Airbus Detumbler For Satellite End Of Life Addresses Space Junk Crisis

Space junk, the debris collected in orbit since space exploration began, is a concern for the sustainability and long-term safety of our endeavors in space and at home. With global connectivity relying on satellite constellations at various orbits, the risk that space debris will grow and that critical communications infrastructure could be damaged has increased.

To address this risk, Airbus has developed the “Detumbler,” a magnetic damping device designed to stabilize satellites at the end of their operational life, making it easier to remove active debris.

Keeping Defunct Satellites Stable

Developed in 2021 and supported by the French Space Agency CNES under the Tech4SpaceCare initiative, Airbus’s Detumbler launched on November 11. An in-orbit demonstration with Exotrail and EnduroSat will take place early in 2024. This device addresses a critical issue in space debris management: the tumbling of defunct satellites, especially in Low Earth Orbit (LEO
LEO
).

How The Airbus Detumbler Works

The Detumbler features a central rotor wheel and magnets interacting with Earth’s magnetic field. In typical operation, the rotor acts like a compass, aligning with the magnetic field. However, if the satellite begins to tumble, the rotor’s movement induces eddy currents, creating friction torque that dampens the tumbling motion. Weighing approximately 100g, the Detumbler is a lightweight yet potent tool for stabilizing satellites after their operational life.

“Dead satellites, especially in low Earth orbit (LEO), often end up tumbling, which is natural behavior due to orbital flight dynamics. Future active debris removal missions will face a greater challenge if spacecraft are tumbling,” Airbus explains.

In-Orbit Demonstration And Future Potential

The upcoming in-orbit demonstration aboard an Exotrail (SpaceVan) mission, including the Exo-0 nanosatellite from EnduroSat, will validate the Detumbler’s effectiveness. By preventing satellites from tumbling, the device could significantly aid future missions aimed at clearing debris, making the capture and disposal of defunct satellites more manageable.

The Growing Problem Of Space Debris

The development of the Detumbler comes at a time when space debris management is increasingly critical. The European Space Agency estimates the total number of space debris objects in Earth orbit to be 29,000 items over 10 cm, 670,000 items larger than 1 cm, and over 170 million larger than 1 mm. When it comes to space junk, size doesn’t matter. Even small pieces can cause severe damage.

“Any of these objects can cause harm to an operational spacecraft,” the ESA states. “For example, a collision with a 10-cm object would entail a catastrophic fragmentation of a typical satellite, a 1-cm object would most likely disable a spacecraft and penetrate the ISS shields, and a 1-mm object could destroy sub-systems on board a spacecraft. Scientists generally agree that, for typical satellites, a collision with an energy-to-mass ratio exceeding 40 J/g would be catastrophic.”

The International Space Station was damaged in 2021 by a two-inch piece of space junk. It wasn’t the first time the ISS grappled with space debris. ISS astronauts have had close calls with space junk several times, leading to emergency evacuations.

As Predicted By ‘The Kessler Syndrome’

Former NASA scientist Donald Kessler and his co-author Burton Cour-Palais published “Collision Frequency of Artificial Satellites: The Creation of a Debris Belt” in 1978. This early warning highlighted an increasing risk of satellite collisions as more spacecraft launch. The authors explained that such collisions would create orbiting fragments, increasing the likelihood of further collisions and leading to a belt of debris around Earth. This debris could surpass natural meteoroid flux and impact future spacecraft designs. This concept, known as the Kessler Syndrome, describes a cascading effect of orbital debris that could impede space activities. The intent was to draw attention to a long-term risk requiring a change to satellite deployment methods.

Kessler’s Syndrome is increasingly relevant as the satellite network grows. As Inmarsat highlights, with tens of thousands of rocket launches planned over the next decade, there is an urgency to address the risk space junk will grow.

“Space sustainability is a cultural mindset that we recommend should be at the heart of all satellite operations, with the aim of using the space domain responsibly and with consideration for all users and for future generations,” wrote Alex Cacioni, Director, Flight Dynamics at Inmarsat.

Space Junk Is Growing Faster Than Policy

International and national entities are working on guidelines and strategies for space travel, satellite deorbiting, and debris removal. The United Nations Committee on the Peaceful Uses of Outer Space and the ESA collaborate on these guidelines. At the same time, the United States has developed its Space Policy Directive-3 and Orbital Debris Implementation Plan. However, the UN established its recommendations 50 years ago, and drafted them before the recent technological advancements that increased space activity and debris. The UN recommendations do not address removing inactive satellites already in orbit. Also, countries can simply opt out.

U.S. Issues First Fine For Improper Satellite Disposal

In October, the U.S. Federal Communications Commission settled with Dish Network for improperly managing the end-of-life of their EchoStar-7 Satellite. The first-of-its-kind settlement included the company admitting liability and agreeing “to adhere to a compliance plan and pay a penalty of $150,000.”

The FCC has rules that require the use of transmission apparatus in space or on Earth to be authorized by the Commission to prevent interference in satellite operations and ensure responsible satellite disposal and minimization of space debris. DISH Network’s
DISH
EchoStar-7 satellite, launched in 2002, was committed in a 2012-approved plan to be moved 300 kilometers above its operational geostationary arc at the end of its mission. However, in February 2022, DISH found that the satellite needed more fuel to follow this plan. As a result, the company retired the satellite at an orbit only 122 kilometers above the geostationary arc, significantly lower than the 300 kilometers required in its debris mitigation plan.

“As satellite operations become more prevalent and the space economy accelerates, we must be certain that operators comply with their commitments,” said Enforcement Bureau Chief Loyaan A. Egal. “This is a breakthrough settlement, making very clear the FCC has strong enforcement authority and capability to enforce its vitally important space debris rules.”

Fixing Orbit Clutter

A McKinsey study grapples with the challenges of clearing space of cumulative debris. As connectivity demand increases, sustainable satellite end-of-life processes will become increasingly critical. McKinsey recommends: “Sustainable space operations should have four components: awareness of the environment, coordination of activities among independent parties, minimizing the growth of space junk, and removal of debris.”

Airbus’ Detumbler represents a promising advance in tackling the space debris problem. By stabilizing defunct satellites, it could make space safer for current and future missions.