Fusion energy has been on the minds of energy experts since the 1950s. At that time, most serious fusion experiments got underway despite attempting what often looks like an elusive goal to initiate a self-sustaining thermonuclear reaction in a bottle. But each year scientists mark their successes and we are creeping closer to the big break-even goal. Fusion power scares some critics, but I believe their fears are unfounded. Fusion employs a clean nuclear power approach that eliminates most of the hot waste generated by todays fission power. It is the stuff that literally fuels the stars. Fusion power has a very promising future in the aerospace field. Plasma technologies learned in fusion research are the basis for advanced space thrusters now being developed. New plasma propulsion systems, by yielding more thrust per pound of fuel and super velocities, will make space travel cheaper well, at least cheaper than todays technology. As a result, our distant planets will be weeks, not months, away. One promising fusion-based rocket technology is the plasma rocket. NASA researchers have been working with fusion labs, such as General Atomics, to develop the VASIMR or Variable Specific Impulse Magnetoplasma Rocket. Sounds like something fictional boy inventor Tom Swift would have loved, eh? Let me explain how VASIMR works. VASIMR doesnt use the conventional chemical reactions of modern rockets and missiles. Instead a plasma rocket such as VASIMR uses the energy of radio waves like those that heat up your cup of coffee in a kitchen microwave oven to heat up rocket fuel (propellant). The propellant is heated to such an extreme degree by the radio waves that it transitions from hot gas to super-hot plasma, the strange fourth state of matter. Thus heated, the excited plasma particles shoot out of the rockets rear-end at extreme velocities. Wow, such a superrocket would deliver astronauts to Mars in half, or less than half, the time of a conventional rocket. This is a serious advancement in space travel technology that is just around the corner. Dr. Chang Diaz, a NASA astronaut, fusion physicist, and director of NASAs Advanced Space Propulsion Laboratory in Houston, invented the VASIMR concept in 1980. Not surprisingly, this UConn and MIT wiz kid read Tom Swift, Jr., novels at a young age. In the last 30 years, he told me, progress in fusion technology has been relentless and steady, leading to remarkable advances in plasma physics and associated technologies. The development of VASIMR builds on these advances, providing an evolutionary path for further growth, but with exciting and immediate applications en route. When it comes to real fusion rockets, the next step beyond plasma rockets, well see thrust levels 1,000 times more than todays chemical rockets. With something like a magnetized target fusion engine at work, astronauts could routinely travel to the distant dwarf planet Pluto in just a few weeks time. Amazing stuff, indeed. Whats in the Sky: Look for the Milky Ways nearest galaxy, M31 Andromeda, in the northeast sky this weekend. This spectacular galaxy is 2.5 million light-years away. From the dark countryside you can see it as a fuzzy patch with the unaided eye. Lou Varricchio, M.Sc., was a NASA science writer. He is involved with the NASA/JPL Solar System Ambassador program in Vermont. He is the author of Inconstant Moon, a 2007 book about lunar research.