Realism Overhaul Discussion Thread

[Phineas Freak]

@AlphaKerman something that i forgot to add: stock engines also have abysmal TWRs. That means you cannot lift as much propellant mass as it is required, meaning that you need more engines and that increases the dry mass. Then you need more propellant to push that extra mass up, leading again to step 1.

The tyranny of rocket equation!

[Warp11]

Hey everyone, I could use some advice on reentrys. I used to fly a 70km perigee lifting reentry with the Mk1 Pod from LEO and it worked fine but now I ran out of ablator and burned up. It worked before, but the capsules lift might have changed.
What is a good perigee for LEO entrys? (lifting reentry)
What is good for the moon?
And also what are good Periapses for Mars and Venus entrys?
Thanks a lot!

I am playing RO in 1.1.3

Edited November 17, 2016 by Warp11

[Phineas Freak]

@Warp11 approximate reentry corridors:

• Venus: 90 to 105 km (ballistic)
• Earth (LEO): -200 km to 50 km (ballistic or lifting)
• Earth (TEI): 30 km to 45 km (lifting)
• Mars: 10 to 30 km (ballistic)

Generally, reentry corridors are always dependent by the trajectory (for direct interplanetary reentries), on the type of reentry (ballistic or lifting) and on the composition of the atmosphere.

[Warp11]

@Phineas Freak Thank you!

[MaxL_1023]

For lunar or hyperbolic (Mars or Venus) returns I perform a variable-lift re-entry. Essentially, I set the PE to about 55-60 KM, orient for a standard lifting re-entry. Normally, this would have you skip back off into space following a lower orbit. However, near PE I roll the pod 180 degrees, essentially inverting the lift vector. The pod is now pushed downwards into a forced orbit by the atmosphere, allowing it to bleed off speed by greatly slowing how quickly it rises. When done correctly, your AP may be only 5-10 KM above your initial PE. Once you reach your new AP (inside the atmosphere) orient back to a normal lifting re-entry orientation and continue to the surface. 

If you are traveling at hyperbolic velocity (12+ km/s) you might need to perform multiple rollovers. The atmosphere can keep you following the curve of the planet at impressively high speeds (above escape velocity if you are low enough) while minimizing the G-forces you encounter on a ballistic or standard lifting re-entry with a much lower initial PE. 

[NathanKell]

FYI I'm back from a trip and will be getting back to working on RO etc.

[Sol Invictus]

6 hours ago, NathanKell said:

FYI I'm back from a trip and will be getting back to working on RO etc.

Hallelujah!

[KroShan]

@NathanKell, i think also @Felbourn and all his viewers will be very pleased. I hope you had a great trip...

Thx for your effort.

[Felbourn]

Indeed, I will be happy to update for RSS+RO.  

[kalizec]

Question:

I'm having difficulty using fuel-cells. I'm already using cryogenic tanks, but the boil-off remains too high to make this a viable solution. How do you store Hydrogen for the 10+ days a lunar landing mission takes without requiring 4+ tons just because of boil-off?

[Phineas Freak]

@kalizec what type of tanks do you use for them? For fuel cell applications the tanks must be of the "ServiceModule" kind.

[MatBailie]

On 27/11/2016 at 4:20 PM, kalizec said:

Question:

I'm having difficulty using fuel-cells. I'm already using cryogenic tanks, but the boil-off remains too high to make this a viable solution. How do you store Hydrogen for the 10+ days a lunar landing mission takes without requiring 4+ tons just because of boil-off?

Have you tried using any radiators?

Also, I believe that vessel orientation matters.  Keeping side on to the Sun increases your temperature more than if you keep your engine pointed to the sun.  Effectively using your engine as a sunshade, whilst also minimising your exposed cross section, to keep fuel temps down, and so reducing boil-off.

Edited November 29, 2016 by MatBailie

[FreeThinker]

If I may make a suggestion

The MM script that rescales/rebalances Solar Panels (making them ligher but also produce less power) should only do so for solar panels that use ElectricCharge. Solar Panel with any other output than electric charge should be ignored. For instance KSPI-E has a 50x50m solar panel which output in Megajoule and it energy output is based on real solar flux density already. So I would appreciate if it doesn't get downscaled twise!

Edited November 29, 2016 by FreeThinker

[Phineas Freak]

@FreeThinker where is that generic config?

[FreeThinker]

42 minutes ago, Phineas Freak said:

@FreeThinker where is that generic config?

I'm referring to RealismOverhaul_Global_Config.cfg in the root of RealsimPverhaul

specificity, this is the config that causes the problems:

// Set up solar panel displays.
@PART[*]:HAS[@MODULE[ModuleDeployableSolarPanel]]:FOR[ROSolar]
{
	@MODULE[ModuleDeployableSolarPanel],*:HAS[!RESOURCE[*]]
	{
		RESOURCE
		{
			name = ElectricCharge
			rate = #$../chargeRate$
		}
	}
	@MODULE[ModuleDeployableSolarPanel],*
	{
		%flowUnits = Watts
		%flowFormat = N1
		%flowMult = 1000
	}
}

This would effectively sabotage any SolarPanel that uses another output than ElectricCharge, Please fix it.

I noticed Realism Overhaul already defines adjustment/overrides the flowrate and mass for most solar panels, so this MM could be removed without much effect

Edited November 29, 2016 by FreeThinker

[Phineas Freak]

@FreeThinker so the problem is that the HAS[!RESOURCE[*]] MM check, right?

[Fizwalker]

I need a little advice.  It's been awhile since I've played RO and I am having issues getting my second stage to fire.  I have an RT connection. What else do I need to consider to light the 2nd stage?

[gemini4]

@Fizwalker Are your fuels settled? For most upper stage engines, the fuel stays stable for a couple of seconds following MECO, but after that, it is often necessary to use RCS or solid motors for ullage. If your're not getting the message "[Engine] has encountered vapor in feed lines and has shut down!" when trying to start your engines, then your fuel is stable. You can see that in the engine icon in the lower left. If it is red, your fuel is unstable, and your engine should not be ingnited. 

Most engines also require certain resources to ignite. For instance, many kerolox engines require TEATEB, although this is included by default, and typically matches the number of ignitions your engine has. Most other engines require ElectricCharge to ignite (presumably using sparkplug ignition systems, or some power to open fuel valves). 

Other than that, the only thing I can think of off the bat is to make sure that your staging is set up correctly. 

[aquilaspqr]

Hi, I'm new here and I'd like to ask one thing - is there a way to have RO without ullage and some other features to make it more realistic that vanilla Kerbal but also more casual than full realism? I'm interested in RSS in smaller size, realistic parts but more kerbal-like in terms of handling the rocket.

I'm totally new to Kerbal modding so I'm not quite sure what to chose.

[Karamon]

You can use SMURFF mod , it will lower the weight of the stock parts, fuel, engines, pods making it more realistic without the need to go trough full realism like ullage or limitet ignitions .

 

And i have a question , are there any mods with "realistic" SCRAM engines? i want to build an SSTO but most of the parts i find are not meant for larger scale systems , everything lacks thrust at speed higher than 3 mah and it is like stock parts modelled towards the 2500 m/s orbital velocity . Feels like i have to stick to vertical launch vehicles

Edited December 16, 2016 by Karamon

[Mad Rocket Scientist]

14 hours ago, aquilaspqr said:

Hi, I'm new here and I'd like to ask one thing - is there a way to have RO without ullage and some other features to make it more realistic that vanilla Kerbal but also more casual than full realism? I'm interested in RSS in smaller size, realistic parts but more kerbal-like in terms of handling the rocket.

I'm totally new to Kerbal modding so I'm not quite sure what to chose.

As @Karamon says, SMURFF.  For a smaller RSS, you'll have to use a Kerbol system rescale mod like x64 or a similar one.  There's also ROmini, which makes parts larger rather then lighter:

https://github.com/KSP-RO/RealismOverhaul/blob/master/ROMini.cfg

[aquilaspqr]

Thanks for replies, but... it's still quite unplayable. I have RSS, with HUGE (when compared to Kerbin) Earth. Unfortunately even with SMURFF and few other downloaded parts it's VERY hard to get even to the orbit. Even my most powerful rockets can barely reach it (which totally wrecks career mode because no contract is profitable). I thought that hacking gravity would be the answer to my problems, because after lowering it to 0.40 I was able to build "appropriate" rockets and send probes to Moon, but new problem emerged - with lowered gravity... maneouvering to Moon became much too difficult - there is no info about target. I set up the maneouver, cross Moon's orbit but purple "Moon position at closest approach" never appear (usually there's this extremely useful purple target, infos about periapsis etc), no matter how I position the maneouver node (yes, orbits are almost perfectly aligned). I have to shoot probes completely blind and then make desperate corrections. I think I'll have to abandon my great current game and install smaller scale RSS. Or I'll try to mod RSS (since it seems that smaller scale mods are not being updated...) and change appropriate values myself.

Edited December 20, 2016 by aquilaspqr

[Parallax59]

Hi All,

For those who have difficulty with Realism Overhaul, I wonder if you could benefit from my series, Rocket Science Advanced.  Follow it and you won't have any trouble reaching orbit in your career game.  I am playing a career game in the series with only 30% funding and so far, so good.  You shouldn't have to hack anything, it works just like the real thing, which is not easy, but is quite doable.  Don't lose hope, you can do this.  Here is the link, I hope you like it (We will be going to orbit in the series very soon).

Rocket Science Advanced

Edited December 20, 2016 by Parallax59

[aquilaspqr]

It won't help me because I do not use RO I don't like the idea of ullage and limited ignition because I'm not looking for a super realistic simulator, I'm looking for a casual gameplay like in KSP but in real solar system with Earth, Moon, Mars etc. Unfortunately RSS Earth is just much too big in diameter for stock unmodified KSP parts to work. And even modified by SMURFF still seem to be too weak for such huge solar system and planets. My only hope is to keep RSS with its Kopernicus data but reduce planet sizes to be more Kerbal-like. I already modded it a bit and reduced size of the planets and their orbits by 1000 so they are 1000 smaller than in RSS and 2x larger than vanilla planets. But unfortunately they began to spin too fast, so I reduced rotation by 1000 to see how it'll work (I don't really care about time, day/night cycles etc). But there is another problem I will have trouble to solve, because I do not understand the parameters. My Cape Canaveral base floats somewhere above Earth and I have no idea how to place it in a proper place on tha smaller Earth I made... 

 

PQSCity
            {
                KEYname = KSC
                lodvisibleRangeMult = 6
                latitude = 28.608389
                longitude = -80.604333
                repositionRadiusOffset = 53
                reorientFinalAngle = -9.395667
            }
            PQSMod_MapDecalTangent
            {
                radius = 10000
                heightMapDeformity = 80
                absoluteOffset = 0
                absolute = true
                radius = 10000
                latitude = 28.608389
                longitude = -80.604333
            }

 

EDIT: LOL, what a mistake. I reduced sizes by 1000 while it seems I had to reduce it by making it only 10 times smaller  And I ended up with Earth having 1 km in diameter Testing new settings now.

 

EDIT 2: haha! I did it! I successfully reduced the size of RSS to make Earth 10 times smaller (it has now 1270 km in diameter). Everything is in appropriate scale, now I hope gravity is ok too and rockets will be able to fly as they should. I only have to tweak Mars a bit because its volcanoes kept the original heigth and are too high. But I think I'll be able to correct that

Edited December 20, 2016 by aquilaspqr

[Phineas Freak]

@aquilaspqr the Stock Size Real Solar System is what you want. It keeps the scale of the stock KSP but using the RSS bodies.