Reentry aerothermodynamics of a deorbiting cubesat with dragsail

Space debris occupying low Earth orbits poses critical threats for future missions, and the popularity of small satellite constellations of CubeSats is likely to significantly augment traffic in such valuable orbits. A CubeSat without any deorbiting mechanism could remain in these orbits for hundreds of years. The aerodynamic deorbit experiment (ADE) CubeSat, developed by researchers at Purdue University, relies on a dragsail to provide accelerated passive deorbiting of a CubeSat post-mission. A good estimation of the aerothermal load on a reentry CubeSat is paramount to ensure a predictable reentry. This study investigates the reentry aerothermodynamics of the ADE CubeSat using the direct simulation Monte Carlo (DSMC) and Navier-Stokes-Fourier (NSF) continuum based methods. The aerothermal load on the CubeSat was determined at various altitudes in the reentry trajectory. The DSMC methods were employed for higher altitude cases and the continuum based methods were utilized for lower altitude cases while resolving the aeroload during CubeSat reentry. The continuum methods offered considerable computational cost savings compared to the DSMC methods - in predicting the aerothermal load on an ADE CubeSat - at lower altitudes, H ≤ 90 km, along the reentry trajectory. The aerothermal analysis suggests that the CubeSat and dragsail encounter considerable aero-heating during the reentry that will likely affect the survivability of the dragsail and increase uncertainty in the reentry corridor.