Large, extremely lightweight structures, sometimes called gossamer structures, are expected to be critical to future space missions. CSA Engineering began its involvement in gossamer spacecraft in 1999. In addition to internally funded research developing means of damping gossamer structures, CSA recently completed a Phase 1 SBIR entitled "Structural Dynamic Tailoring for Membrane and Inflatable Structures" for NASA JPL and we recently received news of our selection for Phase 2 negotiation. Contract start is anticipated in January to April 2001.  In Phase 1, the feasibility of a wide variety of technologies and approaches critical to predicting and modifying the structural dynamic behavior of gossamer structures was demonstrated. Accomplishments included demonstrating the ability to measure the complex stiffness and loss of typical gossamer structure materials, modeling stretched membranes and more complex built-up structures, measuring the dynamic response of stretched membranes and successfully enhancing their inherent damping with add on treatments. This work will be continued and expanded upon in Phase 2.

CSA is also examining attitude control for tethered formation flying in the Air Force Research Laboratory's PowerSail project. In this effort, CSA models the orbital dynamic behavior of a 20 m square rigger membrane structure with thin film solar cells connected by a tether to the host satellite. In addition to modeling the typical on-orbit disturbances, thruster and sensor locations and the effects of flexible body dynamics are taken into account.

CSA's existing product line of gravity offload devices can be adapted to support vacuum chamber testing of large but lightweight inflated structures. These offload systems use pneumatic and pneumatic/electromagnetic devices that offload weight using frictionless support to allow testing of structures in simulated zero-g. The application to testing of gossamer structures requires a modification to the standard product.

Products and Solutions: Space, On-Orbit