[1.12.X] RealChute Parachute Systems v1.4.8.3 | 24/01/21

SportsFanatic57 · November 22, 2015

[quote name='Gryphon']Did you try to complete it? If you stage it, the contract parameter should complete, regardless of whether the chute actually deploys. Also, some part tests require you to click a "Run Test" button on the part instead.[/QUOTE]

I tried it but the mission still did not want to complete. I did some more testing and rolling the pod around on the launch pad seemed to make it work. Thanks for the help!

stupid_chris · November 24, 2015

[quote name='SportsFanatic57']I tried it but the mission still did not want to complete. I did some more testing and rolling the pod around on the launch pad seemed to make it work. Thanks for the help![/QUOTE]

I don't control what missions it gives you. Stock does all that.

riocrokite · November 24, 2015

hey stupid_chris,

Is there any way to increase strength of a drag parachute against drag forces (so it can survive higher reentry speeds), i'm trying to update inline ballutes mod for new version of FAR and RealChutes and so far it doesn't look too good.

I've also noticed that upper atmo has changed in new FAR/RealChute. 1.0.4 version of them had a nice aspect where the edge of atmosphere (45-70km above kerbin) didn't produce heat however had drag which was similar to conditions where ballutes work in real life. No such luck with ballutes in new version FAR/Realchute, where heat kicks in hard from 70k :(

stupid_chris · November 24, 2015

[quote name='riocrokite']hey stupid_chris,

Is there any way to increase strength of a drag parachute against drag forces (so it can survive higher reentry speeds), i'm trying to update inline ballutes mod for new version of FAR and RealChutes and so far it doesn't look too good.

I've also noticed that upper atmo has changed in new FAR/RealChute. 1.0.4 version of them had a nice aspect where the edge of atmosphere (45-70km above kerbin) didn't produce heat however had drag which was similar to conditions where ballutes work in real life. No such luck with ballutes in new version FAR/Realchute, where heat kicks in hard from 70k :([/QUOTE]

Sorry, the heating is pulled out of actual real life values. Can't help you turn that down.

riocrokite · November 25, 2015

[quote name='stupid_chris']Sorry, the heating is pulled out of actual real life values. Can't help you turn that down.[/QUOTE]

no worries, thanks for replying:)

softweir · November 25, 2015

I have no idea whether it would work, but perhaps you could add an ablator (heat-shield) module to the ballute .cfg to make it less sensitive to re-entry heat?
[code]MODULE
{
name = ModuleAblator
ablativeResource = Ablator
lossExp = -7500
lossConst = 0.1
pyrolysisLossFactor = 6000
reentryConductivity = 0.01
ablationTempThresh = 500
}
[/code]

You'd have to play with the values to make it survive normal re-entry but fail for excessively steep and fast re-entry.

Starwaster · November 25, 2015

[quote name='stupid_chris']Sorry, the heating is pulled out of actual real life values. Can't help you turn that down.[/QUOTE]

I think you should re-examine it. You're using Mach^3 to find heat flux but then you're also throwing in vessel.convectiveCoefficient which also (*I think; obviously take this with a grain of NathanKell) incorporates mach heating. It seems like over kill to do both.

riocrokite · November 25, 2015

[quote name='softweir']I have no idea whether it would work, but perhaps you could add an ablator (heat-shield) module to the ballute .cfg to make it less sensitive to re-entry heat?
[code]MODULE
{
name = ModuleAblator
ablativeResource = Ablator
lossExp = -7500
lossConst = 0.1
pyrolysisLossFactor = 6000
reentryConductivity = 0.01
ablationTempThresh = 500
}
[/code]

You'd have to play with the values to make it survive normal re-entry but fail for excessively steep and fast re-entry.[/QUOTE]

Maybe it could work for stock (I have it already balanced). It won't work for RealChute since the mod is using different temperature variable to calculate when to cut (destroy) parachute. :)

[quote name='Starwaster']I think you should re-examine it. You're using Mach^3 to find heat flux but then you're also throwing in vessel.convectiveCoefficient which also (*I think; obviously take this with a grain of NathanKell) incorporates mach heating. It seems like over kill to do both.[/QUOTE]

After many hours of trying different values in Real Chutes I gave up and just put some unrealistically high numbers for a ballute max temp and emissivity so it doesn't break upon deploying @ 68.000 m above Kerbin no matter what the speed. All in all I guess ballutes would need to have a separate plugin since they differ in too many ways from parachutes and thus would require additional parameters to work correctly. Edited November 25, 2015 by riocrokite

Starwaster · November 25, 2015

Wrote up some quick debugging code and stuck your formula in compared to the convective heating a part gets and there's.... a LOT of heat.

Note that this is per mÃ‚Â² and for RC flux is also before temperature delta, so it's actually a lot higher for RC than this image indicates. Over a gigawatt of heat for that same altitude and reentry profile. Peak was on the order of a [I]terawatt[/I].

[URL="http://[img]http://i.imgur.com/pjIThPE.png[/img]"][IMG]http://i.imgur.com/pjIThPEh.png[/IMG][/URL]

stupid_chris · November 26, 2015

[quote name='Starwaster']I think you should re-examine it. You're using Mach^3 to find heat flux but then you're also throwing in vessel.convectiveCoefficient which also (*I think; obviously take this with a grain of NathanKell) incorporates mach heating. It seems like over kill to do both.[/QUOTE]

The whole heating code *is* NathanKell's.

Starwaster · November 26, 2015

[quote name='stupid_chris']The whole heating code *is* NathanKell's.[/QUOTE]

Yeah, I spoke to him and it's a bug that it doesn't take into account low dynamic pressure. It's in stock too.

NathanKell · November 27, 2015

Yep, gonna be fixed for next KSP, but RC can fix it sooner (woo!). The mach multiplier should fade out with Q, yeah.

Starwaster · November 27, 2015

[quote name='NathanKell']Yep, gonna be fixed for next KSP, but RC can fix it sooner (woo!). The mach multiplier should fade out with Q, yeah.[/QUOTE]

I've been thinking that given the already magnitude of the mach multiplier, wouldn't it be better limit it by static pressure? Unless you're thinking to lerp it and clamp it.

Even better though would be to handle chute stress separately as discussed in:

[URL="https://solarsystem.nasa.gov/docs/06%20Parachute%20Inflation%20Wolf.pdf"]https://solarsystem.nasa.gov/docs/Parachute Inflation Wolf.pdf[/URL]

and

[URL="https://solarsystem.nasa.gov/docs/14%20Parachute%20Materials%20and%20Stress%20Analysis%20Wolf.pdf"]https://solarsystem.nasa.gov/docs/Parachute Materials and Stress Analysis Wolf.pdf[/URL]

The basic formula is fairly simple:

Fmax = Ck*Cd*A*Q

Where each chute would be given an FMax rating which if exceeded, the chute fails. (Ck is shock opening factor and ranges from 1-2 depending on mass ratio between atmosphere and chute. The other value's definitions should be obvious)

Although it talks about chute opening, the formula is suitable for all other phases of the descent after inflation.

stupid_chris · December 1, 2015

Hello everyone! Quite shaken up by this new environment but we'll get used to it. Hopefully everyone made it through!

@Starwaster @NathanKell I'm not quite fond of updating/working on RealChute 1.x when I'm so far into RealChute 2.0, but if you guys send me a code update/PR/whatever, I'll see if I can swiftly deploy it.

Starwaster · December 1, 2015

9 hours ago, stupid_chris said:

Hello everyone! Quite shaken up by this new environment but we'll get used to it. Hopefully everyone made it through!

@Starwaster @NathanKell I'm not quite fond of updating/working on RealChute 1.x when I'm so far into RealChute 2.0, but if you guys send me a code update/PR/whatever, I'll see if I can swiftly deploy it.

I do have an update I can send in as a PR that scales just the mach component by (dynamic) pressure in atmospheres. So nothing fancy, just a modification to the current system and so far I think works well for upper/thin atmospheres. I want to test it a bit more first and make sure it's still sufficiently punishing at lower atmospheres.

Edited December 1, 2015 by Starwaster
my first reply made it sound like I sent one in already

Starwaster · December 2, 2015

Sent in a PR for the Mach issues. That'll allow for ballutes or Duna deployments.

And very high altitude Kerbin deployments which will still burn up normal chutes if you're going too fast. (or shred them if you're going too fast too low)

stupid_chris · December 2, 2015

I'll try to release it tomorrow, will depend on uni schedule. Thank you

stupid_chris · December 3, 2015

And done, here we go!

Changelog:

December 2nd 2015
v1.3.2.5
-Fixed a bug with early reentry giving chutes an exagerated amount of heat (thanks to Starwaster!)

Cheers guys

EDIT: Also I hope you enjoy your new creepy stare.

Edited December 3, 2015 by stupid_chris

ss8913 · December 3, 2015

anyone else seeing completely game-breaking behavior after this latest update? none of my craft will load in VAB/SPH, attachment nodes don't work, etc... log shows the first instance of any major errors to be calling out RealChute parts, but that's not necessarily a problem with realchute. Before I investigate further, has anyone else noticed this or is this a "just me" problem?

Edited December 3, 2015 by ss8913
changed 'this' to 'this latest update'

_Augustus_ · December 3, 2015

2 minutes ago, ss8913 said:

anyone else seeing completely game-breaking behavior after this latest update? none of my craft will load in VAB/SPH, attachment nodes don't work, etc... log shows the first instance of any major errors to be calling out RealChute parts, but that's not necessarily a problem with realchute. Before I investigate further, has anyone else noticed this or is this a "just me" problem?

I have this problem as well!

ss8913 · December 3, 2015

Here's the log section that makes me think it's realchute - this is going into SPH/VAB, selecting a cockpit, adding a part (in this case a mk1 crew cabin), and then attempting to remove the crew cabin. the part does not remove in the editor, and i get this nullreferenceexception from RealChute: