Allow Re-entry heat to be stronger than 120%

[Commander Jebidiah]

Hi, Today I propose that the max Re-Entry heat gets increased from 120% to 200%.

Currently I'm playing sandbox with max heat at 120% and you can land a Mk1-2 Command pod on kerbin without a heatshield.

My re-entry pod is only a Mk1-2 Pod and a Mk 16 XL chute and this all makes it back from a 120km orbit.

This makes the heatshields nearly useless other than aerobreaking at Kerbin, Eve or Jool.

This also means a Kerbin Orbital Pod that carries a heatshield is only carrrying dead weight.

Then you also have the fact that the Fairing around a 2.5m heatshield sticks out and is incredibly ugly. (See pic below.)

I think for version 1.1 we should have; More Deadly Re-Entry and a nicer heatshield fairing.

Thanks Squad for a great game.

Edited May 1, 2015 by Commander Jebidiah

[Ryds]

I think you forgot about DRE. There'll be a new version of it soon which will cover all of the above. Personally I see stock as a simple training game to get people used to the mechanics of the game. There's no sense of achievement in doing anything in stock as it's too easy. Get DRE and nufar when they're released.

[Commander Jebidiah]

I used to always use DRE but i wanted to use 1.0 stock with KER but i guess ill be using DRE aswell.

[tater]

It's hilarious that people were afraid of reentry, and even posted that it should not be added. YOu have to work hard to botch reentry (or use the heat shields as stock in 1.0, hands off

[Giggleplex777]

It's hilarious that people were afraid of reentry, and even posted that it should not be added. YOu have to work hard to botch reentry (or use the heat shields as stock in 1.0, hands off

Have you flown a spaceplane in 1.0? 80% of them don't survive reentry.

[tater]

Have you flown a spaceplane in 1.0? 80% of them don't survive reentry.

I don't do spaceplanes, never even unlock the parts.

[Giggleplex777]

I don't do spaceplanes, never even unlock the parts.

Then you won't understand why people are afraid of the reentry heating.

[Feradose]

Reentry heating is terrifying! The heat just keeps rising even in space, I cant even imagine why you would want deadlier reentries. (The pod instability issue moves the reentries from horror to extra warm nightmare)

[GusTurbo]

From what I've read, there are some wonky things going on with the heat system. Craft should require a heatshield to survive reentry. I feel like there must be a way to accomplish this while still making spaceplanes feasible.

[Commander Jebidiah]

May i remind everyone here that im playing with reentry heating at 120% and reentering is no problem, you know you can fix the heatshield bug.

[MacroNova]

Are you abusing the parachute bug to slow yourself down?

[Kerbart]

Currently I'm playing sandbox with max heat at 120% and you can land a Mk1-2 Command pod on kerbin without a heatshield.

My re-entry pod is only a Mk1-2 Pod and a Mk 16 XL chute and this all makes it back from a 120km orbit.

Not mentioning specifics forces the reader to make assumptions.

I'm assuming you're deploying the parachutes at 55km height and that's where the real problem is. Parachutes are way overpowered and indestructable once deployed, so they can slow your descend down before prolonged exposure to heat really becomes an issue. The issue is mainly with the parachutes in that case.

Now, when you're doing a reentry without deploying chutes (at least not until the heat is gone) and you're coming in too steep you'll simply penetrate the surface at 1.5km/s. I agree that in those cases we should simply be burning up.

It definitely is fun that reentry is now a nailbiting experience, as your capsule is roaring through the sky, leaving a fiery trail. And the COM bug adds some additional realism as you're really not *sure* that you're going to survive it!

[Commander Jebidiah]

Nope i deploy the chutes while subsonic usually 6km.

[Guest]

I must say that I, too, feel that reentry is underpowered for space rocket-things but overpowered for spaceplanes. I did a reentr from 150km with 100% reentry heat without any heatshield, coming in very steep, and I survived without loosing a single part. Parachutes deployed at 1000m. However as far as I read on the forums it seems near impossible to re-enter with a SSTO (haven´t tried myself, I´m rubbish at spaceplanes.)

I suggest that maybe lift and the steepness of your orbit are more important.(Rockets -> No lift, coming steep -> High heat / Planes -> High lift, low descent -> Low heat).

[Kerbart]

Nope i deploy the chutes while subsonic usually 6km.

I'll have to try that. I usually burn up when I'm on a trajectory that gets me subsonic at higher altitudes and expose anything else but the heatshield. Perhaps no heatshield works better?

[panzer1b]

I don't do spaceplanes, never even unlock the parts.

Yeah, tat says it all, if you ONLY use pod+heatshield+chute, then ofc setting reentry heat to 200% isnt gonna be enough for you. One parachutes right now FUNCTION at interplanetary speeds (any real life chute would be instantly vaporized at 4km/s), so you get massive airbrake functionality for a somewhat light object that doesnt have much inertia. Until chutes are fixed you dont even need heatshields let alone anything else.

As for spaceplanes, i feel its perfect at 100%, perhaps a teeny bit too much, but its all a matter of limiting the way you aerobrake. Ive managed to get to laythe (from a encounter trajectory) using under 50 fuel, JUST by aerobraking over jool a few passes until my AP matched laythe's, and waiting for a capture, then it was a matter of a minor course correction to get the right PE for a aerobrake into laythe orbit.

Its perfectly balanced right now, it allows you to do stuff like aerobraking, aerocaptures, and reentry without shields at very shallow trajectories from relatively low orbits, but it stops those unrealistic 8km/s straight at planet's center instantaneous stop braking attempts (which are both unrealistic, unplausible, and make no logical sense from any perspective). It honestly does exactly what i expected it to do, and makes the gameplay much more logical. That said, i wouldnt mind a minor (maybee 5-10% at most) decrease to reentry heat, would make it a tad easier to reenter with some SSTOs, but it wouldnt make anything too easy.

[regex]

I must say that I, too, feel that reentry is underpowered for space rocket-things but overpowered for spaceplanes.

As I understand it that's because of the shape of objects.

H. Julian Allen and A. J. Eggers, Jr. of the National Advisory Committee for Aeronautics (NACA) made the counterintuitive discovery in 1951[6] that a blunt shape (high drag) made the most effective heat shield. From simple engineering principles, Allen and Eggers showed that the heat load experienced by an entry vehicle was inversely proportional to the drag coefficient, i.e. the greater the drag, the less the heat load. If the reentry vehicle is made blunt, air cannot "get out of the way" quickly enough, and acts as an air cushion to push the shock wave and heated shock layer forward (away from the vehicle). Since most of the hot gases are no longer in direct contact with the vehicle, the heat energy would stay in the shocked gas and simply move around the vehicle to later dissipate into the atmosphere.

So basically, when you reenter your spaceplane, you need to have the nose pointing up at a very high angle. The Space Shuttle held a 40-degree nose-up attitude while performing S-turns to help reduce speed. This helped protect it from the majority of reentry heating effects.

The wing parts in KSP shed heat very quickly and also have a high thermal mass for their mass (four times as much), but because the wings are so light they really don't have much thermal mass to multiply in the first place. Therefore, you need to take care during reentry. E; If you come in nose-first, or even at a shallow angle with your spaceplane, more air will strike the surface of the plane, heating it quicker.

Edited April 30, 2015 by regex

[jnz]

I have yet to destroy a SSTO from LKO with either steep reentry or shallow. Just keep the nose pointed up, you don't even see reentry heat effects. However a MK1 Pod will die if you enter at a shallow angle, but is fine if you come in very steep!

[Brotoro]

Yes, I was surprised. When I kept the nose of my spaceplane up at 30 degrees, it came through reentry without even showing any flames...which seemed very odd.

[Fel]

You could just edit persistent.sfs, rentryheat is a float/double and doesn't seem capped at 1.2, just limited by the slider.

[Commander Jebidiah]

Its amazing that everyone thinks i wanr reentry to be harder. What i actually want is the ability to increase it above 120%

[DundraL]

Its probably the title.

[Commander Jebidiah]

Ill edit that