Detecting and characterising temperate rocky exoplanets within the habitable zones of nearby stars is now a central goal in astronomy. To advance this field, ESA is developing a space-based nulling interferometer that will use multi-aperture interferometry to suppress starlight and capture a planet’s mid-infrared thermal emission for detailed study. The four-aperture system must stow four 2.5 m telescopes inside the Ariane 6 long fairing and deploy them to baselines of 8 m, 16 m or 32 m in linear or X-array layouts. This thesis establishes a high-level mechanical design for the deployable structure and quantifies how structural and deployment choices govern stowed volume and dynamic behavior.

A trade-off compared articulated, truss, and telescopic mechanisms. Telescopic booms emerged as the best option that combines high stiffness with stowage efficiency. Subsequent material screening selected high-modulus pitch-based carbon-fiber-reinforced polymer for the telescopic booms, owing to its exceptional stiffness-to-density and near-zero coefficient of thermal expansion, both critical for optical-path stability. CAD assemblies confirm that both four-telescope linear and X-array configurations with baselines up to 32 m fit within Ariane 6 while stowed.

Finite-element analyses in ANSYS evaluated modal, static-deflection, and buckling performance for all configurations. The 8 m and 16 m designs satisfy the 2 Hz fundamental-frequency requirement. X-array variants achieve higher stiffness and broader frequency margins than their linear counterparts. The 32 m layouts fall short of the 2 Hz target, but preliminary analysis shows the possibilities of adopting an elliptical boom cross-section and increasing wall thickness. This lifts the L32 first mode to 2 Hz, indicating that combined shape-and-thickness optimization could allow for longer baselines to achieve the minimum 2Hz first natural frequency requirement.