Abstract
The focus of this research is the determination of a structural design for the lunar lander spacecraft currently being developed by the Texas Space Grant Consortium to transport a regolith oxygen production experiment to the surface of the moon. An analysis of the mission requirements and the oxygen plant operation constraints resulted in a vehicle configuration featuring a tensile thrust structure, load-carrying propellant tanks, and a retractable ramp for payload deployment. The structural configuration selected for the lander was a triangular truss structure constructed of graphite-epoxy struts and titanium ball joints. This configuration was selected since it offered the greatest stiffness per unit weight, resulting in an efficient and lightweight structure. The required diameter and thickness of each strut in the truss was determined with two finite element models subjected to static and dynamic mission loads. Static loads arising from launch accelerations, main engine burns, and lunar landing were the primary load cases that sized the structure. Modal and random vibration analyses were also performed to verify that the structure met all dynamic requirements. Numerous iteration cycles were performed with these loads before a converged solution was obtained. A parametric cost analysis of this design showed that while the graphite-epoxy structure is approximately $450,000 more expensive than an aluminum structure, it is also 41% lighter. This weight savings made it possible to meet the weight requirements of the mission and increase the chances for mission success.
Baccus, Ronald Kregg (1996). Structural design of a lunar lander spacecraft for the Texas space grant regolith oxygen production experiment. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1996 -THESIS -B33.