Ultra-Lightweight, Ultra-Stable RoboSiC Additively Manufactured Lasercom Telescope

Of interest to JPL, GRC and GSFC are laser communications telescopes (LCTs) with 30 to 100 cm clear aperture, wavefront error (WFE) less than 62 nm, cumulative WFE and transmission loss not to exceed 3-dB in the far field, advanced thermal and stray light design for operation while sun-pointing (3-degrees from the edge of the sun); -20deg; C to 50deg; C operational range (wider range preferred), and areal density lt;65kg/m2.nbsp; Telescope dimensional stability, low scatter, extreme lightweighting, and precision structures are a common theme across the NASA 2017 Physics of the Cosmos and Cosmic Origins Program Annual Technology Report.nbsp; Multiple Priority Tier 1-4 technology gaps can be found, and the higher priorities require a solution in time for the next Decadal Survey. A common solution of interest that has been cited is silicon carbide and 3D printing or additive manufacturing.nbsp; RoboSiC technologies provide both.nbsp; GT proposes to design, 3D print and additively manufacturenbsp;a prototypenbsp;Gregorian LCTnbsp;using the patent pending RoboSiC-S technology demonstrated in Phase I, including bolts, truss structures, mirror mounts.nbsp; Off-axis mirrors will be printed.nbsp; RoboSiC-S provides the degree of passive athermality required for the LCT optical pathlength and wavefront error stability, concomitant with low areal density mirrors (7.75-10 kg/m2) and structures (4-5 kg/m2), and a theortical first unit cost for an LCT with a fast steering mirror is $1.5M, a factor of 3-4 less than current LCTs.nbsp; A Phase IIE project is planned which will integrate 3D printed RoboSiC mirrors into the telescope and perform environmnetal and other tests to raise the TRL to 6 for commercial sales.