Space debris poses a huge problem for global communication systems and space exploration efforts. Over 50,000 pieces of orbital debris are actively tracked by the Space Surveillance Network, while over 170 million smaller pieces that cannot be tracked, also pose catastrophic collision risks. Though tiny, these items of space junk, often from colliding decommissioned rockets, can have as much energy as grenades and bullets and can tear through spacecraft causing extensive damage.

This poses lethal dangers to astronauts and drives up satellite launch costs through thick shielding requirements (additional mass), increasingly common avoidance manoeuvres (programmed when a collision risk is identified via space surveillance) and insurance premiums. Space debris also presents a barrier for emerging space-faring nations who cannot afford these expensive mitigation strategies.

Now, The University of Warwick-led project, 'Revealing the Orbital and Atmospheric Responses to Solar activity' (ROARS), aims to tackle the problem with a "swarm" of satellites. The new research concept is being announced today - during World Space Week (4-10 October).

The concept of using a satellite "swarm" is that by distributing scientific instruments across multiple smaller inter-linked spacecraft, a "swarm" will possess observational capabilities far in excess of a standard, large satellite.

The mission idea has led to a 26 institution-strong consortium from across nine countries, with a core team leading the study from Universities of Warwick, Birmingham, Northumbria, Bath, UCL, Stuttgart, Imperial and Calgary, alongside industrial partner, OpenCosmos, the Space Research Institute in Austria, and Southwest Research Institute in the USA.

The team are examining how the swarm of small satellites known as CubeSats, these ones about the size of a microwave, can fly in Low Earth Orbit (LEO), just 500 km above the Earth, a region home to exponentially growing satellite mega-constellations. They hope the swarm can provide a "missing" set of measurements necessary to accurately predict and prevent satellite and debris collisions.

The multiple satellites feature a dizzying array of new technologies. These include the latest atmospheric and magnetic field sensors, state-of-the art global navigation satellite systems (including GPS) and inter-satellite laser communications. A further integral mission component is ground radar, laser and optical observations, including from University of Warwick's SuperWASP observatory on La Palma, Canary Islands.

The team will investigate how satellite drag from the Earth's upper atmosphere; a force on near-Earth orbiting satellites, is modulated by solar activity and space weather. When solar storms interact with the Earth's magnetic field - they are responsible for the impressive Northern and Southern Lights (Aurora Borealis and Aurora Australis), but they can also heat our upper atmosphere and play havoc with spacecraft trajectories.

In February 2022, 40 Starlink satellites were lost, due to the effects of successive solar storms which caused a large atmospheric expansion and increased atmospheric drag, and ultimately caused the satellites to burn up in the upper atmosphere.

Dr Ravindra Desai, of University of Warwick's Centre for Fusion, Space and Astrophysics and Principal Investigator of the mission, said: "This mission concept seeks to comprehensively understand how space weather deposits energy into our upper atmosphere, and how this threatens the satellites we increasingly depend upon for our day-to-day lives.

"We hope this will provide a step change in our ability to safely use our space environment and enables ESA's Terrae Novae vision to provide Low Earth Orbit as a safe haven for further exploration of the moon and Mars."

The research is led through the University of Warwick's cross-departmental Centre for Space Domain Awareness (CSDA). The CSDA has been established to tackle issues relating to the safety and sustainability of satellites, including: the timely acquisition of precise datasets to detect, track and/or characterise objects in orbit; the fusion of physical and human-based information for improved object tracking; the modelling and prediction of space weather, and quantification of associated risk.

Professor Don Pollacco, of University of Warwick's Astronomy and Astrophysics Cluster, added: "In 2009, a hypervelocity collision between an active Iridium satellite and defunct Kosmo satellite created thousands of additional pieces of debris. Satellites are currently being launched at an exponentially increasing rate and resultant orbital congestion means that it is a matter of when, not if, another major collision will occur.

"It is important that we act now before it is too late, and many orbits become unusable".

A further important factor in the swarm design is the ability for collision avoidance manoeuvres and safe deorbit within five years at the end of life. This is important so that the swarm itself doesn't contribute to the very problem it is trying to address.

ESA released the 86 million pounds ( euro 100 million) campaign for Innovative Mission Concepts Enabled by Swarms of CubeSats at the start of this year and received 74 submissions, from which seven were competitively selected for Phase 0 funding to develop their concepts towards a flight opportunity.

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