[WIP] Inline Ballutes

[riocrokite]

new release with tweaked stock values:

https://github.com/riocrokite/InlineBallutes/releases/tag/0.2

Tweaked config for stock aerodynamics:

• set max skin temperature to 1400 - advanced heat resistant material that is also heavier than nylon (compared to parachutes)
  
• tweaked diameter of ballutes to get them inline with stock parachutes (ballutes have 1/4 of a drag of a normal parachute)
  
• tweaked mass of ballutes (still on the lighter side, however they weigh now 1, 2 and 4t. From my calculations they should weigh even 70% more when balancing against stock chutes)
  

I've tested 2.5m version with 30t rocket. Stock aero. Ballute weighs 2t which corresponds to 6.6% mass fraction of the rocket. It has a drag comparable to 1 XL-16 parachute (bigger area X smaller Cx).

It is able to decelerate it from orbit to ground (from 900 to about 100m/s terminal speed). Also aerobraking / aerocapture from about 2-2.5km/s initial speed is doable. Kerbin reentry is barely possible (ballute is heating to about 1200-1300 with max 1400 skin temp). Jool don't work (I don't know but it seems atmosphere jumps to very thick even at the border of it.

edit:

testing ballute for semi-powered stage recovery. 3.75m version with stock:

5m version with SpaceY parts:

Edited September 14, 2015 by riocrokite

[nikokespprfan]

There are 2 tanks which store liquid nitrogen or hydrogen and a pump to inflate ballute quickly.

I have a question:

Could you make a seperate version that only requires stock resources to use. Nitrogen and hydrogen seem to me as resources that you would find in a RSS modpack, it doesn't feel kerbal to me.

Just wondring if that could be possible?

[riocrokite]

I have a question:

Could you make a seperate version that only requires stock resources to use. Nitrogen and hydrogen seem to me as resources that you would find in a RSS modpack, it doesn't feel kerbal to me.

Just wondring if that could be possible?

Yah, there won't be any resources, tank and resources masses are just added into general part's weight and are for visuals.

[nikokespprfan]

Yah, there won't be any resources, tank and resources masses are just added into general part's weight and are for visuals.

oh, ok

lets download then...

[riocrokite]

Another test version is up:

https://github.com/riocrokite/InlineBallutes/releases/tag/0.21

• introduced 5m ballute - 33% larger diameter than 3.75m version
  
• tweaks to configs - stock areo should work fine
  
• slight change to FAR config for ballutes to be less op in aerobraking
  

Ballutes should work best for:

- 1.25m (1t) for 15t vessel

- 2.5m (2t) for 30t

- 3.75m (4t) for 60t

- 5m for (5.3t) for 80t

Stock aerodynamics:

Aerocapture and aerobraking works as it should in my opinion. So all in all ballute can be used for both things.

Duna scenario - it slows down a craft to about 80-90 m/s near the ground so it works better than heatshield and complementary to standard parachutes. It is able to slow down craft from speeds 2+ km/s using less dense atmo.

Kerbin scenario - it is possible to reentry 1st stage or other stuff using inline ballute. Should work nicely when constructing reusable stages (SpaceY as well). Still requires powered landing however not much fuel is required.

Jool aerobraking - doesn't work or work very poorly at best (very narrow altitude band when heating doesn't kill ballute). I don't think it is possible for it to work since if I tweak values to be sustainable for Jool stuff the parachute would become too op for other scenarios.

You can modify sensitivity of parachutes by modifying skinMaxTemp.

FAR aerodynamics:

FAR simulates perfectly upper parts of atmospheres unlike stock aerodynamics where heat kicks in even in the uppermost part of atmosphere. Thus FAR can simulate real aerobraking scenarios when ships incoming with high interplanetary speeds can decelerate effectively in upper parts of atmosphere where there's almost no heating involved.

Unfortunately FAR replaces stock ModuleParachute with RealChuteFAR module which has several values set as static (so they cannot be changed), for example parachute max temperature 220C, drag, etc. Ferram won't touch this stuff (I've asked him) so any further tweaks would need a dependency such as RealChute or a custom mod.

How it works now:

- it's great for aerobraking - getting into eliptical orbits decelerating from high interplanetary speeds in upper atmosphere where there's practically no heat involved,

- it's no good for aerocapture - 220 max temp and other constants set by RealChuteFAR makes it so that parachute breaks instantly when crossing certain atmosphere threshold (where heat kicks in).

Kerbin aerobraking scenario: great aerobraking potential till about 38km threshold when temperature suddenly kills a ballute. Still can bleed about 800 m/s before ballute is killed.

Duna scenario: great aerobraking potential and due to thin atmosphere it's possible to aerocapture and slow down to about 80-100 m/s near the surface.

Jool aerobraking: great potential however orbit needs to be set precisely since only uppermost atmosphere layer doesn't heat up stuff.

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Haven't tested Laythe scenario however I guess it will be similar to Kerbin scenarios in both aerodynamics.

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I won't do further testing since I think configs are doing now what they can to simulate ballute under stock and FAR aerodynamics (without reverting to RealChute dependency or else).

Any further heat/drag tweaking I guess will need to be done using RealChute dependency.

In other words as soon as I get texture from Enceos I'm ready to release it. Then if there's substantial interest I can try RealChute version of ballutes (or my own spin-off of RealChute or RealChuteFAR since they weren't optimized for ballutes).

Edited September 14, 2015 by riocrokite

[nikokespprfan]

Does it work for the outer planets mod scenario's?

[riocrokite]

Does it work for the outer planets mod scenario's?

should have - it's for you to find out! I'll appreciate a feedback

[Svm420]

I say use real chute as a dependency if you are making one for stock at should be enough. I am surprised ferram wouldn't cooperate.

[riocrokite]

I say use real chute as a dependency if you are making one for stock at should be enough. I am surprised ferram wouldn't cooperate.

I want to keep things as simple as possible and I don't think RealChute helps with stock aero (lots of heat in upper atmosphere which is unrealistic and can't be easily changed). I also believe that Ferram have valid reasons to keep those values static so I can understand that.

[riocrokite]

Enceos has just sent me awesome textures for 2.5m (1.25m) version, cheers man

Edited September 17, 2015 by riocrokite

[genericeventhandler]

Oh, I just found another reason not to complete my mun base. I'll be testing this for the next couple of days.

[kiwiak]

Im definetly using this one on my Jool mission..

[riocrokite]

Release thread:

http://forum.kerbalspaceprogram.com/threads/134573-1-0-4-Inline-Ballutes-IB-%28v1-0%29-18-9-2015?p=2202191#post2202191

[nikokespprfan]

the swimming duck ballute is called the swimming pool in its description.

[riocrokite]

the swimming duck ballute is called the swimming pool in its description.

thx, fixed that and updated download