A SpaceX rocket is expected to be launched from California early this Wednesday (24), when NASA will attempt to demonstrate a pioneering planetary defense system designed to deflect an asteroid from a potentially fatal collision with Earth.
The Dart (Double Asteroid Redirection Test) mission will test NASA’s ability to alter the trajectory of an asteroid with kinetic force — by colliding with a high-speed robotic spacecraft, deflecting the space rock far enough to keep you on track far from our planet.
Dart’s target is a fraction of the size of the cataclysmic asteroid Chicxulub that crashed into Earth some 66 million years ago, killing most of the planet’s animal species. It is not on a course that will cause it to collide with Earth for the foreseeable future.
But scientists say that smaller asteroids are much more common and pose a much greater theoretical threat to Earth in the short term.
NASA has hired Elon Musk’s SpaceX to launch the Dart aboard a Falcon 9 rocket this Wednesday at 3:20 am EDT from Vandenberg Air Force Base off the coast of California, about 150 miles northwest of Los Angeles.
If takeoff is delayed, NASA will have an 84-day window to try again.
Once launched into space, Dart will travel for ten months to its destination, some 11 million kilometers from Earth.
Its target is an asteroid “moonlet” (small moon) the size of a football stadium, which orbits a much larger rock — about five times — in a binary asteroid system called Didymos, a Greek word for “twins”.
The moon, called Dimorphos, is one of the smallest astronomical objects to be given a permanent name. But at 157 meters in diameter, its size is typical of known asteroids — debris left over from the formation of the solar system 4.6 billion years ago.
Simpler than Armageddon
Scientists chose the Didymos system because its relative proximity to Earth and the double asteroid configuration make it ideal for observing impact results.
The key to avoiding a killer asteroid is detecting it well in advance and being prepared with the means to change its course, NASA Planetary Defense Officer Lindley Johnson said in a statement to the press this month.
“We don’t want to be in a situation where an asteroid heads for Earth and then we need to test that kind of capability,” he said.
The Dart project team has determined that firing an automobile-sized projectile at an asteroid the size of Dimorphos at 24,000 km an hour should suffice.
The Dart spacecraft, a cube-shaped box with two rectangular solar panels, is expected to meet the Didymos-Dimorphos duo at the end of September 2022.
Cameras mounted on the impactor and a mini-spacecraft the size of a briefcase dropped from the Dart about ten days earlier will record the collision.
Observations from Earth-based radar and telescopes will measure how much the small moon’s orbit changes around Didymos.
The Dart team hopes to shorten the orbital trajectory by about ten minutes, but would consider at least 73 seconds a success.
The total cost of the Dart project will be approximately $330 million (BRL 1.8 billion), according to Lindley, far less than many of NASA’s more ambitious missions.
Translated by Luiz Roberto M. Gonçalves.
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