UNDERSTANDING SPACE DEBRIS: DEFINITION AND IMPACT ON THE PLANET

Space debris, also known as orbital debris or space junk, refers to man-made objects in Earth orbit that have ceased to serve an operational function. This category of objects includes various items such as fragments of deactivated satellites, rocket parts, nuts, bolts, and even tiny particles from past collisions. With nearly 34,000 objects larger than 10 centimeters tracked in orbit and millions of smaller ones that elude monitoring, space debris represents a major challenge to space safety. This debris can cause significant damage to operational satellites and spacecraft, as well as to astronauts and space station crews. The continued growth in the amount of space debris underscores the importance of monitoring and managing these objects to ensure the long-term safety of space activities.

Space debris poses several hazards to the planet and space activities. First, it poses a threat to operational satellites and spacecraft. In addition, space debris in low orbit can fall back to Earth, endangering people and property. Finally, this debris can also contribute to the collision cascade effect, where each collision generates more debris, increasing the risk of further collisions and worsening the problem.

Space debris in orbit can travel at extremely high speeds, often several kilometers per second. If it collides with an operational satellite or spacecraft, even a small piece of debris can cause significant damage or even total destruction of equipment . These collisions can result in loss of communications, the disabling of essential services such as GPS navigation, or even the incapacitation of weather satellites crucial for weather forecasting.

When a collision occurs between two objects in orbit, it can generate a large amount of additional debris, making the initial problem worse. This phenomenon, called collision cascade or Kessler syndrome, increases the risk of new collisions and makes space debris management even more complex.

Debris in low orbit can gradually lose altitude due to atmospheric drag and eventually fall back to Earth. Although most debris disintegrates upon reentry, some fragments may survive reentry and reach the Earth's surface, posing a risk to people and property below the fallout trajectory.

In addition to the immediate risks to space activities and the safety of populations, space debris can also impact the space environment as a whole. Excessive accumulation of debris can render certain orbits unusable for space missions, thereby limiting access to space and compromising the future development of space exploration.

In summary, space debris poses significant hazards to the planet and space activities, ranging from the destruction of vital equipment to the potential threat to the safety of Earth's populations. Effective management of this debris is therefore essential to ensure the safety and sustainability of the space environment.

To mitigate the threat of space debris, several approaches are being considered. First, better management of existing debris , including tracking and predicting the trajectories of objects in orbit, is essential to avoid collisions. In addition, proactive measures, such as designing satellites and rockets with safe end-of-life technologies , reducing debris during launches, and developing deorbiting methods to remove debris from active orbits, are crucial to prevent future accumulation of space debris.

In 2019, Spacefox organized a scientific competition to allow young entrepreneurs to benefit from a grant of 3,000 euros to help finance their scientific project related to the space sector. In a few days, we received no less than a hundred fabulous projects. Among them, the work of Clément Linglois and Anthony Dréano stood out. The Xinetis project, initiated by these two ENSMA students, aimed to contribute to the reduction of space debris by developing CubeSats specialized in deorbiting. Their short-term objective was to provide CubeSat structures to space organizations, followed in the medium term by the supply of equipment for these satellites and, in the long term, by the deorbiting of small space debris or their movement to graveyard orbits. The Xinetis project is an example of an initiative aimed at solving the growing problem of space debris, crucial to ensuring the sustainability of future space activities.

This student project ended in 2023 but other space companies are keen on reducing space debris, such as the GAMA company, which plans to deploy solar sails that could allow satellites to be deorbited (we interviewed the CEO of GAMA in 2023, find this interview on our YouTube channel if you are interested in this subject)