New Spacecraft Propulsion Method Could Be Out Of This Solar System

NASA's Institute for Advanced Concepts last week awarded a two-year, $500,000 grant to a UW team headed by geophysicist Robert Winglee to continue research on Mini-Magnetospheric Plasma Propulsion. If laboratory work and tests in space succeed, he hopes in 10 years to launch an M2P2-equipped spacecraft that would become the first from Earth to leave the Solar System.

That would be quite a feat, considering the craft would have to overtake Voyager I, launched in 1977 and now about 6.8 billion miles away but still within the solar system.

Winglee, an associate geophysics professor, has been working on M2P2 the last nine months with geophysics professor George Parks and John Slough, a research associate professor of aeronautics and astronautics. They are developing a prototype and are preparing for tests in the UW's Redmond Plasma Physics Laboratory.

Their system would use a plasma chamber about the size of a large pickle jar, perhaps 10 inches by 10 inches, attached to a spacecraft. Solar cells and solenoid coils would power the creation of a dense magnetized plasma, or ionized gas, that would inflate an electromagnetic field 10 to 12 miles in radius around the spacecraft. The field would interact with and be dragged by the solar wind.

Creating the field would be akin to raising a giant sail and harnessing the solar wind, which moves at 780,000 to 1.8 million miles an hour - or "here to Washington, D.C., in 10 seconds," Winglee said. There is enough power in the solar wind to move a 300-pound spacecraft at speeds up to 180,000 miles per hour or 4.3 million miles a day. By contrast, the space shuttle travels at about 18,000 miles per hour or 430,000 miles a day.

At such speeds, an M2P2-equipped spacecraft launched today could overtake Voyager I within eight years, despite Voyager's 22-year head start. The idea for M2P2 grew from the study of plasma jets forming around young stars, and was formalized in a $75,000 startup grant from the NASA Institute for Advanced Concepts.

The system has built-in advantages over solar sails, which are very large, thin sheets of reflective material such as Mylar that can turn sunlight into a propelling force. Solar sails are typically many times larger than the spacecraft they propel and must be deployed mechanically. The M2P2 plasma chamber is far lighter and less bulky than sails. Just a few kilowatts of power would support the magnetic field and only about 100 pounds of additional propellant would be required. Adding the device to a spacecraft might cost $1 million, but it would provide substantial cost savings for the overall mission and would provide easier access to the planets and beyond, Winglee said.

M2P2 could be a major advancement in space travel, but it might be too tame for two generations that have grown up with science-fiction adventures such as Star Trek and Star Wars.

"It's amazing how many people say, 'That's not fast enough,'" Winglee said. "People want to go to warp drive so they can get to the next solar system."

However, Star Trek's warp drive and the hyperdrive propulsion from Star Wars, both of which can exceed light speed (186,000 miles per second in a vacuum), are not possible under the current understanding of the laws of physics.

For now, at least, plasma propulsion could prove to be the best option to the science fiction propulsion systems. If tests on M2P2 succeed, Winglee expects the system's first use in space will come on a mission NASA already will have scheduled.

"If it works, we'll have some real fun then," he said.