Heat Transfer Mitigation Along Superorbital Reentry Trajectories Using Magnetohydrodynamic Aerobraking

This paper investigates the use of magnetohydrodynamic (MHD) aerobraking as a method for reducing heat loads during Earth re-entry. A three degree-of-freedom trajectory code was coupled to Porter and Cambel’s (1967) analytical MHD drag model. Radiative and convective heat fluxes were estimated by scaling the correlations of Brandis and Johnson (2014) according to changes in shock standoff distance and pressure drag coefficient respectively. This method was compared to previous MHD trajectory predictions made by Fujino and Shimosawa (2016) that utilised high-fidelity computational fluid dynamics simulations. Similar trends were observed for both methods, with observed discrepancies being attributed to differences in the magnetic field and electrical conductivity definitions. The computational efficiency of this technique allowed a wide range of trajectories to be simulated, whereby vehicle nose radius, entry velocity, initial flight path angle, and stagnation point magnetic flux density were varied. The model predicts that MHD aerobraking is most effective at reducing peak total heat flux, and total integrated heat flux, in flight cases where radiation makes up a small percentage of total stagnation-point heat flux. In addition, the use of MHD aerobraking is predicted to reduce the minimum allowable entry flight path angle that can be used without causing the vehicle to skip out of the Earth’s atmosphere.