Image: NASA/Johns Hopkins Applied Physics Lab
Will smashing a spacecraft into a rogue asteroid help save lives on Earth? A new NASA experiment will help determine that; they’ve awarded SpaceX launch services to help them find out. As part of the Double Asteroid Redirection Test (DART), scientists will learn whether a spacecraft impact can deflect an asteroid’s trajectory.
Earlier in the week, NASA selected SpaceX in Hawthorne, California, to provide launch services for the agency’s DART mission which will be the first-ever mission to demonstrate the capability to deflect an asteroid by colliding a spacecraft with it at high speed – a technique known as a kinetic impactor. The DART mission currently is targeted to launch in June 2021 on a Falcon 9 rocket from Space Launch Complex 4E at Vandenberg Air Force Base in California. By using solar electric propulsion, DART will intercept the asteroid Didymos’ small moon, known as a moonlet, in October 2022, when the asteroid will be within 11 million kilometers (or 6.8 million miles) of Earth. NASA’s Launch Services Program at Kennedy Space Center in Florida will manage the SpaceX launch service. The DART Project office is located at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, and is managed by the Planetary Missions Program Office at Marshall Space Flight Center in Huntsville, Alabama, for NASA’s Planetary Defense Coordination Office in Washington.
The binary near-Earth asteroid (65803) Didymos 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. While DART is designed to crash into the moonlet, a small cubesat called LICIAcube will detach from the spacecraft just prior to impact to take photos and beam back to Earth. While that occurs in space, telescopes on Earth will subsequently observe Didymos to see if the transit times change based on regular dips in the system’s light curve. A subtle change in orbit measured by the telescopes on Earth of the moonlet would be a sign of success.
The second part of the mission is the European Space Agency’s Hera. Hera is a small observation spacecraft that is scheduled to launch in 2023 and eventually take observations of Didymos B in 2027 to verify measurements made by the Earth telescopes.
There has been significant interest of late of potential asteroid impacts into Earth and developing technology to be aware of and avoid them. Earlier this summer, using data and images captured by telescopes in Hawaii, NASA’s ATLAS, scientists were able to predict a meteorite impact near Puerto Rico; weeks later, they were able to detect a near-miss by other space objects. In April, NASA and FEMA along with other first responder groups simulated an asteroid impact in Earth during a multi-day drill.
“We have to make sure that people understand that this is not about Hollywood, it’s not about movies,” NASA Administrator Jim Bridenstine said, referencing the so-called “giggle factor” that he believes causes the public to write off the severity of the risk from an asteroid impact. “This is about ultimately protecting the only planet we know right now to host life, and that is the planet Earth.”
In March, NASA disclosed that a space rock several meters in size exploded 16 miles above the Bering Sea with 10 times the energy of the Hiroshima atomic bomb in December. NASA says such an impact or explosion happening again isn’t a matter of if, but when. Impacts from asteroids the size being tested in the DART experiment could wipe-out large cities or even an area the size of a state. While not an Earth-wide extinction event, such a disaster would be one of the largest to be seen by mankind.
It is believed an even larger impact brought about an end to the dinosaur era on Earth. “We have to use our systems, use our capabilities to ultimately get a lot more data, and we have to do it faster,” Bridenstine said. “We know for a fact that the dinosaurs did not have a space program. But we do, and we need to use it.”
