Deployment analysis of the Olympus Astromast and comparison with test measurements

An analytical procedure is presented to predict deformations and member loads of a coilable, deploy able, continuous-longeron space mast (Astromast) in the transition zone from stowed to deployed configuration. A nonlinear, three-dimensional, finite-element model is set up to represent each truss member and the initial prestress of the deployed mast. By applying an appropriate loading procedure, the mast is forced into its characteristic helical transition zone. In this zone, the truss elements are highly loaded and the coiling of the longerons is initiated for the mast-stowed configuration. The geometry change of the mast from the deployed state into the coiled configuration is computed with the large strain/displacement nonlinear finite-element program LARSTRAN. The analytical results are verified by test measurements on a demonstration mast model. There is good agreement between the analytical results and test measurements.