JAXA Sample Return Capsule

Over the 2025-2026 Summer, I worked with the University of Melbourne on research for the Japanese Aerospace Exploration Agency (JAXA). I assisted a PhD student in starting his research on transonic instabilities of JAXA’s Sample Return Capsule, which were discovered during a drop test in Alice Springs, Australia, and were not previously found in JAXA modelling. The capsule is based on the Hayabusa 2 capsule, and is to be used on the upcoming Martion Moon eXploration (MMX) missions. I applied the drag and trajectory modelling skills I learnt at ARES to regenerate a full trajectory of the capsule for use in boundary conditions for higher-fidelity simulations using UoM’s custom transonic CFD code. My trajectory modelling included determing a steady-state drag curve with RANS CFD, reverse-engineering the geometry of the capsule from simplified drawings, and using reanalysed weather data from the time and location of the drop test. I also tested how well lower-fidelity models (sub-10 million cell LES) captured transonic oscillations, so that passive/active control methods could be explored and designed to reduce the oscillations.