1. Buckling of Circular Conical Shells under Axisymmetrical External Pressure
2. nuclear rockets and dual electric-nuclear rockets for Mars trips. It was found that the dual electric-nuclear system reduced the gross weight of the vehicle in initial earth orbit to 0.4-0.6 of the gross weight of the all-nuclear vehicle. Comparison was not made, however, with an all-electric vehicle.
3. It is therefore possible to conclude that the dual electricnuclear rocket system would reduce the gross weight of a comparable all-electric vehicle to approximately the same degree (M).4-0.6) that it would reduce the gross weight of an all-nuclear vehicle.