Solar sail technology is continuing to rapidly move towards its potentially game-changing role in the future of space flight. NASA will be launching in 2014 what is, as of now, the world’s largest solar sail ever constructed. This solar sail spacecraft, dubbed Sunjammer, will serve as a test and demonstration for the technology, and will then likely be used in the future in missions to near-Earth asteroids (NEAs), and possibly in missions to objects at the edge of and beyond the solar system.
The technology stands out for its relative affordability and complete lack of fuel use. It is accelerated entirely by photons from the Sun. The somewhat different electric solar sail also possesses many of the same advantages as the conventional solar sail, but is probably further off into the future.
“Dubbed Sunjammer, the giant solar sail measures about 124 feet on a side and boasts a total surface area of nearly 13,000 square feet,” Space.com writes. “The project is under the wing of NASA’s Space Technology Program, within the agency’s Office of the Chief Technologist.”
The Sunjammer was built by L’Garde Inc. of Tustin, California, after being contracted by NASA to build the spacecraft. They have worked previously with NASA on several projects. The name ‘Sunjammer’ apparently comes from a fictional story about a ‘yacht race’ in space done using solar sails, written by the author Arthur C. Clarke.
Interestingly, the Sunjammer will be launched by SpaceX (the rocket and spacecraft company started by Elon Musk of Tesla Motors and Paypal), on top of one of its Falcon 9 rockets. The solar sail technology itself seems as though it will be very attractive to many private space companies, potentially allowing for the cheap harvesting of resources from asteroids.
“NASA is keen to infuse solar sail technology into other potential game-changing mission capabilities. Possibilities (that) include the collection and removal of orbital debris, deorbiting spent satellites, providing a direct communications link to Earth’s south pole, as well as for deep space propulsion.”
“All space travel right now is limited by expendables,” said Billy Derbes, the chief engineer for Sunjammer. “If you show a technology not limited by expendables — and Kapton (the material the solar sail is constructed from) is a long-lasting film material — what new applications will people think up? We’re opening up a whole new kind of thinking about how you do things in space.”
One of these applications is for visiting multiple NEAs. NASA recently completed a study on the use of a solar-sail-propelled spacecraft for this purpose.
“We found that a Sunjammer-derived sail could visit up to six NEAs within six years of being launched. This would be impossible with chemical rockets and might not be achievable by electric propulsion. And it’s all because the sail uses no propellant … deriving its thrust from sunlight, making it a very ‘green’ space propulsion system,” Les Johnson, deputy manager of the Advanced Concepts Office at NASA’s Marshall Space Flight Center in Huntsville, AL, said.
“For me, I’m most excited about using a solar sail unfurled close to the sun, inside the orbit of Mercury, and using the increased solar pressure there to accelerate a large solar sail to speeds that will allow it to reach well beyond the edge of the solar system and into interstellar space within my lifetime.”
The economic advantages of the solar sail, compared to currently used space exploration technologies, are so enormous that it would be hard to imagine that the technology does not end up being used on a large scale, potentially even in exploration beyond the solar system. But that is presuming that space exploration/resource extraction remains viable into the future, as climate change and its effects on civilization intensify.
Image Credit: NASA and L’Garde