West Virginia University is studying the use of artificial intelligence-powered space lasers to redirect space debris to reduce the risk of collisions. Supported by NASA, the program aims to handle debris of all sizes and is currently validating its algorithms and models.
Earth's low orbit is filling up with junk that poses a threat to space assets. New research from West Virginia University explores whether space-based lasers can remove tiny particles or large pieces of debris from orbit where they might collide with objects such as satellites or space stations. Image credit: West Virginia University Illustration/Savanna Leech
If the research proves successful, a coordinated network of space lasers could divert debris that litters Earth's orbit and poses a threat to spacecraft and satellites away from potential collision trajectories.
Hang Woon Lee, director of the Space Systems Operations Research Laboratory at West Virginia University, said that a large amount of man-made debris is accumulating around the earth, including defunct satellites. The more debris in orbit, the higher the risk that some of it will collide with manned and unmanned space assets. He said he believes the best way to prevent these collisions is to install multiple laser arrays on space platforms. These artificial intelligence-powered lasers can maneuver together to respond quickly to debris of any size.
HangWoonLee is an assistant professor of mechanical and aerospace engineering in the Benjamin M. Statler College of Engineering and Mineral Resources at West Virginia University; director of the Space Systems Operations Research Laboratory at West Virginia University. Image Credit: West Virginia University Photo
NASA Support and Research Advances
Lee, an assistant professor in the Department of Mechanical and Aerospace Engineering in the Benjamin M. Statler School of Engineering and Mineral Resources, has received NASA's prestigious 2023 Early Career Faculty Award for potentially groundbreaking research. NASA is funding Lee's rapid-response debris removal research with $200,000 per year for up to three years.
The work is currently in its early stages, and the team is validating whether the algorithm they propose to develop to run the laser system is an efficient, cost-effective solution. "Our long-range goal is 'multiple space-based lasers actively perform orbital maneuvers and collaboratively handle orbital debris,' which will help avoid collisions with high-value space assets in a timely manner," Li said. "The current goal is to develop a reconfigurable space-based laser network and a set of algorithms. These algorithms will be the enabling technologies to make such a network possible and maximize its benefits."
The growing challenge of space debris
If a natural object (such as a micrometeoroid) strikes a man-made object (such as the remains of a launch vehicle), the resulting debris can spread rapidly, and even fragments as small as a speck of paint can have the force to puncture the side of an observation or communications satellite or the International Space Station. This has become an urgent problem because space is becoming increasingly cluttered. In particular, Earth's low orbit has attracted commercial telecommunications systems like SpaceX's Starlink, which uses satellites to provide broadband internet to users. Low orbit is also home to satellites used for weather forecasting and land cover analysis, as well as a staging ground for deep space exploration.
"The increased number of objects increases the risk of collisions, jeopardizing manned missions and jeopardizing high-value scientific and industrial missions," Lee said. He added that collisions in space can trigger a domino effect, known as "Kessler syndrome," which triggers a chain reaction that increases the risk of further collisions and makes space unsustainable and hostile.
Laser Advantages Compared to Other Technologies
Other researchers are developing debris-removal technologies such as hooks, harpoons, nets and sweepers, but these only work on large debris. Lee's method should be able to handle debris of almost any size.
The suite of algorithms that Li's team will develop could potentially be adapted to lasers mounted on large satellites, or it could power lasers mounted on their own purpose-built platforms. As part of his research, he will evaluate various forms that laser networks might take. In either form, the technology will be able to make many decisions on its own, perform actions independently, and set priorities.
The system will decide which laser combinations to target which debris, while ensuring that the resulting trajectories are collision-free.
When a laser hits a piece of debris, it doesn't destroy it. Instead, the debris is pushed to a new orbit, usually by laser ablation. This means that the laser beam vaporizes a small portion of the debris, creating a high-speed plasma plume that pushes the debris out of orbit.
Laser ablation and photon pressure processes cause changes in the target fragment's velocity, ultimately changing the size and shape of its orbit. That's the motivation for using lasers. The ability to change the orbit of debris can be effectively controlled through a laser network, allowing space debris to move or deorbit and avoid potentially catastrophic events such as collisions," Li explained.
"Using a system of multiple lasers can create multiple opportunities for contact with debris, allowing for more effective trajectory control. Multiple lasers can act simultaneously on a target over a wider range of intensities, changing its trajectory in ways that a single laser cannot."
Lee will work with Scott Zemerick, principal systems engineer at Fairmont-based TMC Technologies, to validate all models and algorithms developed throughout the project in a "digital twin environment." Li said this will ensure the product can be used in flight software.