LDR structural technology activities at JPL

The status of the Large Deployable Reflector (LDR) technology requirements and the availability of that technology in the next few years are summarized. The research efforts at JPL related to these technology needs are also discussed. LDR requires that a large and relatively stiff truss-type backup structure have a surface accurate to 100 microns in space (initial position with thermal distortions) and the dynamic characteristics predictable and/or measurable by on-orbit system identification for micron level motion. This motion may result from the excitation of the lower modes or from wave-type motions. It is also assumed that the LDR structure can be ground tested to validate its ability to meet mission requirements. No program manager will commit a structural design based solely on analysis, unless the analysis is backed by a validation test program.