1. Anon. "The Planet Saturn (1970)," Report SP-8091. June 1972, X X A .
2. Anon. "The Planets Uranus, Neptllne, and Pluto (1971) ,"Report SP-8103, Vovember 1'372, NASA.
3. Outer planet probe entry thermal protection. II - Heat shielding requirements
4. Allen, H. J . and Egg,rs, A. J. "?$ Study of the Notion and Aercdynamic ileating of Ballistic Nissiles Entering the cart> s Atmosphere a t Nigh Supcrsonic Speed," Report 1383, 1958, NACA.