The New Horizons high gain antenna: reflector design for a spin-stabilized bus at cryogenic temperatures

The New Horizons antenna system is subjected to cryogenic temperatures during the Pluto and KBO encounters. The RF performance of the high gain antenna (HGA) during and after these encounters is critical for the science and communications mission requirements. In order to satisfy these requirements, the angular alignment of the HGA bore-site and spacecraft spin axis must be maintained within 0.2/spl deg/. The mechanical design and RF performance of the NH HGA performance at cryogenic operational temperatures and gradients across the reflector surface are described. The RF calculations are performed using Ohio State University Satellite Antenna Consortium Software. Mechanical finite element analysis is used to predict surface distortion resulting from gradients across the surface.