Development of a prototype elastic memory composite stem for large space structures
This paper describes an engineering program for the development of a seven-meter-long Elastic Memory Composite (EMC), Storable Tubular Extendible Member (STEM) boom, and its deployment-control system. EMC STEM booms have the potential to be much larger, in cross section and lighter in weight than conventional metal STEM booms. This increase in size is directly related to the fact that most of the strain energy induced during packaging is "frozen" within EMC material, thus dramatically reducing the containment requirements and the hazards associated with large elastically packaged booms. The present program was conducted to prove the feasibility of an EMC STEM system. A prototype system, including the EMC STEM and a deployment-control system, has been designed and fabricated. In addition, the EMC STEM has been successfully packaged and deployed, vertically and horizontally, in a 1-g environment in both air and vacuum. Specifically, this paper discusses the following: 1) the development of an EMC material and the process for prepreg fabrication; 2) design and construction of the seven-meter EMC STEM boom; 3) design and construction of the deployment-control system, and 4) results from testing the boom and deployment-control system.