Mars Pathfinder entry temperature data, aerothermal heating, and heatshield material response

The Mars Pathfinder probe contained instrumentation that measured heatshiel d temperatures during entry. A description of the experiment, the data, and an analysis of the entry environment and material response are presented, Navier-Stokes forebody heating calculations show a peak unblown radiative-e quilibrium heat Bur of 118 W/cm(2) at the stagnation point and 120 W/cm(2) on the shoulder for turbulent flow. The heat load is 3.8 W/cm(2) on the nos e, decreases along the frustum, then increases to 2.7-3.1 kJ/cm(2) on the s houlder depending on the onset time for turbulence. One-dimensional charrin g material response is calculated using three different models. Stagnation point temperature data are consistent with about 85% of fully catalytic lam inar heating. Shoulder temperature data are inconclusive, but are consisten t with fully catalytic laminar heating or with 85% of fully catalytic heati ng with early onset of turbulence, Aft temperature data indicate a peak hea t flux and heat load of about 1.3 W/cm(2) and 70 J/cm(2), respectively. The aft heating profile is about 20 s longer than the forebody heating profile , Bondline temperature data, although not useful for quantitative analysis of aerothermal heating, clearly show the heatshield had adequate thickness margins for the actual entry.