Air Breaks for Reentry

[Zosma Procyon]

Increase the temperature tolerance of the A.I.R.B.R.E.A.K.S. to at least 3300, so they can be used during reentry without them exploding, or having to cheat. They can cut the deceleration time needed considerably. And they look cool.

[Superfluous J]

So you want the game to implement your cheat (you word) so you don't feel so bad for doing it?

[AlamoVampire]

@Zosma Procyon Take a gander, you might find this interesting. No cheat was used if you were wondering.

all 8 of those air brakes survived reentry.

Edited April 14, 2016 by AlamoVampire

[pandaman]

Reentry is difficult and dangerous IRL, and KSP mimics RL to a reasonable degree, if the game gave us a 'magic' solution like that many players could get the impression that reentry is not actuall very risky if you just slap airbrakes on something.  Apart from that, the challenge and sense of achievement would be greatly reduced, and therefore some of the fun would also be lost IMO.

[Pthigrivi]

Yeah I like the tolerance where it is but a set of these could be cool: 

[John FX]

I believe even the falcon needs to do a retro burn to slow down so re-entry isn`t too hot.

 

[Malich]

Set a slightly higher re-entry, cycle the brakes up and down until you've slowed to where you can use them safely. I've used them for EVE and Kerbin entries successfully doing this.

[Armisael]

I agree with OP in that airbrakes should have a higher critical temperature - 1200K is really low. 3300K is probably too much though.

I do think that it'd be neat to see a new airbrake or streamer or something that had ablator on it. I might end up using the inflatable heatshield as a skirt at the back of the rocket for aerodynamic stability during high-speed reentries.

[Pthigrivi]

2 hours ago, John FX said:

I believe even the falcon needs to do a retro burn to slow down so re-entry isn`t too hot.

 

Oh it definitely does, Im just saying a purpose designed re-entry fin would be cool. You can already abuse them as is though. This is a refueling tanker aerobraking as it comes in from minmus:

Edited April 14, 2016 by Pthigrivi

[MaxL_1023]

Airbrakes let you slow down higher in the atmosphere, where heating is not as large of an issue. 

If your craft launches inside a fairing, try just using an oversize heatshield with most of the ablator removed. A 2.5m heatshield has 4 times the area of a 1.25m, meaning that you can put a 1.25m pod behind it and slow down much higher up  and get an easier re-entry overall. 

[AlamoVampire]

Falcon 9 does a boost back to slow stage 1 down for re entry.

 

now, 1200K is only 1700.33 F which is low, but kerbin is smaller than earth so could be reasonable? But 3300K is 5480.33F which is better suited for earth, but way high for ksp. Something in the middle would be nice.

side note, those things on the falcon 9 pic are control surfaces not brakes.

Edited April 14, 2016 by AlamoVampire

[Pthigrivi]

3 hours ago, AlamoVampire said:

side note, those things on the falcon 9 pic are control surfaces not brakes.

What "re-entry fin" isn't the right term? haha. My impression was they were there to guide the top of the rocket to keep it stable on retrograde, drag must be a factor there right? 

[Alshain]

It's all about the angle of re-entry.  If you spend forever in the heat because you came in too shallow, you are going to burn up.  If you pass into the thick of the atmosphere too quickly because you came in too steep, you are going to burn up.  Gotta find that sweet spot.  Changing the parts to be ridiculously heat tolerant is not the answer here.

Edited April 14, 2016 by Alshain

[AlamoVampire]

58 minutes ago, Pthigrivi said:

What "re-entry fin" isn't the right term? haha. My impression was they were there to guide the top of the rocket to keep it stable on retrograde, drag must be a factor there right? 

Steering is their game for sure! When i made the post you quoted it seemed to me people thought or someone did that they were for slowing. Admitedly i was in a hospitality and hotel management class in college at the time lol.

[Snark]

I'd say that the whole point of airbrakes having such a low temperature tolerance is that they're not supposed to be used for reentry.  In other words, the low heat tolerance is a feature, not a defect.

Remember when airbrakes were first added to the game?  They had a much higher tolerance-- I think it was around 2400, about the same as most parts in the game.  They were incredibly effective.  Too effective.  Made reentry too easy.

It's pretty obvious that Squad deliberately nerfed them with the explicit intent to make them impractical for orbital reentry.  That's what heat shields are for.  If airbrakes were a good idea for orbital reentry, that's what everyone would be doing IRL.

If you personally would like to use airbrakes for entry, go right ahead!  It's easy to mod it to whatever temperature tolerance you like, with just a snippet of ModuleManager config.  But I'd say the chance of Squad actually raising the temperature on them at this point would be practically zero.

(And I gotta say that I'm pretty happy about that.) 

[MaxL_1023]

If you think re-entry is hard now, try it in RSS/RO. Even from LEO your pod can randomly explode (or kill crew due to G-forces) due to a 10m/s delta-v application error.

In stock, I have had craft survive coming in backwards (nose forward) due to a design error, and have a parachute be enough to withstand LKO entry on 100% heating. Unless you are doing some hyperbolic or straight-down trajectory you should be fine using a normal heatshield. 

[Foxster]

In the latest 1.1 build, airbrakes went from a max temp of 1200°K to 2000°K. 

[cantab]

On 14/04/2016 at 2:51 PM, Pthigrivi said:

Yeah I like the tolerance where it is but a set of these could be cool:

They're not airbrakes, they're grid fins. And they're not used during re-entry, the Falcon 9 first stage doesn't get anywhere near orbit to begin with.

[Pthigrivi]

Yeah I know we talked about that just above  Using a thin peice of metal isn't a great idea for re-entry braking period, but I have found them useful both at high altitude and and low altitude to assert stability. All I was suggesting is a part that's purpose made for this would be cool. 

Edited April 16, 2016 by Pthigrivi