NEA Scout: NASA mission will study smallest asteroid ever visited by a spacecraft

Among a gamut of secondary payload missions being sent into space during Artemis I, is a new mission that involves studying a near-Earth asteroid (NEA) using the brand new technology of solar sail. The asteroid in target is the 2020 GE, which is less than 60 feet across and would be the smallest asteroid to be ever examined by a spacecraft.

The mission is named NEA Scout which is composed of a small, shoebox-sized CubeSat that launches aboard NASA’s Space Launch System (SLS) rocket from the Kennedy Space Center on August 29. The US space agency says that it is a technology demonstration that will enhance scientists’ understanding of NEAs. 

About the NEA Scout mission

Developed by NASA’s Jet Propulsion Laboratory (JPL), the NEA CubeSat, once in outer space, will unfurl its solar sail to get propelled toward the 2020 GE asteroid. According to NASA, the spacecraft will use stainless steel alloy booms to unfurl the solar sail that will expand to about 925 square feet (86 square meters).

Made from plastic-coated aluminum which is thinner than human hair, the solar sail will propel the spacecraft by reflecting the sunlight striking its surface. While most of the spacecraft’s propulsion will be provided by the solar sail, the engineers have also fitted small cold-gas thrusters with a limited propellant supply to assist with maneuvers and orientation. 

(Solar sail unfurled at NASA facility; Image: NASA/JPL)

After reaching its destination, the spacecraft will use its camera to gather data on the asteroid’s size, shape, rotation, and surface properties while looking for potential dust and debris surrounding it. 

“Thanks to the discoveries of NEAs by Earth-based observatories, several targets had been identified for NEA Scout, all within the 16-to-100-foot (5-to-30-meter) size range,” Julie Castillo-Rogez, the mission’s principal science investigator at JPL said in an official statement. “2020 GE represents a class of asteroid that we currently know very little about”.

While this mission is dedicated to studying the relatively tiny asteroid, testing the feasibility of the solar sail technology is another major objective. Les Johnson, the mission’s principal technology investigator at Marshall Spaceflight Center says that solar sails are a high-performance propulsion system which makes them suitable for missions involving low-mass and low-volume spacecraft.

"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,” said Castillo-Rogez. “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.” Interestingly, the NEA Scout mission will set the stage for similar missions in the future such as the Solar Cruiser. Targeted for launch in 2025, the mission would see a spacecraft deploy an 18,000-square-foot (nearly 1,700-square-meter) solar sail to travel toward the sun.