# Destroying Dangerous Space Debris Using Game Theory

According to NASA, there are nearly 500,000 objects that are found in orbit around Earth. These objects are known as space debris and circle around the Earth at a speed close to  20,000 miles per hour. Space debris poses a serious threat to damaging very expensive equipment and satellites that scientists from around the world have sent into space for research and services. The reason why no country has taken the initiative to try and stop the infiltration of space debris into Earth’s orbit is because it is a very difficult, expensive task. Many ways have been designed to try to stop the issue, but none have prevailed. However, researchers at the University of Liverpool have come up with a way to deal with this issue using mathematics. In particular, they use concepts from game theory to help monitor the amount of debris that enters Earth’s orbit.

Game theory is a mathematical model that uses probability and risk to determine the outcome of logical situations. Although game theory is used widely in economic and political concentrations, it can be applied to any problem that is in need of a solution. The idea derived from the study of game theory that is applied in this situation is known as the tragedy of the commons. By definition, the tragedy of the commons is a situation that occurs when there is a tendency to overuse and heavily rely on a common resource. As a result, the resource is not controlled properly and deterioration of the resource occurs.

In this case, the resource that is deteriorating is Earth’s orbit as more and more space debris enter this widely-used field of space. The problem is that although many countries are using this open-access area, not a single one is devoting time to fixing it. Each country would rather wait until another country decides to take on this responsibility. However, if everyone thinks and acts like this, nothing will ever be done. No one will ever take the initiative to preserve this important area. As time goes on, the number of space debris to enter the orbit will increase, and at the same time increasing the likelihood of damage to space satellites and equipment. Therefore, by avoiding the cost of removing the space debris, each country is taking an active part in increasing the cost for everyone if and when damage to the equipment occurs.

Computer scientists are proposing ways to reduce the production and quantity of space debris within the orbit. Their goal is to “organize the commoners in order to save the commons.” They are discovering these strategies through mathematical models similar to those used in game theory. They believe that everyone who uses this space for research can play a proportional role in this effort of elimination. Using technology, they are creating different programs that mimic the process of human decision-making which have governments and businesses as their “players” of the game. Using hundreds of different simulations, the computer scientists can then figure out which of the players’ strategies will help make for the best space debris removal technique. With hope, the researchers believe this information will help the world see that this growing issue can be resolved with little cost.

https://www.inverse.com/article/8537-scientists-use-game-theory-to-seek-and-destroy-dangerous-space-debris