A technology that uses a magnetic balloon to sail
ionized particles shed by the
Sun could speed humans to the
Jovian moons in less than two years and push a probe past Voyager 1 to
become the first spacecraft beyond our Solar System.
The low-cost Mini-Magnetosphere Plasma Propulsion, or M2P2, propels
spacecraft at speeds far greater than today's chemical and even ion
propulsion systems, and its magnetic-field sail would even protect
travelers from deadly solar and Jovian radiation.
"The technology seeks to do what space does -- deploy a magnetized sail
to travel with the winds," says University of Washington scientist Robert
Winglee, who came up with the idea after 10 years as a geophysicist
studying Earth inside and out to its radiation environment. The Sun is
constantly shedding high-speed particles, called the solar wind, that race
out from it at speeds averaging 800,000 mph (400 km/sec).
If M2P2 were used for a mission to the Jovian moon
Europa, it would take only 1.5 years to arrive. Using conventional
chemical propulsion, such a trip could take 5 years.
Other technologies also are designed to sail the solar wind, but
they rely on a lightweight material that could be penetrated by meteors.
Winglee's magnetic fields would operate unperturbed by meteors.
How it works
The M2P2 sail starts with an eight-inch magnet that creates a tiny
magnetic field. That field is expanded like a balloon by filling it with
an inert gas split into electrons and ionized particles. That superheated
gas, called plasma, then is amped up by a solenoid that acts as a switch
to create a larger magnetic field.
The magnetic "balloon" eventually can inflate around a spacecraft to
create magnetic field lines reaching as far as 25 miles (40 kilometers)
across. The solar wind then "blows" against the large bubble to propel the
spacecraft, with the sail acting like an umbrella braced against a bad
storm. Only in this case, the umbrella loses and the spacecraft can put
away up to 4.3 million miles a day.
The system can make a craft travel at speeds 10 times as fast as the
space shuttle, up to 180,000 mph (50 km/sec). At that rate, an M2P2
spacecraft could catch up with Voyager 1, currently the furthest man-made
object in space at 7.5 billion miles (12 billion kilometers) from Earth,
before it reaches the edge of the Solar System.
Honors and the new millennium
Winglee was honored this month by Discover Magazine for his aerospace
innovation, along with seven other inventors.
SPACE.com Founder Lou Dobbs introduced Winglee at the ceremony, saying,
"This technology may enable us to establish a permanent presence in space,
something existing technologies will not allow us to do."
There are hopes that M2P2 soon will be used on a couple smaller
experiments or even missions in
, which focuses on speeding up space exploration by validating new
technologies in flight.
The tech readiness scale
Hoppy Price, manager of solar sail tech development at NASA's Jet
Propulsion Laboratory, sits on a committee that evaluates technology
proposals for New Millennium missions.
"It's a neat concept," he said of M2P2. "It has a lot of potential but
it's also very early in the research phase."
"Most of the solar sail technologies we are looking at now are at tech
readiness level four, which means we have some laboratory demonstrations
of the technology," he said. M2P2 is at a lower level of readiness for the
moment, he said, although fast development of prototypes and testing could
make it available for use in some of the approaching New Millennium
missions, such as Space Technology 7.