The Speculist

The concept of solar sails has been around awhile. But the idea of providing our own "wind" is newer. This morning Wired reported that a University of Washington team is working on magnetized-beam plasma propulsion. This group just received $75,000 in funding from NASA's Institute for Advanced Concepts.

[What's the matter guys? Feel the private sector breathing down your neck? – ed.]

The idea is to push a spaceship equipped with a sail with a mag-beam shot from a space station. This would, in theory, be able to propel the ship to incredible velocities – 26,000 miles per hour. At that speed a trip to Mars and back again would take about three months.

Once shot off into space, onboard propulsion units would provide a spacecraft some power for minor flight corrections, but not enough to decelerate, which would be handled by a plasma station orbiting the destination.

Not having to carry the mass of the fuel required for acceleration and deceleration within the craft is a big advantage here. Going to Mars by traditional rocketry would be very slow, 2.6 years for a round trip, and prohibitively costly.

Obviously there are a lot of questions to answer. Presumably the plasma stations will have to deal with Newtonian physics, and this gun would have quite a kick. In order to keep from having to compensate, it might be best if it was located on a large and, relatively, unmovable object such as the Moon.

Also, does a mag-beam have the range to accelerate and decelerate a craft at a sufficient distance? Nobody knows yet.

And a commentor at FuturePundit thought of another problem:

How accurate does the incoming craft's trajectory have to be to balance perfectly on the decelerating beam? Think about it. You're essentially pushing against a huge amount of inertia with a magnet - which is damn slippery. Unlesss I'm misunderstanding something it seems like the decelerator would have to be absolutely perfectly over the craft's center of gravity to not push it off course. It would be like decelerating a bullet without deflecting the bullet.

My guess is that engineers will address these issues in time. And I'm glad that NASA is thinking beyond the Shuttle.