NASA’s Double Asteroid Redirection Test (DART), the world’s first full-scale mission to test technology for defending Earth against potential asteroid or comet hazards, launched Wednesday at 1:21 a.m. EST on a SpaceX Falcon 9 rocket from Space Launch Complex 4 East at Vandenberg Space Force Base in California.
Just one part of NASA’s larger planetary defense strategy, DART – built and managed by the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland – will impact a known asteroid that is not a threat to Earth. Its goal is to slightly change the asteroid’s motion in a way that can be accurately measured using ground-based telescopes.
DART will show that a spacecraft can autonomously navigate to a target asteroid and intentionally collide with it – a method of deflection called kinetic impact. The test will provide important data to help better prepare for an asteroid that might pose an impact hazard to Earth, should one ever be discovered. LICIACube, a CubeSat riding with DART and provided by the Italian Space Agency (ASI), will be released prior to DART’s impact to capture images of the impact and the resulting cloud of ejected matter. Roughly four years after DART’s impact, ESA’s (European Space Agency) Hera project will conduct detailed surveys of both asteroids, with particular focus on the crater left by DART’s collision and a precise determination of Dimorphos’ mass.
“DART is turning science fiction into science fact and is a testament to NASA’s proactivity and innovation for the benefit of all,” said NASA Administrator Bill Nelson. “In addition to all the ways NASA studies our universe and our home planet, we’re also working to protect that home, and this test will help prove out one viable way to protect our planet from a hazardous asteroid should one ever be discovered that is headed toward Earth.”
DART’s one-way trip is to the Didymos asteroid system, which comprises a pair of asteroids. DART’s target is the moonlet, Dimorphos, which is approximately 530 feet (160 meters) in diameter. The moonlet orbits Didymos, which is approximately 2,560 feet (780 meters) in diameter.
“We have not yet found any significant asteroid impact threat to Earth, but we continue to search for that sizable population we know is still to be found. Our goal is to find any possible impact, years to decades in advance, so it can be deflected with a capability like DART that is possible with the technology we currently have,” said Lindley Johnson, planetary defense officer at NASA Headquarters. “DART is one aspect of NASA’s work to prepare Earth should we ever be faced with an asteroid hazard. In tandem with this test, we are preparing the Near-Earth Object Surveyor Mission, a space-based infrared telescope scheduled for launch later this decade and designed to expedite our ability to discover and characterize the potentially hazardous asteroids and comets that come within 30 million miles of Earth’s orbit.”
The spacecraft will intercept the Didymos system between Sept. 26 and Oct. 1, 2022, intentionally slamming into Dimorphos at roughly 4 miles per second (6 kilometers per second). Scientists estimate the kinetic impact will shorten Dimorphos’ orbit around Didymos by several minutes. Researchers will precisely measure that change using telescopes on Earth.