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Update: The NASA official said the DART spacecraft arrived at Vandenberg on September 27 appears to have been incorrect and may have accidentally confused the arrival of an “forward team” with the arrival of the spacecraft itself.
Science communicator and author David Brown was reportedly on site on September 29 to watch the DART spacecraft being carefully packaged for the trip from Johns Hopkins University of Maryland to its launch site in California, obviously making a two-day VSFB arrival impossible. before. Still, now stowed away in an environmentally controlled shipping container, DART is still expected to arrive in Vandenberg within a week or two.
Revealed in note during the space agency’s live coverage of the successful Landsat-9 launch, NASA said the Double Asteroid Redirect Test (DART) spacecraft has arrived at Vandenberg Space Force Base (VSFB) ahead of a SpaceX Falcon 9 launch less than two months from now.
Weighing around 690 kg (~ 1,500 lb) on takeoff, NASA has confirmed that the DART spacecraft and its Italian-made companion LICIACube smallsat are on track to launch from SpaceX’s VSFB SLC-4E pad on a rocket. Falcon 9 at the earliest (NET) November 23, 2021. Carrying its small passenger, DART will then head towards the pair of binary asteroids Didymos and Dimorphos. Measuring around 800 and 170 meters in diameter respectively, DART will ultimately target the smallest of the pair and accelerate to an impact speed of around 6.6 km / s (4 mph or Mach 19).
DART will then rely on an integrated telescope and closed-loop targeting software to focus and crush Dimorphos, ultimately using the small asteroid system as a sort of sandbox to test any asteroid redirection theories that could one day help humans prevent earth-impact disasters.
Originally slated to launch in June 2021 when NASA awarded SpaceX the $ 69 million launch contract (now up to $ 73 million after two small changes) in April 2019, DART slipped about five months. in the 2.5 years since a few minor technical issues have arisen overdue. in development. Impressively, almost none of these delays appear to have been caused by the COVID-19 pandemic, which cannot be said for a number of other NASA, US military and commercial satellites and launches. .
With a total cost of around $ 250 million including launch services, DART’s primary goal is to determine the exact behavior of an asteroid when impacted by a high-speed spacecraft. While representations of asteroids “redirecting” in popular science fiction tend to lean towards the “send an arsenal of nuclear bombs” approach, the reality is that bombarding most asteroids and comets large enough to threaten Earth’s surface would add more uncertainty than it does. mitigate the threat.
Given the limited information available on the physical characteristics of asteroids, attacking one with a bomb might simply split a killer asteroid into a number of smaller, still deadly asteroids – now split into a rifle-like pattern. hunting for undetectable fragments instead of a large, visible object. Instead, most modern scientists in the field now believe that the best route to redirection is a combination of early detection and (relatively) low-energy impact. Much like the concept of the butterfly effect, a relatively mild impact (still similar to 2.5 tons of TNT with DART) years or decades in advance could drastically change the trajectory of the asteroid or comet. threatening, causing him to miss Earth. DART will not directly prevent an asteroid from impacting Earth, but hitting the moon of a larger asteroid should actually amplify the effect of the small impact on its orbital characteristics.
DART will also serve as a technology demonstration, launching both satellite-type solar panels and the NEXT-C electric propulsion system developed by NASA. Hopefully, this will also help scientifically prove that humans could use a similar approach to save us from a catastrophic event in space years or decades away.
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