Diffractive photo voltaic sails, depicted on this conceptual illustration, may allow missions to hard-to-reach locations, like orbits over the Solar’s poles.
MacKenzi Martin
NASA on Tuesday mentioned it is investing $2 million over two years to advance the event of a brand new photo voltaic sail idea known as diffractive lightsailing. With diffractive lightsails, NASA may probably propel a constellation of science spacecraft into orbit across the Solar’s poles — one thing that is troublesome to realize utilizing typical spacecraft propulsion.
A lot in the best way a sailboat makes use of the wind to maneuver ahead, photo voltaic sails use the strain exerted by daylight to propel a automobile by way of house. Massive sails made up of reflective materials like Mylar seize the momentum of the Solar’s photons. The photons bounce off the sail, sending it in the wrong way.
Nevertheless, as NASA factors out, present photo voltaic sail designs depend on very massive and really skinny sails. They’re additionally restricted by the route of the daylight — in different phrases, it is onerous to navigate with out sacrificing solar energy.
In contrast, diffractive lightsails would use small gratings embedded in skinny movies to diffract the sunshine — spreading it out because it passes by way of a slim opening. This may enable a spacecraft to make extra environment friendly use of daylight with out giving up maneuverability.
“Diffractive photo voltaic crusing is a contemporary tackle the many years outdated imaginative and prescient of lightsails. Whereas this expertise can enhance a mess of mission architectures, it’s poised to extremely impression the heliophysics neighborhood’s want for distinctive photo voltaic commentary capabilities,” Venture chief Amber Dubill, of the Johns Hopkins College Utilized Physics Laboratory, mentioned in an announcement. “With our group’s mixed experience in optics, aerospace, conventional photo voltaic crusing, and metamaterials, we hope to permit scientists to see the Solar as by no means earlier than.”
The Diffractive Photo voltaic Crusing mission is a part of NASA’s Modern Superior Ideas (NIAC) program. The most recent spherical of funding is a part of the mission’s development to Part III of the NIAC.
To this point, Dubill’s group has designed and examined several types of diffractive sail supplies. They’ve additionally designed new navigation and management schemes for a possible diffractive lightsail mission orbiting the Solar’s poles.
With the brand new funding, researchers will work on optimizing the sail materials and carry out floor exams, in preparation for a future potential demo mission.
Whereas it is funding the diffractive lightsailing idea, NASA already has different photo voltaic sail missions deliberate. When the Artemis I uncrewed take a look at flight to the Moon launches later this 12 months, it’s going to carry with it the NEA Scout — a small spacecraft powered by photo voltaic sail expertise, designed to go to near-Earth asteroids. To succeed in asteroid 2020 GE, NEA Scout will unfurl a photo voltaic sail, demonstrating how properly the expertise works in deep house.
In the meantime, in late 2022, NASA’s Superior Composite Photo voltaic Sail System will deploy a photo voltaic sail from a CubeSat. After that, Photo voltaic Cruiser, an 18,000-square-foot photo voltaic sail expertise demonstration, will use daylight to journey towards the Solar in 2025.
There are additionally nongovernmental entities creating the expertise. In 2019, the US-based nonprofit Planetary Society launched LightSail 2, a spacecraft at the moment working below an prolonged mission to additional advance photo voltaic crusing expertise.
