The growing congestion in Earth’s orbital space poses significant challenges, especially as more than 20,000 satellites have been launched since the dawn of the space age. This figure is set to rise, with orders for thousands more planned in the coming years. While some of these satellites have either disintegrated upon re-entry into the atmosphere or descended into the ocean, over 13,000 remain in orbit. Alarmingly, around 20% of these satellites are inactive, contributing to a burgeoning collection of space debris, or “space junk.” Collisions among these defunct satellites have consequently generated fragments that number in the millions, further complicating space traffic management.
This increase in detritus is not merely an inconvenience; it represents a tangible danger to current active satellites and even to the International Space Station (ISS). The potential for collision is so high that various monitoring systems worldwide focus on tracking larger objects, enabling the adjustment of spacecraft trajectories to avoid possible collisions. This preventative measure is essential, given the constant threat posed by space debris and the need for increased maneuverability and responsiveness in orbit.
To address these challenges, British startup Magdrive is pioneering a new propulsion system that promises to enhance both mobility in space and potentially reduce the volume of space debris. Mark Stokes, a co-founder of Magdrive established in 2019, emphasizes that their innovative solid metal propulsion technology could increase the maneuverability of satellites by tenfold while reducing the mass allocated for propulsion systems by the same order of magnitude. This breakthrough could significantly mitigate the risks and inefficiencies associated with traditional satellite propulsion systems.
Magdrive aims to create three distinct versions of its propulsion systems. The unique aspect of this technology is its potential to utilize space debris itself as fuel. This approach could convert harmful trash into usable energy for spacecraft, thereby fostering a more sustainable space economy. Propulsion systems are crucial for satellites for several reasons, including orbital adjustments, combating atmospheric drag, collision avoidance, and eventual deorbiting.
Currently, most satellites rely on chemical or electric propulsion, both of which possess distinct drawbacks. Stokes outlines the efficiency issues inherent in chemical propulsion, which, while providing high thrust, offers poor efficiency. In contrast, electric propulsion systems excel in efficiency but struggle with thrust output. The trade-off between these two systems complicates ambitious plans for satellite operations, such as asteroid mining or deploying extensive satellite networks, because the power-versus-efficiency dilemma must be solved prior to launch.
Magdrive’s propulsion system, referred to as “Warlock,” is set to debut in June 2025. This system is equally innovative in design, operating on solar power like existing electric propulsion systems. However, rather than using chemical gases, it ionizes solid metal into a dense plasma, which propels the spacecraft. The choice of solid metal is advantageous due to its density, which requires less onboard space compared to traditional pressurized gas tanks. This eliminates several complications associated with handling pressurized gases and the associated risks of explosions.
Nevertheless, the implementation of metal as a propellant introduces its own challenges. The heating and cooling cycles of the metal during propulsion can alter its atomic structure, which may affect consistent thrust generation. Additionally, there are concerns regarding contamination from metal particles onto sensitive spacecraft surfaces. Stokes assures that the reaction produces what he describes as “dispersed inert material” rather than hazardous debris.
Looking forward, the idea of retrieving and utilizing existing space junk as fuel appears theoretically feasible. However, various regulatory hurdles exist, including the implications of the UN Outer Space Treaty, which states that ownership of objects launched into space remains intact, thus complicating the recycling of old satellites without proper consent. Moreover, the technical challenges related to capturing uncontrolled decommissioned satellites remain daunting and are compounded by the diverse materials used in satellite construction.
In conclusion, while Magdrive’s innovative propulsion system could significantly alter the landscape of satellite technology by enhancing maneuverability and potentially utilizing debris as fuel, significant challenges must be addressed in the realms of technology, regulation, and logistics. The future of satellite operations hinges not only on innovative propulsion technologies but also on sustainable practices that prioritize a clean and navigable near-Earth space environment.