Spaceplane Reentry

[Colonel_Camel]

No matter what I try, my spaceplane wings burn up on reentry. I've read so many articles, ect. on re-entry with spaceplanes (many of which contradict one another), but nothing I try works.

I've tried setting the perapsis at all kinds of heights, 53km, 40km, 37km, 24km - even 0km. I've tried coming in at radial out, tried coming in at prograde and all manner of angles in between.

I've tried coming in with my airbrakes on and I've tried coming in with them off.

But no matter what I try, my main wings rapidly overheat and explode.

Can anyone tell me what I'm doing wrong?

[Cato]

Which wings did you use? Is it just the wings that are having problems? The reason I ask is some componets have a lower heat tolerance than others which will cause them to blow up - I know this becuase i tested some desgins and have had wings fall off.

[Purplefairy22]

You could always try "burning off" some speed with retrograde burns (providing you have enough Fuel) To slow down re-entry speed.
I find the AOA (angle of attack) is best kept shallower. Coming in too steep Causes alot of Air resistance which in turns builds up excess heat.

[Colonel_Camel]

Originally posted by RoofCat:

yeah, wrong wings. Right wings never explode. All the rest of the ship would do so before.
I bet you have the wide, airliner wings with 1200K. Don't use those for orbital flights. You need wings with 2000K.

Well, I needed something big for lift and for space to mount all the engines I need...

Sounds like it's back to the 'good ol days' for me of trying to build a giant wing out of other wing plates. :(

[Azunai]

the BigS (spaceshuttle) wings are also fairly large, double as fuel tanks (just like the airliner wings) and have the required heat resistance for reentry.

[GeneralVeers]

Originally posted by Colonel_Camel:

I've tried setting the perapsis at all kinds of heights

What altitude is the APOapsis when you dive into atmosphere......?

The higher your APOapsis, the faster you'll be going when you hit air, therefore more heat.

My current SSTO spaceplane design doesn't use any special design tricks. No heatshields or any of that. It has normal wings (well, it uses FAT-455 tailfins, that way my plane gets the Imperial insignia on its wings!) and always re-enters from a standard orbit at 71k-75k altitude. On contacting atmosphere, she enters with the nose up at a high angle, presenting a large cross-section to the oncoming air and slowing down sooner. The wings get pretty warm, but they never explode.

Are you establishing low Kerbin orbit before re-entry, or are you cannonballing it straight down from the Mun? If you do it the second way, yeah. You're gonna seriously go fireball.

[Astronaut]

try space plane plus. adds heat tiles on the bottom of spaceplane parts.


"The higher your APOapsis, the faster you'll be going when you hit air, therefore more heat."
it actually produces more friction, and that leads to more temperature.

[GeneralVeers]

So I cut out the linguistic middleman. No big deal.

[Colonel_Camel]

Originally posted by GeneralVeers:

Originally posted by Colonel_Camel:

I've tried setting the perapsis at all kinds of heights

What altitude is the APOapsis when you dive into atmosphere......?

The higher your APOapsis, the faster you'll be going when you hit air, therefore more heat.

My current SSTO spaceplane design doesn't use any special design tricks. No heatshields or any of that. It has normal wings (well, it uses FAT-455 tailfins, that way my plane gets the Imperial insignia on its wings!) and always re-enters from a standard orbit at 71k-75k altitude. On contacting atmosphere, she enters with the nose up at a high angle, presenting a large cross-section to the oncoming air and slowing down sooner. The wings get pretty warm, but they never explode.

Are you establishing low Kerbin orbit before re-entry, or are you cannonballing it straight down from the Mun? If you do it the second way, yeah. You're gonna seriously go fireball.

This first test run for my plane was just coming down from about 7Mm - about halfway to the Mun. But my hopes for the framework was that it would eventually be able to return home from a departure from Duna.

Fuel is the major issue if I need to think about reducing Apoapsises to 70-80K. This last mission I did only left me with enough fuel to cut down the apoapsis from 7Mm to just under 1Mm.

Mind you, there were no opportunities to refuel on that mission either. I have a good fuel production opperation in Minmus orbit and I expect to have one at Duna in the near future, too.

[GeneralVeers]

Yup, that 7M apoapsis is gonna result in fireballage when you say hello to Kerbin.

In a pinch, you can aerobrake by lowering your periapsis to 60k or so and doing several orbits, aerobraking on each one, but that takes a while.

[Washell]

Originally posted by camichint:

it actually produces more friction, and that leads to more temperature.

Common misconception. While more friction does indeed lead to more heat, when it comes to reentry, the heat on the heatshield/spacecraft is primarily the result of adiabatic compression.

When you correct people, make sure you're right. ;)

[GeneralVeers]

How about just "if you go faster, more heat"???

Why are people making it so complicated?? This isn't rocket science.

[Astronaut]

more friction produces more heat. make sure you are correct when you correct a right answer just google "more friction more heat' and you don't even have to click anything to prove me right.

[Chibbity]

Originally posted by camichint:

more friction produces more heat. make sure you are correct when you correct a right answer just google "more friction more heat' and you don't even have to click anything to prove me right.

We're talking about a video game here, not real life.

KSP doesn't model friction as it exists in real life in any meaningful sense. GeneralVeers is correct in his statement that as far as the physics engine is concerned "more faster + atmo = more hotter."

Also, you weren't even right if we were talking about real life as Washell pointed out.

Originally posted by Washell:

Originally posted by camichint:

it actually produces more friction, and that leads to more temperature.

Common misconception. While more friction does indeed lead to more heat, when it comes to reentry, the heat on the heatshield/spacecraft is primarily the result of adiabatic compression.

When you correct people, make sure you're right. ;)

[Astronaut]

i bet you didn't even google it. if you rub your arm, you can feel heat building up, because of friction. now, since you clearly don't understand what i mean, go loom up "friction" and "heat" in a dictionary, then google more friction more heat. I will not believe you until you do so.

[Purplefairy22]

Originally posted by camichint:

go loom Look up "heat" in a dictionary,

Okay i will cause i know for a fact Heat means anything above absolute 0.
Ergo, vis-a-vis Concordantly, -10 Celsius is still heat.

heat
n.
1. Physics
a. A form of energy associated with the kinetic energy of atoms or molecules and capable of being transmitted through solid and fluid media by conduction, through fluid media by convection, and through empty space by radiation.
b. The transfer of energy from one body to another as a result of a difference in temperature or a change in phase.

Hmmmmm, maybe? But lets look up latent heat.

latent heat - heat absorbed or radiated during a change of phase at a constant temperature and pressure
heat of transformation
heat, heat energy - a form of energy that is transferred by a difference in temperature
heat of condensation - heat liberated by a unit mass of gas at its boiling point as it condenses into a liquid; "the heat of condensation is equal to the heat of vaporization"
heat of fusion - heat absorbed by a unit mass of a solid at its melting point in order to convert the solid into a liquid at the same temperature; "the heat of fusion is equal to the heat of solidification"
heat of solidification - heat liberated by a unit mass of liquid at its freezing point when it solidifies
heat of sublimation - heat absorbed by a unit mass of material when it changes from a solid to a gaseous state
heat of vaporisation, heat of vaporization - heat absorbed by a unit mass of a material at its boiling point in order to convert the material into a gas at the same temperature

So what is this Absolute zero i was on about then?

Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance.
Absolute zero is the point at which the fundamental particles of nature have minimal vibrational motion, retaining only quantum mechanical, zero-point energy-induced particle motion.
By international agreement, absolute zero is defined as precisely; 0 K on the Kelvin scale, which is a thermodynamic (absolute) temperature scale; and –273.15 degrees Celsius on the Celsius scale.
Absolute zero is also precisely equivalent to; 0 degrees R on the Rankine scale (also a thermodynamic temperature scale); and –459.67 degrees F on the Fahrenheit scale.

So, I was Right, Nothing Can be Colder than -273.15c meaning -273c is actually hot! Ergo Heat!

The important thing is today, we all learnt something.