NASA launches spacecraft to assess asteroid defense
LOS ANGELES — NASA launched a spacecraft Tuesday night on a mission to smash into an asteroid and test whether it would be possible to knock a speeding space rock off course if one were to threaten Earth.
The DART spacecraft, short for Double Asteroid Redirection Test, lifted off from Vandenberg Space Force Base atop a SpaceX Falcon 9 rocket in a $330 million project with echoes of the Bruce Willis movie “Armageddon.”
If all goes well, the boxy, 1,200-pound craft will slam head-on into Dimorphos, an asteroid 525 feet across, at 15,000 mph next September.
“This isn’t going to destroy the asteroid. It’s just going to give it a small nudge,” said mission official Nancy Chabot of Johns Hopkins Applied Physics Laboratory, which is managing the project.
Dimorphos orbits a much larger asteroid called Didymos. The pair are no danger to Earth but offer scientists a better way to measure the effectiveness of a collision than a single asteroid flying through space.
Dimorphos completes one orbit of Didymos every 11 hours, 55 minutes. DART’s goal is a crash that will slow Dimorphos down and cause it to fall closer toward the bigger asteroid, shaving 10 minutes off its orbit.
The change in the orbital period will be measured by telescopes on Earth. The minimum change for the mission to be considered a success is 73 seconds.
The DART technique could prove useful for altering the course of an asteroid years or decades before it bears down on Earth with the potential for catastrophe.
A small nudge “would add up to a big change in its future position, and then the asteroid and the Earth wouldn’t be on a collision course,” Chabot said.
Scientists constantly search for asteroids and plot their courses to determine whether they could hit the planet.
“Although there isn’t a currently known asteroid on an impact course with the Earth, we do know there is a large population of nearEarth asteroids out there,” said Lindley Johnson, of NASA. “The key is finding them well before they are an impact threat.”