NASA physicist discusses Nanotechnology in Space
A senior physicist at one of the world’s leading space agencies gave a seminar about space photovoltaics on Feb. 1, in the UALR Student Service Center auditorium
Sheila Bailey of the NASA Glenn Research Center in Cleveland, Ohio, discussed the agency’s goal of making solar cells cheaper and more efficient. She claimed that solar cells will be around for years to come. In fact, she said that communication satellites, used to stream this year’s Super Bowl, are powered by solar cells.
“Solar cells are used for communication purposes as well as surveillance for the military,” Bailey said.
She introduced the topic by giving a brief history and explaining the origin of solar cells. Russian satellite Sputnik was the beginning of the space activity, according to Bailey. But she described the lifespan of solar cells back in 1957 as being relatively short, with batteries lasting only 20 days. She also revealed some of NASA’s current endeavors.
“We are developing the crew vehicle for the international space station; it will be the emergency vehicle,” she explained. “This vehicle is powered by solar cells.” Bailey recalled that on her first day of work, her boss gave her simple instructions: “Make a better solar cell.”
“So I went off to make a better solar cell and I’ve been trying to do that for the last 28 years,” she said.
Solar cells have come a long way in terms of efficiency, according to Bailey. “When we started back in the ‘80s, solar cells were about 6 percent efficient,” which means only that amount of the sunlight is turned into electric power.
“We are now up to 36 percent for space cells,” she said. For audience examination, Bailey brought an actual solar panel, which was small and lightweight. She said that size is a major limitation for solar cells, and that it currently costs around $10,000 per pound to put anything into space.
There are several ways to lower costs, but Bailey does so by working with nanostructure material. She said that solar cells with up to 40-percent efficiency are not out of reach. Two new innovations include making thin-film cells on a flexible structure and cells that peel off. She noted that solar cells used outside of our solar system have lower efficiency than their terrestrial counterparts.
Bailey also discussed the triple-junction cell: “This is the best commercial space cell — you can go buy one right today.” It has 29.9 percent efficiency and is currently on the market at prices as high as $750 per cell, which according to Bailey is quite expensive.
The seminar drew students from variety of disciplines. Kelly Singer, English and French double major, was among audience members. “I love learning about NASA itself, there are so many more aspects to it than just putting astronauts in space and improving the international space station,” Singer said.
Bailey invited students seeking employment to visit NASA’s website (nasa.gov). The agency offers jobs to those seeking employment as administrators, engineers, scientists and skilled craftsmen. She said that employment at the agency has been stable in recent years and will continue to be so in the future.