Small Deep Space Transponder


The Small Deep Space Transponder is a transponder designed by JPL specifically for deep space probes. It unifies a number of communication functions -
receiver, command detector, telemetry modulator, exciters, beacon tone generator, and control functions - into one 3-kg package. The SDST is designed to handle X band uplink and both X band and Ka band downlink. JPL estimates that performing the same functions with separate units requires over twice the mass and 4 or 5 individual subassemblies.

Functions

The capabilities of the SDST include:

SDST has been used in the following missions:
As many tightly constrained, high-performance systems, the SDST has a number of idiosyncrasies in operation. However, as the Dawn telecom 'lessons learned' section points out, the use of common hardware such as the SDST allows knowledge of these characteristics from previous projects.
For cubesat missions, the SDST is too big, heavy, and power-hungry. For these missions, the Iris transponder could be considered instead.