A method to interpret properly surface measurements near the leading edge of sharp slender bodies in hypersonic flow is described. The results, using a two‐sided Maxwellian distribution function at the surface, are used to relate: (a) the surface molecular flux,&PHgr;, topc, the pressure in a cavity connected through a sharp lipped orifice to the surface, and (b) the surface normal stress,pyy, topcand either (method 1) the surface number density or (method 2) the surface heat transfer and shear stress. Attention is drawn to the importance of the correct treatment of normal momentum accommodation coefficient, angle of attack, and orifice geometry. The present method is compared with others in whichpy yis obtained frompcand while it agrees with them in the continuum and slip regimes, it is the only method to agree with the correct free‐molecular flow limit. Flat plate pressure measurements, although made through tubes rather than sharp lipped orifices, are reviewed. Despite the attendant errors, which have been confirmed by very recent work, the following conclusions are drawn. (i) Results from methods (1) and (2) are consistent. (ii) Previous calculations ofpy yare in error by up to a factor of three when the shear stress is finite. (iii)py ynear the leading edge approaches somewhere near the free molecular limit.