Another emerging space technology is solar sails — specifically, diffractive solar sails.

Solar sails, in general, work due to the force of photons – which do have mass equivalent through energy – hitting the sails, reflecting off, and causing an equal/opposite reaction. This process produces a very, very small but constant thrust, allowing spacecraft to build up speed gradually over months and years. This technology could get spacecraft to orbits not possible with chemical propulsion, such as orbiting the Sun’s poles.

Diffractive solar sails add small patches of diffraction grating to the sail, using them to make the sail lighter and produce even more thrust by focusing light in the grates. Diffraction is also why you may get soft images with a camera if you step down the lens aperture a lot. The small diffraction patches also let the spacecraft steer more easily by allowing the spacecraft to move further away from the Sun and still produce thrust.

A team from the Johns Hopkins Applied Physics Laboratory was recently given a $2 million phase three grant from the NASA Innovative Advanced Concepts (NIAC) program to bring these diffractive sails to a flight demonstration in a few years. The team is led by Amber Dubill, who was recently a guest on the Weekly Space Hangout, our sister podcast. We’ll link to her interview in our show notes at DailySpace.org.

More Information

NASA press release