Traditional emergency systems, such as EPIRBs and satellite communications, are effective, but are prohibitively expensive for many and prone to failure under extreme conditions. THELSAR SAR4SAR reflectors are designed to operate without electronics, batteries, or compressed gas, offering a reliable, passive alternative that enhances survivability when conventional tools fail or are inaccessible. The intended RRP is NZD $50–60 (USD $29–32) per unit, ensuring that the technology is accessible.

Initial development involved laboratory testing of candidate materials to maximise radar return while maintaining buoyancy and structural integrity. Multiple reflector geometries were prototyped and evaluated in simulations, then in terrestrial and coastal environments. Subsequent trials focused on folding mechanisms, hydrodynamic stability, and satellite visibility under operational conditions. In early 2025, prototypes were successfully deployed in the Southern Ocean aboard HMNZS CANTERBURY, where they remained afloat and detectable in 50-knot wind conditions, validating both mechanical resilience and radar performance in high-energy maritime environments.

The next phase of the project includes final scientific field trials in June and July 2025, AI model training for robust automatic detection in SAR imagery, and progression to manufacturable designs. The aim is integration into real-world search and rescue systems, particularly those serving the seafaring cultures of the Pacific, where affordability, reliability, and independence from electronic infrastructure are essential.

This is a project from the University of Auckland in collaboration with Defence Science & Technology (NZDF).