ICLR Structures Sub-team / 2024 to 2025
Pluto is a liquid bipropellant sounding rocket designed and built by Imperial College London Rocketry, a student team of about 150 people. It stands 4.5 metres tall, weighs 81 kg at liftoff, and is powered by GOOFY, a 6 kN regeneratively cooled engine running on nitrous oxide and isopropanol. The team entered it in the 9 km apogee category at EuRoC 2025 in Portugal.
I led the stringer design within the structures sub team, supervising two undergraduate engineers. The airframe uses a skeletal architecture instead of a conventional skin. Three aluminium 6082 T6 stringers sit in threefold symmetry, aligned with the fin positions, and form the primary load path between the engine and the propellant tank.
The stringers carry the full 6 kN compressive thrust load from the engine truss into the tank's lower bulkhead. I sized them initially through Euler buckling analysis (Pcr = π²EI / Leff²) and then mass optimised them by adding cutout holes along their length to reduce weight without losing structural integrity.
I ran detailed buckling simulations in Abaqus CAE to validate the final geometry. The first buckling mode returned a safety factor of 3.6, giving good margin against the design load. The analysis captured both local and global buckling behaviour to make sure the cutout pattern didn't introduce unexpected failure modes.
The stringers were waterjet cut from aluminium plate. They connect at their base to a generatively designed engine truss, additively manufactured in AlSi10Mg, which we compression tested to the full 6 kN engine load before clearing it for flight.