A VESSEL GLISTENS IN THE REFLECTION OF THE SUN'S LIGHT. Its gossamer sails tack to capture the maximum force as it accelerates. In the vacuum of space, the vessel silently races ahead. No rockets push it along; unlike its earthbound sailing counterparts, this vessel is not driven by the wind. Its power is the glow of the sun as light photons dance upon its expansive yet ethereal sails, propelling it forward -- to the moon, Mars, beyond?

 

Some may say it's the stuff of science fiction and runaway imaginations, but integrated science and technology professor Joe Blandino knows better. The concept of solar sails is being tested and pursued by NASA and others, and it's also the focus of ongoing research being conducted by Blandino, colleague Jonathan Miles and a handful of their students.

Blandino, his boyish delight with the prospects of this budding technology barely concealed, believes solar sails just might be the future of space exploration. "We're explorers by nature," Blandino explains. And just as explorers of old ventured on the high seas to distant, unknown lands, Blandino envisions solar-sail spacecraft gliding to Mars and beyond. Given the landings of the Spirit and Opportunity rovers on Mars and President Bush's call in January for renewed emphasis on manned space exploration, with the moon as a steppingstone to the universe, Blandino's enthusiasm is justified.

Solar sails are one of three propulsion technologies now being studied by NASA. According to Blandino, the solar-sail technology is perhaps the most promising of the three for long-duration missions of five years or more. What solar-sail technology has that others don't is both weight and cost advantage. It doesn't rely on fuel for propulsion, so it doesn't need to bear the mass or expense of a fuel supply.

Rather, the sails -- large lightweight reflectors that are about 100-times thinner than a sheet of paper -- capture the power of photons, tiny packets of quantum energy that hit the surface of the sail membrane. The force of that hit plus the force of the photon reflecting off the sail surface gives the sail momentum. Granted, it's not a huge amount of force -- only one one-thousandth of the force of Earth's gravity. But its result is constant acceleration. And since the vessel is traveling in the zero gravity vacuum of space, over a period of time, the sails pick up speed -- lots of speed. Under some scenarios, interstellar solar sail crafts could reach speeds of up to one-tenth the speed of light -- about 18,628 miles per second.

The possibilities are staggering. More modest, practical applications include using solar-sail technology to propel spacecraft out of Earth's orbit to study the polar regions of the sun or serve as an early warning system for solar flares like the kind that wreaked havoc on satellites and communication networks last fall. But stretch your imagination a bit, and new possibilities come into focus -- solar-sail supply ships for a Mars colony, for instance. Blandino imagines solar sails measuring 1 kilometer square being deployed on a regular basis, "like sailing ships that resupplied the colonies on Earth."

Blandino, Miles and their student researchers plan to be there every step of the way. "I'm hoping we're going to take it all the way to space," Blandino says. The goal is for NASA to conduct a flight demonstration of a solar sail within five years.

Both professors are part of NASA's efforts to develop a solar sail. Blandino and Miles are on a team led by Richard Pappa at the NASA Langley Research Center in Hampton. The team is developing an Optical Diagnostic System for solar sails. The team is made up of eight research groups throughout the country that communicate through scores of e-mails, a weekly teleconference and group meetings every other month. Other members of the team are South Dakota School of Mines and Technology, Texas A&M and industry partners Ecliptic Enterprises and Tethers Inc.

"I think our relationship is a win-win situation," Pappa says. "NASA Langley benefits from receiving high-quality technical work at a cost significantly less than the fees typically charged by aerospace companies for similar work. Also, the research nature of much of the work in Phases 1 and 2 make the university environment a better place to perform the work. I'll add that Dr. Blandino has worked with us for the past two summers in the NASA Faculty Fellowship Program and built the foundations of our relationship during these periods. Seeing the quality of his work, the ODS team invited him on the team at the beginning to help write the proposal for the work."

The team's job is to come up with an array of cameras, sensors and data recorders to monitor the operations of the solar sail while it is in space. This optical diagnostic system must provide the information controllers on Earth needed to make sure the spacecraft is behaving like they thought it would.

JMU's research is funded by more than $315,000 in NASA money, awarded in phases, plus other grants. Additionally, ILC Dover, the company that designed the Apollo, Skylab and Space Shuttle space suits and is working on inflatable booms for solar-sail applications, has provided $5,000 for a boom structural characterization study at JMU and has provided JMU with two booms that cost $10,000 each. Blandino has also collaborated with ILC Dover and Luna Innovations Inc. of Blacksburg on the first successful Small Business Innovative Research grant in JMU's history. The award will be used to develop a fiber optic-based shape sensor for solar sail applications.

In 2002 the team of Blandino and Miles received a $415,000 grant from the National Science Foundation, with JMU adding another $80,000 for the purchase of equipment needed for their solar-sail research. "It was sort of a snowballing effect," Miles says. "The research led to the realization that you could do more with more equipment. And more equipment will lead to even more research possibilities for students." Miles notes that a major reason the NSF cited for awarding JMU the grant was the educational benefit for students this equipment could bring. "A key selling point for them was student involvement. We have a fair number of students who have published in premier research journals or presented at national conferences."

"What surprises most people," Blandino notes, "is that we do it all with undergraduates." From an academic standpoint, the beauty of such a research approach is that it affords JMU students a tremendous opportunity to be involved in current, relevant research.

"We're finding a niche here," according to Miles. "There are special elements of ISAT that are lacking in some traditional engineering programs -- primarily the hands-on mentoring, instruction, special attention and diversity of topics."

Add commitment and enthusiasm. Mentoring undergraduate research "is very time consuming," Blandino stresses. "You have to be there 90 percent of the time. But then there's that moment of discovery, when students find that missing piece to the puzzle. That's the fun part. What our students may lack in experience, they more than make up for in enthusiasm."

That enthusiasm is contagious. Danielle Rockwood, now a graduate student at the University of Delaware, worked with several other students on research that eventually led to the development of an instrument that can measure tropospheric carbon monoxide by using the full moon as a radiant source and measuring how much infrared radiation from the full moon is absorbed at different wavelengths. To get those measurements, the research team needed a full moon, good weather and a healthy dose of Miles' infectious exuberance. "How else would he get us on top of the roof of [the] ISAT [building] at 7 p.m. in January?" Rockwood asks. Miles recalls even more unconventional meeting times. "We even were out as early as 5 a.m. one morning two years ago."

JMU's Infrared Development and Thermal Testing Laboratory, home to the solar-sail research and other efforts, provides not only the place and equipment but also the challenges to launch students into graduate school and careers.

"Much of the research in the IDTTL is graduate-level work," student researcher Stef Bourne, a junior, says. "I feel that working in the lab has offered me a competitive edge over my peers. Being involved in such prestigious research projects is truly an honor, and I feel that it has prepared me for potential research that I may encounter in graduate school."

JMU alum Daniel Evanchik ('02), now pursuing a Master of Science degree in systems engineering at the University of Virginia, agrees. "One day my academic path may lead to a doctoral degree, and I associate that completely to the spark I got in the NASA lab at JMU."

Evanchik notes that his JMU research, under the mentorship of Blandino, gave him "a unique insight into research that I could not have received in a classroom ... I learned how to see a complex research topic through from developing a test plan; designing, purchasing, building of the test apparatus; designing software; conducting tests; analyzing the data; and formulating the results in the form of a thesis paper."

Blandino's role as mentor was one of providing guidance while giving students the freedom to make mistakes and learn from their errors. "He took the time to show me how I made the error, why I did, how to fix it and then how to prevent me from making it a second time," Evanchik says. "This, to me, showed a distinct commitment to educating rather than instructing."

This style demands a level of trust between professor and student. Junior Chelsea Jenkins notes that Miles "assigns tasks and has no doubt that we will be able to finish them. This independence forces us to explore areas we are not very familiar with, which provides an environment for learning."

Like the NSF grant, the research itself can snowball into new opportunities. "This experience, in conjunction with other research projects, has definitely helped me in seeing more of how the 'real world' works," Jenkins says. As a result of her research at JMU, Jenkins will intern this summer as part of the Langley Aerospace Research Summer Scholars program at NASA's Langley Research Center. She and Bourne conducted a separate infrared study last fall for Freightliner LLC. They traveled together to Freightliner headquarters in Portland to implement the test plan they devised with Miles back at JMU.

This level of research has students' heads spinning with the possibilities. "I just find it hard to believe that real NASA and other scientists in the field are judging our work and considering the use of our research in order to potentially see the flight of a solar sail," says Christopher Smith, a junior working under Miles.

JMU's role in the NASA research of solar-sail technology and its accompanying student involvement began about three years ago and currently involves Blandino, Miles and about eight students. Their primary contribution to the Optical Diagnostic System for Solar Sails is to determine the thermal performance of the sails -- how they behave in the temperature fluctuations of space.

As part of their research, the JMU team is charged with predicting the thermal strain on the solar-sail structure, which can change dramatically with temperature variations of 1 degree Celsius from one side of the massive sail to the other. These variations can have dramatic effects on how the craft behaves and responds to control inputs.

The team of Blandino and Miles operates under the assumption that "two heads are better than one," Miles notes, with each bringing his own area of expertise to the table. Blandino's expertise is in thermal structural interaction, while Miles specializes in infrared sensing, imaging and analysis.

The JMU researchers currently are testing a miniature infrared imager, "about the size of two or three Tic Tac boxes glued together," as a possible component for the optical diagnostic system, Miles says. It's hoped that the imager will provide the information needed to determine the sail's temperature variations. "We're at the point that we're just learning how to interpret images from such a complex material," Miles says. "We've developed a model to predict temperatures." Now it's time to see if the images and the model match up.

The challenge is that all this testing must involve noncontact measurement techniques. The sails are low mass and flexible structures. They are designed to operate beyond Earth's gravity. Instruments attached to the sail surface will alter the behavior of the structure. That's why thermal imaging is used to measure the sail temperature. Blandino is also working with NASA Langley to develop methods to measure sail shape. He is using a technique called close-range photogrammetry. This is a tool used by geographers to develop contour maps but is also well suited to profiling the surface of solar sails.

However, "ground testing is important to validate the design calculations," Blandino says. "The only way you can demonstrate the capabilities of a sailcraft is with a flight demonstration." So the final phase of testing will, he hopes, be a test flight. "Once you are in space, you can always have surprises; but if you do thorough ground testing, you will minimize the surprises."

This summer the testing will ratchet up a notch with scheduled ground testing of a

10-meter sail at NASA's Langley research facility. In February 2005, testing on a 20-meter model will take place at NASA's Plum Brook facility in Ohio.

When they finally make it to test flight, the solar sails, which will be launched into space on a rocket, will deploy from a small container with a volume of about 1 cubic meter opening the gigantic membrane of super-thin material. A demonstration sail will be approximately 40 by 40 meters, while larger ones may stretch to 100 by 100 meters. These mammoth dimensions are needed because as mass of the payload increases, the size of the sail increases. "It takes a huge membrane to move a useful mass around," Blandino notes.

Once deployed, the "sailing" techniques used to guide the vessel are remarkably similar to those used on nautical sail boats. "You can tack just like a sailing ship," Blandino says, "only instead of tacking against the wind you're tacking against light pressure by changing the angle of the sail to the sun."

Blandino and Miles hope that solar-sail technology will provide an economy of scale never realized with previous NASA programs. Blandino vividly remembers a NASA presentation he attended as a boy. The speaker predicted that with the launch of the then-future space shuttle, people would travel into space for as little as $80 a pound. The young Blandino quickly did the math, figured he'd need a bit more than $4,000 to make the trip and started saving. Unfortunately, those predictions were wrong. Today, it costs about $8,000 to send something the size of a can of soda into space on the space shuttle, Blandino says. A trip to Mars for something that small would cost between $30,000 and $50,000.

But Blandino also notes it's often tough to factor all the economic and social benefits that past NASA programs have amassed. "Things that we take for granted today in our everyday communications and in the health-care field -- computer networks, image processing, medical telemetry, weather satellites and more -- are all technologies from the space program. The lunar landings gave us the 'children of Apollo' -- the kids who were motivated to study science and engineering and developed America's technology-based economy." These have direct ties to the space program, Blandino says. "So maybe there was a pretty good return on our investment."

Even so, solar sails, propelled by sunlight, could push the economic potential of missions to new levels. "All sorts of neat things are waiting to happen," Blandino says with a grin. And he, Miles and their handful of student researchers plan to be a part of it all.

 

Story by Margie Shetterly

Photos by Casey Templeton ('06)

Illustration and design by Troy McDevitt