A computational analysis of the Mach 20 Reentry-F vehicle is performed in order to assess current capabilities for prediction of turbulent base heating. The detached eddy simulation (DES) methodology is employed to model the unsteady wake of the vehicle. Comparisons between traditional Reynolds-averaged Navier- Stokes (RANS) methods and DES reveal no improvement if the computational grid is insufficiently resolved. On the other hand, where RANS gains little from refinement of the grid, DES shows substantial improvement. Prior studies of the Reentry-F vehicle have generally neglected its slight angle of attack, an approach which fails to account for the asymmetry present in the forebody transition profile and base heating distribution. In this paper, we present a three-dimensional analysis of the entire vehicle to address these issues. The computed results reveal a strong dependence on vehicle orientation especially at lower altitudes where the vehicle experienced significant thermal distortion. Despite this difficulty, solution accuracy is demonstrated to lie within the bounds of the experimental uncertainty provided sufficient care is taken to define flight conditions. This suggests DES to be a capable tool for unsteady aerothermal analysis.