A hyperthermal molecular beam apparatus, utilizing a heated seeded supersonic nozzle capable of producing fast intense beams of atmospheric species, has been employed to study vibrational excitation of plume species carbon dioxide and carbon monoxide. The apparatus is provided with a novel neutral beam detector for measurement of beam intensity and velocity distribution. The excitation mechanism is studied through monitoring of the infrared emission from the plume species by the use of lead sulfide, lead selenide, and indium antimonide. Lack of measurable signals is analyzed in terms of signal to noise ratios and it is shown that excitation cross sections generally have an upper limit of 10 to the 19th power per square centimeter showing that transfer of translational energy into internal energy does not take place efficiently. (Author).