Having problem with Glide-based atmospheric re-entry

[Jestersage]

I have been playing with the Mk-II bodies using a wingless lifting body design, and so far, I still have occasional overheating, exploding nuclear battery (actually hide it in the Mk-II docking part, and always coming in too fast in a ballistic manner (prograde angle always being  -30~-50 ) ... long story short, I am unable to produce some kind of glide landing.

My glide entry are usually done as follow:
-Drop the PA altitude to around 43000m
-Once it start heating, angle up to +20~+30 degrees
-Once the atmosphere burn is complete, point the nose down close to prograde, as long as it's <-20 degree. Otheriwse I tried to bring it up to -20

Not sure what i did wrong. I decided to actually put in a pair of structural wing A (which actually makes it resembles dyna-soar), but have not test it yet. Anyone got some pointers before I test it out??

Edited June 23, 2016 by Jestersage

[Tiberius K]

It just sounds like you don't have enough lift:weight to pull-out of the dive.  Also could mean your centre of lift is too far behind your CoM so your lifting surfaces are not very effective (especially at high speed).

Have you tried taking off from the runway without the fuel and payload (maybe a throwaway solid booster to get moving) to test how it should glide upon re-entry?

[Jestersage]

Without fuel, lift orb is within CoM; with fuel, lift is ahead of the CoM. Not sure how to see the amount of lift.

Edited June 23, 2016 by Jestersage

[Vanamonde]

I'm not clear about what you're describing, but I think your problem might be the RTG's sensitivity to heat rather than the way you're flying your plane. Have you tried tucking it inside a service bay? Or what I do is mount it on the upper surface of the craft, where it's most shielded from the heat. 

[Gojira1000]

Your CoL should be behind your CoM for stability - and the Mk2 body usually needs a couple of strakes to have enough lift, at least for my piloting.

[Jarin]

Screenshots would help. Aerodynamics questions are almost always about the details.