NASA wants to propel a shoebox-sized spacecraft to an asteroid using a solar sail, the first deep space mission by the agency to use such a mechanism.
The Near-Earth Asteroid Scout (NEA Scout) is a small craft called a CubeSat, and it will be one of 10 secondary payloads on the upcoming Artemis I uncrewed test flight (currently slated for March 2022). The satellite is only about the size of a shoebox, but the reflective sail that will haul it through space unfolds to 925 square feet. Gas thrusters will put the CubeSat on a trajectory for the nearby asteroid target, but the solar sail will do the propulsion work for the rest of the two-year journey.
Solar sails harness the momentum of the Sun’s photons to propel spacecraft forward. Because rocket fuel is a considerable factor in the weight of spacecraft and their lifetimes in space, it pays to need as little of it as possible. The bigger the solar sail, the more sunlight the craft can capture. By changing the position of the sail to the angle of sunlight, the NEA Scout can alter its trajectory.
The scout will be heading to an asteroid called 2020 GE, which was first seen in March 2020 (hence its name.) The asteroid is less than 18.29 m across, and because asteroids its size have not been explored up close before, it’s a great research target. Smaller rocks can still have damaging impacts if they hit Earth, such as the Chelyabinsk meteor in 2013.
“Although large asteroids are of most concern from a planetary defence perspective, objects like 2020 GE are far more common and can pose a hazard to our planet, despite their smaller size,” said Julie Castillo-Rogez, the principal science investigator for the NEA Scout mission at NASA’s Jet Propulsion Laboratory, in an agency release. “2020 GE represents a class of asteroid that we currently know very little about.”
The CubeSat has a camera on board to gather information on the makeup, size, and properties of 2020 GE. It could be a solid rock, or an amalgamation of dusty and smaller rocks glommed together, like asteroid Bennu. Asteroids continue to be a point of interest for NASA; the Lucy mission to study Jupiter’s Trojan asteroids launched in October 2021 and the Psyche mission is set to launch this August.
Asteroids aside, the NEA Scout is also paving the way for two other solar sail missions: the Advanced Composite Solar Sail System, to launch no earlier than mid-2022, according to the NASA website, and the Solar Cruiser, which will head toward the Sun in 2025 with a whopping 18,000-square-foot sail. The future for sail technology in space is bright.