Interplanetary Aerobraking

[SelectHalfling0]

I am in the midst of designing an interplanetary ship in career, and I was wondering how one goes about aerobraking now (Duna, Eve, and Kerbin).

Do I need heat shields all over the front of the vessel, or can I hit the upper atmosphere at a large angle?

Edited June 25, 2015 by SelectHalfling0

[Green Baron]

So far i've only been to solar orbit in 104. A 2.5m heatshield on the back of my capsule with the whole staple of science experiments was used up half when aerobraking from about 3600m/s, initial perapsis was at about 34km, second round about 20km.

edit: added 3 abouts :-)

[Starhawk]

I did Duna aerocapture yesterday just using the engine of my transfer stage as a heat shield.

The only problem was getting the altitude just right.

Happy landings!

[SelectHalfling0]

Has anyone tried using fairings as large heatshields? They do have good heat resistance.

[Dilli]

The engines are good enough it seems to protect whats above it - fuel tanks, pods, service bays....

However surface mounted items (battery's, antenna, science equipment, ladders, solar panels) seem very vulnerable to re-entry heat. So either put them in a fairing or service bay then you wont have a problem; else use occlusion to keep them save (seems to work but less certain than the other two).

Also ensure drag isn't going to flip your craft - air brakes are excellent at keeping you pointed the right way and also for varying drag (and consequently your orbit). They can start to overheat at high speeds when fully deployed (in 1.0.2, no idea how they will manage now).

Aerobraking into eve orbit in 1.0.2 had to be done fairly high

[Signo]

Engines (imo) are the best heatshield you could find around at the moment. About Eve, if you go to a lower altitude than 45000m at an airspeed of more than 2300 m/s your ship will explode, no matter the skin or core temperature of the parts.

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[nekogod]

You'd rarely if ever want to put heatshields on the front of your craft. You should pretty much always aerobrake in the retrograde position, you're remaining fuel is at the back of the craft so it's likely the heavier end and you'll likely have shed any wings you had as they're normally on early stages meaning that the back of the craft is now the heavy end and the front is the draggy end meaning it's much more aerodynamically stable flying backwards.

Also engines have really high heat tolerances!

[1of6Billion]

I am trying to aerobrake in Jool's atmo. Only 15km in (185km). But my ship explodes on contact with the atmosphere. Really explodes, not even the 4 LV-N's survive.

Is it me or is Jool not suitable anymore for aerobraking? In that case, my mission is doomed. DdoooOOOOoOooOOmed!

[DCWarHound]

I am trying to aerobrake in Jool's atmo. Only 15km in (185km). But my ship explodes on contact with the atmosphere. Really explodes, not even the 4 LV-N's survive.

Is it me or is Jool not suitable anymore for aerobraking? In that case, my mission is doomed. DdoooOOOOoOooOOmed!

I think Jool changed in one of the patches,i had to aerobrake at 195-197km to avoid burning up.

[Old Foxboy]

Some ever forget about the incredible high speeds you hit the JOOL atmosphere with. It's not just 3000 m/s like Kerbin or the inner planets. It's a whopping 8000+ in most cases. Now that's not just more than 2 times the heat, but it means about 8 to 10 times the heat because of the way heat is calculated.

Even though you will hit only the very thin upper layers of the atmosphere, it's still incredibly fast, and since the speed of an air molecule is more important than it's mass, the aerobraking maneuver with such high speeds is very difficult.

To aerocapture at Jool, better try to approach the planet at the lowest possible speed. If you can't use the moons, try to reduce your orbital speed BEFORE you hit the atmosphere, not AFTER you hit it. Every m/s of velocity you can reduce before the aerocapture will greatly improve your survivability.

It's generally much better to use high drag parts and only gently touch the outer atmosphere layer than to enter deeper with a streamlined ship. The drag is not the factor that will rip your ship apart. It's the heat.

[KerikBalm]

seems like a laythe aerobrake maneuver is a much better idea.... you don't have to go so far down the gravity well and reach such high velocities.

I *expect* Eve to be rather difficult to deal with... but I hope Duna is still relatively benign... if for nothing other than the low transfer dV and the low orbital dV.

I'm told drag decreased.... thats going to make it harder to capture though