NASA’s DART Protection Project is a Step in a New Direction
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NASA launched the Double Asteroid Redirection Test mission (DART) on Wednesday, November 24, 2021, at approximately 1:00 a.m. EST from the Vadenberg Space Force Base in California. The mission was assisted by a SpaceX Falcon 9 rocket, and it marks NASA’s first project involving space defense technology against potential extraterrestrial bodies.
The target for this mission is an asteroid binary system––two asteroids called Dimorphos and Didymos. Dimorphos is the smaller of the two, orbiting Didymos like a natural satellite. It is analogous to the Moon orbiting Earth in an elliptical path—the only difference is that Dimorphos orbits Didymos from a mile away and completes an orbit in only 11 hours and 55 minutes. NASA’s goal is to test whether the launched spacecraft and its on-board technology is capable of deflecting and altering Dismoprhos’ trajectory. This will prove extremely challenging because of the precision required and the novelty of the mission. Didymos measures just half a mile long and Dimorphos measure only 525 feet across—these measurements are drastically different from the hulking planetary bodies typical of NASA missions. Based on scientists’ calculations, the space probe will visit the two asteroids between September and October of 2022.
NASA’s methods involve maneuvering the spaceship, which weighs approximately 1,200 pounds and is the size of a small car, to initiate direct impact with Dimorphos. The spacecraft will orbit Earth many times, using a solar panel and an electric thruster to accelerate and achieve the velocity needed to escape orbit. Onboard the space probe, DART has a high-resolution camera called DRACO, which is used for navigation. The space probe also features an advanced guidance and control system that works in tandem with algorithms called “Small-Body Maneuvering Autonomous Real Time Navigation” (SMART Nav). This algorithm will identify Dimorphos and direct the space probe toward it. Just five days before the impact, the CubeSat camera, which was built by the Italian Space Agency, will be released prior to the collision event to capture images of the resulting cloud of ejected matter. At this point, the spacecraft will have traveled too far for NASA to operate in real-time, which is when the spacecraft will employ its autonomous navigation to steer itself into Dimorphos. After the impact, scientists at NASA will measure the change in Dimorphos’s orbit around Didymos.
DART will crash at a speed of 41 miles (6.6 kilometers) per second, and the impact is predicted to speed up the duration of the orbit and shift Dimorphos slightly closer to Didymos.
An incoming, Earth-bound asteroid may sound terrifying to most people. However, the mission is actually just a simulation for future planetary defense scenarios involving incoming asteroids or comets. The purpose behind this mission is to show that an autonomous spacecraft is capable of deflection through direct asteroid contact to save Earth’s population. NASA’s chief of Planetary Defense, Lindley Johnson, expresses agreement with initiating this project early. “We’re doing this work and testing this DART capability before we need it,” he said. Instead of facing haste and uncertainty in the event of an asteroid emergency, we have already tested and perfected it. This mission will provide important information to prepare for future emergencies.
The $324 million DART mission may seem unusual for NASA, a civilian agency that focuses mainly on exploration, climate monitoring and hunting for signs of past life in our solar system. Though NASA occasionally works with the U.S. Department of Defense, the organization has not traditionally been responsible for efforts involving the protection of planet Earth. This mission is NASA’s first venture into planetary protection.
The reason behind this new and unconventional space project can be traced back to 2005, when Congress assigned the agency the imperative of protecting the planet from dangerous objects that orbit the sun. Since then, NASA’s Near-Earth Object Observations Program has kept vigilant watch over asteroids that are in close proximity with the Earth—close enough that they could potentially cause catastrophic damage. The program works by tracking and cataloging asteroids larger than a football field in close proximity with the Earth. Related to these aims, NASA set up the Planetary Defense Coordination Office in 2016, which collaborates on asteroid tracking and notifies the Defense Department and Federal Agencies of any threats. The DART mission represents another example of NASA embracing its role in conducting research and ensuring the protection of planet Earth.
This mission could give NASA a confirmed planetary-defense weapon, but more importantly, introduces the possibility of nuclear weaponry in space. Scientists have proposed that blasting incoming asteroids or large debris may be more effective than using the kinetic energy of a spacecraft alone. In fact, a nuclear explosive-tipped spacecraft may not be too far into our future. However, if this idea were to be implemented, it would change the way we wage war and may become a serious threat to national security in the future. Though the Outer Space Treaty essentially bans nuclear weapons from being deployed in space, the terms of the treaty could be resolved in an emergency United Nations meeting if necessary.
Moreover, NASA may conduct similar missions in the future to collect more information about our solar system. These missions may even allow NASA to collect samples from rogue asteroids. Ideally, the space probe would collect a sample and determine its composition. Asteroids like these are analogous to a time capsule, and could give scientists new insights into the conditions during solar system formation. In addition, some of the asteroids in our solar system have originated from extremely distant places, which means that traces of organic compounds and water may give us clues to other forms of life in the universe.
Despite the space probe’s inability to support human life onboard the aircraft, this decreased burden may even allow NASA to test the speed limits of spacecraft engines. The NASA DART mission is just the tip of the iceberg in the future of planetary defense.