We can look forward to hearing more about the next generation of space thrusters over the next few years, starting this weekend on a promising looking new science show called Brink. This weekend's episode sounds like it will include an introduction to a revolutionary new propulsion system once found only in the pages of a science fiction novels. The plasma drive.
Existing space probes are violently blasted away and then essentially fall, like hapless cannon balls, making tiny course changes, taking advantage of clever gravity assists along the way, to ensure they land at a precise spot at an exact time the end of their usually epic trajectory. But change is in the air, or rather in the vacuum of deep space.
Unlike chemical rockets which oxidize highly flammable substances like kerosene or hydrogen, the ion engine is an electric rocket. Atoms are ionized, given an electric charge, and then accelerated by a powerful magnetic field out the rear of the rocket producing thrust.
The first operational ion powered mission was Deep Space 1. Another craft, NASA Dawn, is even now under ion power on the way to the asteroids Vesta and Ceres. Both these probes used the NSTAR ion motor. NSTAR produces a modest thrust, less than a pound. But the bang for the buck is worth it; it can burn for months on end. NSTAR turns a free falling cannon ball into the first full blown spaceship.
But the star of the future is the Variable Specific Impulse Magnetoplasma Rocket. VASIMR uses the ion thruster equivalent of an afterburner. This more sophisticated approach can produce a variable thrust ranging between a whopping 30 to 300 k/s exhaust velocity using radio wave to excite the fuel. The same intense radio wave field used to whip the ionized gas into a blazing quantum soup offers a freebie of sorts: an electromagnetic shield, protecting delicate payload in the event of a deadly solar flare.
A future portfolio of relatively low cost, standardized probes built by international coalition, launched by Atlas or Ariane booster and inserted into strategic points in deep space by ion drive is a realistic, achievable goal over the next ten to fifteen years. It's part of a comprehensive exploration methodology that offers standalone and cumulative benefits; we glean the data returned from the probes themselves, and they can serve as the first elements in a growing interplanetary navigational and tracking network infrastructure.
But one key component crucial to ion power in need of further development is the power source. Somewhere between the asteroid belt and the planet Jupiter is what NASA calls the edge of sunlight.' It's the point where the sun's power is so diluted by distance that existing solar panels either become enormous or they become unusable. For our next batch of ion powered probes, we'll have to push the envelope on solar power. To one day realize the dreamier velocities down the road, large spaceships able to accelerate to tens of kilometers per second in a matter of weeks, we'll need even more efficient, lightweight, and sturdy solar panels.
Which brings us oddly enough right back down to earth: If ever there was a golden opportunity for a new President interested in practical alternative energy, moved by sheer scientific discovery, and under the gun to create revolutionary new industries, research and development of economical solar cell technology is one hell of a candidate. Imagine the applications, buying solar cells by the square meter for the price of plywood. Dirt cheap, mass produced solar cells built into your home's shingles and siding. Your car or home's surface finished with photovoltaic 'paint' that self assembles into nanosolar cells in your choice of stylish color. Imagine the obscene wealth and gobs of jobs that kind of mass product line would create for CEOs and entry level employee respectively. Considering the quality of the research expertise on hand, and the convergence of interest in cutting edge solar power systems, NASA would be a good place to start the ball rolling.