MICHIGAN UNIV ANN ARBOR HIGH ALTITUDE ENGINEERING LAB
The analysis and tests of mylar falling spheres described herein contain results on several theoretical and experimental factors related to the success of the falling sphere program. A careful study of the literature and experimental methods used to obtain sphere drag coefficients has led to recommended tables of sphere drag coefficients. Studies of flight experience and theoretical studies of initial sphere temperatures, isopentane evaporation, radiation effects, convective heat transfer to the atmosphere, heat transfer within the sphere and chemical reaction on the sphere surface provide information which may possibly be used in future work to compute a realistic reliable temperature-time history of falling spheres. The results of the Viper- Dart sphere test program suggest that thermal problems during the rocket ascent or during sphere ejection and inflation may be the principal cause of flight failures of falling spheres. Remedies are suggested.