In July, the European Space Agency released its Space Environment Report 2024, revealing an alarming surge in space debris. The report finds that over 35,000 objects are currently tracked in Earth’s orbit, out of which 26,000 are non-operational debris. Additionally, an estimated 1 million fragments in Low Earth Orbit (LEO) can cause catastrophic collisions. Amid this growing challenge, CubeSats — small, lightweight satellites of about 1kg, offer valuable advantages. On the contrary, their dense clustering and limited deorbiting measures at the end of their operational lives intensify the risk of debris build-up. Therefore, sustainable changes need to be made in the CubeSats design to reap the full benefits of CubeSats, whilst enabling a clean space eco-system.
CubeSats can operate as single units or combine into multi-unit configurations with a maximum of 24 units, providing a low-cost solution for diverse space applications. They are excessively used for scientific research and commercial purposes. For instance, they gather data on the Earth’s magnetic field, which predictive models use for earthquake detection. They are also used for practical experience in mission design, from launch to operations. They are also used commercially in telecommunications and Earth observation to capture and sell high-resolution imagery for agriculture and urban planning applications.
To date, 2396 CubeSats have been launched and this trend is increasing as they are fast to develop and more affordable. With a typical build time of about two years, their simple design utilises standard parts and requires minimal thermal insulation, keeping the costs of production low. Additionally, they follow a modular structure which makes them adaptable to various missions without needing a complete redesign. They are often used as test beds for new technologies before deploying them in larger, more expensive missions.
Although, CubeSats have valuable economic and technological benefits, their operational lifespan is limited to 3-12 months. It restricts mission duration and requires frequent replacements to sustain on-going space operations. Therefore, more CubeSats are continually deployed, contributing to the mounting issue of space debris.
Prioritising sustainability from the outset, Pakistan’s approach with ICUBE-Q sets a crucial benchmark for other emerging space programs; highlighting that scientific advancement and environmental stewardship in space can go hand in hand
Most of the CubeSats are concentrated in low-Earth orbit, accelerating the onset of Kessler syndrome. It is a scenario where space debris collisions trigger a self-sustaining chain reaction of fragmentation. Due to their short operational life span, many CubeSats are abandoned in orbit without adequate end-of-life deorbiting measures. This leads to a build-up of inactive satellites in heavily congested areas. As the number of CubeSats continues to rise, the likelihood of accidental collisions among these inactive units increases, posing risks to other satellites and space infrastructure.
In May 2024, Pakistan took a significant step in sustainable space exploration by launching its first CubeSat, ICUBE-Qamar. It operates in a controlled, short-duration orbit and is engineered to burn up upon re-entry. This makes ICUBE-Q unlikely to remain in orbit in the form of abandoned debris. By prioritising sustainability from the outset, Pakistan’s approach with ICUBE-Q sets a crucial benchmark for other emerging space programs; highlighting that scientific advancement and environmental stewardship in space can go hand in hand.
Keeping in view the emerging trend of CubeSats and space debris, there is a need for strategic design, advanced tracking, and end-of-life deorbiting solutions. One effective approach is to equip CubeSats with small propulsion systems that allow them to perform collision-avoidance maneuvers during their operational life. For the post-operational phase, operators can activate thrusters to decelerate CubeSats enough for them to re-enter Earth’s atmosphere. In this way, they will burn up in the atmosphere rather than lingering on as potential debris.
In addition to this, CubeSats could be used to track other objects in orbit more precisely, thus improving collision prediction. As there are millions of small fragments in low-Earth orbit, CubeSats can be developed in a way that they are equipped with tools to de-orbit inactive satellites. This will enhance their potential as proactive agents in space sustainability and pave the way for a safer orbital environment.
To sum up, as the CubeSats continue to proliferate, their potential contribution to the space debris problem, especially the low-Earth orbit demands immediate attention. There is a need to adopt a balanced approach towards the benefits of CubeSats technology with the responsibility to maintain a safe orbital environment. Therefore, the space community must prioritise sustainable practices, such as mandatory propulsion for deorbiting and enhancing collision avoidance capabilities. It is also essential to implement timely measures before the problem becomes irreversible.