Moon Viewed As Source
For Future Earth Energy
WASHINGTON -- A solution to world energy woes and rising gasoline prices might require looking off Earth at our nearest celestial neighbor -- the moon.
Power-beaming satellites have been advocated for numbers of years as a way for energy-hungry Earthlings to develop new sources of power to meet needs in the 21st century.
At the moon, Earth already has a heavenly equivalent to a wall plug, says David Criswell, director of the Institute for Space Systems Operations at the University of Houston in Texas.
"There's no need to build the moon," Criswell told By mid 21st century, enough lunar solar power can be imported Earthward to supply the world's population of 10 billion people to meet all basic human needs, he said.
Solar farms
For the last two decades, Criswell has been on a lunar crusade of sorts. Starting in the 1970s, he and engineering colleague, Robert Waldron, promoted the idea of turning lunar soils and rocks into useful products.
Thanks to the Apollo program, moonwalking astronauts were the first prospectors of another world. Hundreds of pounds of lunar samples have been studied, showing great potential for manufacturing.
The moon: Earth's future power hub?
There are no "magic" resources or technologies needed, Criswell said. Any handful of lunar dust and rocks will do. That lunar material contains quantities of silicon oxygen and metals, such as iron and aluminum, he said.
Lunar dust can be used directly as thermal, electrical and radiation shields. Also, the dust can be converted into glass, fiberglass and ceramics, not to mention solar cells, electric wiring, microcircuitry and other items.
"Solar-cell technology here on Earth is done in vacuum or near-vacuum conditions. And those conditions are certainly available on the moon, at almost no cost," Criswell said.
On-the-spot beaming
Criswell envisions that large fields of made-on-the-moon solar cells can energize sets of microwave transmitters. These transmitters would be in synch to deliver microwave power to receivers on Earth.
In order to provide inexpensive electric energy to Earth, most of the lunar-situated hardware must be manufactured on the spot, Criswell said. Some high-technology items would be ferried to the moon from Earth, he said.
Pairs of solar farms would be planted in the lunar highlands, on the east and west limbs of the moon, near the equator.
As part of the Lunar Solar Power System, beams of microwaves from the moon are directed to receiving antennas on Earth called "rectennas". They operate when they are in view of the moon. Simple reflectors or active re-transmitters in Earth orbit can redirect energy beams to ground rectennas at times when they are not in sight of the moon.
Solar sails circling the moon would be required to reflect sunlight down to the lunar sites, especially when the moon is in eclipse of Earth, and when the site is no longer in sunlight.
"The more sunlight that can be directed to the site, then the more energy output for Earth," Criswell said.
Not only Earth could benefit from moon beaming.
In full operation, re-targeted lunar-based transmitters could supply power out past Jupiter, Criswell said.
Step-by-step plans
How soon can a Lunar Solar Power System plan be started? "This is like having a baby. You can have it in 100 years or 10 years," Criswell said. "It can be done in 10-year increments," he said.
A first step would be 10 years of planning -- sketching out business plans and carrying out hardware demonstrations here on Earth. Building up the technical community to run such a lunar power base is key, Criswell said.
To demonstrate the idea's practicality, sets of lunar-landing robots can be dispatched to the moon. Once there, they would unfurl solar arrays, then operate in tandem to transmit a collective low-energy beam back to Earth.
"This type of activity could be started very quickly," Criswell said. Follow-on stages would mean sending equipment to the moon, showing how products can be made of lunar soil and rock.
Eventually, the moon would be dotted with factories, robot tractors and repair shops -- all part of building up the Lunar Solar Power System, Criswell said.
Given the closeness of the moon, one-way radio signals from Earth take only 1.3 seconds to cross space. On-duty robots, controlled from Earth could do the building, operation and maintenance of lunar power-beaming sites, Criswell said. "You will need some people, but how many, I'm not sure at this point," he said.
The price tag for bringing the moon on line, and churning out power for Earth is about $150 billion, roughly twice the cost of the Apollo program in today's dollars, Criswell said. Capable of churning out more and more power over the years, by 2015, 1,000 gigawatts of power could be pumped to Earth from the moon, he said.
"Everybody's grandchildren right now would be energy prosperous by 2050," he said. "If you don't have access to cheap energy, that's one of the things like not having enough air."
Weaning the Earth off our current carbon-based energy system is a must, Criswell said. "Otherwise we're going to stay in a precarious situation. If you want a prosperous world, there just are no other options," he added.
Robots need supervision
Not everyone is ready to hook up to Criswell's lunar power supply, however.
"My own feeling is that he may well be right, but the idea is downstream," said Bryan Erb, president of the Sunsat Energy Council, based in Houston, Texas. The group backs a first-things-first approach, namely the building of satellite power stations in Earth orbit.
"It takes a big investment to get back to the moon," Erb said. "I just don't see a graceful migration path to get to a lunar power system without a massive up-front investment," he said.
Erb said he views the Criswell proposal as a "vast undertaking" that would be very costly. "If you could overcome that hurdle, then there's a lot of promise in his idea of using the moon," he said.
Taking a wait-and-see attitude is Paul Werbos, program director for control networks and computational intelligence at the National Science Foundation. He recently co-sponsored with NASA a workshop that looked over the Criswell plan, among other space-research issues.
"We don't have a definite verdict, but I am much more optimistic than before," Werbos said. "The opportunity is so great, we should not lose the opportunity."
Werbos said that a critical aspect of Criswell's idea is use of tele-autonomy, that is, how to coordinate human beings on Earth with on-the-job robots stationed on the moon. "That's the key concept in my mind in order to build any kind of large-scale space power system -- on the Earth or on the moon," he said. "How do you get robots smart enough to do their job under a kind of loose supervision arrangement?"

This Site Served by TheHostPros