A Booster Plane Study :: Gliding Back

I came back to finish this mission.

What I did after taking off was to burn the fuel in a straight line until the fuel reached about 20% left, then did a 90o up climb until the fuel is over.

Well... I reached 60K high, losing all authority over the attitude on the way up and from that point all I could do is to tumble up and then down until the craft reached around 20K high, when then recover authority over the attitude and glided back to KSC, managing airspeed versus altitude.