Main-Reflector Manufacturing Technology for the Deep Space Optical Communications Ground Station

The Deep Space Network (DSN) has plans to develop a 10-m-diameter optical communications receiving station. The system uses the direct detection technique, which has much difierent requirements from a typical astronomical telescope. The receiver must operate in daylight and nighttime conditions. This imposes special requirements on the optical system to reject stray light from the Sun and other sources. One of the biggest challenges is designing a main-re∞ector surface that meets these requirements and can be produced at a reasonable cost. The requirements for the performance of the re∞ector are presented. To date, an aspherical primary re∞ector has been assumed. A re∞ector with a spherical re∞ector has a major cost advantage over an aspherical design, with no sacriflce in performance. A survey of current manufacturing techniques for optical mirrors of this type was performed. Techniques including solid glass, lightweight glass, diamond-turned aluminum, and composite mirrors were investigated.