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Space debris: a real threat © NASA Orbital Debris Program Office |
Having accumulated in orbit since the beginning of the space conquest, space debris has become, over time, an unavoidable problem because of the risks it poses for active gears and future missions. The different space agencies, as well as the private actors of this sector, have to find solutions to minimize the threats of impacts.
A worrying situation
While breakdowns and other equipment losses caused by space debris are still infrequent in orbit, the situation could rapidly escalate due to the planned end of life of many satellites, as well as the launch of programs. such as the constellations of OneWeb satellites (more than 600 satellites), or the Starlink project of SpaceX which intends to form a network of nearly 12,000 satellites! In addition, the ability of some emerging countries to cut down satellites, as did India last April with the Shakti mission or China in 2007 with Fengyun-1C, only aggravates an already worrying situation.
A very real threat
Particularly dangerous because of their high kinetic energy, space debris likely to collide with active machines with an average speed of 10 km /s. At this rate, debris less than 1 cm can punch and degrade equipment, which can lead to breakdown or loss of gearin the worst case. In addition, these collisions generate new larger or smaller debris that will become a threat in their turn. Although the likelihood of large debris striking an active machine, or other large debris, such as the unfortunate Envisat - the largest orbit currently in orbit with its 8,200 kg - is relatively small, the consequences such a collision would be disastrous and would only accelerate this problem to a point of no return, a chain reaction, a sort of "snowball effect".
Jan Woerner, Director General of ESA, says that the European Space Agency must " very regularly change the course of its satellites to avoid the largest objects ."
According to him, like climate change " no one can deny that this debris is there "; he believes that action is needed and that all stakeholders in this sector are aware of it. Jan Woerner explains: " Imagine that when your car no longer works, you are allowed to leave it 25 years in the middle of a crossing, it would be totally stupid. It is not possible. [...] space is something like that - like a road, a street. It's an infrastructure and we have to clean it up "
Minimize risks
Although ESA is not alone in its effort to solve space debris problems - NASA or Airbus is also on the spot - the European Space Agency intends to take the bull by the horns with its initiative Clean Space.
Playing on several boards, this initiative is not only aimed at " cleaning space ", but also, and above all, at making sure to produce as little space debris as possible in the near future. Thus, several projects are currently underway to stem this increase in space debris to avoid the snowball effect of which we spoke a little higher.
First, e.Deorbit project explores the possibility of a "debris removal" mission. It will consist of capturing an ESA abandoned satellite in orbit in order to bring it back to a controlled atmospheric reentry so that the vehicle burns in the Earth's atmosphere.
The ESA has also made some time ago a test allowing researchers to better understand why some instruments are not consumed during their reentry. The researchers burned a magneto-coupler - a particularly robust instrument for orienting certain satellites in space - in the plasma blower at DLR German Aerospace Center in Cologne. In addition to watching this instrument burn up dramatically, the agency hopes to study and help design instruments that would not pose a threat to people and property, or to wildlife, as they fall. from heaven.
Although this ESA initiative is still in its infancy, it nonetheless aims to raise public and politicians' awareness of a problem that is only growing and should logically continue to grow. over the years. Human lives (risk on the ground after uncontrolled atmospheric re-entry, ISS, manned flights, etc.) are at stake, and many expensive and difficult-to-develop scientific instruments are threatened by space debris: it is, therefore, necessary to act quickly and ESA will lead by example through its Clean Space initiative .
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