NASA - The National Aeronautics and Space Administration

11/24/2021 | News release | Distributed by Public on 11/24/2021 07:08

NASA, SpaceX Launch DART, First Planetary Defense Test Mission

NASA's Double Asteroid Redirection Test (DART) mission - the world's first full-scale mission to test technology for defending the planet against potential asteroid or comet hazards - launched Tuesday, Nov. 23, at 10:21 p.m. PST 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 send a spacecraft to impact a known asteroid that is not a threat to Earth, to slightly change its motion in a way that can be accurately measured via ground-based telescopic observations. DART will show that a spacecraft can autonomously navigate to a target asteroid and intentionally collide with it-a method of asteroid deflection called kinetic impact. The test will provide important data to help us better prepare for an asteroid that might pose an impact hazard to Earth, should one ever be discovered.

"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."

At 11:16 p.m. PST, DART separated from the second stage of its launch vehicle. Minutes later, mission operators at the Johns Hopkins APL received the first spacecraft telemetry data and started the process of "detumbling" the spacecraft to a safe orientation for deploying its solar arrays.

"At its core, DART is a mission of preparedness, and it is also a mission of unity and international collaboration," said Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington. "An international collaboration that involves DART, the Italian Space Agency's LICIACube that will watch DART's impact, and the European Space Agency's Hera investigations and science teams to follow on, will help researchers worldwide to extract the best possible information for planetary defense and solar system science from these groundbreaking space missions."

DART's one-way trip is to the Didymos asteroid system, which is comprised of a pair of asteroids - one small and one large - that orbit a common center of gravity. DART's "target" is the asteroid moonlet Dimorphos, which is approximately 530 feet (160 meters) in diameter and orbits Didymos, which is approximately 2,560 feet (780 meters) in diameter. Since Dimorphos orbits the larger asteroid Didymos at much slower relative speed than the pair orbits the Sun, the slight orbit change resulting from DART's kinetic impact within the binary system can be measured much more easily than a change in the orbit of a single asteroid around the Sun.

"While there are currently no known asteroid hazards to Earth, a mission like DART requires a hazard to be identified years to decades in advance-an endeavor that is ongoing and possible with the technology we currently have" said Lindley Johnson, planetary defense officer at NASA Headquarters. "This test, in tandem with the Near-Earth Object Surveyor Mission, an infrared space-based telescope scheduled for launch later this decade designed to help expedite our ability to discover and characterize most of the potentially hazardous asteroids and comets that come within 30 million miles of Earth's orbit, are important steps to helps us learn all we can should we ever be faced with an asteroid hazard."

The spacecraft will intercept the Didymos system in late September of 2022, intentionally slamming into the smaller Dimorphos at roughly 4 miles per second (6 kilometers per second), so that the spacecraft alters the asteroid's path around Didymos. Scientists estimate the kinetic impact will shorten Dimorphos' orbit by several minutes and will precisely measure that change using telescopes on Earth. The results will both validate and improve scientific computer models that are critical to predicting the effectiveness of the kinetic impact technique as a reliable method for asteroid deflection technology.

"It is an indescribable feeling to see something you've been involved with since the 'words on paper' stage become real and sent hurtling into space," said Andy Rivkin, DART team investigation lead at APL. "This is just the end of the first act, and I know the investigation team will stay busy over the next year preparing for the burst of activity to follow DART's kinetic impact - but there is a lot to celebrate right now!"

DART's single instrument, the camera DRACO (Didymos Reconnaissance and Asteroid Camera for Optical navigation) camera, will turn on a week from now and provide first images from the spacecraft. DART will continue to travel just outside of Earth's orbit around the Sun for the next 10 months until next fall when Didymos and Dimorphos will be a relatively close 6.8 million miles (11 million kilometers) from Earth. A sophisticated guidance, navigation, and control (GNC) system, working together with algorithms developed at APL called SMART Nav (Small-body Maneuvering Autonomous Real Time Navigation) will enable the DART spacecraft to identify and distinguish between the two asteroids at Didymos and then, working in concert with the other GNC elements, direct the spacecraft toward Dimorphos, all within roughly an hour of impact. LICIACube (Light Italian Cubesat for Imaging of Asteroids), provided by the Italian Space Agency (ASI), will ride along with DART be released prior to DART's impact. If all goes according to plan, LICIACube will capture images of the DART impact, the resulting ejecta cloud, possibly a glimpse of the impact crater on the surface of Dimorphos created by DART's impact, as well as the back side of Dimorphos, which DRACO will never have a chance to see, to gather further data to help prove out the kinetic model.

The Johns Hopkins APL manages the DART mission for NASA's Planetary Defense Coordination Office as a project of the agency's Planetary Missions Program Office. The agency provides support for the mission from several centers, including the Jet Propulsion Laboratory in Southern California, Goddard Space Flight Center in Greenbelt, Maryland, Johnson Space Center in Houston, Glenn Research Center in Cleveland, and Langley Research Center in Hampton, Virginia. The launch is managed by NASA's Launch Services Program, based at the agency's Kennedy Space Center in Florida. SpaceX is the rocket provider for the DART launch.

For more information about the DART mission, visit: