More than 3,000 defective satellites and numerous smaller pieces exist in the Earth's atmosphere and rotate at very high velocity around the planet. The useless parts may collide and produce more "space garbage" or they may crash into a functioning satellite and destroy it.
ESA is planning to address the issue as soon as possible with utilization of robotics technology. The first mission, ClearSpace-1, will be preliminary and will include the usage of a 4-armed robot to eradicate a malfunctioning satellite which is in an orbit around 800km above the Earth since 2013. The robot will grab the satellite and drag it into the Earth's atmosphere where both devices will be destroyed. The total cost of mission will be about $133 million and it will be launched in 2025.
ESA is cooperating with ClearSpace, a Swiss junk-removal startup company, to achieve the mission. “In the coming years, the number of satellites will increase by an order of magnitude. The need is clear for a ‘tow truck’ to remove failed satellites from this highly trafficked region," Luc Piguet, founder and CEO of ClearSpace, stated.
Removing just one defective object from the Earth's orbit has minimum impact in the attempt to clear the atmosphere. However, ESA stated that the project will be the guiding mission for more efficient attempts in the future.
Those future mission are known as Active Debris Removal/ In-Orbit Servicing and their aim is to destroy multiple parts of debris in the same manner (by dragging them into Earth's atmosphere where they will burn) as ClearSpace-1.
According to Luisa Innocenti, manager of ESA’s Clean Space initiative, removing satellite debris from space is not adequate. New technologies that will significantly reduce the debris produced by satellites need to evolve. “Even if all space launches were halted tomorrow, projections show that the overall orbital debris population will continue to grow, as collisions between items generate fresh debris in a cascade effect,” Innocenti mentions.
Still some issues about space debris removal remain puzzling. Firstly, funding is not guaranteed so financial support needs to be found. Secondly, it has not been clarified what is the property regimes of "space debris" and finally, what will drive launching agencies to reduce the space debris produced at the beginning of a space mission?