Published: June 12, 2001

Students from the University of Colorado at Boulder, Arizona State University and New Mexico State University are teaming up in a unique space project to design, build and fly three identical satellites in formation.

The primary goal of the mission, dubbed Three-Corner Sat, is to obtain stereo images of small, quickly changing space phenomena like cloud formations, pollution plumes, and sand or dust storms, said Colorado Space Grant Consortium Director Elaine Hansen. Three-Corner Sat is a joint effort of the three universities, NASA and the Air Force Office of Scientific Research.

By observing cumulus cloud towers, for example - which are dangerous to air traffic due to highly unstable air - the small satellites can collectively obtain three-dimensional images showing cloud thicknesses and altitudes inaccessible to conventional radar systems, said Hansen, a CU-Boulder faculty member. The project is being undertaken by students, primarily undergraduates, at the schools as part of the NASA-sponsored Space Grant Consortium program begun in 1989.

The Three-Corner Sat mission is being developed by CU-Boulder, which is responsible for mission control, science, the command and data-handling system and camera imaging systems. ASU students are developing the structure, power and attitude control systems, while NMS is building the communication system.

The six-sided, 35-pound satellites - each about 18 inches across and 10 inches deep - will be launched in 2002 via space shuttle in a "stack" formation. Released at roughly 250 miles above Earth, the stack will separate and the three satellites slowly will drift apart.

As soon as they are about 6 miles apart, the satellites can begin collecting data to assemble into three-dimensional stereo images. The images will be analyzed by CU-Boulder students on the ground, Hansen said.

Each satellite will carry four digital cameras pointing in different directions and will continue to gather data until the three spacecraft drift roughly 200 miles from each other, said Hansen. At that point, which is expected to occur two to three months following launch, the mission will terminate.

"It is a proof of concept study to test artificial intelligence software and stereo-image quality," she said. "In theory, precise measurements of cumulus cloud towers, for example, could cut down unnecessary commercial air traffic diversions."

Artificial intelligence software developed by NASA's Jet Propulsion Laboratory in Pasadena will allow each satellite to make onboard decisions during the mission, according to NASA officials. The smart software, for example, can detect unexpected events like volcanic explosions and solar flares, triggering cameras to change targets and record such events, retaining only the sharpest digital images.

All the data collected by the Three-Corner Sat mission will be posted on the Web for access by K-12 schools and other colleges around the world, said Hansen.

"We uplink our goals to the spacecraft, and the software responds," said junior engineering major Jennifer Michels, Three-Corner Sat project manager for CU-Boulder. "While we retain a lot of control from the ground, each spacecraft is programmed to take advantage of unexpected atmospheric events."

Michels is responsible for overseeing data systems for the campus satellite, including software, hardware and mission operations. "When I first came here, I never dreamed I would be participating in a NASA satellite mission," said the Anchorage, Alaska native. "It has opened my eyes to a career in space engineering."

Approximately 100 CU-Boulder students, primarily undergraduates, have been involved in the Three-Corner Sat effort during the past two years, said Chris Koehler, deputy director of the CSGC. "These students are doing hands-on research, facing the same challenges as engineers in industry or government," he said. "The experience they get at CU makes them extremely marketable graduates."

CU-Boulder's CSGS students have designed, built and operated three space shuttle and three sounding rocket experiments. They are now finishing the Citizen Explorer Satellite, an educational spacecraft that will involve K-12 students from around the world.