Realism Overhaul

[Guest]

Thanks. Is there some way to tell it that the given thrust is SL thrust? I don't have figures for vacuum thrust, and I don't really feel like deriving them from Isp.

[NathanKell]

Usually, if it says only "thrust" that's vacuum thrust, and sea level thrust = Isp(sealevel) / Isp(Vac) * thrust.

But when I looked up the Soyuz U (and Soyuz FG) launchers on astronautix (Soyuz U: http://www.astronautix.com/lvs/soya511u.htm and Soyuz FG: http://www.astronautix.com/lvs/soyuzfg.htm ) and then I went to each stage, I got complete stage info; for each stage if you scroll down you can go to the engine name and click on it, and it will give you thrust in vacuum, Isp at SL and Vac (or Isp in Vacuum only if the engine doesn't work at SL; in that case just put 100 for IspSL...), and ox:fuel ratio for the engine.

Note that for some engines, not all of that info is available but as far as I can tell it _is_ for Soyuz.

[frizzank]

Give me a bit (a day or two)and I will extract the unity and model files so you can non uniform scale them without the uglyness....

[asmi]

Give me a bit (a day or two)and I will extract the unity and model files so you can non uniform scale them without the uglyness....

Why don't you just ask mod authors for models? I assume you're talking about modded parts.

[asmi]

Usually, if it says only "thrust" that's vacuum thrust, and sea level thrust = Isp(sealevel) / Isp(Vac) * thrust.

But when I looked up the Soyuz U (and Soyuz FG) launchers on astronautix (Soyuz U: http://www.astronautix.com/lvs/soya511u.htm and Soyuz FG: http://www.astronautix.com/lvs/soyuzfg.htm ) and then I went to each stage, I got complete stage info; for each stage if you scroll down you can go to the engine name and click on it, and it will give you thrust in vacuum, Isp at SL and Vac (or Isp in Vacuum only if the engine doesn't work at SL; in that case just put 100 for IspSL...), and ox:fuel ratio for the engine.

Note that for some engines, not all of that info is available but as far as I can tell it _is_ for Soyuz.

When testing Soyuz, keep in mind that its launch sequence includes igniting engines at T-15 at 30% throttle, T-7 at 70%, and T-3 at 100% (apparently 3 seconds are necessary for the engines to reach full thrust).

Edited October 28, 2013 by asmi

[NathanKell]

Why don't you just ask mod authors for models? I assume you're talking about modded parts.

But frizzank is the mod author for Gemini...

I've gotten the shield to give good performance even at 25x multiplier in DRE, btw. So, here we go.

Here is Frizzank's Gemini in Real Scale: https://www.dropbox.com/s/ch4sfa31wth9qyg/Frizzank_Gemini_Realscale.zip

Requires MFSC and DRE. This will overwrite a file in MFSC v3 to give you aerozine; when I push v3 beta, it will include aerozine itself and re-overwrite the file...

Electrical charge balanced for 300watt draw. Yields 20 days of power if you use the fuel cell.

Due to not being able to make bipropellant RCS, all the OAMS thrusters (ingame both RCS and engine) use Monopropellant. But don't worry, the Isp and fuel mass is identical. You will be shown > 222m/s dV, but that's because it can draw from the capsule's own supply. Shut that tank off until reentry.

If using MechJeb, ascent path I've been using (unoptimized, but works for 0 degree inclination) is Turn Start 1.3km, Turn End 110km, 0 degrees final pitch, Turn Shape 45%. Note that if you want a less-than-400km apoapsis, you'll have to shutdown the LR-91 early, it's not throttleable.

The CFGs have some comments if you're interested. The main point is I used half the contingency mass allotments for the reentry module and the equipment module.

Note that what was the "SAS/RCS Module" in frizzank's version is in fact the retro module; stage-activate it to decouple the equipment module and active a 101m/s (or so) solid retro. Stage when burn is done.

Try a periapsis of 9km when coming in from approx 390; that's survivable. At 15km, space to activate drogue. Drogue will deploy at 6.4km. At 3.2km, stage again to jettison nosecone and drogue; main chute will semi-deploy. At 2.74km, main deploys.

Edited October 28, 2013 by NathanKell

[pina_coladas]

I like how technical this is all getting. Mimicking the optimized ascent profiles of real life rockets will be pretty damn hard, but by not simulating things like unburned propellants and pre-liftoff throttle-up we can leave a little leeway for pilot error and hopefully still make it to orbit.

And I agree with Dragon about the need for a new preset in KIDS. Even before Kerbin was re-sized all I wanted KIDS to do was to make thrust scale with ISP (and re-rate different engines as sea level or vacuum) without all the weird shenanigans to increase dV costs. With Earth-sized Kerbin that's definitely all you would want KIDS to do. I could see people getting pretty confused if they didn't already know what they were doing when setting these things up.

[frizzank]

Why don't you just ask mod authors for models? I assume you're talking about modded parts.

Yes I gave permission to use my stuff. Kind of hard not too, it's an awesome idea.

[ferram4]

@pina_coladas: You can do that quite easily. Just create a new preset, leave the dV numbers where they are and activate the thrust corrector. You do know that the presets aren't hardcoded, and that you can create your own, right?

[pina_coladas]

Yeah of course I know that, and I did make my own preset. I'm just saying that preset should be in by default now.

[NathanKell]

Speaking of KIDS, ferram, to ease your supporting MFS I just added three new variables to ModuleEngineConfigs

Now all you have to do is, for any ModuleEngineConfigs module, setfield("ispSLMult", (float)your_SL_Mult) and the same for ispVMult.

Then SetField("correctThrust", (bool)enableThrustCorrection). (All three are static).

Then part.SendMessage("SetConfiguration") for each ModuleEngineConfigs and MFS will update the engine module with your multipliers, and keep using those multipliers any time configuration is changed.

I'll post v3 beta with these changes Real Soonish, once I put all the old masses back. Will that make it easier?

[ferram4]

Sounds good. I haven't done much work on KIDS, mainly because I've been busy with my other project, but I think I can put some time into that now, failing horrendous game-breaking bugs appearing.

[NathanKell]

Ergmahgerd, you released it! Nice!

From my POV you certainly picked the right thing to work on.

[Guest]

Here is Frizzank's Gemini in Real Scale: https://www.dropbox.com/s/ch4sfa31wth9qyg/Frizzank_Gemini_Realscale.zip

Requires MFSC and DRE. This will overwrite a file in MFSC v3 to give you aerozine; when I push v3 beta, it will include aerozine itself and re-overwrite the file...

Have you checked out the engine ignitor mod? I'm using it with Soyuz. Also, I've added Ioncross Crew Support to it. They're completely optional, but quite fun to use.

Also, you could talk to the guy who made the ignitor mod for a better MFS integration. It should be able to tell hypergolic fuels from normals ones, and act accordingly. Also, ignitor number and max ignitions could be modified via MFS interface.

[NathanKell]

Yeah, I was actually heavily involved in that thread (before I got busy with this thread...); I'll add a tag to the fuel definition and ask HoneyFox to check for it. And add the MFS tweakables, good idea!

[Guest]

Also, it'd be nice to run it with Gemini. It's a no-brainer about the Titan (nothing is really re-startable there, ullage seems to be done Soyuz-style) and Gemini uses hypergolic fuel in pressurized tanks (IIRC), so it should be easy to implement.

Oh, and Ioncross, while we're at it. I recall Asmi working on some sort of life support plugin for BobCat, but Ioncross is the best we have now, and it works fine for me.

[ferram4]

@NathanKell: Just as a clarification, 64% scaling of rockets refers to diameters and lengths, correct?

Which would mean that the constant for scaling areas would be 0.64^-2, which works out to ~2.44.

[NathanKell]

I'm thinking with your joint work we might not even need to scale rockets. Someone mentioned launching with a 12m diameter core stage in your thread, and even that seemed to work. If we can expand the VAB (and even if not, just move the rocket up and down lots ), I'm not sure it's worth trying to run a smaller scale.

But yes, at present lots of stuff is visually 64% diameter, so ~2.44x surface area. That should give the Mk1-2 Pod a much nicer reentry, among other things.

[rosenkranz]

Is there a way to scale the kerbals themselves? I was watching Mannley's vid on this and it looks like the ground gets super squishy. If ferram's new mod will make full size rockets doable, maybe we need full size kerbals

[pina_coladas]

Rescaling Kerbals is the logical end-point of all of this I think... Except they are proportionally very weird. How big would the helmet of a human-sized Kerbal be?

[Lucchese]

Hi, while recording something for the city lights and clouds mod i came across a little bug that I think is related to this rescale project.

Its around 1:25

[NathanKell]

Sorry, can you explain? Too dark to see.

[Lucchese]

Sorry, I meant to say I left my "rocket" on the launchpad and went back to the space center.

Entered the tracking station, got back into the rocket but ended up on the grass.

"that is not where i left you..."

Edited October 29, 2013 by Lucchese

[AbeS]

I can confirm it, I posted it before

Little bug when reverting flight to launch (sometimes).

...

[MedievalNerd]

Sorry, can you explain? Too dark to see.

It's an extreme version of the issue I was talking to you about. The slight 90' offset each time you switch from 'orbital' to 'polar' coordinates (With time accel). I'm saying it wrong, but you get it right?

Maybe when you go to space center and go back to the vessel it's even worse than the time accel one.