Was chuck norris born on Eve?

[Cannon]

Seriously guys, i lowered my periapsis to 90k while my apoapsis was at 100k and i let the atmosphere slow me down but no matter how hard i try, the ship always starts spinning like hell at 70k (approximately) and the heat shield and the top of the ship switch places eventually and of course, the capsule on the top doesn't even last one second, it overheats and explodes in an instant. Why is it happening, how to prevent it?
Here's the ship I'm using:

[dafidge9898]

5 hours ago, Cannon said:

 

Seriously guys, i lowered my periapsis to 90k while my apoapsis was at 100k and i let the atmosphere slow me down but no matter how hard i try, the ship always starts spinning like hell at 70k (approximately) and the heat shield and the top of the ship switch places eventually and of course, the capsule on the top doesn't even last one second, it overheats and explodes in an instant. Why is it happening, how to prevent it?

 

Use RCS to stabilize your ship so it doesn't flip forward. It helps to have the CoM below the CoL when reentering. It makes it more stable. However it looks like that's the case with your craft, having the engines and the heat shield, although it (heatshield) may get noticeably lighter as it burns through ablative material. 

And I'm sorry, but I don't think that will make into orbit from Eve.

[Rath]

Those fins drive the COL forwards.  You need to have larger ones at the top.  put them on decouplers so it can launch

[James Kerman]

Chuck Norris gave birth to Eve.

[fourfa]

The 10M shield is very hard to use - it has so much drag that nearly every ship will flip around so that the heatshield is at the rear.  Stopping that takes some engineering - colossal drag fins in the back, airbrakes, lots of powerful Vernor thrusters, as much SAS as you can afford, high-speed spin stabilization, etc.  Or try something really simple and have one on the bottom and another on top, and take care not to get sideways.

For a simple test, try putting it on the nose, entering atmo prograde, and see if your fins at the back can help keep it straight.  It's possible that when you slow enough, it will flip retrograde and get ready for landing.

Also the 10M heatshield does not have ablative material at all; it doesn't get lighter.

Seconded that I don't see a successful Eve ascent rocket there yet.  It's a pretty long build process (many find Eve ascent the hardest job in stock KSP), but tons of fun if you have the patience to work the problem.  Don't be afraid to consult other people's successful designs before losing interest.

[Plusck]

The easiest way to survive entry into Eve's atmosphere - for a vessel big enough to make it back out again - is to use engines to slow down on the way in. Obviously this means a significant increase in the size of the craft you need to get into low Eve orbit to start with...

It took me a huge number of attempts to get down without using engines. I too was constantly blowing up at the 67-70km mark.

One useful tip: for aero control on the ascent from Eve, you really only need minimal control surfaces. Those fins you have are certainly overkill. Generally speaking, 4x smallest aileron thingies will probably do the job. Cutting down on the fins will reduce some of the main problems on re-entry (like, for example, the fact that the controls are reversed and will tend to amplify the slightest deviation from retrograde), and make it easier to put draggy throwaway surfaces near the top of the rocket.

[Magzimum]

I had exactly the same problem. So I asked a similar question in this thread. The most recommendations I got were variations to the theme of adding more drag at the top: fins, wings, airbrakes, etc.

The option to use engines on the descent is not so appealing to me: I think that I need enough dV as it is, and I don't particularly look forward to adding another 2500 m/s worth of dV. That would just mean more refueling, or an even larger rocket.

On a sidenote, I did add a lot of airbrakes at the top in a later version, and while the descent into Eve's atmosphere became smoother and the lander slowed down a whopping 1000 m/s to around 2200 m/s, it then still flipped. So, I am now building version 6.0 of my Eve lander... Jeb still has not made the return trip to Eve successfully.

 

[Edit] You should not ask yourself the question "Why does it flip?". Ask yourself instead the question "If it turns 10-20 degrees, what happens next?". If the answer to the last question is: "It will correct itself and turn back retrograde", then you got a good design. Because in Eve's atmosphere, it will start to tumble a bit.

Edited August 19, 2016 by Magzimum

[N_Danger]

For me air brakes mounted high, SAS and a low CM was the key. But it was still a little unstable, you just have to keep experimenting.

I went through 5-6 designs before getting one that worked.

Edited August 19, 2016 by N_Danger

[Signo]

50 minutes ago, Magzimum said:

[Edit] You should not ask yourself the question "Why does it flip?". Ask yourself instead the question "If it turns 10-20 degrees, what happens next?". If the answer to the last question is: "It will correct itself and turn back retrograde", then you got a good design. Because in Eve's atmosphere, it will start to tumble a bit.

I loved this ^ - feels like JFK: do not ask what your rocket can do for you but ask yourself what you can do for your rocket!

 

[Cannon]

Thanks for all the responses, I'll try again and let you know how it goes