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The year is 2122, Saturn's high-tech galactic space force is threatening to obliterate the Earth with icy projectiles. The United States Space Force isn't afraid, this is what the 2022 DART test has prepared us for. The Saturnians are defeated by a barrage of tiny defense missiles that send the projectiles back where they came from. The Saturnians flee into the farther reaches of the Milky Way and the USSF has saved all of humankind.

That is one possible future use of the knowledge learned from the DART test: defending the Earth from aliens. Though there is currently no proof of extraterrestrial beings in space, there are other known threats that come from the sky: asteroids.

The Double Asteroid Redirection Test (DART) was a NASA mission aimed at testing a method of planetary defense against near-Earth objects. The asteroid the mission targeted, Dimorphos, was not hurtling toward the Earth but was chosen as it orbits a much larger asteroid, Didymos. The gravitational attraction that Dimorphos had to Didymos made it a safe asteroid to test the DART spacecraft on.

“There's no science for this mission. It's really just crashing a spacecraft into an asteroid to change its trajectory,” said Ye Lu, Ph.D., assistant professor in the College of Aeronautics and Engineering. “It was done as a technology demonstration, to show that this is a viable solution if there's an asteroid that we might discover that has a crash course with the Earth.”

Lu says that there is no immediate threat of any asteroids hitting the Earth, but there is always a small probability. The purpose of the DART test is to see how NASA can slightly change the path of any projectile coming toward the Earth by using a momentum exchange.

“Cars may be the best example. If you drive straight, assuming everything is perfect, tilting the steering just so slightly, keeping it that way, changes your steering wheel input,” explained Lu. “It makes sure that your car is going relatively straight. But over a long period it’s going to go off course. That's what the crash is doing. It changes the trajectory very small, slightly initially. But over the course of 10, 20 years, it changes a lot.”

With the low probability of an asteroid crashing into Earth or aliens making contact with the Earth in the next 50 years, the United States Space Force doesn’t have many threats to worry about in the near future.

With strong evidence of water on Jupiter's moon and a mission probing the icy surface of Saturn, Lu says in about 10 to 20 years we may have information suggesting life in space.

“This particular defense may eventually become part of a space force. It’s natural that its defense, it's not defense of the nation but defense of human beings,” said Lu. “There might be a joint space force that would have the resources available when events like this happen, but it's like in the movies where aliens attack, everybody comes together. Right now we’re not there yet”

To learn more about Lu and the College of Aeronautics and Engineering, visit www.kent.edu/cae.