Space Debris

Introduction

In 1957, the first satellite, Sputnik, was launched into space. Today there are approximately 1400 satellites, which we rely on heavily. They form an essential element in the infrastructure of 21st century society. Technologies that depend on satellites include communications, television, navigation, weather monitoring and military reconnaissance to name a few. This adds up to a global market worth over $300bn (£233bn). According to NASA estimates, there are more than 100 million pieces of debris smaller than 1 cm, about 500,000 pieces 1–10 cm long, and around 21,000 larger pieces are estimated to be in orbit. As each piece travels at around 40,000 kph they pose a threat to the 1400 unmanned satellites and the 1 manned satellite, the International Space Station (ISS). For example, travelling at 35,400 kph a 1 cm paint fleck can do the same amount of damage as an object on Earth weighing 250kg travelling at 27m/s [1].

Kessler Syndrome

Collisions with debris in orbit are a source of further debris, with each collision supplying hundreds more pieces, which in turn increase the risk of further collisions. There is a theoretical limit where the density of space debris becomes so large it causes a cascade effect, greatly increasing the problem and potentially making earth orbit uninhabitable for satellites or people. This would hamper all modern technology that relies on satellites, remove the opportunity for human space travel and exploration, and potentially pose a re-entry threat to people on Earth [1].

Task

The US government, worried by the danger posed to their military satellites (GPS, reconnaissance and earth monitoring) have issued a request to tender for solutions. Your task is to find a solution to the impending problems caused by Kessler Syndrome. This could involve a space debris clean-up solution, methods for coping with space debris or a method to slow the rising amount of debris. You may address the entire issue, or tackle a smaller section of it, as it is expected that multiple solutions from different agents will be required. 

Considerations

·      Context

First, you must identify the problem you are trying to solve. Will you either try to remove the debris that is currently in orbit or will you come up with a way to prevent further debris from new satellites? 

·      Technical

You need to show that you have considered the scale of the problem, including all relevant factors such as distances and speeds of debris and current operating satellites. You will also need to consider what materials would be suitable for such application. What materials can cope with the conditions in the Earth’s orbit and what physical properties are required?

·      Environment

How will your proposal be implemented and how will it interact with the existing space infrastructure?.

·      Costs

The budget committed to this problem is extremely large, however your solution will be competing against other solutions and must offer good value for money. For this reason, your proposal must be fully costed, practical and be built for reliable operation.

·      Sustainability

The solution should aim to be robust with a well-engineered lifecycle, considering the materials used, maintenance and decommissioning of the equipment.

References

[1] Paul Ratner, "How the Kessler Syndrome can end all space exploration and destroy modern life", in Big Think, Aug. 29, 2018. Available: https://bigthink.com/paul-ratner/how-the-kessler-syndrome-can-end-all-space-exploration-and-destroy-modern-life. [Accessed October 9, 2023].