by Quang La
Image by Javier Miranda via Unsplash
Overview of the DART Mission
The Double Asteroid Redirection Test, or DART, was the first-ever space mission aimed at proving a kinetic impact method of asteroid deflection. On September 26, 2022, the DART mission of NASA successfully crashed a spacecraft into the asteroid moonlet Dimorphos in an attempt to change the spacecraft's orbital course around the bigger asteroid Thatos.
Characteristics of the DART Target
The binary asteroid system of Didymos and its tiny moonlet Dimorphos was the target of DART. The moonlet Dimorphos is 160 meters (525 feet) broad, while Didymos is around 780 meters (0.5 miles) in diameter. Between the two asteroids, Dimorphos orbits Didymos at a distance of 1.2 kilometers, or 0.74 miles, around their common center of mass. Dimorphos took 11 hours and 55 minutes to complete one circle around Didymos before DART collided with it.
DART Spacecraft Design and Launch
The DART spacecraft was comparatively modest, with two roll-out solar arrays allowing it to expand to a width of approximately 12 meters (40 feet) from its cube-shaped core, which was only a meter across. On November 24, 2021, DART was launched from California's Vandenberg Space Force Base on a SpaceX Falcon 9 rocket.
DART's Approach and Impact
DART launched LICIACube, a CubeSat developed by the Italian Space Agency, to monitor the approaching collision as it got closer to its target. Then DART went into autonomous navigation mode, utilizing software and its onboard camera to distinguish between Didymos and Dimorphos and navigate itself in the direction of the smaller moonlet. DART made a successful collision with Dimorphos on September 26, 2022, traveling at a speed of 6.6 kilometers per second (4.1 miles per second).
Outcome of the DART Impact
The goal of the DART collision was to slightly but significantly alter Dimorphos' orbital period around Didymos. The real effect was much more significant, decreasing Dimorphos' orbital period by around 33 minutes, compared to the only 4.2 minutes that were projected. This proved that the kinetic impactor method of asteroid deflection works well.
Collaboration with the Hera Mission
NASA and the European Space Agency (ESA) are working together on the Hera mission to investigate DART's effects on Dimorphos in more detail. In order to better comprehend the repercussions of the kinetic hit, Hera is scheduled for launch in 2024 and will carry out extensive surveys of the Didymos system, including the crater left by DART's collision.
References
Society, P. (2024, June 7). DART, NASA’s test to stop an asteroid from hitting Earth. The Planetary Society. https://www.planetary.org/space-missions/dart
Double Asteroid Redirection Test (DART) - NASA Science. (n.d.). https://science.nasa.gov/mission/dart/
DART. (n.d.). https://dart.jhuapl.edu/Mission/