A Deployable Truss Beam for Long or Lightly Loaded Space Applications

This paper describes development of a deployable graphite truss beam that enables construction of very large space structures such as kilometer-sized solar sails or large sparse-aperture interferometers. The development’s objective was to demonstrate that the beam could be fabricated, stowed and deployed as described in the original concept, and this was accomplished. Innovations include roll-up stowage that allows use of highest modulus graphite and unrestricted beam diameter, precise deployment by a powered mechanism and snap-together joints, the ability of the deployment mechanism to walk along the beam after deployment to integrate the beam into a larger system, and a means to increase beam hierarchy. The rigid nodes provide a significant increase in beam strength, compared with pin-jointed beams, for applications with very great L/D ratios