Torsional Buckling of the Hubble Space Telescope Solar Arrays

Abstract

The buckling behavior of a flexible rolled-up solar array used on the Hubble Space Telescope (HST) is investigated analytically and experimentally. Analytically, the solar array is modeled assuming the booms are linear, elastic beams of open cross-section, and the solar blanket is represented as an inextensible membrane. The analyses determine critical buckling loads for flexure and torsion. The behavior of the solar array is also investigated by experiments conducted using a model solar array with (1) closed cross-section booms, and (2) tubular booms like those used on the HST. The analyses and experiments show that the Hubble's solar arrays were deployed with a preload that caused them to buckle in torsion. Based on the study, an hypothesis is suggested for the failure of the solar array's booms that was discovered by the astronauts in 1993.