Traveling Salesman to the Max

Talk about "eXtreme Traveling Salesman" problem...Engineers at the University of Missouri have implemented an algorithm that determines the most efficient path for a spacecraft's journey from point A to point B--no matter how far away.

In validating the algorithm, Craig Kluever, a professor of mechanical and aerospace engineering in the College of Engineering, and former MU student Aaron D. Olds, tackled the 1997 Cassini Mission -- one of the most complicated explorations ever undertaken.

The trajectory generated by Kluever and Olds, described in their paper Interplanetary Mission Design Using Differential Evolution (published in the Journal of Spacecraft and Rockets), matched that created at the Jet Propulsion Laboratory (JPL), which developed Cassini's 7-year route. Their mission-design software, which relies on optimization methods patterned from genetic evolution, makes sending a rover to Mars look relatively easy, Kluever said.

"You don't need complicated mission software for Mars missions," he said. "If you look at the trajectory, it doesn't require a lot of twists, turns and gravity assists. It's a straight shot. You need complicated mission software for ambitious missions to a comet, asteroid, moon of Saturn or beyond. We're talking about missions where an unmanned spacecraft would fly by Venus to do a gravity assist and then fly by Jupiter to do a gravity assist. Before that, it may have to coast a year and half to come back to Venus for another gravity assist. These very high-energy targets require orbital tricks. Timing all of these maneuvers to find the optimal solution is complicated."

Kluever said complex missions are launched roughly every three years with the goal of learning more about the origins of the universe. He said the mathematical principles behind the mission software developed at MU have been embraced primarily by the European Space Agency but thinks it could attract NASA's attention. He said when NASA begins planning future robotic missions "it will need software like this to solve those types of problems. But a lot of it depends on what NASA's going to do with human space travel over the next 10 to 15 years."

Posted by Jon Erickson at 07:54 PM  Permalink