Inflatable heat shield. WOuld <3 to Deflate

[magnemoe]

On 11.5.2016 at 3:21 AM, DrMarlboro said:

No not really. The problem is that it would basically be useless after reentry. They work more like a high speed/high altitude parachute with some ablator on the underside than a heat shield, and I think the one nasa tested (HIAD I believe is what it's called) was only for use on planets with thinner atmospheres like mars. I could be wrong in that aspect, but as far as heat shields go they are single use. 

However in KSP the second nice thing about the inflatable is that it don't have ablator and don't get used up. The other benefit is that its large. 
Have two ships with nose mounted inflatable and both had done around 10 aerobrakes. 

An deflateable would let you tail mount it this would be nice for tugs, now you need an fairly long tug to not interfer with cargo and an counterweight ballast tank

[Guest]

3 hours ago, MacLuky said:

Hmm, I did not get that to work, did anyone else manage to deflate it? If so, can you post the entire patch file? Really like the idea.

@Pthigrivi @5thHorseman

Alshain has a thead filled with quality of life configs and this is one of them.

//Allow deflating inflatable heat sheield
//Author: Chris97b
@PART[InflatableHeatShield]:AFTER[Squad]
 {
    @MODULE[ModuleAnimateGeneric]
     {
        @allowAnimationWhileShielded = true
        @disableAfterPlaying = false
     }
 }

 

Edited August 19, 2016 by Guest

[Empress Neptune]

On 5/11/2016 at 5:57 PM, fireblade274 said:

And actually since it does have favorable conditions going high speed high altitude, it fits the bill for advanced, large interplanetary SSTO's (and Multiple stage ones too) when coming in from Jool or Eloo so they can save DV by aerobreaking at Kerbin rather then having to slow down with your engines or do an Eve gravity assist first which takes a long time and is difficult to do without KAC or Mechjebs porkchop plots. The only reason they cant be used now in this way its because they can't be deflated once you reach low altitude and will turn your plane into a rock, and good luck trying to jettison it while flying into it also. Adding a large heat shield that can be deflated and reused is beneficial to the game IMO.

I don't think they're useless for return trips. I was curious about using the shield for SSTO reentry, so I put one on a craft returning from the edge of Kerbin SOI. Landing with the shield inflated wouldn't be possible, but I came up with two solutions that would allow me to remove the shield.

The first was to break the reetrny into multiple phases by leaving the atmosphere after the initial reentry. This makes it easy to jettison the heat shield. You would only need to slow down to roughly LKO velocity before jettisoning, which should be survivable for most SSTO's.

The second option was to jettison in the atmosphere after slowing down. This is actually what I did in my test flight. I just pitched up to about 90 AoA and jettisoned. It was not enough and the shield didn't fly off, so I had to oscillate pitch until the angle was enough to drag the shield off the nose, but it did work. Obviously, getting this to work the first time every time would be the goal. While it might take some work, I don't think it's impossible at all.

A deflate option would certainly be useful though.

[MacLuky]

Thanks @String Witch the link is awesome too! will try tonight

[EpicSpaceTroll139]

It should definitely require a kerbal or a significant mass cost to retract it (at least in space), because when you think about it, when in space, a non-elastic balloon (which is what I guess the heatshield would be) won't exactly deflate if you take the air out of it. It would just become less rigid. It would need to be shoved back into place. Inside the atmo the pressure might be able to repack a deflated one, but even then that's iffy.

[MacLuky]

I'll send my highest ranking engineer

[GoSlash27]

I like this idea for interplanetary motherships where I'm aerobraking at both ends. I currently have to leave the shield inflated. Previously, I replaced the ablators in orbit during refit/ refueling using clamp-o-trons.

It'd be nice to be able to stow them when not in use.

 

Best,
-Slashy

[Firemetal]

On ‎5‎/‎10‎/‎2016 at 6:15 PM, 5thHorseman said:

Is deflating a heat shield like this even a reasonable thing to expect? I don't know but it sounds kinda difficult. The heat shield is already neigh-on indestructible and essentially infinitely useful. Being able to stow it and reopen it seems a bit ... much.

Some mod I had installed at one point (I suspect probably Tweakable Everything) added that option in flight.

Uh actually, you're wrong. The inflatable heatshield can't survive much more than 5500 m/s re-entry speeds.

Ablative heatshields are better for faster re-entry speeds. It's not exactly that overpowered.  

[Superfluous J]

On 8/21/2016 at 9:09 AM, Firemetal said:

Uh actually, you're wrong. The inflatable heatshield can't survive much more than 5500 m/s re-entry speeds.

"Nigh on" (which I did misspell. Oops) means "nearly." In stock, 5500m/s is pretty fast. I stand by my words. 

Except of course "neigh, " which should have been "nigh"

Edited August 31, 2016 by 5thHorseman

[Firemetal]

Just now, 5thHorseman said:

"Nigh on" (which I did misspell. Oops) means "nearly." In stick,  5500m/s is pretty fast. I stand by my words. 

Except of course "neigh, " which should have been "nigh"

Heh sorry. It sounded as if you thought it could survive like 7000 m/s! Misunderstood.

However I think engineers should be able to stow the heat shield like parachutes. It would make a lot of sense and not be to OP either.

[septemberWaves]

Personally I have grown used to designing vessels with the inflated heat shield in mind. On my Phasma-class Deep Space Transports (which are currently in still in development) I feel like it looks somewhat better if the heat shield remains inflated.

And whilst I can understand technical reasons why one might want to deflate one (e.g. on a reusable landing vehicle for a planet with a somewhat thick atmosphere) but really the inability to deflate them also seems to be a fair price to pay for the fact that the heat shield does not deplete.

[fireblade274]

On 8/19/2016 at 9:31 AM, Empress Neptune said:

... two solutions that would allow me to remove the shield.

The first was to break the reetrny into multiple phases by leaving the atmosphere after the initial reentry. This makes it easy to jettison the heat shield. You would only need to slow down to roughly LKO velocity before jettisoning, which should be survivable for most SSTO's.

The second option was to jettison in the atmosphere after slowing down. This is actually what I did in my test flight. I just pitched up to about 90 AoA and jettisoned. It was not enough and the shield didn't fly off, so I had to oscillate pitch until the angle was enough to drag the shield off the nose, but it did work. Obviously, getting this to work the first time every time would be the goal. While it might take some work, I don't think it's impossible at all.

A deflate option would certainly be useful though.

I wish the first option would work for me, as I usually am trying to re-dock at my space station and not land. However, using the inflatable heat shield as a means to aero-break can be difficult to Incorporate in to crafts that are meant to be reused. If you want to continue using it, you'll have this large bulky tube in front of you for all subsequent missions, and make it impossible to dock from the front.

Your second point I think helps further my point that giving the shield a deflate option is useful. It may not be impossible to use it for large SSTO/MSTO's, but it is certainly difficult to incorporate it into the designs. Having to pitch up to 90 AoA (though not hard to maintain if you have a good craft) is quite dangerous if your also trying to shake off an oversize shield.

Though I lament the idea and think the shield should be reusable after a hypothetical deflate option, I'd be willing to compromise and say at the very least give it a single use deflate so craft coming back for landing can return with the heat shield. Giving the shield only one deflate use would make it less OP, even though I still don't think it would be that OP with multiple inflate/deflate cycles; the inflatable heat shield has slightly less heat tolerance then standard ablator heat shields.

This is the first time I've made a post to KSP in months; this is important to me, and it looks like the number of people who've voted yes outnumber no 2 to 1

[Armisael]

Obviously it'd be useful to be able to deflate it. No one's arguing that.

It'd also be useful to have a engine with 10^9 Isp. The inflatable heatshield already feels like it's verging on hilariously OP to me - please don't make it even more so.

[Pthigrivi]

Re-packing it could make a cool high-tier engineer ability though

Edited September 16, 2016 by Pthigrivi

[Francois424]

I like the idea of being re-usable, but IMHO it should have ablator or w/e stat you want to use.
After you've used it a couple of time it would become far too risky to use it again.

In the meantime I finally have a reason to use the 6-attackment module.  I just stick a stowed inflatable heatshield on a Docking port SR and dock it to all four sides of it, keeping the fore/aft to connect the rest of my landers/mothership/etc.
When I've used one I just discard it.

[problemecium]

I'm also on Team Deflation, but I hear the complaints about it being OP. I propose one or more of the following compromises:

- Require a Kerbal to EVA and repack the shield a la a parachute
- Have a cheaper, lighter heat shield that cannot deflate, and a heavier, more expensive shield unlocked later in the tech tree that can be deflated.
- Put ablator in the inflatable shield. I don't entirely understand why it isn't there already.
- Get really schwifty and have a completely different sort of part take the role of the deflatable heat shield: rather than inflate and deflate, have it fold and unfold with good old-fashioned hinges and motors/pneumatics/hydraulics. I'm imagining something with an array of triangular "petals" that fold down sideways, allowing the shield to transform between a shallow cone and a long, narrow pyramid. Or maybe instead of a contiguous shield have the new part be a surface-mounted flap that can shield parts behind it.

As far as believability goes, perhaps the deflatable heat shield contains an arrangement of internal cables that can be reeled in so as to pack the shield while in a vacuum.

[Sharpy]

I agree - one inflate/deflate cycle. I believe the right approach would be a completely different model for 'deflated' than for 'packed' - just loose cloth scattered all around. It should need more than a 3-star engineer to repack.

[fireblade274]

All this stuff is really great guys. I truly believe a deflatable addition to the inflatable heat shield, or a second version of the current inflatable heatsheld that has a deflate option would be a great addition to the game in increase the capability of what we can do in KSP. Even if you have criticism of the idea thank you, perhaps we can work out how to make it not OP, such as having only 1 inflate/deflate cycle or a small number of uses before its unsafe. I really hope Squad gets a look at this forum, we have way over 2k views and I posted this months ago! I can totally see this being a special addition for the 1.3 graphics update. +++ we has high poll numbers in favor of the deflatable heat shield

Some main ideas I've gathered from reading this that people have suggested:

-require a high level (4-5) engineer to EVA and re-inflate after deflation

-require electrical charge for re-compression

-only allow 1 or very few inflate/deflate cycles to simulate ware and tare, or add ablator, to make it less OP

OR

add a new version of the current inflatable heat shield that is top tier science level that has a deflate option, possibly with all the above suggested parameters

[OHara]

There is a stock way to deflate the heat shield now, if we configure the capability explicitly in the VAB before launch.

It uses the Axis Groups that appeared with KSP version 1.7.  Probably we don't want to re-use an axis like 'Throttle' or 'Pitch' to also control the heat shield.  So at  Main Menu => Settings => Input => Vessel, we have to assign some keys (like PageUp/PageDown) to 'Custom01'

Then in the VAB, open the Action Group panels, and select 'Custom01' under 'Axis Groups' in the list at the lower left.  Now we can choose heat shield and link its 'Deploy Limit' to the Custom01 axis.

 

[VoidSquid]

This mod maybe?

 

[RealKerbal3x]

There's a patch in here that allows deflation of the inflatable heatshield, scroll down to Gameplay Changes:

 

[VoidSquid]

What a lot of useful little mods, many thanks for the link, @RealKerbal3x! 

 

[mattinoz]

On 5/12/2016 at 7:57 AM, fireblade274 said:

@5thHorseman

It makes sense heat shields are single use in real life, and I agree it can behave like a high speed high alt parachute, but I would argue this does not make them useless after reentry. From my point of view, this is KSP, where I've used heat shield's and the massive amount of ablator they have multiple times because I can in its reduced physics.

Judging by the way the inflatable heat shield is currently implemented into the game, it does not use ablator. It uses a super heat resistant fabric that does not break down on the exterior like its cousins, but its max core temp is less then that can be held with the standard ablating heat shield. It can take on more heat, but must spend less time in it,  Therefore, looking through the lens of the game and how things are implemented, it makes sense that as long as the inflatable heat shield is not destroyed, it is reusable for reentry and not useless. The only reason it is currently useless for reentry is because it can't be deflated!

And actually since it does have favorable conditions going high speed high altitude, it fits the bill for advanced, large interplanetary SSTO's (and Multiple stage ones too) when coming in from Jool or Eloo so they can save DV by aerobreaking at Kerbin rather then having to slow down with your engines or do an Eve gravity assist first which takes a long time and is difficult to do without KAC or Mechjebs porkchop plots. The only reason they cant be used now in this way its because they can't be deflated once you reach low altitude and will turn your plane into a rock, and good luck trying to jettison it while flying into it also. Adding a large heat shield that can be deflated and reused is beneficial to the game IMO.

In the case noted couldn't you do a multipass aerobrake. say 3 passes so you could dump the heatshield for the final pass when the craft is slow enough to deal with reentry heat.

Add a small probe core and engines on the shield boosts it out of atmosphere  set it up to rendezvous with a tug to take it back. Although kOS makes these sorts of things more fun build test fly once get to use them on going. Deflation would still be useful here to make the easy to pack on to a tug for the return journey.

 

[Zarkov2]

They can be deflated if they are launched inflated (sorry if this already was mentioned). Works well during Eve landings, much less risk of random explosions when detaching them).