All eyes will Be on the moon as the inaugural launch of the Artemis mission hurtles toward our lunar neighbor in a few weeks, but the rocket won’t be the only new spacecraft to take to space. After NASA’s Orion capsule separates from the Space Launch System (SLS) rocket, the SLS will deploy 10 tiny satellites, each about the size of a shoebox, which will then fly in different directions. The SLS will provide a luxurious ride into space for the probes that researchers normally launch into low-Earth orbit aboard much smaller rockets.
One of the miniaturized spaceships, called Near Earth Asteroid Scout, will target a particularly distant target: it will pan past the moon on its way to the near-Earth asteroid and take detailed pictures there. The satellite is driven there by a sweeping solar sail. Despite its small size, the NEA Scout, as it is known for short, can conduct cutting-edge research while aiding in the search for the type of asteroids that future missions of larger classes will wish to visit.
“We want to map everything possible about the asteroid’s rotation, its size, its brightness and its local environment,” says Julie Castillo-Rogez, planetary scientist at NASA’s Jet Propulsion Laboratory and leader of the NEA Scout science team. The spacecraft is equipped with a high-end miniature camera with a resolution similar to that onboard NASA’s OSIRIS-REx, a much larger asteroid probe ship. “It’s very powerful, but very small,” she says.
NEA Scout and his nine comrades demonstrate the many uses of nanosatellites, known as CubeSats. Each consists of sets of dice measuring about 4 inches on a side. While some CubeSats consist of three units in a row called 3U, the spacecraft on board Artemis 1 are 6U.
The Capstone spacecraft, the first CubeSat launched under the Artemis program, is a 12U. Launched in June, Capstone will survey orbit around the Moon for the proposed Lunar Gateway space station, which astronauts will assemble during future Artemis missions. All of these satellites use miniaturized technology, packing a battery, electronics, cameras and other tools into an extremely compact space, allowing for cheaper research than building larger spacecraft, which can cost hundreds of millions of dollars.
After being dropped from the SLS rocket, the NEA Scout will fly past the moon and slowly unfold its solar sail a few days later. Like everything else, the sail is first packed into a small box that fits exactly one-third of the way into the boat. But not for long. “As soon as we give this command, four metal outriggers spring up and pull the sail from a spool. It’s 925 square feet, about a school bus for a school bus,” says Les Johnson, leader of the NEA Scout technology team at Marshall Space Flight Center.
The sail is coated in reflective aluminum that’s thinner than foil — like Saran Wrap, but not tacky, Johnson says. Unlike a boat, the small spacecraft’s sail propels the craft when it catches rays of light, rather than gusts of wind. When light reflects off the sail, it gives off a little energy that is converted into extra thrust on the sail and the spacecraft.