November 24th, at 1:21 AM Est from SLC-4E at Vandenberg Space Force Base
Imagine this, you wake up and start brewing your coffee. As it drips you open your tablet and browse through the mornings news. You reach a headline saying “Earth in peril, asteroid strike coming” You aren’t sure what to make of it at first. sounds like a few movies you’ve seen before, only later at work people are talking, it’s now all over the national news. An asteroid hitting Earth is imminent and could possibly wipe out a large part of the planet. This has always been science fiction, now it’s real, what can we do? Well that’s what NASA is trying to figure out. In the infinity of space it seems somehow likely that one day another asteroid like the one which ended the dinosaurs could destroy civilization as we know it. NASA’s DART or Double Asteroid Redirection Test mission is launching this evening to figure out if we have a viable way to save humanity from impending doom.
The mission itself is a matter of planetary defense. It will be the first mission of its kind, a kinetic impactor technique to change the trajectory of an asteroid in space. DART is a spacecraft designed to crash into, or impact an asteroid as a test of our technology. The targeted asteroid, Dimorphos is not a threat to our planet but is the perfect testing ground to see if we can can effectively change its course by impacting it with the spacecraft. In fact there is currently no known asteroid larger than one-hundred-forty meters in size that has a significant chance to hit Earth in the next one-hundred years.
Once launched, and separated from the launch vehicle DART will deploy a ROSA (Roll Out Solar Array) which will provide the power needed for DART’s electric propulsion system. The craft will demonstrate the NASA Evolutionary Xenon Thruster or NEXT-C. That’s a next generation system based on the Dawn spacecraft propulsion system developed at NASA’s Glenn Research Center in Cleveland, Ohio. Using an electric propulsion the mission could benefit from significant flexibility to the timeline while demonstration the next generation ion engine technology that can become applicable to future NASA missions. DART will be equipped with a lone scientific instrument, named Didymos Reconnaissance and Asteroid Camera for optical navigation (DRACO). This camera will also be capturing images of the Binary it’s headed to and provide support for the spacecrafts autonomous navigation system. DART won’t be travelling alone on this multi million mile journey either. a cubesat named LICIACube will separate from DART about ten days prior to impact. Designed by the Italian Space Agency, this craft will capture images of the encounter using two cameras, dubbed LUKE & LEIA. It will then transmit these images back to Earth so we can watch the dinosaurs vengeance in all its glory.
Asteroids are typically the left overs of the solar system, posing no threat to our Earth, but when a rock’s path crosses that of Earth’s where the two objects intersect at the same time, a crash may occur. An impact on our planet with an asteroid less than 300m across could explode with several times the force of the energy that a typical nuclear bomb has. This would devastate populated areas, and could cause tens of thousands of causalities. Asteroids with a diameter larger than 300m and larger could create continent wide destruction. An asteroid the size of Dimorphos, 780m across would come close to planet wide devastation.
Once DART escapes the gravity of Earth it will continue on to the binary which is about 6.7 million miles from us in September of 2022. Once DART smashes into the moonlet at a speed of around 15,000mph it should change the speed of the object by a mere fraction of a millimeter per second. This will alter its course around Didymos in a very small way. Though its course will be just slightly altered it should be enough to prevent a collision with Earth should it have been on a path to crash into our home. Of course the car sized spacecraft built by Johns Hopkins Applied Physics Laboratory won’t survive, but that’s okay because NASA is testing the technologies required to prevent such a disaster from happening.
Of course, we have to be sure that the impact has changed the asteroids course, this is where the ESA’s (European Space Agency) Estrack Network will track the progress of the mission using antennas in Argentina, and New Norcia. Using an Ultra-precise deep space navigation technique, the mission controllers will be able to track the spacecraft along its mission to a few hundred meters. NASA says ground-based telescopes and planetary radar will be used to measure the change in momentum imparted to the asteroid.