A mission to deflect the asteroid enters the final phase

The very first asteroid deflection mission for planetary defense has entered its final phase of design and assembly. The mission, Double Asteroid Redirection Test or DART, should be launched in 2021.

Asteroids, comets and other objects close to the Earth represent a threat of collision with our planet because their orbits sometimes bring them dangerously near the Earth. The observatories closely monitor all nearby objects and follow their movement. But NASA is also working on ways to protect the Earth from any possible impact, and the DART mission is a small part of a global plan to prevent asteroids from crashing into Earth.

DART is a refrigerator-sized spacecraft that will demonstrate the kinetic impactor technique on a small asteroid, which is to hit the object to move its orbit. His target is the asteroid Didymos who will make a distant approach to the Earth in October 2022, then again in 2024. Didymos is a binary asteroid consisting of two bodies: Didymos A and B. Didymos has about 800 meters in diameter and is orbited by a smaller 160-meter asteroid called Didymos B. DART will hit only the smaller of the two bodies during the mission.

The spacecraft will deliberately crash on Didymos B at a speed of 6 kilometers per second, about nine times faster than a bullet. The collision will change the speed of the asteroid a small fraction of its total speed, but it should be enough to move its trajectory from the Earth. The ground observatories would examine the impact and determine the resulting change in Didymos B.'s orbit. If it succeeded, the kinetic impact could be used as the main strategy for defending the Earth against asteroids potentially dangerous.

"With DART, we want to understand the nature of asteroids by seeing how a representative body reacts when it is touched, in order to apply that knowledge if we have to deflect an incoming object," said the laboratory. applied physics of Johns Hopkins University. Andrew Rivkin, who co-directs the DART survey. "In addition, DART will be the first planned tour of a binary asteroid, which is a large subset of near-Earth asteroids that we have not yet fully understood."