NASA has launched its Double Asteroid Redirection Test (DART) mission to demonstrate a possible way to deflect asteroids that could pose a threat to the Earth sometime in the future. Today at 1:21 am EST (06:21 GMT), the robotic probe lifted off atop a Falcon 9 rocket from Space Launch Complex 4E at Vandenberg Space Force Base in California.
Today's launch occurred under clear skies with light winds and only one percent cloud cover. The Falcon 9 booster lifted off without major delays, with the first stage engines shutting down at the 153-second mark before the second stage ignited and burned for 322 seconds. The DART spacecraft then separated from the second stage 58 minutes after launch. Meanwhile, the first stage executed a re-entry burn to execute a powered landing on the Of Course I Still Love You autonomous drone barge in the Pacific Ocean.
The next phase of the joint mission with Johns Hopkins Applied Physics Laboratory (APL) will involve the DART probe deploying its Roll Out Solar Arrays (ROSA) and, after system checks have been completed, powering up its Evolutionary Xenon Thruster – Commercial (NEXT-C) solar-electric propulsion system. Based on the Dawn spacecraft propulsion system, this will accelerate the spacecraft to the necessary velocity to intercept its target in late September 2022.
The target is the Dimorphos binary asteroid system that consists of Didymos A, which has a diameter of about 780 m (2,500 ft), and is orbited by the smaller Didymos B with a diameter of about 160 m (530 ft). These asteroids don't pose a threat to Earth, but were chosen as a ready-made laboratory to test how to deflect dangerous celestial bodies.
To do this, DART will be directed by its Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO) to crash into Didymos B at a speed of about 6.6 km/s (14,764 mph). This should be a big enough impact to shift Didymos B by a fraction of one percent – enough to be seen by telescopes and radar on Earth 11 million km (7 million miles) away, and from ESA's Hera deep space probe that will be launched to Dimorphos in 2024.
The video below is a repeat of the live feed of the DART launch.
Source: NASA