Trying to achieve the hard achievement!? Heres the easiest way how. Upgrade to the max airplane for maximum fuel. Drag the plane to the bottom left corner and throw it straight up, hold space to expend your fuel down to 1 bar. Use the remaining bar of fuel for control and let yourself glide through space until you have enough stars. You do not need max skills, I was able to complete the achievement with Max Airplane and Emergency Booster.
 "MoMiner"){kind=icon}
 "Ragdoll Achievement 2"){kind=icon}
 "Swords & Potions 2"){kind=icon}
 "Flight"){kind=icon}