On November 24, 2021, the first planetary defense mission, the Double Asteroid Redirection Test mission (a.k.a. the DART mission), will launch aboard a Falcon 9 rocket in Vandenberg Air Force Base in California. Find out what this mission is about and why it’s essential in this article.
What is the Destination of DART?
Unlike the Lucy mission, the DART mission won’t receive any gravity assists along the way. This is because its target is a near-Earth asteroid called (65803) Didymos and its satellite, where the spacecraft will reach September next year. The mission is not about exploring the compositions and physical properties of the asteroid but impacts the satellite of Didymos, Dimorphos, at a high relative velocity.
Keep in mind that both Didymos and Dimorphos are less than one kilometer wide. Didymos is about 780 meters wide, and its mass is about 523 billion kilograms, while Dimorphos is about 160 meters wide, and its mass is about 4.8 billion kilograms.
What is the Structure of DART?
From the outside, DART looks like a typical spacecraft. Since it only travels through the inner Solar System, it uses solar panels for electricity. It also has an engine like other space probes, but it’s an ion engine powered by electricity, but not traditional fuel. Specifically, the engine model is called NEXT-C, which stands for NASA Evolutionary Xenon Thruster – Commercial. DART also carries an imager called DRACO, which stands for Didymos Reconnaissance & Asteroid Camera for OpNav, and is similar to a long-range reconnaissance imager.
What is the Purpose of DART?
DART demonstrates a planetary defense technique using a kinetic impactor. In a kinetic impactor mission, a spacecraft is sent to impact a target at very high speeds, thus causing it to accelerate and change its orbit. Specifically, the DART spacecraft will hit the asteroid at a relative velocity of approximately 6.6 km/s. The more massive an asteroid, the less effective this technique is since more force is required to accelerate a more massive object than a less massive object by the same amount of speed.
Keep in mind that the DART mission only hopes to cause minor changes in the orbital trajectory of the satellite of Didymos, Dimorphos. Specifically, NASA expects the relatively lightweight spacecraft to cause the orbital period of the moonlet to change by just a few minutes. However, if we’re facing a real threat and we’ve deflected it by a small amount well in advance, it could completely miss our planet instead of crashing into it.
In this article, we briefly explored the first planetary mission, the DART mission, that will launch just a few days later. If you want to learn more, please read the webpages in the references below. Moreover, if we missed any crucial points, please leave them in the comments below to improve the article.
References and Credits
- (n.d.). Double Asteroid Redirection Test (DART) Mission. Retrieved November 17, 2021, from https://www.nasa.gov/planetarydefense/dart
- Daisy Dobrijevic. (2021, October 29). DART asteroid mission: NASA’s first planetary defense spacecraft. Retrieved November 17, 2021, from https://www.space.com/dart-asteroid-mission
- Chelsea Gohd. (2021, October 27). NASA’s DART spacecraft, humanity’s first asteroid defense mission, less than one month from launch. Retrieved November 17, 2021, from https://www.space.com/nasa-dart-asteroid-mission-launch-one-month