Theseus IV is the best performing rover to date, placing 2nd in the Australian Rover Challenge 2025. Steady, incremental optimisations to the design have resulted in continuous improvement throughout the Theseus program.

Between Theseus III and Theseus IV, the program was moved to a two-year design cycle. Many of the structural components of Theseus IV are common with Theseus III, with only targeted modifications made to improve performance.

This two year design cycle allowed large improvements to be made to the payloads and electronics, including a vastly improved robotic arm and water extraction system along with a more efficient chassis layout.