NASA to Test Planetary Defense Technology With DART Mission

NASA will be conducting a mission next month to test its planetary defense technology on two deep-space asteroids.

The Double Asteroid Redirection Test, abbreviated as the DART Mission, involves sending a spacecraft out to the two asteroids — known as the Didymos binary — on November 24. The spacecraft will be part of the SpaceX Falcon 9 rocket launched from Vandenberg Space Force Base in California.

DART aims to make impact with one of the asteroids, known as Didymoon, at around 13,500 mph (21,726 kmh) on October 2, 2022 — almost an entire year after launching.

Didymoon is over 500 feet wide and orbits a gigantic space rock called Didymos. Didymos is roughly five times the size of Didymoon.

NASA will use kinetic impact to reach Didymoon asteroid

NASA officially deems any near-Earth object (NEO) to be “potentially hazardous” when it is within 0.05 astronomical units (4.6 million miles) and measures over 460 feet in diameter. While Didymoon is not a threat to Earth, it matches the profile of NEO’s that NASA aims to protect the planet from with this technology, so has been selected for the test demonstration:

“While the Didymos primary body is approximately 780 meters across, its secondary body (or “moonlet”) is about 160-meters in size, which is more typical of the size of asteroids that could pose the most likely significant threat to Earth. The Didymos binary is being intensely observed using telescopes on Earth to precisely measure its properties before DART arrives,” NASA said in its overview of the DART mission.

The space agency says that DART will use the “kinetic impactor” technique for the first time:

“DART will be the first demonstration of the kinetic impactor technique, which involves sending one or more large, high-speed spacecraft into the path of an asteroid in space to change its motion,” NASA said.

They had previously explained kinetic impact in 2017:

“Kinetic impaction involves sending one or more large, high-speed spacecraft into the path of an approaching near-earth object. This could deflect the asteroid into a different trajectory, steering it away from the Earth’s orbital path. NASA demonstrated on a small scale with the Deep Impact mission of 2005. If preparations were made in advance so that kinetic impactors were available upon detection, the National Academy of Sciences would require a warning time of at least 1 to 2 years for smaller asteroids.”

“If an approaching asteroid were detected tomorrow, perhaps 20 years would be required to build and launch an impactor, to reach and impact the target, and to nudge the asteroid from Earth’s path. However, decades or more might be required to deflect larger asteroids (hundreds of kilometers in diameter) that present the most catastrophic threats.

“If time allows, a mission to study the asteroid up close and send information back to Earth before sending the impactor could greatly increase the chance of success. Kinetic impactors may not be effective in changing the orbit of the very largest asteroids,” the agency added.