“NASA plans to test a method for protecting Earth against an asteroid impact. The agency selected SpaceX Falcon 9 to launch the ambitious mission called the Double Asteroid Redirection Test (DART). It will be NASA’s first flight demonstration for asteroid defense that will attempt to shift an asteroid’s direction and orbit through kinetic impact. It will involve “sending one or more large, high-speed spacecraft into the path of an asteroid in space to change its motion,” the agency said in a press release. “Its target is the binary near-Earth asteroid Didymos and its moonlet.”
NASA’s DART spacecraft will be launched by SpaceX towards the binary asteroid system in November. It will liftoff atop a Falcon 9 rocket from Vandenberg Air Force Base in California. NASA announced today that they target to lift off on November 23 at 10:20 p.m. PST. “After separation from the launch vehicle and over a year of cruise – it will intercept Didymos’ moonlet in late September 2022,” the agency said. During the interception period, the Didymos system will be within 11 million kilometers of Earth to enable observations by astronomers’ ground-based telescopes and planetary radar.
The larger asteroid, Didymos, measures about 2,540 feet (775 meters) wide, and the smaller asteroid called ‘Dimorphos,’ measures 540 feet (165 meters) across. The two asteroids are orbiting one another, the DART vehicle will attempt to change the course of the smaller asteroid by deliberately impacting it at a speed of approximately 6.6 km/s (kilometers per second) with the aid of an onboard camera (named DRACO) and high-tech autonomous navigation software. “The collision will change the speed of the moonlet in its orbit around the main body by a fraction of one percent, but this will change the orbital period of the moonlet by several minutes – enough to be observed and measured using telescopes on Earth,” NASA representatives said. This planetary defense demonstration mission will test whether a spacecraft impact could be used to deflect an asteroid on a collision course with Earth. The main objective is to evaluate technology to prevent a hazardous asteroid from striking Earth.” Tesmanian
Comment: I suppose that asteroids with their own moonlet are fairly rare. So, they must reckon that they can move a big one without that feature? pl