By Wayne Smith
In his youth, NASA technologist Les Johnson was fascinated by the 1974 novel “The Speck in the Eye of God,” by Jerry Pournelle and Larry Niven, in which an extraterrestrial spacecraft powered by solar sails visits humanity. . Today, Johnson and a NASA team are preparing to test similar technology.
NASA continues to roll out plans for solar sail technology as a promising method of deep space transportation. The agency achieved a key technological milestone in January with the successful deployment of one of four identical solar sail quadrants. The display was on display Jan. 30 at Redwire Corp.’s new facility in Longmont, Colorado. NASA’s Marshall Space Flight Center in Huntsville, Alabama, leads the solar sail team, comprised of prime contractor Redwire, which developed the deployment mechanisms and nearly 100-foot-long barriers, and subcontractor NeXolve, of Huntsville, which provided the sail membrane. In addition to leading the project, Marshall developed the algorithms necessary to control and navigate the sail when it flies in space.
Sailing is a propulsion system powered by sunlight reflected from the sail, much like a sailboat reflects the wind. While only a quarter of the sail was deployed in the deployment at Redwire, the entire sail will measure 17,780 square feet when fully deployed, thinner than a human hair at 2 and a half microns. The sail is made of an aluminum-coated polymer material.
NASA’s Science Mission Directorate recently funded solar sail technology to reach a new technology readiness level, or TRL 6, meaning it is ready for proposals to be carried out on science missions.
“This was a last important step on the ground before it is ready to be proposed for space missions,” said Johnson, who has been involved with sail technology at Marshall for about 25 years. “The next thing is for scientists to propose the use of solar sails in their missions. “We have met our objective and we have shown that we are ready to fly.”
A solar sail traveling through deep space offers many potential benefits for missions using this technology because it requires no fuel, allowing for very high propulsion performance with very little mass. This space propulsion system is well suited for low-mass missions in novel orbits.
“Once you get away from Earth’s gravity and into space, the important thing is efficiency and enough thrust to travel from one position to another,” Johnson said.
Some of the missions of interest that use solar sail technology include the study of space weather and its effects on Earth, or advanced studies of the north and south poles of the Sun. The latter has been limited because the propulsion necessary to carry a spacecraft space to a polar orbit around the Sun is very high and is simply not feasible using most of the propulsion systems available today. Solar sail propulsion is also possible to enhance future missions to Venus or Mercury, given their closeness to the Sun and the greater thrust a solar sail would achieve in the more intense sunlight there.
Plus, it’s the ultimate green propulsion system, Johnson said: As long as the sun shines, the sail will have propulsion. Where sunlight is less, he imagines a future in which lasers could be used to accelerate solar sails to high speeds, pushing them out of the solar system and beyond, perhaps even to another star. “In the future, we could place large lasers in space that shine their beams on the sails as they leave the solar system, accelerating them to higher and higher speeds, until they eventually go fast enough to reach another star in a reasonable amount of time.” time. time.”
To learn more about solar sails and other advanced space technologies from NASA, visit:
Marshall Space Flight Center, Huntsville, Alabama.