One particular space plane keeps overheating

[Valkyria90]

I am no stranger to space planes, and I've built probably a hundred successful planes in any way shape or form. Now I'm building a space plane that is gonna bring 10 kerbonauts from the surface of Laythe to low orbit. After much testing I finally got a design that is capable of reaching orbit around Kerbin, which is my testing ground. Out of the 5-6 different crafts I made this week, this one has a weird problem, both during ascent and during re-entry. The standard MK2 cockpit that is the most front part of my craft keeps overheating so easily. It spikes up to over 2000 kelvin quickly, and it is the ONLY part of my vessel that shows any sign of overheating. From the orbit I'm de-orbiting from, 35 000m altitude is not something excessive, and all of my crafts ever has had no problems with this altitude. However this crafts cockpit explodes from overheating at any altitude, even when I tried 42 000 in an attempt to glide across the whole planet, but even this just keeps pushing my temperature slowly upwards to breaking point. I tried experimenting with some radiator panels attached to it, but it has no effect. Does anyone have any ideas what might be causing this crazy overheating at this particular craft?

Screenshots

http://steamcommunity.com/sharedfiles/filedetails/?id=601049979

http://steamcommunity.com/sharedfiles/filedetails/?id=601050027

[Melfice]

Very odd.
Obviously it's always going to be dipping in nose first, but maybe if you raise the nose up to... maybe 15 to 20 degrees above the horizon? It might relieve some of the heat-stress.
Also, are there any parts right behind the cockpit that would gather or even produce (extreme) heat? I'm thinking the PB-NUK primarily, but maybe you have some other bits there?
Maybe part-clipping is affecting the heat generation as well?

[Valkyria90]

No clipping and no RTGs on this one. I noticed that by aiming the nose 15-20 degrees upwards the temperature would increase slower, but still overheat, and its impossible to keep it stable through the atmo. And the heating problem is still there, even though it's slightly less.

Here you can see the craft how it looks like in the SPH

http://steamcommunity.com/sharedfiles/filedetails/?id=601168470

If anyone is interested in trying the craft for yourselfes, you can check out the craft file in the Dropbox link. Only mod required are Adjustable Landing gear:

https://www.dropbox.com/s/zmxt6dsur3voe80/Laythe%204.craft?dl=0

[Snark]

Just out of curiosity, if you turn on the thermal debug menus as it's overheating, what does it say?  Anything interesting?

[fourfa]

The pointy Mk2 cockpit has an overheating problem. Don't know that it's a bug per se, or just that its mandatory position at the very front ensures that it gets more heat than it can reliably handle. I've seen the same problem myself, and in twitch streams where the streamer got very 'salty' about the issue. 

Try swapping for the inline Mk2 cockpit and a shorty tapered fuel tank in front. Should solve the problem, if that design still works with your plan

IIRC the Mk3 cockpit has a higher heat rating, and I NEVER have a problem with that one. You could just buff the Mk2 cockpit cfg with the Mk3's heat tolerance

[Guest]

For now, I'd try entering higher up.  Maybe around 50 KM.  You'll need to aerobrake.

[Val]

12 hours ago, Valkyria90 said:

Here you can see the craft how it looks like in the SPH

http://steamcommunity.com/sharedfiles/filedetails/?id=601168470

Just a theory as I'm not at my KSP computer:

I notice that you have a lot linear RCS ports on the cockpit. As physicsfree parts they transfer some of their properties to their parent part.

Could you try moving the RCS ports to a part further back to see if that lessens the heating of the cockpit?

[David104]

Heyho!

I was playing around a lot with ssto´s yesterday and had a simular design of my spaceplane and the same problem. How I got it to work was deorbit with an 20-30 degree angle over the horizon and putting my Periapsis at almost 0m. It sounds strange, as I would think you just gonna explode as you entering the thicker atmosphere to fast, but that actually solved the problem..

Even did the same thing with an Mk1 cockpit which has a lower tolerance for heat (I think up to 1500K) and it worked as well..

[Valkyria90]

5 hours ago, Val said:

Just a theory as I'm not at my KSP computer:

I notice that you have a lot linear RCS ports on the cockpit. As physicsfree parts they transfer some of their properties to their parent part.

Could you try moving the RCS ports to a part further back to see if that lessens the heating of the cockpit?

I'll try this when I come from work today. Sound like a good approach. If I wanted to keep the RCS ports where they are, could I change some values on the part to make them not transfer their properties to the part they are attached to? I need RCS on my craft, but the 4 way thruster have too low heat tolerance for a space plane, and the Vernor engine needs oxidiser, which my craft lacks.

[ForScience6686]

I would shoot for at least 30 above prograde as that is generally the best angle for lift from the wings.  In the upper atmosphere I'm generally 90 from prograde and adjust down as required to make it to the runway.  at 20 you're not putting much resistance to the airflow.  

Conversely, I have also tried the steeper descent and it has been successful, but I was deflecting as much as possible the entire way down, and with a light craft.  Remember the heavier the craft the harder it is to slow down.

 

[Valkyria90]

On 16/01/2016 at 0:03 PM, Val said:

Just a theory as I'm not at my KSP computer:

I notice that you have a lot linear RCS ports on the cockpit. As physicsfree parts they transfer some of their properties to their parent part.

Could you try moving the RCS ports to a part further back to see if that lessens the heating of the cockpit?

Tried this tonight, no difference

 

On 16/01/2016 at 2:47 AM, Snark said:

Just out of curiosity, if you turn on the thermal debug menus as it's overheating, what does it say?  Anything interesting?

Nah, nothing interesting. It just overheats and explodes. 

I don't wanna go into the part file and increase the tolerance to over 9000, but I wish the game could stop being so buggy at times that I'm tempted to turn to "cheats"

[SGamer11]

I have never had this problem before, try using the MK.2 inline with the long mk2- mk1 converter with the NCS adapter, then use the smallest heat sheild.

[AeroGav]

Always use inline cockpits.    Even the mk3  , with it's heroic heat rating, can get into trouble because it is more or less the front part of the ship (yes, it has a frontal 1.25m attach node meant for a radome, but that only covers a small % of its total area)

You will have fewer overheating troubles with mk1 inline parts than with a mk3 cockpit.    In recent versions of KSP, parts near the front of a stack are much more strongly heated than those at the back.

 

[Spricigo]

 

New poster notice: The OP either solved his problem or gave up still in 2016