December 2004 -


Around the Solar System in 90 Days?

A new method of space travel could dramatically cut the time needed for astronauts to travel to and from Mars, UW researchers announced in October. The new propulsion system could make humans a permanent fixture in space.

With magnetized-beam plasma propulsion, or "mag-beam," quick trips to distant parts of the solar system could become routine, says Earth and Space Sciences Professor Robert Winglee, who is leading a NASA research project on the system.

Currently, using conventional technology and adjusting for the orbits of both the Earth and Mars, it would take astronauts about two and a half years to travel to Mars, conduct their scientific mission and return.

"We're trying to get to Mars and back in 90 days," Winglee says. "Our philosophy is that, if it's going to take two-and-a-half years, the chances of a successful mission are pretty low."

Under the mag-beam concept, a space station would generate a stream of magnetized ions that would interact with a magnetic sail on a spacecraft and propel it through the solar system at high speeds. Those speeds can increase depending on the size of the beam. Winglee estimates that a control nozzle 32 meters wide would generate a plasma beam capable of propelling a spacecraft at 11.7 kilometers per second. That translates to more than 26,000 miles an hour or more than 625,000 miles a day.

But to make such high speeds practical, another plasma unit must be stationed on a platform at the other end of the trip to apply brakes to the spacecraft.

"This would facilitate a permanent human presence in space," Winglee says. "That's what we are trying to get to."Winglee envisions units being placed around the solar system by missions already planned by NASA. One could be used as an integral part of a research mission to Jupiter, for instance, and then left in orbit there when the mission is completed. Units placed farther out in the solar system would use nuclear power to create the ionized plasma; those closer to the sun would be able to use electricity generated by solar panels.

Winglee acknowledges that it would take an initial investment of billions of dollars to place stations around the solar system. But once they are in place, their power sources should allow them to generate plasma indefinitely. The system ultimately would reduce spacecraft costs, since individual craft would no longer have to carry their own propulsion systems. They would get up to speed quickly with a strong push from a plasma station, then coast at high speed until they reach their destination, where they would be slowed by another plasma station.

"This would facilitate a permanent human presence in space," Winglee says. "That's what we are trying to get to."

Mag-beam is one of 12 proposals supported by NASA's Institute for Advanced Concepts. Each gets $75,000 for a six-month study to validate the concept and identify challenges in developing it. Projects that make it through that phase are eligible for as much as $400,000 more over two years.