According to the European Space Agency, there are about 9,200 tons of orbital debris, space junk. About 35,000 objects larger than 10 centimeters, from various artificial objects placed in orbit, from satellites that have completed their useful life to those that have exploded. And, according to NASA estimates, "26,000 fragments equal to or larger than a baseball, enough to destroy a satellite" may be traveling through low Earth orbit. In fact, they have a specialized Orbital Debris Program Office area.
The space race of the 1960s derives in part, and in the 21st century, in a whole scientific adventure to alleviate this situation beyond our atmosphere. As highlighted by Sener Aerospace, a provider of aerospace systems for more than 50 years, «the satellites that orbit the Earth move at very high speeds, about 7-8 kilometers per second.
Therefore, in the event of colliding with another object, they cause great damage and, in general, a cloud of shrapnel that is very dangerous for the rest of the satellites. For example, in 2009, the inoperative Russian satellite Kosmos-2251 collided with the operational US satellite Iridium 33, generating more than 2,000 fragments larger than 10 cm in size.
From the company they also highlight how the amount of space debris is currently under what is known as 'Kessler syndrome', by exceeding the critical threshold of density that triggers an uncontrolled cascade of collisions and an increase in the number of objects in orbit. A progressive increase that will entail huge additional costs, as more resources are dedicated to monitoring objects in orbit, predicting their probability of collision, and, if necessary, carrying out an evasive maneuver, which will consume fuel and shorten the life of the satellite. A whole chain that can even involve the displacement of this type of shrapnel to other orbits.
The projects have received European funding (European Innovation Council-EIC), the Government of Spain (two Dynamization Grants), the Community of Madrid (Talent Attraction contract and an Industrial Doctorate) and the European Space Agency. Funds to implement developments for the benefit of all, in a joint effort in which the Spanish company Advanced Thermal Devices, Rocket Factory Augsburg, the University of Padua, the Technical University of Dresden and the IKTS Fraunhofer Institute also participate. An initiative that adds to others such as the mission projected by ClearSpace (with researchers from the Federal Polytechnic School of Lausanne).
Gonzalo Sánchez Arriaga, professor at the Carlos III University of Madrid and coordinator of the E.T.PACK and E.T. PACK-Fly highlights the importance of the aid: «For example, the fact that the European Innovation Council has decided to finance the continuation of the E.T.PACK project through E.T.PACK-Fly has been a great satisfaction. Not only does it give us stability and funding to continue developing technology, but it is also a boost of morale and recognition for the consortium, ahead of the in-orbit demonstration scheduled for 2025. By funding E.T.PACK-Fly, the EIC shows its commitment to the development of technologies that can open new markets and contribute to the sustainable use of the space environment.
«For Spain (continues Sánchez Arriaga) it would be very special if the mission were successful. The deorbiting equipment is based on what is known as a 'naked mooring', a concept already proposed in 1993 in a scientific article signed by three Spanish aeronautical engineers. The E.T.PACK initiative is a legacy of the dedication of the first of them, Professor Juan Sanmartín, to space tethers. Professor Jesús Peláez is, without a doubt, another notable figure for his extremely important contributions to dynamics».
The consortium highlights the economic and operational advantages of space tethers: "They do not need fuel, since their operation is based on three elements of the space environment: satellite speed, geomagnetic field, and what is known as ionospheric plasma...". And, logically, they will not become space debris: "Our deorbiting equipment, like the satellite, is destroyed during reentry into the atmosphere."