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Session 60 - Next Generation Space Telescope.
Oral session, Tuesday, January 14
Piers 4/5,

[60.06] A Reflecting Polymer Film Petal Concept for the NGST Primary Mirror

G. Horner, D. Stoakley, A. StClair (NASA LaRC)

A low cost, light weight reflecting polymer film is proposed as the primary mirror for Next Generation Space Telescope. The concept discussed in this paper is based upon the TRW High Accuracy Reflector Development (HARD) concept. The TRW HARD antenna concept has six hexagonals surrounding a center hexagonal. The proposed hexagonal reflecting polymer film is fabricated such that the assembled petals lie on the surface of a paraboloid of revolution to give the desired telescope aperture and focal length for the primary mirror. Each of the six surrounding hexagonals is identical so that the polymer film for each hexagonal can be fabricated by replication which is the most cost effective means. We will discuss recent advances in polymer film research which gives hope that high reflectivities can be achieved. Fabrication concepts which integrate the polymer film to a hexagonal backup structure will be described. Actuators will be integrated into the backup structure to correct for distortions in the film that may occur once the petals are deployed. These actuators will shape the polymer film to the desired surface accuracy. Some concepts for actuators that will be discussed include, electrostatic, electromagnetic, and superconductors. Some of the material and structures issuses related to the problems of mirrors, actuators, and backup structures at cryogenic temperature will be discussed.

Program listing for Tuesday