aerobraking in Duna withvn deadly reentry?

[TheScareCake!]

How should i aerobrake and land later without burning up?

Edited March 7, 2014 by TheScareCake!

[TerLoki]

Uh, I think you mean "aerobrake", "lithobrake" means braking by hitting the ground, your craft still being in one piece is optional. You need to set your periapsis down around... iDunno, 10, maybe 11 kilometers? It all depends on how much drag your craft has and how fast it's coming in.

[TheScareCake!]

Yeah, aerobraking, will edit it. I know how to do it but im afraid that my ship will blowup during reentry. Its too big for shields.

[Taki117]

Duna's atmosphere isn't that thick, as long as you are not screaming in you should be gine, however, Deadly Reentry should come with an inflatable heat shield that you can put on the front (Or back depending) of your craft to protect most of it.

[celem]

When combining aerobraking manouevers with the DRE mod I always like to err on the side of caution. This means I cant give you a height at which it will go BANG...because I dont let it happen.

One of my favorite ways of going about this is to take a less exact transfer trajectory. Lets say you didnt have DRE installed, you would shoot for a Duna periapsis as low as possible without hitting the deck before you even enter Duna space, then burn retro at periaps to help the aerocapture. Now this isnt ideal in DRE since you are hitting the atmosphere at transfer velocities as you realised. So my preferred method is to enter Duna SoI with a periaps considerably higher, certainly well outside the atmosphere, lets say...500km. Once you are into the SoI then you begin a retrograde braking burn (try something like 5-10 mins before periaps), this has the combined effect of both reducing your incoming speed as well as lowering the periaps. So make this burn until your 500km becomes 10 or so. You will notice as you perform this burn that as the periaps drops to your aerobraking level the ejection angle also comes sweeping round due to the decreased speed, you should aerocapture nicely once you do hit the clouds.

This is even more vital for your return leg as Kerbins atmosphere is pretty unforgiving (try Eve sometime...). Transferring from outside Kerbin's SoI directly into any kind of aerobraking with DRE and no shields is asking for fireworks. Again I come in with a really high periaps and burn it down as I enter the area.

These manouevers take a bit more fuel of course.

The inflatable heatshield is certainly awesome, and can protect pretty large ships, but your design doesnt always lend itself to the addition of shields. The good news is that you really dont need the shield to land on Duna, its atmosphere is just too wussy, its only the initial aerobrake that is an issue. By contrast you will need a shield to land back on Kerbin, as even re-entering from 70x70 involves some serious warming unless you go for a full-on powered landing.

Ensure you are pointing perfectly retrograde as you pass through the 40km mark, engines are in all likelihood the toughest part of your ship when it comes to heat tolerance, and if you are aligned properly then DRE will reflect some of the incoming heat. (5% by default I think for being aligned on the retro or prograde markers)

As people above me have pointed out, Duna is the least threatening re-entry, it has a really poor atmosphere until down around 9-10km, and even then its like 35km over Kerbin, you shouldnt have major issues, but its best to learn to handle this now before you start hitting the big boys.

Edited March 7, 2014 by celem

[DonLorenzo]

I've been struggling hard on landing on RSS Duna (Mars), I hit air at about 6km/s and after braking terminal velocity at ground level seems to be ~1km/s. Parachutes wreck everything and the rest crashes half a second later. I'm going to have to incorporate some landing rockets!

[TheScareCake!]

Big thank you, celem, that was really helpful! You earned a cookie. Landed my first interplanetary mission! Will post some pics in my description as it was a huge win for me! I had to put three shields on it.