Exploring farther out into the cosmos requires innovative, cutting-edge technologies to drive the missions. The NASA Innovative Advanced Concepts (NIAC) program helps to unlock visionary ideas.
Recently, the NIAC program selected the Diffractive Solar Sailing project for the Phase III study. This solar sail concept could carry science to new destinations.
Solar sails use the pressure exerted by sunlight to move a vehicle across space. It is similar to how a sailboat uses the wind to span the ocean. Existing reflective solar sail designs are often huge and thin, and they are constrained by the direction of the Sun, necessitating power and navigation choices. Small gratings embedded in thin films would be used in diffractive light sails to take advantage of diffraction, a feature of light that causes light to spread out when it passes through a narrow hole. This would allow the spaceship to utilize sunlight more efficiently while maintaining agility.
Mike LaPointe, acting program executive for the NIAC program at NASA Headquarters, said, “NIAC allows us to foster some of aerospace’s most creative technology concepts. Our goal is to change the possible and diffractive solar sailing promises to do just that for several exciting new mission applications.”
Diffractive light sailing would extend solar sail capability beyond what’s possible with missions in development today. The project is led by Amber Dubill of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. The feasibility of the concept was previously studied under NIAC’s Phase I and Phase II awards, led by Dr. Grover Swartzlander of Rochester Institute of Technology in New York, who continues as a co-investigator on the project. ‘
Les Johnson, lead for two of NASA‘s upcoming solar sail missions at NASA’s Marshall Space Flight Center in Huntsville, Alabama, also is a co-investigator. Under the earlier awards, the team designed, created, and tested different types of diffractive sail materials, conducted experiments, and developed new navigation and control schemes for a potential diffractive lightsail mission orbiting the Sun’s poles.
NASA noted, “Phase III study will optimize the sail material and perform ground tests supporting this conceptual solar mission. Orbits passing over the Sun’s north and south poles are difficult to achieve using conventional spacecraft propulsion. Lightweight diffractive lightsails, propelled by the constant pressure of sunlight, could place a constellation of science spacecraft in orbit around the Sun’s poles to advance our understanding of the Sun and improve our space weather forecasting capabilities.”
Dubill said, “Diffractive solar sailing is a modern take on the decades-old vision of light sails. While this technology can improve many mission architectures, it is poised to highly impact the heliophysics community’s need for unique solar observation capabilities. With our team’s combined expertise in optics, aerospace, traditional solar sailing, and metamaterials, we hope to allow scientists to see the Sun as never before.”