NASA’s Artemis I will deploy a solar sail satellite toward a nearby asteroid

NASA's NEA Scout will sail on sunlight

The NEA scout mission is a joint project between NASA's Marshall Space Flight Center (MSFC) in Huntsville, Alabama, and NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California. It's one of several missions deploying solar sailing technology after the Planetary Society proved the technology is viable with its LightSail 2 mission in 2019.

In a February interview with IE, Planetary Society CEO Bill Nye (also known as "Bill Nye the Science Guy") said, LightSail 2 completely "exceeded" his expectations and that he was excited to see what NASA and others would do with the technology.

In NASA's statement, Les Johnson, the mission’s principal technology investigator at Marshall, suggested the solar sail technology will be key to keeping mission costs relatively low. "The genesis of this project was a question: Can we really use a tiny spacecraft to do deep space missions and produce useful science at a low cost? This is a huge challenge," Johnson said. "For asteroid characterization missions, there's simply not enough room on a cubesat for large propulsion systems and the fuel they require."

Investigating asteroid 2020 GE

The NEA Scout will travel to asteroid 2020 GE, a small space rock approximately 60 feet (18 meters) across that orbits the Sun once every 368 days. To get there, the cubesat will travel past the moon for a gravitational boost. Aside from that gravitational assist, it will also use its solar sail, which measures 925 square feet (86 square meters).

The NEA Scout probe does also have small thrusters, though they will only be used to power a small number of specific maneuvers. Otherwise, the cubesat's solar saill will propel the mission towards 2020 GE using particles of the sun, photons. This means it will have to carry a minimal amount of liquid or solid fuel, lowering the cost of the mission.

"NEA Scout will accomplish probably the slowest flyby of an asteroid ever — at a relative speed of less than 100 feet [30 meters] per second," explained Julie Castillo-Rogez, the mission's principal science investigator at JPL. "This will give us a few hours to gather invaluable science and allow us to see what asteroids of this class look like up close."

The NEA Scout is expected to reach the asteroid in 2023, at which point it will use its cameras to capture images of the space rock. Scientists back on Earth will then study its rotation, shape, debris field, and other characteristics. 2020 GE is part of the smallest class of asteroids, which measure 330 feet (100 meters) or less in diameter. This will be the first time scientists study such a small asteroid in detail. According to NASA, this "will help close gaps in knowledge about near-Earth asteroids."

NASA's Artemis I mission, via NEA Scout, will teach us more about potentially hazardous space rocks at the same time as providing the next chapter in the exciting journey of solar sail technology. Another solar sail mission, by private space firm Breakthrough Initiatives, plans to eventually power a lightsail probe using millions of lasers, allowing it to reach our nearest star system, Alpha Centauri, within our lifetimes. When you think about spacecraft sailing on sunlight, it's hard not to dream big.