“NASA plans to test a method for protecting Earth against an asteroid impact. The agency selected SpaceX Falcon 9 to launch the ambitious mission called the Double Asteroid Redirection Test (DART). It will be NASA’s first flight demonstration for asteroid defense that will attempt to shift an asteroid’s direction and orbit through kinetic impact. It will involve “sending one or more large, high-speed spacecraft into the path of an asteroid in space to change its motion,” the agency said in a press release. “Its target is the binary near-Earth asteroid Didymos and its moonlet.”
NASA’s DART spacecraft will be launched by SpaceX towards the binary asteroid system in November. It will liftoff atop a Falcon 9 rocket from Vandenberg Air Force Base in California. NASA announced today that they target to lift off on November 23 at 10:20 p.m. PST. “After separation from the launch vehicle and over a year of cruise – it will intercept Didymos’ moonlet in late September 2022,” the agency said. During the interception period, the Didymos system will be within 11 million kilometers of Earth to enable observations by astronomers’ ground-based telescopes and planetary radar.
The larger asteroid, Didymos, measures about 2,540 feet (775 meters) wide, and the smaller asteroid called ‘Dimorphos,’ measures 540 feet (165 meters) across. The two asteroids are orbiting one another, the DART vehicle will attempt to change the course of the smaller asteroid by deliberately impacting it at a speed of approximately 6.6 km/s (kilometers per second) with the aid of an onboard camera (named DRACO) and high-tech autonomous navigation software. “The collision will change the speed of the moonlet in its orbit around the main body by a fraction of one percent, but this will change the orbital period of the moonlet by several minutes – enough to be observed and measured using telescopes on Earth,” NASA representatives said. This planetary defense demonstration mission will test whether a spacecraft impact could be used to deflect an asteroid on a collision course with Earth. The main objective is to evaluate technology to prevent a hazardous asteroid from striking Earth.” Tesmanian
Comment: I suppose that asteroids with their own moonlet are fairly rare. So, they must reckon that they can move a big one without that feature? pl
The reason for hitting one of a binary system is that the deflection measurement is now an easily observable differential/relative measurement. It simplifies things by several orders of magnitude, which is important because the change is so small. It would probably be unmeasurable, or take a very long time otherwise.
we are suppose to believe nasa is remotely capable of interfering or destroying an object at hypersonic speed (6.6km/sec is just under 15000 mph). who is kidding whom.
the usa military or any other department has ”’nothing”” that can destroy an object at supersonic speed never mind mach 15-20.
and nothing even close to ready to deploy. the whole excersize is money sinkhole, expect nothing!
tedrichard
“the usa military or any other department has ”’nothing”” that can destroy an object at supersonic speed never mind mach 15-20.” You are not paying attention. DART aims at nudging the big rock into a different trajectory.
It is not appropriate to use the expression “hypersonic” in space where there is no atmosphere and man-made objects ca reach 150 km/sec without any friction.
According to Nature (2008 article on rotational breakup of asteroids) about 15% of asteroids are in pairs. This number may be significantly low because there has been relatively less searching for pairs until recently.
The reason for this test is that by impacting just one element of a pair they can get much more accurate assessment of the results of an impact. It doesn’t mean that impacting a single asteroid would have a different result. It’s just much easier to measure the change in orbit of a pair than to measure the change in orbit around the sun.
The DART wiki page says the Italians are sending another probe later to measure the deflection, which suggests they anticipate a change that may be so small it will be difficult to measure from earth at all.
https://en.wikipedia.org/wiki/Double_Asteroid_Redirection_Test
Something to look forward to: DART will detach a small camera vehicle to record the impact. 1100lbs at 4.1 miles per second? Be still my adolescent soul, which yearns ever for big kerbooms! We can deduce total mass, but how well that bit of rock is glued together is largely speculation. For all we know the impact could bust it apart. So much to learn and so few good bangs in which to learn it.
DART will also try out the NEXT ion drive, for the first time in space, and some new solar panel tech.
All well and good.
The critical concern, however, is whether NASA’s DART project is observing Equity and Diversity mandates.
Artemesia
An impending asteroid collision might be an ideal excuse to rid ourselves of CRT theorists, Equity coordinators, Diversity quota managers and the like. In Douglas Adams’ imagined world of Golgafrincham the inhabitants managed to remove the useless third of their population. An impending apocalypse was invented and the ‘middle men’, having been persuaded of their vital role in setting up a new colony (on Earth as it happens) left on Ark Fleet Ship B. Perhaps we could send the Earthly equivalent to Mars, ahead of a broader colonization of course*. This would ensure that the Martian colony hits the ground running with diversity targets, a societal equity policy and so on already set up, for when the rulers and workers arrive.
*https://hitchhikers.fandom.com/wiki/Golgafrinchan_Ark_Fleet_Ship_B#Origins
Didymus, of course, means “twin”. See, for example
https://en.m.wikipedia.org/wiki/Thomas_the_Apostle
What could possibly go wrong with an experiment to interfere with the trajectory of a couple of sizeable chunks of space debris speeding around the Galaxy? Hubris, anyone?
It’s not hubris to study ways to deflect meteors, and the only way to do that is to start messing with them.
Related, there’s emerging evidence a Tunguska-like meteor explosion destroyed a bronze-age city in the Levant, if Tunguska wasn’t enough. Let alone the end of the dinosaurs.
https://www.smithsonianmag.com/smart-news/destruction-of-city-by-space-rock-may-have-inspired-biblical-story-of-sodom-180978734/