A tiny instrument that can measure the gravity levels of an asteroid has completed its ground tests, pushing the European Space Agency’s (ESA) Hera mission closer to launch. Hera will complete the first post-impact survey of the asteroid that NASA’s Double Asteroid Redirection Test (DART) collided with in September 2022, and the gravimeter for small solar system objects (GRASS) is the small device that will be carried by Hera to measure the minuscule gravity levels of Dimorphos, the orbiting moonlet of the 65803 Didymos binary system.
GRASS is one of the core parts of Hera that will work with the other instruments to provide a clearer picture of the impact made by DART, and is scheduled to launch in October 2024, for a December 2026 rendezvous with Dimorphos.