320. An Approach to the Design of a Practical Minimum Weight, High L/D, Manned, Lunar Reentry Vehicle

Paper

Abstract

This paper was presented at the Twenty-first Annual National Conference of the Society of Aeronautical Weight Engineers at Seattle, Washington, May 14-17, 1962. What shape and size must a vehicle be to accomplish a manned, lunar exploratory mission? The formulation and development of the design considerations to answer this question are presented in this paper.
The basic configuration follows the standard design approaches for lightweight, lifting vehicle. On the basis of past studies, it employs high wing loading and ablation-radiation heat management. It is an integral vehicle including both the living quarters and flight duty stations. The emphasis, however, is on the crew requirements which really dictate the vehicle size. From data compiled on man’s behavior patterns in a closed environment, his psycho-physiological free volume requirement is determined. When equipment volumes are added to this, the preliminary total volume requirement in established. This volume is iterated several times before being firmly set. In this case. Equipment redundancy is employed on a selective basis and is complemented by the use of the crew in the loop so that volume and weight can be minimized without sacrifices in reliability. Indications from Colonel Glenn’s Mercury flight uphold the soundness of this approach. His ability to take over control manually permitted three orbits where only one would have been possible in a purely automatic system.
Based on the foregoing considerations, the internal arrangement of the vehicle is laid out so that the resulting envelope presents the least surface area. The final configuration, a high L/D winged ellipsoid, is believed to be a practical size vehicle for the lunar mission. The structural design is presented in summary form.