Seems a bit odd to do at this point, and will probably lead to many double takes from veteran players. ("Launch! Wait wat...I thought...Oh that's right, they updated that") But other than that I don't see the problem with changing the exhaust color. I'd expect it to be on the bottom of the priority list for the devs, though.

I don't really understand how making veteran players double take about a cosmetic change is a 'problem'.

Who would argue against this? It's just a cosmetic change to be a little bit more accurate to real life using assets that already exist in the game. Only some change-fearing weenie desperate to start an argument, any argument, would care enough to bother.

[Rage097]

I'm not arguing against it. The double take is due to something they've been used to for quite a while being changed possibly without their knowledge. When they suddenly see orange rather than blue exhaust they'll go "wait, what?"

It isn't really a problem, I'm cool with it and I'm sure most other players are as well.

[BostLabs]

I don't care either way. As it is only a cosmetic change I do believe it should come after much more important issues though.Careful with the name calling though.

[Zeroignite]

Wouldn't this be entirely moddable now? Not saying it shouldn't be stock, but we have almost all of the effects we need

[Rulare]

I'm not arguing against it. The double take is due to something they've been used to for quite a while being changed possibly without their knowledge. When they suddenly see orange rather than blue exhaust they'll go "wait, what?"

It isn't really a problem, I'm cool with it and I'm sure most other players are as well.

Didn't mean to imply that you in particular took huge issue with it, sorry. I misread your post, thinking it was presenting that as a problem.

(if the word 'weenie' directed at nobody in particular in is unacceptably offensive here, BostLabs, I'm going to just laugh and then sigh a little whilst I shake my head in a condescending manner because that is very silly)

[TMS]

Agreed, this would be a nice touch.

Aren't the flame parameters defined in the part file?

[DerekL1963]

Cryogenic exhaust: (current blue exhaust)

LV-T30

LV-T45

Poodle

LV-909

Aerospike

LV-N (exhaust is pure hydrogen)

Hydrocarbon exhaust: (orange exhaust)

Mainsail

Skipper

Rockomax 24-77

Rockomax 46-7S (funnily enough these two already have a miniaturised version of the turbulent orange exhaust)

So, what do you do when you have a stage with engines from both groups? (Which is not exactly uncommon.)

[Zeroignite]

So, what do you do when you have a stage with engines from both groups? (Which is not exactly uncommon.)

Well, until realistic fuels are implemented, you feed everything via LFO, and each engine has its own exhaust color. You can already get mismatched effects in stock with engine clusters.

[Whirligig Girl]

I asked on the pre-0.21 stream if C7 wanted to re-do the engine effects, He said that he'd like to re-do them. I'd suspect they'd also change it for each engine.

[UbioZur]

You can try to play around with the FX definition in the part.cfg of the engine. take the one from the engine you like, and put it on the engine you want it to.

Else you could suggest it to the modders, as I don't think it would take that much to create several exhaust color and get a tool to change the .cfg file to those colors.

[jwenting]

the colour of your exhaust is defined not (just) by what you're burning but by how hot you're burning it and how efficient your burn is.

So just saying "fuel X gives exhaust colour Y is wrong.

And saying "engine X looks like engine Y so should have the same exhaust colour is also wrong.

[ZenithRising]

Agree that this would be a nice touch, and seems fairly easy to implement.

[ouion]

I disagree.I would make fuel type instead.

[John FX]

Myself I would like to see the plumes of smoke from the launch tower in the energetic way that real rockets produce. That and the funky spiral patterns in the blue exhausts would be cool.

Of course I support OP in their suggestion for coloured exhaust plumes.