"We propose to develop such a system," Howe explained. Along with Hbar Technologies co-founder and partner, Gerald Jackson, the firm is designing "a very straightforward system" that will produce a specific impulse of one million seconds. That system can be throttled, steered, and demonstrated within the next two years, the Hbar researchers report.

The Hbar proposal is to utilize antiproton-induced fission to directly propel a small sail. By illuminating a thin foil of uranium with a stream of antiprotons, a million second propulsion system will be created - with no high temperatures, no magnetic fields, and no massive power supplies.

The researchers envision a lightweight sail that holds a trap of antimatter using a series of lightweight cables. For deep space missions to the Kuiper Belt, early results indicate that only 30 milligrams of antimatter are needed. For a mission to Alpha Centauri, a few tens of grams are required. The antimatter will be in the form of antihydrogen and will be stored as nano-flakes or as distributed atoms.

However, high capacity storage of antihydrogen is work in progress, although that capability appears reasonable to expect in the near future, Howe said.

The sail-mounted trap need only have the ability to release pulses of particles at intervals. The cloud of particles will escape the trap and expand into the vacuum. Striking the uranium-coated sail will cause fissions. The captured fission products will propel the sail forward.

"By pursing this path of research, we hope to develop the one technology that will allow humanity to reach farther than ever before and see what lies beyond," Howe said.

Over the last two years, a major gathering of worldwide experts in microwave and laser power beaming has been held -- in the United States in 2002 and this year in Japan. A third confab is to take place in Troy, New York in 2004.

The international symposiums on beamed energy propulsion have shown that steady progress is being made, said Andrew Pakhomov, Associate Professor of Physics at the University of Alabama in Huntsville.

"These are serious scientific meetings," Pakhomov said. Along with the experts from the United States and Japan, scientists and engineers from Russia, Germany, France, Canada, Brazil, Korea and India attend the meetings to share results in power beaming research, he said.

Laser power beaming work is in the lead, with more money being applied to that technology, Pakhomov commented. "Maybe in two or three years, I hope we see a serious breakthrough."

Pakhomov saluted a recent experiment that highlights the increasing intensity of work.

Power beaming has moved a step closer to becoming workable thanks to researchers at NASA's Marshall Space Flight Center in Huntsville, Alabama, Dryden Flight Research Center at Edwards, California, along with experts at the University of Alabama in Huntsville.

The team has repeatedly flown a small-scale aircraft that flies solely by means of propulsive power transmitted via ground-based laser. The laser tracks the aircraft in flight, directing its energy beam at specially designed photovoltaic cells carried onboard to power the plane's propeller.

"It's practical proof…and that's important," Pakhomov said.

"We're clearly at a threshold," said Leik Myrabo of Bennington, Vermont. He is the just elected President of the newly formed International Society for Beamed Energy Propulsion (ISBEP).

Myrabo is no newcomer to power beaming. On October 2, 2000, after years of study, trial and error, his Lightcraft design rode a powerful shaft of laser light to a world altitude record at the Army's White Sands, New Mexico test site.

That breakthrough experiment utilized a ground-based laser to pulse a cavity of air on the Lightcraft to the point that it repeatedly exploded, propelling the spacecraft forward. In the future, highly energetic fuels could be super-heated in a similar way. A network of power beaming stations on the ground, as well as in Earth orbit, could support skyway and spaceway traffic lanes.

"Power beaming is definitely a worldwide phenomenon. Nobody is getting rich on the research…but the foundations are being set right now for what I think will become a revolution," Myrabo told SPACE.com. "It's going to change everything. It will change the way we get around the planet and venturing off our world," he said.

Myrabo envisions vehicles of the future dropping by your local neighborhood to pick you up, rather than having to fight traffic en route to any air or spaceport. Individuals can be "tractor beamed" through the sky in these craft, transported anywhere in the world in 45 minutes...or directly into space in a few minutes time.

"I see the Earth-Moon system as being colonized. Beamed energy propulsion will be the way of getting to orbit, to-and-from high orbit, and to-and-from the Moon. Much will change," Myrabo believes. The Moon seems to be a logical place to build communities. Terra firma already exists on the Moon, he added, rather than waiting for the construction of gigantic colonies. Those too will come in time.

An early objective of ISBEP is to capitalize on big lasers and microwave devices that are already in service around the world. "We want to set these up as user facilities. Researchers can use these facilities, get their data…all for a reasonable price. This way you avoid the big expenditures that created so many false starts in the past," Myrabo said.

Like the laser beam aircraft tests done at Marshall Space Flight Center, more experiments are needed, Myrabo explained. One idea is use of a platform-mounted laser in orbit, modest in power, to accelerate a vehicle through space "just to make a point that it can be done."

Lab work on the Lightcraft idea and other vehicle concepts is ongoing, Myrabo said. "The Wright Brothers had an edge over everybody else because they could control their machines…and that's needed now to go to ever-higher altitudes with power beaming."

We have so much in our hands right now, as far as technology, to create a power beam-based revolution, Myrabo said.

"There's a lot of physics today we are not applying to our propulsion and power systems. Many engineers are pre-occupied with chemical fuels. We really are talking about energetics. Imagine turning up the energetics a factor of ten or a hundred. That could radically transform what engines we use with that propellant…and what vehicles those engines can propel."

"The physics of flight will change. Right now we've got vehicles that by future standards are under-powered. The future ones…you're going to blink and they are gone," Myrabo predicted.