Desirable Apollo Solar Particle Alert Network (SPAN) Camera, measuring approximately 11.75" x 6.5" x 11.5", with a Northridge Research manufacturer's plate on an exterior door: "Model T-17D-2, Serial 776, Volts 28, Amps 2." The panel opens to reveal an internal clock and data card, which is annotated in pencil on both sides: "Solar Viewing Interrupted, Reason: Clouds / Severe Storm Predicted." These cameras were utilized during the Apollo program to detect solar radiation that could put crews at risk during the missions. By studying the relationship between sunspot activity and intense solar flares, NASA hoped to predict radiation hazards to astronauts. Cameras were positioned at multiple locations around the globe to provide continuous coverage/observation of the solar disc as the Earth rotated.