Scientist and television personality Billy Nye recently discussed how solar spacecraft can revolutionize space travel. He also explained how this type of spacecraft can be used as part of Earth's planetary defence against asteroids.
Earlier this year, The Planetary Society launched the LightSail 2 through SpaceX's Falcon Heavy rocket. Once in space, LightSail 2 deployed its large solar sail to gather energy from the Sun.
Revolutionizing Space Travel
The LightSail 2 relies on solar radiation as its main means of propulsion. It moves through the pressure applied by solar photons on the sail. According to Nye, The Planetary Society's executive director, LightSail 2 perfectly demonstrates how solar energy can be used to power spacecraft, an idea that was conceptualized by 17th-century astronomer Johannes Kepler.
"There's something about sunlight that must carry force, the same way wind carries the force of sailboats at sea," Nye said according to Space.com. "[Kepler] predicted one day people would be sailing through space, carried by light. That was a tremendous idea, just based on inference and observation."
Solar Spacecraft for Planetary Defense
Aside from space travel, Nye also believes that solar spacecraft can be used as part of a monitoring system that keeps track of dangerous asteroids. The scientist noted that this can be achieved by equipping a solar spacecraft with an infrared imaging instrument and placing it in between the Earth and the Sun. That way, the spacecraft's view will not be hindered by the Sun's brightness.
For Nye, a solar spacecraft can be used as a cost-efficient tool that can constantly monitor space for asteroids which might be on a collision course with Earth. It can serve as an early warning system for approaching asteroids. "Looking for asteroids is like looking for charcoal briquettes in the dark, which is hard at visual wavelengths, but with the right instrument you can see them," Nye explained.