Structural Architectures for Imperfect Deployable Lunar Towers

Abstract

The load-carrying performance for deployable lunar tower architectures using thin-ply composite booms is parametrically evaluated. These towers support a communications and sensor platform on the lunar surface. The primary design consists of the corrugated rollable tubular boom (COROTUB) acting as the primary tower mast that supports the payload tip mass. Guy wires connecting the boom tip to spreader bars attached at the base serve to correct lateral eccentricities and increase dimensional accuracy. The analysis compares the maximum tip mass that this primary design can carry relative to a reference design that does not contain any guy wires or spreader bars. The results provide insights into whether the additional system mass and complexity associated with the cable-stayed design are worth the increased payload mass that can be supported. By setting the design limiting condition to a maximum allowable deflection, the analysis reveals that the primary design has better performance when the spreader bar length relative to the tower height exceeds a critical value. The analysis is extended to lunar towers with collapsible tubular mast (CTM) booms, and similar trends are observed. Finally, the analytical load displacement behavior of the COROTUB and CTM reference towers is verified with finite element simulations.