Why Space Debris Mitigation is Important for Long-Term Sustainability

The number of Space activities has mushroomed and will continue to do so in the coming years as more technologies are developed to meet the growing needs that improve the daily lives of people globally. While it is a good sign of progress, at the same time, the accumulation of space debris and the threats that it poses cannot be overlooked because everything is interdependent.

In November 2021, the “orbital altitude of the International Space Station (ISS) was increased to avoid collision with space debris,” as confirmed by Roscosmos State Corporation for Space Activities (Roscosmos). The debris was identified as a part of the Fengyun-1C, a Chinese weather satellite, which was launched in 1999 and was decommissioned in 2002. The satellite turned to debris and stayed in the low Earth orbit (LEO) since it was later destroyed by China in 2007.

In 2009, a derelict Russian military satellite, Kosmos-2251, slammed into an active communications satellite, Iridium 33 at speeds in excess of 26,000 miles per hour (41,800 kph). This single collision resulted in at least 1,800 large pieces of space debris that remain scattered in the orbit to this day. The number of active satellites has jumped up by 68% from a year ago and by more than 200% from five years ago.

The U.S. Department of Defense has tracked more than 27,000 pieces of space junk, including approximately 23,000 objects larger than a softball, which include old satellites, rocket bodies, and fragments of exploded or decaying spacecraft of varying sizes. Since the start of space exploration, around 6,000 satellites have been launched into orbit. That number is expected to increase massively, particularly if all the ‘mega-constellations’ with thousands of satellites become reality. Vytenis J. Buzas, Co-Founder and CEO, NanoAvionics Corp., states, “The much greater danger than this simple increase would be a non-stoppable snowball effect if satellites collide and create catastrophic clouds of Space debris, which eventually would make low Earth orbits, where most of the small satellites are, unusable.”

The real problem is that there is absolutely no track of these floating pieces of junk, and because of that it is impossible to know when a piece of junk, travelling at what speed might collide with something and cause a chain of collisions. At speeds of up to 17,500 mph (28,100 kph) they are fast enough for even a relatively small piece of orbital debris to damage a satellite, a spacecraft and pose a risk to astronauts aboard the International Space Station.

This is why new techniques are being experimented to observe, track, and then start cleaning up those growing space debris in low Earth orbit.

There are 8,055 satellites roaming Earth’s orbits, 42% of them inactive, according to Seradata, which tracks the statistics.

While Earth’s atmosphere naturally cleans the debris by pulling the fragments downward into its lower atmosphere, the increasing carbon emissions have reduced the density of our planet’s upper atmosphere, lessening the effect.

Researchers from the University of Utah, US state that since there is no easy solution to growing carbon emissions, researchers aim to clear this mess by spinning magnets and creating magnetic fields that can manage space objects even if they are not magnetic.

The European Space Agency (ESA) awarded ClearSpace a USD 104 million contract to launch a mission to remove a debris object from orbit in 2025. The Japan Aerospace Exploration Agency (JAXA) selected Astroscale to send a spacecraft into orbit in 2023 to inspect a discarded rocket upper stage, a step that would pave the way for a debris-removal mission.  Astroscale also signed an agreement with New Zealand to study advanced concepts for orbital debris removal. And it won a contract from the UK Space Agency to study the removal of two defunct satellites from low Earth orbit by 2025.

New age technologies to provide solutions

Anirudh Sharma, CEO & Co-founder, Digantara, states that the threat of satellite-satellite and satellite-debris collision is an alarming problem more complicated than satellite operation itself to the space industry today and its complexity is increasing with the growth of the space industry. With relative velocities over 14 times the speed of bullet (or 30 times the speed of sound) even a 1 cm object in space can annihilate an entire satellite, destroying the dependent business model and stalling the concerned company’s growth. Current tracking systems are ground-based radars and telescopes with woefully inadequate space object detection resolution of 10 cm. Hence, out of 1 million objects greater than 1 cm, over 0.95 million objects lesser than 10 cm are untracked.

“We have an active surveillance (LiDAR) system in space that allows us to monitor objects accurately without relying on additional light sources. It provides us unprecedented data when compared to other passive systems such as cameras and telescopes.

The atmosphere greatly affects ground observations, requiring weather-restricted viewing and limiting resolution to 10 cm or bigger spheres. Furthermore, passive space surveillance techniques lack an intrinsic lighting source; instead, they rely on the Sun for illumination and can only be used at night, against a dark background. When combined, these factors can reduce sensor usage to as low as 10%,” Sharma adds.

Reliving the formation days, the Sharma recalled, “the inadequacy of space surveillance was evident and we realized that active surveillance derived out of orbit can change that”.

Sustainable solutions for safer missions

Since 2014 RUAG Space has the goal, that all our products are 100% debris-free, i.e., are designed not to create any additional debris in space. We also put efforts in developing new sustainable technologies, like using natural fibers (bio-composite) instead of carbon fibers for satellite structures.

In addition, they are contributing with key products to space debris removing missions from ‘Astroscale’ or ‘Clear Space’.

“The idea behind this Bio-Composite Structure in Space Applications project was to investigate the use of natural fibres in place of their carbon equivalents,” explains ESA structural engineer Tiziana Cardone.

He further states, “There are two main reasons why: firstly to reduce the environmental impacts of space manufacturing, which is one of the main goals of ESA’s Clean Space initiative. Our detailed Life Cycle Analysis shows this can cut carbon dioxide emissions by up to 75% compared to matching carbon fiber parts.

“In addition, in another link to Clean Space, we’ve been seeking out novel materials that can ‘demise’ more easily, meaning they can burn up more rapidly and completely during atmospheric reentry. This has been driven in turn by the requirements of Europe’s space debris mitigation policy, requiring a less than 1 in 10,000 risk to people or property when satellites are disposed of at their end of life.”

Anders Linder, Senior Vice President Satellites, RUAG Space states that RUAG Space has provided its GNSS-equipped computer to command Astroscale UK‘s ELSA-M Servicer, a spacecraft designed to remove space debris. He explains, “The ELSA-M servicer will be optimized to remove multiple retired satellites from low Earth orbit in a single mission. Astroscale’s ELSA-M servicer is specifically designed for the servicing of constellation satellites, such as those launched by the global satellite communications network OneWeb.

For these kinds of missions, a high performing ‘brain’ (On Board Computer) is needed. The computer from RUAG Space will include a Global Navigation Satellite System (GNSS) receiver and interface unit, all in one box. Once in orbit the computer controls the ELSA-M spacecraft, enabling repeated multi-debris removal manoeuvers and management of equipment, reaction wheels and magnetometers linked to it. The computer system developed in partnership with RUAG Space – with the software from Astroscale and the hardware from RUAG Space – will support the rendezvous between Astroscale’s servicer spacecraft and the client spacecraft, a retired or defunct satellite.”

“For the ‘Clear Space-1’ mission we are delivering structures for the satellite capture mechanism for this particular mission as well as the Solar Array Wing which is a subsystem of the whole satellite attached to the satellite structure. The Solar Array Wing subsystem includes the Solar Array drive mechanisms, the solar array populated with solar cells, the deployment and release mechanisms of the highest reliability. Our mechanism continuously aligns the solar arrays to get the maximum amount of sun light. Solar power is the main energy source for satellites,” he adds.

ESA’s ClearSpace-1 will be the first space mission to remove an item of debris of orbit, planned for launch in 2025.

Demand for private-public partnerships and support to R&D programs

Lack of long-term funding remains one of the largest challenges faced by space-tech startups. “With national governments and space agencies continuing to be two of the largest investors or customers for startups, becoming part of their funding programs is vital. Over the last few years, getting access to these programs, such as the EU’s Horizon 2020, has become easier and improved much. Newly created space policies, especially those that target urgent issues such as debris and defunct satellite removal, have also opened up opportunities and triggered active space-tech startups to emerge,” says Buaz.

Linder says, “Public-private partnerships are key to ensure space sustainability.”

“In general, the space sector needs to further support research & development. This alone allows Europe to differentiate and remain competitive on a global scale. Industrial policies of public institutions must allow for a) fair competition, b) fair reimbursement and c) a level-playing field within Europe and with non-European, institutions,” he adds.

There is widespread agreement in the space sector that we need an effective and efficient system of governance for outer space to deal with issues like space debris, potential collisions and frequency interference. Buzas adds, “The only way this can be developed and put into place globally is through cooperation and good communication between regulatory bodies, space agencies, military organizations, and the private sector. The aviation industry has been operating such a system for decades and the space industry could start there for best practice. One key element to help improve situational awareness and prevent collisions would be active information sharing about objects in space between those groups.”

“Another important aspect is the introduction of R&D funding programs aimed at improving collision prediction models, space weather forecasting (hazardous bursts of radiation and charged particles can critically damage satellites, causing even more space debris), active space debris removal programs, propulsion systems for deorbiting satellites after the end of their missions, and other innovations. Such grants and programs, extended to the private sector, will result in more diverse solutions and as a second positive side effect contribute to the development of the space economy.”

Even though public policies helped in establishing space-tech startups as an essential part of the NewSpace ecosystem but there are challenges faced by small companies that need urgent attention. To ensure space sustainability we need not only modern technology but innovations that can support the future missions without compromising on growth and development. Above all it needs to be addressed immediately as well as collectively.