Game Theory Applied to Space Engineering.
We don’t think about this topic very often, but it is a fact: many of our modern day technologies such as GPS devices, smartphones, and television, all depend primarily on satellites that are revolving around the earth, floating in outer space. These satellites are our main method of communication and information transportation, but they also have a myriad of other uses for people on Earth. Military defense systems rely on satellites to provide them with accurate geo-location data; satellites help climatologists and meteorologists create accurate weather forecasts and climate change models for the news. Even reading this blogpost wouldn’t be possible without the use of geostationary satellites. Artificial satellites govern so many aspects of our daily lives, so it would seem ridiculous that when it comes to the vulnerability of our satellites, there hasn’t been much action done to provide them with protection, for satellites aren’t the only things floating in outer space. Pieces of space rock, or space debris, pose serious risks to businesses and governments who rely on satellites for stability. A piece of space debris only 10 centimeters in diameter has the capability of destroying an entire satellite or spacecraft. Imagine the damage that would occur from one piece of debris that small. One piece of space debris could potentially inconvenience millions of people on Earth by disintegrating a few satellites, as well as putting the lives of people working in the International Space Station in danger, and the worst part is- there are over 29000 pieces of space debris currently floating around in Earth’s orbit, the majority of which are definitely larger than 10 centimeters across.
Karl Tuyls, a professor of computer science at the University of Liverpool, and his colleagues are designing a strategy, based on mathematical models and game theory, to help these organizations in need to “play” the right moves so as to avoid major disasters in outer space as well as the side-effects that collisions in space could cause.
Here is Tuyls’ big problem, which depicts game theory very adequately in a real-life environment: National space agencies and private satellite and communications companies all want to reduce the amount of space debris in orbit, so as to prevent future collisions. One organisation attempting to remove debris would benefit everyone operating in space. However, doing so will be very complex and expensive, so the apparent best option for any one of these players is to wait until somebody else decides to take action first, and thus, provide all of the other organizations with a cleaner space to operate in without the expense of clearing it up themselves. Herein lies the big problem, which is that if everyone thinks like this, then the amount of debris will never be cleaned up, and Earth’s orbit will gradually begin to accumulate more debris. This is because apart from all the dust and rocks, or the remnants of other celestial bodies floating around in space, we also have to worry about aging satellites and used rocket launchers that are creating new debris all the time. Over time, this constant addition of new space debris could result in a buildup large enough to create collisions, and from that collision more collisions, in a phenomenon known as the Kessler Syndrome.
The section that describes Tulys’ solution reminded me the most of what we learned in class, that strategic situations can often times be represented as a game featuring several players that each have a choice of several actions, and each player chooses which action to take based on their own preferences and the strategies of the opposing players. Tuyls’ team is attempting to create a realistic computer model of debris removal strategies that bases its analysis on game theory. They intend to design a model that will explain the different ways entities involved in space debris build-up behave. For example, it could predict the amount of effort each entity would be willing to invest on clean-up given the known risk factors that are potential dangers for the satellites. As an added bonus, they could use the model to incentivise/encourage the self-interested players to take actions, while trying to avoid a “tragedy of the commons” situation. For example, internationally agreed upon taxe/fines could force removing or preventing the growth of space debris to become a highly prioritized task for certain countries/organizations. The whole campaign lies primarily on the willingness of cooperating “players” to take action because, without said actions, the huge pile of accumulating space debris is only likely to get worse.
Link to source: https://theconversation.com/how-to-clean-up-space-debris-using-game-theory-50347