riocrokite

[1.3.0] Inline Ballutes [IB] (v1.2.8) [30.05.2017]

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I've merged pull requests.

So I guess ballutes can now be used for Kerbin/Laythe aerobraking too:)

I'm still playing with numbers and I think I got a very favorable balance. Testing currently on different vehicles.

Thanks to Nathankell I now understand the meaning the stock modules I'm tweaking.

My current results allow me to aerocapture vehicles from 4.5-6km/s with periapsis 55km near Kerbin. Atmospheric pressure there is 150 higher than what Mars aerobrake simulations use around 100km altitude. So we're not cheating here.

Edited by Enceos

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does this mean it's compatible with realchutes already, or is it in the works, or...?

Sorry for being a noob and not understanding right away!

Thanks

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does this mean it's compatible with realchutes already, or is it in the works, or...?

Sorry for being a noob and not understanding right away!

Thanks

yah, it's should be compatibile, testers needed :)

just released 1.2.1 version with corrected MM patch for RealChutes

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I've been testing EVE aerocapture and I don't really know what to do. Since atmosphere in KSP starts immediately there's so little time to aerobrake.

Everything is fine at 4.7 km/s (Return from Eve). But at 6.5 km/s (EVE encounter and return from Jool) everything starts exploding below 65km Kerbin and 86km EVE.

Time to reduce the speed to aerocapture is 25 seconds which is 10 times less than what we have in real life. During this time the vessel should loose around 3.5km/s speed which means the drag should be very significant.

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I guess we couldn't provide for every scenario out there. Considering 4.7 km/s is fine and 6.5 km/s is not you still save a lot of dV compared to a heatshield(?).

From interesting news, I was able to reduce Jool-aerobrake by about 800 ms using 2.5m heatshield and 2.5m ballute. The problem was heatshield that couldn't withstand periapsis below 194km :P

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I guess we couldn't provide for every scenario out there. Considering 4.7 km/s is fine and 6.5 km/s is not you still save a lot of dV compared to a heatshield(?).

From interesting news, I was able to reduce Jool-aerobrake by about 800 ms using 2.5m heatshield and 2.5m ballute. The problem was heatshield that couldn't withstand periapsis below 194km :P

Yeah, that's the problem I'm trying to solve :) if you need a heatshield then ballute doesn't do its job.

800m/s an average result. We usually encounter Jool at around 8.5 km/s. To reduce the speed to a good aerocapture we gotta loose 1.5km/s and not heat up.

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A word about Jool: Jool physics are going to be a lot less of a problem in 1.1 and will also be less of a problem with RealHeat installed. (Jool's atmospheric composition will see changes in 1.1 and is changed by RealHeat)

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A word about Jool: Jool physics are going to be a lot less of a problem in 1.1 and will also be less of a problem with RealHeat installed. (Jool's atmospheric composition will see changes in 1.1 and is changed by RealHeat)

I probably should start testing with RealHeat installed. Cause current thermodynamics give me headaches.

EDIT: I must say RealHeat is awesome! We probably should make it a prerequisite for Ballutes before 1.1 comes out.

Edited by Enceos

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I probably should start testing with RealHeat installed. Cause current thermodynamics give me headaches.

EDIT: I must say RealHeat is awesome! We probably should make it a prerequisite for Ballutes before 1.1 comes out.

Cool, wait what is realheat?

I think I've found one more usage for ballutes:

Stage recovery for mun/minimus slingshots: for example you can accelerate the rocket (all stages) to mun/minimus orbit, then release payload (lander/satelite), make correction at the apoapsis to reenter kerbin and use ballute to semi-powered land all spent stages all together (more funds returned at the cost of merging 1st-2nd stage into one).

pic: kerbin reentry after slingshooting 60t payload into mun orbit:

Vs7mTJ9.jpg

edit: I have nothing against using heatshield and ballute together for denser atmospheres, they could work in tandem especially since heatshield isn't braking effectively around Jool at the moment. The more options the better \o/

Edited by riocrokite

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I probably should start testing with RealHeat installed. Cause current thermodynamics give me headaches.

EDIT: I must say RealHeat is awesome! We probably should make it a prerequisite for Ballutes before 1.1 comes out.

Recommend it maybe but not a prerequisite. (if you're referring to CKAN for instance)

@riocrokite, RealHeat makes thermodynamics even more realistic. Its contribution to the Jool problem is that it alters atmospheric density. That's something that KSP supports but did not implement for Jool because there was no time when the problem originally surfaced. Basically, Jool is treated as though its atmosphere composition is the same as Kerbin's, which makes reentries very hard. RH (and 1.1) treat it as though it's atmosphere is closer to Jupiter's so, for a given atmospheric pressure, its density will be a lot lower so less heat is transferred during reentry

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@riocrokite, RealHeat makes thermodynamics even more realistic. Its contribution to the Jool problem is that it alters atmospheric density. That's something that KSP supports but did not implement for Jool because there was no time when the problem originally surfaced. Basically, Jool is treated as though its atmosphere composition is the same as Kerbin's, which makes reentries very hard. RH (and 1.1) treat it as though it's atmosphere is closer to Jupiter's so, for a given atmospheric pressure, its density will be a lot lower so less heat is transferred during reentry

Cool, can't wait for 1.1 (for one more reason:)).

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So with RealHeat all the thermal problems I had are gone. How could I forget about this mod, I use it in my main install.

As for the drag, I found the drag modifier of 1.35 is the margin which allows to aerobrake from 6.5km/s to 3.3 km/s on Kerbin and EVE at safe altitudes of 50km and 80km respectively. Peak deceleration is 11g, in real life we would have 1.1g deceleration, but since we have 10 times less time to do it 11g seems pinpoint for the task.


MODULE
{
name = ModuleDragModifier
dragCubeName = SEMIDEPLOYED
dragModifier = 1.35
}

MODULE
{
name = ModuleDragModifier
dragCubeName = DEPLOYED
dragModifier = 1.35
}

The change in these attributes does not work until PartDatabase.cfg file is deleted. After deleting, the game will regenerate the drag cubes and Ballutes will behave as they should.

I advice to cut the ballute when the velocity drops below Mach 5. Ballutes have Helium in them, a lighter than air gas for airships, so it's realistic that your vessel will descend very slowly into the atmosphere. In real life they have hours to spare at NASA so descent with a deployed ballute is always a good option for them but not for us.

Still this drag won't allow to land without extra chutes:

tUHdCS6.png

UPDATE: Stock is good on my paper. Time to see what the RealChute config brings to the table.

Edited by Enceos

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Is it just me or are these things ludicrously huge? Unless they are made out of graphene my brain says, "is it even remotely possible for that material to be contained in the pod it supposedly came from?" Probably I guess?

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Is it just me or are these things ludicrously huge? Unless they are made out of graphene my brain says, "is it even remotely possible for that material to be contained in the pod it supposedly came from?" Probably I guess?

The material is actually Zylon, the casing is IMHO quite big compared to real life so could easily pack deflated ballute inside imho. You can check how efficiently was packed i.e. Miriam2 ballute.

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So with RealHeat all the thermal problems I had are gone. How could I forget about this mod, I use it in my main install.

As for the drag, I found the drag modifier of 1.35 is the margin which allows to aerobrake from 6.5km/s to 3.3 km/s on Kerbin and EVE at safe altitudes of 50km and 80km respectively. Peak deceleration is 11g, in real life we would have 1.1g deceleration, but since we have 10 times less time to do it 11g seems pinpoint for the task.

That'll be pretty harsh in an RSS environment?

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That'll be pretty harsh in an RSS environment?

In RSS environment you would probably need only a fraction of that drag. I don't have an RSS install, can't test it out.

P.S. Current RealChute configs don't work for me, ballutes don't want to deploy stating the reason: Too high.

Couldn't make them open by tweaking pressure in the config, not sure what else defines the behavior.

Edited by Enceos

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Is it just me or are these things ludicrously huge? Unless they are made out of graphene my brain says, "is it even remotely possible for that material to be contained in the pod it supposedly came from?" Probably I guess?

global_aerospace_ballute.jpg

In RSS environment you would probably need only a fraction of that drag. I don't have an RSS install, can't test it out.

P.S. Current RealChute configs don't work for me, ballutes don't want to deploy stating the reason: Too high.

Couldn't make them open, not sure which numbers to tweak in the config.

Example config

You probably need to set minIsPressure to True

Increase deploymentAlt to match minDeployment


MODULE
{
name = RealChuteModule
caseMass = 0.08
timer = 0
mustGoDown = true
cutSpeed = 0.5
spareChutes = 5


// Single main chute
PARACHUTE
{
material = Nylon
capName = cone
parachuteName = RC_triple_canopy
preDeploymentAnimation = RC_triple_chute_semi_deploy
deploymentAnimation = RC_triple_chute_full_deploy
preDeployedDiameter = 2.5
deployedDiameter = 50
minIsPressure = false
minDeployment = 30000
deploymentAlt = 700
cutAlt = -1
preDeploymentSpeed = 2
deploymentSpeed = 6
}
}

Edited by Starwaster

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In RSS environment you would probably need only a fraction of that drag. I don't have an RSS install, can't test it out.

P.S. Current RealChute configs don't work for me, ballutes don't want to deploy stating the reason: Too high.

Couldn't make them open by tweaking pressure in the config, not sure what else defines the behavior.

Have you tried the most recent version of Inline Ballutes (1.2.1)?

With MM config from ABZB max deployment alt = 120000 and minPressure = 0.0000001 so should work pretty much from the border of atmosphere.

Without RealChute minPressure is clamped I think to 0.000001 (and max alt = 10000), slight but significant difference.

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Anyone knows how can we turn off this glow?

Kp2qGpf.jpg

It really spoils the picture.

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Anyone knows how can we turn off this glow?

http://i.imgur.com/Kp2qGpf.jpg

It really spoils the picture.

press F10 BEFORE it starts to heat up. There's a material bug in the temperature gauges code that causes it to not want to go away

On the subject of materials, regarding my earlier RealChutes reply, you also want to change the material. You could just go with Kevlar but its maxTemp is probably too low.

Look in the Materials folder in RealChute; pay attention to maxTemp, specificHeat and emissivity.

Also, look at this document, page 11, if you haven't already seen it. That should give you some ideas for appropriate values

http://www.ssdl.gatech.edu/papers/conferencePapers/IEEE-2011-1312.pdf

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A Zylon ballute would have a chute/material maxTemp of ~600C (873.15 K)

Actually, maybe add 50 K to that... to represent its actual failure temperature

Here's a preliminary RealChute material config for it. Its dragCoefficent, areaCost and specificHeat are the same as for Kevlar as I'm unsure what those should be.


MATERIAL
{
name = Zylon
description = For ballutes
areaDensity = 0.000076
dragCoefficient = 1.25 // ???? No idea here
areaCost = 0.08 // No idea
maxTemp = 923.15
specificHeat = 1420 // no idea; can't find specific heat data on Zylon???
emissivity = 0.85
}

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I found several mistakes in the current RealChute patch. I'll fix it, tweak the values to our latest data and create a pull on Github.

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I found several mistakes in the current RealChute patch. I'll fix it, tweak the values to our latest data and create a pull on Github.

ok, bear in mind that I might not want to further increase durability of ballutes unless having a good reason.

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ok, bear in mind that I might not want to further increase durability of ballutes unless having a good reason.

RS is much more intuitive and realistic in this field.

EDIT: About Zylon specific heat capacity, found this figure:

LjPzoJq.png

I didn't quite understand it, can anyone read it and tell the number from it?

Edited by Enceos

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