Students Designing Device to Collect Energy From the Sun in Space

By Mark Johnson

While classmates built Baja racers and worked on other earthbound projects, six students at the Milwaukee School of Engineering spent the last year figuring out how to generate power for colonies on the moon.

The students have designed a device that would sit atop a tower some 300 feet above the moon’s south pole, collecting energy from the sun to drive a turbine, while sending the excess energy out into cold space.

Their adviser, Michael J. Swedish, an associate professor of mechanical engineering who goes by the handle "The Energy Emperor," is already planning spin-off projects that will allow future seniors to investigate and refine various aspects of the lunar power plant.

"When you tell people about it, their eyes light up. We’re not designing a bridge or a doorknob," said Kyle Momenee, who traveled with the other engineering students on this year’s team to Huntsville, Ala., to discuss the project with engineers at NASA’s Marshall Space Flight Center. "Anyplace we go in space, we’re going to need some source of power."

To many experts, the notion of lunar colonies is no longer science fiction.

In December, NASA announced plans to build a permanent base on the moon sometime after 2020 and "probably into the 2024 time frame," according to Scott Horowitz, an associate administrator at the agency.

In June, Rutgers University will host a symposium on lunar settlements.

"It will definitely happen. People who are in their 20s and 30s today, they will see people living on the moon within their lifetimes," said Haym Benaroya, a professor at Rutgers and director of the school’s Center for Structures in Extreme Environments.

No less an authority than British physicist Stephen Hawking has suggested that in the face of such threats as nuclear war and global warming, mankind’s survival may depend on establishing colonies on the moon or Mars.

And there are other motives that may lead humans to settle the moon.

"To offer mankind a larger vision, manifest destiny, that kind of thing," Benaroya said. "It will certainly change the lives of our children and grandchildren."

Nevertheless, the National Aeronautics and Space Administration’s plans for lunar settlements have drawn some skepticism. James Benson, founder and president of the space tourism firm Benson Space Co., said the moon lacks the natural resources that would make establishing colonies there financially worthwhile.

"The bottom line," he said, "is that if we want to go to space to stay, space has to pay."

Power generation a key

If NASA does pursue lunar colonies, one of the challenges the agency will face is the very problem the Milwaukee students tackled — generating power on the moon.

"Energy is a prime driver for anything we want to do on the moon, so what these kids are doing is really a first-order endeavor," said Larry Taylor, who served as one of 20 or so "back-room" advisers guiding astronauts during the Apollo 17 mission in 1972. He now directs the Planetary Geosciences Institute at the University of Tennessee.

Taylor said power will be vital not only for running permanent settlements, but also for operating lunar stations to refuel vehicles traveling back to Earth. A specific plan for generating the power has yet to be developed, though Taylor said, "we’re pretty much going to be restricted to using the sun in one form or another."

At MSOE, the power plant project was conceived in 2005 by student Mark Cichon. He was looking for a venture that would involve thermodynamics, the study of the relationship between heat, work, temperature and energy. While reading an article about the huge temperature shifts on the moon, he recognized how this might prove advantageous for generating power.

Unfortunately for Cichon, the students he planned to work with eventually chose another project, a Baja racer. Cichon wound up working on a heat recovery system for Lakefront Brewery.

Still, adviser Swedish, 54, liked Cichon’s idea and proposed it to a new group of students, who embraced it instantly.

For senior Jeffrey Reiter, the project offered the chance to pursue a childhood interest in space that included visits to the Kennedy Space Center, construction of model rockets and hours spent staring through telescopes and watching television’s "The X-Files."

Moon’s south pole is ideal

The students decided on an ideal location for the power plant: the moon’s south pole at the rim of the Shackleton crater, which receives almost perpetual sunlight. Atop a tower would sit a reflective panel, about 100 feet by 50 feet, fitted with pipes. The panel would collect the sun’s energy, heat a fluid running through the pipes and use the energy from that heat to run a turbine. The panel would rotate to capture the maximum amount of sunlight.

The low temperatures of space would allow the plant to vent excess energy, much the way a car’s radiator prevents it from overheating.

The students realized they would need to learn everything they could about the lunar surface.

"Know your enemy," said Ron Goodman, 22.

One of the major challenges would be synchronizing the collector to the moon’s movements in relation to the sun. To better understand this, Reiter designed a computer program to track the moon-sun relationship.

"At night," he said, "I wouldn’t sleep a lot of hours because I wanted to dive right into it — trying to figure out the sun, the Earth, the moon, how do they move in relation to each other?"

Meanwhile, Michael McCambridge, 22, focused on the thermal cycle, figuring out how hot the fluid in the pipes would need to be and how much power the turbine would supply. Momenee worked on designing a control system that would make the collector follow the sun. Goodman tackled questions about the size of the system — in particular, how long the pipes on the collector would need to be. Tim Swets, 22, researched the best sites on the moon for the power plant, and Chris Edwards, 22, worked on the plant layout.

In February, the students visited the Marshall Space Flight Center to present their project and hear presentations by NASA engineers on the lunar surface and orbital mechanics.

The student project is "very relevant to what we’re trying to do," said Richard G. Schunk, an aerospace engineer at Marshall. "NASA is looking at long-term human habitation of the moon, potentially staying there permanently or months at a time. . . . For the first human colonies on the moon, you’d probably need 10 kilowatts."

That’s roughly more than the amount needed to power a home but less than what’s needed to power a school. The plant the students have envisioned would have a much greater output — about 200 kilowatts.

For their final grade, the students will submit a 150-page report on the project. They are hoping, though, that new groups of seniors will tackle some of the problems they didn’t have time for: an assessment of what fluids would work best in the pipes on the collector; a structural analysis for the tower; and an examination of how materials could be packaged and transported as efficiently and inexpensively as possible.

"This hopefully doesn’t end with us," Momenee said.