Three Corner Sat spacecraft stacked in launch configuration. Photo: NASA/JPL

NASA software that thinks for itself and makes decisions without help from ground controllers will fly as the brains of triplet satellites in 2002.

The software builds on previous efforts to use artificial intelligence to control a spacecraft (such as NASA's Remote Agent experiment, which controlled the Deep Space 1 spacecraft during portions of several days in 1999). However, this new software uses more advanced technology to respond more quickly to events and will command a mission continuously for a period of approximately three months.

The Continuous Activity Scheduling, Planning Execution and Replanning (CASPER) software will guide a constellation of three identical miniature satellites, each weighing less than 15 kilograms (33 pounds). The three satellites will be launched from the Space Shuttle in a stack configuration and fly in formation as part of the Three Corner Sat mission.

"The onboard software performs the decision-making function for the spacecraft. Like a brain that uses inputs from the eyes and ears to make decisions, this software uses data from spacecraft sensors, such as cameras, to make decisions on how to carry out the mission," said Dr. Steve Chien, principal scientist and lead researcher in automated planning and scheduling technologies at NASA's Jet Propulsion Laboratory, in Pasadena, Calif.

The mission goal is to demonstrate stereo imaging, formation flying, and innovative operations and commanding. The Three Corner Sat mission is a joint project of Arizona State University, Tempe; the University of Colorado at Boulder; New Mexico State University, Las Cruces; the Air Force Office of Scientific Research and NASA.

"Low-quality science images or short-lived phenomenon could be discarded to free up space for newer science images. The onboard sensors and software might detect a volcanic eruption or solar flare might trigger science imaging," said Chien.

The software is a dramatic shift in the way mission operations are conducted. Typically all science data, good or bad, is sent back to Earth. This software will have the ability to make real-time decisions based on the images it acquires and send back only those that it deems important. This will eliminate the need for scientists to preview thousands of low-priority images and let them focus on only the high-priority data transmitted back. Less time will be needed to transmit the data, freeing up power and allowing the spacecraft to concentrate on other important tasks. Ground controllers will have the ability to de-activate the onboard decision-making software and operate the spacecraft conventionally if necessary.

"This capability represents a significant advance from traditional ground-based operations and offers promise to dramatically increase mission science for this and future missions," said Colette Wilklow, Three Corner Sat mission operations team member and senior engineering major from the University of Colorado.

The decision-making capability of the software is being considered for a wide range of NASA applications including automated ground communications stations, autonomous planetary rovers and autonomous robot aircraft. Software with similar capabilities has been used by commercial companies for managing the distribution networks for groceries and other retail goods and for controlling the production of computers, automobiles, semiconductor chips, and consumer goods such as shoes.

NASA's Office of Office of Space Science and Office of Aerospace Technology, Washington, D.C., fund the development of the CASPER software. JPL is managed for NASA by the California Institute of Technology in Pasadena.