THE’European Space Agency (Esa), on April 1st, issued his annual report on the state of Space debris Around the earth, the so -called “space garbage”. The relationship has as its objective to both keep track of the number of debrisand to update the international community oneffectiveness of reduction strategies of the same, in order to improve the long -term sustainability of space flights. Unfortunately, the relationship does not bring good news with it. Although there is a growing adherence to the mitigation standards of spatial debris by public and private companies, the number of new debris which is formed by collision of no more operational satellites is far greater than the space garbage that burns in the atmosphere. Even in certain altitude bands the number of active satellites is of the same order of magnitude as that of space debris. The report underlines how the situation is so much serious that even without new launches, the number of debris would still increase by collision of the objects existing in orbit including satellites, an effect known as Kessler syndrome. The ESA therefore recommends accompanying the good practices put in place for the new launches with the “active” removal of debrisin order to allow launches with human crews in complete safety towards the low orbit and the moon.
The number of spatial debris is growing strongly
The ESA estimated that there are more than 1.2 million space debris larger than 1 cm in orbit around the earth. Although very small, these fragments move to Very high speedsmaking them practically bullets able to create catastrophic damage to other objects in orbit. The International Space Station itself must occasionally carry out the emergency maneuvers to increase its orbital share in order to avoid the collision with a space debris. It is therefore understood how the monitoring of these objects is of fundamental importance. The ESA is currently able to trace about it 40 000which are those that are generally larger than 10 cm.
The number of satellites has increased in recent years, to the point that in the low terrestrial orbit, around the 550 km altitude, there are many active satellites as many spatial debrisand this is mainly due to the orbit of large satellite constellations, such as Starlink. This crowding of the orbit unfortunately makes the Collings between debris and active satellitesbut also between debris themselves. In the last year the ESA has recorded a increase of 3 000 units In objects to be traced due to fragmentation of the spatial garbage.
How to mitigate the problem
Since some years the ESA, like other space agencies, has proposed “Good practices” To mitigate the phenomenon of space garbage. The number of satellites that have returned by burning in the atmosphere at the end of their useful life has increased in recent years. This is a precise choice to conform to the guidelines for the reduction of space debris, removing the satellites at the end of their life cycle with the most crowded orbits. The number of returns of the bodies of the rockets and the useful loads launched in orbit is also increasing, especially by private companies. About 80% of the launches also comply with the new and more restrictive standard of abandonment of the orbits within 5 years, adopted by ESA for their activities in 2023.
Another factor that contributes to the increase in return in the last two years is the peak of the solar cyclewhich has the effect of increasing the atmospheric friction and thus accelerating the times of returning to the land of space garbage.
What is expected for the next few years
Although public and private companies are doing everything possible to mitigate the problem of space garbage, in the last year (2024) The net number of debris has increased. There is so much spatial garbage in orbit that even if we stopped launching new satellites, the number of debris would also increase due to the fragmentation events. The collisions between small and large objects add new debris faster than the debris themselves can naturally fall within the atmosphere, a phenomenon also known as Kessler syndrome. This cascade event therefore makes the development and implementation of “active” removal methods spatial garbage, a project to which ESA is already working with missions such as Clearspace-1.
Keeping the “clean” terrestrial orbit is of fundamental importance. Even small debris such as a coin can irreparably damage a spacecraft. If we want to continue to send human beings in the space around the earth and to the moon, you need to Keep the orbital corridors free from the space garbage. The lessons we are learning here on earth will then have to be applied from the beginning for the satellites around the moon, since the lack of atmosphere around our satellite prevents the natural destruction of debris for atmospheric return.
