A Modular Terminal Descent Radar for Landing and Proximity Operations

Mars Science Laboratory's unprecedented “sky-crane” landing utilized a new “Terminal Descent Sensor” (TDS), a Ka-band pencil beam radar for high accuracy measurements of line-of-sight range and velocity. While Mars 2020 will utilize the same design from remaining parts and new builds, the availability of the TDS for future missions is unclear due to problems of obsolescence and reproducibility; in addition, the TDS is quite large, prohibitively so for smaller missions. Remote Sensing Solutions is currently funded under a NASA Small Business Innovative Research program to revisit the TDS design, and, notably, reduce the size, weight, and power; improve the manufacturability; and maintain or improve the performance. In this paper, we discuss the results of RSS's design efforts. The RSS Terminal Descent Radar (TDR), is a modular design, allowing customization of the RF center frequency for different applications, from a small, reproducible package. It is similar in function and operation to the MSL TDS, but is implemented based around RSS's ARENA software-defined digital transceiver and miniature Ka-band up/down conversion modules, both of which have clear paths to space qualification. The resultant sensor promises to provide similar if not improved performance as the TDS from a significantly smaller package.