A document discusses the use of computer-aided evolution in arriving at a design for X-band communication antennas for NASA’s three Space Technology 5 (ST5) satellites, which were launched on March 22, 2006. Two evolutionary algorithms, incorporating different representations of the antenna design and different fitness functions, were used to automatically design and optimize an X-band antenna design. A set of antenna designs satisfying initial ST5 mission requirements was evolved by use these algorithms.

The two best antennas — one from each evolutionary algorithm — were built. During flight-qualification testing of these antennas, the mission requirements were changed. After minimal changes in the evolutionary algorithms — mostly in the fitness functions — new antenna designs satisfying the changed mission requirements were evolved and within one month of this change, two new antennas were designed and prototypes of the antennas were built and tested. One of these newly evolved antennas was approved for deployment on the ST5 mission, and flight-qualified versions of this design were built and installed on the spacecraft. At the time of writing the document, these antennas were the first computer-evolved hardware in outer space.

This work was done by Jason D. Lohn of Ames Research Center and Gregory S. Hornby of the University of California Santa Cruz and Derek S. Linden of JEM Engineering. For more information, download the Technical Support Package (free white paper) at www.techbriefs.com/tsp under the Software category. ARC-15568-1