The growing number of vehicles and satellites operating in space is driving the need for more advanced technologies to enhance space situational awareness (SSA), particularly in regions beyond Low Earth Orbit (LEO).

Existing ground-based surveillance networks, such as the US Space Surveillance Network (SSN), are capable of tracking objects as small as four inches within LEO. These systems rely on extensive ground-based radar arrays, often spanning kilometres, like the latest upgrade to the Space Fence. However, these ground-based solutions face significant limitations when attempting to monitor traffic in cislunar space, the region encompassing the Earth and Moon, due to the extreme distances involved.

The fundamental challenge for coherent radar systems is that the required array size grows proportionally with the distance to the target for a consistent detection performance. This makes the implementation of ground-based arrays for cislunar surveillance highly impractical. Consequently, a shift towards space-based SSA platforms is emerging as a more viable approach, as it allows for a reduction in sensing distance.

While space-deployed radar systems offer distinct advantages in terms of sensing capabilities, the vast distances associated with cislunar surveillance still demand exceptionally large apertures to achieve adequate performance. This requirement poses considerable practical challenges, primarily due to the current limitations of modern deployable structures, which struggle to consistently achieve the necessary scale and precision for such large apertures.

In response to these challenges, the concept of robotically assembled electromagnetic metamaterials is being investigated. This innovative approach aims to facilitate the creation of the large-scale structures required for advanced, long-range space situational awareness, potentially enabling more effective monitoring of the expanding population of objects in cislunar space.