Deadly Rentry Question

[superkurbol2014]

I'm still farily new to the game. I had decied to try deadly rentry to give the game a little more realisim. I'm having a hard time figureing out how to safely reenter, and blow up. I did it once but have no clue how I did it. I was looking at the map, being picky about where I landed and forgot I put deadly renetry on. When I closed the map I was through and the chutes were opening. All I can say is I pointed to kerbin and burned what I had left of the fuel. The last time I blew up was a shock I thought I had it perfect, I had the perieapps at 2400M and I still blew up. Anyone have any suggestions. Thanks

[Taki117]

you need to come in shallower. A periapsis of about 20km should do it (2.4km is way too shallow) if you are trying to land at a specific spot you want your periapsis to be at least 1/3rd the circumference of Kerbin ahead of where you want to land (And you may still come up short) Also make sure your pod has a head shield. (The Mk1 pod has one installed, all others need one) And that you deploy your parachutes about 10km up (Or after reentry effects have stopped, whichever is lower)

[dudester28]

I pointed to kerbin and burned what I had left of the fuel

If you are pointing straight down to de-orbit, you are both wasting fuel and making re-entry speeds higher. The most effective way to lower your orbit is to point retrograde (opposite of the direction you are travelling).

[MoonMan22]

Point retrograde just as dudster28 said and burn until you bring your periapsis to about 25km this way your trajectory will be less steep. The faster you hit the atmosphere the more heat due to friction, depending on where your coming from, your velocity will vary. For example on a return form the moon you will be traveling faster when hitting the atmosphere than if you were in Low Kerbin Orbit (75km). If you don't dip deep enough into the atmosphere you will simply skip back out int space, if you dip too deeply you will decelerate too rapidly and burn up. Thus it is important to judge based on you velocity.

Here's an image that illustrates the re-entry corridor on earth: http://www.aerospaceweb.org/question/spacecraft/re-entry/corridor.jpg

[Starstrider42]

I've found 30 km works well for everything from LKO to a direct return from Minmus.

Another trick that I found extremely helpful when I was first learning Deadly Reentry was to attach a heat shield to the bottom of my Mk I pod. This doubled the amount of ablative material I had, essentially turning the pod's built-in heat shield into a backup in case the extra heat shield failed.

[maccollo]

If you use far you can angle the pod to generate lift and stay in the upper atmosphere longer.

[maccollo]

Accidental double post.

Edited February 27, 2014 by maccollo

[Champ]

I suggest you install realchute and set your chutes to these magical settings :

Predep diam : 10

Predep alt : 50000

Dép diam : 50

Dép alt : 700

The only time i saw this fail was on an interplanetary reentry at more than 6000m/s

[Starstrider42]

I suggest you install realchute and set your chutes to these magical settings :

Predep diam : 10

Predep alt : 50000

Dép diam : 50

Dép alt : 700

The only time i saw this fail was on an interplanetary reentry at more than 6000m/s

Really? You deploy your parachute at 50 km, and it doesn't burn up?

[Taki117]

Really? You deploy your parachute at 50 km, and it doesn't burn up?

It's a tad like cheating, but it slows you down enough before you get into the thicker atmosphere (About 36km) I personally would rather plan my reentry accordingly and deploy drouges at 10km.

[Javster]

Really? You deploy your parachute at 50 km, and it doesn't burn up?

No, it isn't realistic, even with DRE

[MoonMan22]

It's a tad like cheating, but it slows you down enough before you get into the thicker atmosphere (About 36km) I personally would rather plan my reentry accordingly and deploy drouges at 10km.

Agreed. Deploying a chute at hypersonic speeds seems a tad bit unrealistic.

[Dwight_js]

So far, from LKO and Mun return I've had good results using the KSP Aerobraking calculator:

http://alterbaron.github.io/ksp_aerocalc/

I set my desired apoapsis to be just above Kerbin's atmosphere (around 80km), and I end up with a re-entry that consists of two braking phases. The initial one as I approach the periapsis that I burned for, then the capsule climbs back up into the higher atmosphere trying to reach the 80km apoapsis, but it has to travel through so much air resistance that it never gets there, then falls back down for a second heating cycle that brings it safely down to the surface. This method does use a lot of the ablative material, and stacking a second heat shield is a good idea.

Finding the ideal altitudes for the desired apoapsis is a bit of trial-and-error. I always shoot for a value that is as high as possible that will keep my reentry vehicle in the atmosphere.

The other thing that you can look at are the Deadly Reentry settings for the shock wave multiplier and exponent. Lowering these gives less heating and makes for easier reentry, raising them has the opposite effect. Read the third paragraph in the first post of this thread:

http://forum.kerbalspaceprogram.com/threads/54954-0-23-Deadly-Reentry-Continued-v4-3-1-11-14

Good luck!