Rocket Exhaust Radiation Measurements in the Upper Atmosphere

Measurements have been made on several launches of the intensity and spectra of the visible (4000–6500 A) radiation emitted by rocket engine exhausts during powered flight at high altitudes. Two closed-circuit television cameras, mounted on a hand-tracked platform, have been used, located on Grand Bahama Island, down range from Cape Canaveral. One TV camera obtained information regarding the spatial persistence and intensity of exhaust radiation. The other employed a dispersing slit and grating and recorded spectra. In each launch, as the missile rose, a glow developed which persisted for several seconds in the wake of the missile. At higher altitudes, the glow faded in intensity but increased in diameter forming a large radiating “bow.” The observed spectra have been compared with those of laboratory flames to provide identification of radiating species. These studies are useful in studying reactions in the atmosphere to heights of about 300 km.