The Double Asteroid Redirection Test (DART) was a mission aimed at testing a method of planetary defense against asteroids that pose a threat to Earth. It was designed to impact Dimorphos, a moon of the near-earth asteroid 65803 Didymos. The asteroid system posed no actual threat to earth, but its proximity to earth made it the perfect test subject for DART.
DART was launched on the 24th of November 2021, atop a SpaceX Falcon 9 rocket.
The impactor did not carry any dedicated science instruments, only a camera, necessary sensors, and navigation equipment. DART made use of many innovative technologies. It made use of the newly developed roll-out solar array, which was about 20% lighter and one fourth the volume of traditional solar panels, while providing the same amount energy. It was also the first spacecraft to make use of a Radial Line Slot Array, a new type of high-gain
antenna.
The most significant technology demonstrated; however, was the NASA Evolutionary Xenon Thruster (NEXT-C). NEXT is a gridded ion thruster, a new form of propulsion that differs greatly from traditional rocket engines. Instead of combusting a propellant and firing it out with a high velocity, an ion engine works by ionizing xenon gas and accelerating it using electric and magnetic fields, reaching exhaust velocities far greater than regular thrusters (up to 150,000kph)! DART did not make great use of the thruster since the Falcon 9 upper stage and the main propulsion system did most of the work, be that as it may, this was still a
revolutionary milestone.
DART was also carrying a little companion, the LICIACube. The LICIACube was a small CubeSat designed by the Italian space agency (ASI) to detach from DART while approaching Dimorphos, and image the binary asteroid system after impact.
DART finally made impact on the 26th of September 2022, slamming into the asteroid at a speed of 6100 m/s (~22,000km/h). The LICIACube got a front-row seat of the collision, capturing the moments after impact with its 2 high quality cameras. It recoiled an estimated 5 million kgs of loose rock from the surface, creating a striking bright tail trailing the asteroid. Alas, the mission was an overwhelming success. NASA had originally defined the minimum change in Dimorphos’ orbit by 73 seconds, though DART far surpassed that by shortening the orbital period by a staggering 32 minutes, painting a perfect picture of our true potential and proving our capability to mitigate potential threats to the life of planet Earth!
Comments