The goal of the Water Vapor Spectrometer project is to measure water vapor in the middle atmosphere (between about 30 and 80 km). Since water vapor is the primary source of the OH radical and other hydrogen compounds, it is important in controlling ozone chemistry. Because the chemical timescales for water vapor are long relative to timescales for transport in the middle atmosphere, it is also an excellent tracer of atmospheric motion. The collected water vapor profiles are obtained by measuring the emission of the 24 GHz transition of water vapor.