SiWave proposes to develop a compact, low-cost MEMS-based pressure sensor for very high temperatures and low pressures in hypersonic wind tunnels. Most currently available pressure sensors use a micromachined diaphragm whose deflection is dependent on pressure. The deflection is typically measured by techniques that are not suited for high temperature (>~200?F) operation, or that are insensitive to small (<~0.1 psi) pressure changes. As a result, no commercial sensors cover 0-5 PSI at temperatures above 200?F, despite the fact that this regime is important for NASA?s hypersonic wind tunnel testing programs, as well as for hypersonic flight avionics. SiWave?s proposed pressure sensor is a novel implementation of squeeze film resonant sensor approach, with a sophisticated multi-element resonator designed for very high Q and temperature stability, made from silicon carbide. The device is controlled by distant external electronics. These innovative features result in a sensor with high accuracy (0.005 PSI) over an unprecedented temperature range (up to 650?F), and the potential to be manufactured in dense arrays.