Solar Sails Could Send Spacecraft 'Sailing' Through Space
Sailing through space? The concept could soon be a reality. NASA could soon travel through space with the use of gigantic solar sails -- some as large as a football field. The sails use the Sun's energy to propel a spacecraft -- much the way wind pushes sailboats across water.
"We are making the stuff of science fiction into reality," said Les Johnson, manager of the In-Space Propulsion Technology Projects Office at the Marshall Space Flight Center in Huntsville, Ala. "It has been a tremendous engineering challenge, and I'm pleased and proud of the teams that have made it happen."
Image right: A four-quadrant solar sail system sits fully deployed in a 100-foot-diameter vacuum chamber at NASA's Glenn Research Center Plum Brook Station in Sandusky, Ohio. NASA's solar sail propulsion team at the Marshall Space Flight Center in Huntsville, Ala., and its industry partner, L'Garde, Inc., of Tustin, Calif., successfully deployed the solar sail system during testing at the Plum Brook facility in early July 2004. Image credit: NASA/L'Garde, Inc.
The excitement surrounds the recent deployment of two solar sails -- each nearly 33 feet in length along one side -- by NASA engineers and their industry partners. The successful deployments reach a critical milestone in the development of a unique propulsion technology -- one that could enable future deep space missions.
Image right: A single-quadrant, 10-meter solar sail system sits fully deployed in a 50-foot-diameter vacuum chamber at NASA's Langley Research Center in Hampton, Va. NASA's solar sail propulsion team at the Marshall Space Flight Center in Huntsville, Ala., and its industry partner, Able Engineering, of Goleta, Calif., successfully deployed the solar sail system during testing at the Langley facility over a five-week period from April to May 2004. Image credit: NASA/Able Engineering.
Solar sail propulsion technology bounces a stream of solar energy particles called photons off giant, reflective sails made of lightweight material 40 to 100 times thinner than a piece of writing paper. The continuous pressure provides sufficient thrust to perform maneuvers, such as hovering at a point in space and rotating the space vehicle's plane of orbit, which would require too much propellant for conventional rocket systems. Because the Sun provides the necessary propulsive energy, solar sails also require no onboard propellant, thus reducing payload mass.
The most recent test was completed in July by L'Garde, Inc., of Tustin, Calif. Able Engineering of Goleta, Calif., successfully completed testing of its own solar sail design in May. The work of both contractors is led by the In-Space Propulsion Technology Projects Office at the Marshall Center.
Image left: Animation shows a solar sail concept in flight, as designed by L'Garde, Inc., of Tustin, Calif. Animation credit: NASA.
View solar sail animation (QuickTime format, 6.0 MB)
L'Garde's sail deployment was conducted in a 100-foot-diameter vacuum chamber at NASA's Glenn Research Center Plum Brook Station in Sandusky, Ohio. The tests included temperatures as cold as minus 112 degrees Fahrenheit to simulate the conditions of open space.
The sail technology used a boom system that inflates and becomes stiff in space environment conditions. The boom is the core of the support structure for the thin, reflective solar sail -- merely a fraction of the thickness of a human hair -- and includes a stowage structure, which is about the size of a suitcase, and a built-in deployment mechanism.
Image left: Animation shows a solar sail concept in flight, as designed by Able Engineering of Goleta, Calif. Animation credit: NASA.
View solar sail animation
In May, Able Engineering also successfully completed testing of a solar sail design at NASA's Langley Research Center in Hampton, Va. This sail technology employed a "coilable" graphite boom, which is extended or uncoiled by remote control -- much the way a screw is rotated to remove it from an object.
These tests were conducted in a 50-foot-diameter vacuum chamber and began in April. Engineers then spent the next five weeks studying its shape and system dynamics -- or how the solar sail functions in relation to force, weight and tension.
Data from both tests will be used to make improvements to future solar sail design and modeling. In March 2005, NASA plans a laboratory deployment of a sail more than 65 feet in length.
For more information about solar sails and in-space propulsion, visit: http://www.inspacepropulsion.com/
For more information, see also:
+ Solar Sails News Release
+ Solar Sails Photos
+ Solar Sails Animations
Martin Jensen, Marshall Space Flight Center