NASA artificial intelligence (AI) software - working on a network of personal computers - has designed a satellite antenna scheduled to orbit Earth in 2005.

The antenna, able to fit into a one-inch space (2.5 by 2.5 centimeters), can receive commands and send data to Earth from the Space Technology 5 (ST5) satellites. The three satellites - each no bigger than an average TV set - will help scientists study magnetic fields in Earth's magnetosphere. NASA scientists have spent two years developing the evolutionary AI software that designed the antenna.

"The AI software examined millions of potential antenna designs before settling on a final one," said project lead Jason Lohn, a scientist at NASA's Ames Research Center, located in California's Silicon Valley. "Through a process patterned after Darwin's 'survival of the fittest,' the strongest designs survive and the less capable do not."

The software started with random antenna designs and through the evolutionary process, refined them. The computer system took about 10 hours to complete the initial antenna design process. "We told the computer program what performance the antenna should have, and the computer simulated evolution, keeping the best antenna designs that approached what we asked for. Eventually, it zeroed in on something that met the desired specifications for the mission," Lohn said.

"Not only can the software work fast, but it can adapt existing designs quickly to meet changing mission requirements," he said. Following the first design of the ST5 satellite antenna, NASA Ames scientists used the software to 're-invent' the antenna design in less than a month to meet new specifications - a very quick turn-around in the space hardware redesign process.

Scientists also can use the evolutionary AI software to invent and create new structures, computer chips and even machines, according to Lohn. "We are now using the software to design tiny microscopic machines, including gyroscopes, for spaceflight navigation," he ventured.

Four NASA Ames computer scientists wrote the AI evolutionary program that operates on 120 personal computers, which work as a team. The scientists wrote the AI software because it can create designs faster than a human being can do so.

"The software also may invent designs that no human designer would ever think of," Lohn asserted. In addition, the software also can plan devices that are smaller, lighter, consume less power, are stronger and more robust among many other things - characteristics that spaceflight requires, according to Lohn.

The Office of Exploration Systems at NASA Headquarters, Washington, is funding development of NASA Evolutionary software. Detailed information is on the Internet at:

http://ic.arc.nasa.gov/projects/esg

Space Technology 5 satellite details are on the Internet at:

http://nmp.jpl.nasa.gov/st5

Publication-size images and an on-line video are available on the World Wide Web at:

http://amesnews.arc.nasa.gov/releases/2004/antenna/antenna.html