Diffractive solar sails, depicted in this concept illustration, could enable missions in hard-to-reach places, such as orbits above the Sun’s poles. Credit: MacKenzi Martin.
NASA wants to invest $2 million over two years to advance the development of a new solar sail concept, called a diffractive light sail. Using these diffractive sails, NASA could potentially propel a constellation of scientific spacecraft into orbit around the Sun’s poles, which is difficult to achieve with conventional spacecraft propulsion.
In the same way that a sailboat uses the wind to move forward, solar sails use the pressure exerted by sunlight to propel a vehicle through space.
Large sails made of a reflective material like Mylar capture the momentum of photons from the Sun. The photons bounce off the sail and send it in the opposite direction.
Material tests and new navigation schemes
However, as NASA points out, existing solar sail designs rely on very large, very thin sails. They are also limited by the direction of sunlight – in other words, it is difficult to navigate without sacrificing solar power.
In contrast, diffractive light veils would use small gratings embedded in thin films to diffract light, i.e. spread it out as it passes through a narrow aperture. This would allow a spacecraft to use sunlight more efficiently without giving up maneuverability.
“The diffractive solar sail is a modern take on the decades-old vision of light sails. If this technology can enhance a multitude of mission architectures, it is poised to have a tremendous impact on the needs of the heliophysical community for unique solar observing capabilities,” said project leader Amber Dubill in a statement. , from the Johns Hopkins University Applied Physics Laboratory. “With our team’s combined expertise in optics, aerospace, the traditional solar sail, and metamaterials, we hope to enable scientists to see the Sun like never before. »
The diffractive solar sail project is part of NASA’s Innovative Advanced Concepts (NIAC) program. The latest round of funding is part of advancing the project to NIAC Phase III. So far, Amber Dubill’s team has designed and tested different types of diffractive sail materials. She also designed new navigation and control schemes for a possible diffractive light sail mission orbiting the Sun’s poles.
The solar sail, a technology exploited elsewhere
Thanks to this new funding, the researchers will work on optimizing the material of the sail and will carry out tests on the ground, in view of a possible demonstration mission.
Although funding the diffractive light sail concept, NASA has already planned other solar sail missions. When the Artemis I uncrewed test flight to the Moon launches later this year, it will take with it the NEA Scout – a small spacecraft powered by solar sail technology, designed to visit asteroids near Earth. To reach asteroid 2020 GE, NEA Scout will deploy a solar sail, demonstrating how well this technology works in deep space.
Meanwhile, in late 2022, NASA’s Advanced Composite Solar Sail System will deploy a solar sail from a CubeSat. Then, in 2025, the Solar Cruiser will use sunlight to head towards the Sun.
Non-governmental entities are also developing this technology. In 2019, the US-based nonprofit Planetary Society launched LightSail 2, a spacecraft currently operating on an extended mission to advance solar sail technology.
Source: ZDNet.com