The positions of the
panels provided a baseline for the truss design. The design was
then optimized to provide maximum rigidity with minimum mass.
Optimization variables included; position of the node-balls and
diameter and wall thickness of the truss elements.
MSC/NASTRAN optimization
module was used to optimize for maximum rigidity, minimum mass
subject to accuracy requirement of < 40 microns RMS distortion
of reflector nodes due to gravity sag.
Made of stainless
steel thin-walled tubing, 0.75 inches in diameter and 0.095 inches
in wall thickness. Especially designed adjustable fittings and
machined aluminum spherical node balls
connect the truss elements.
Consists of 60 struts
and 21 nodes. The entire telescope is supported by three flexured
bipods which attach the test bed to the isolation platform.