Skylab. NASA Skylab space station

This 1970 photograph shows Skylab's Infrared Spectrometer Viewfinder Tracking System, a major component of an Earth Resources Experiment Package (EREP). It was designed to evaluate Earth resources sensors for specific regions of the the visible and infrared spectra and assess the value of real time identification of ground sites. The overall purpose of the EREP was to test the use of sensors that operated in the visible, infrared, and microwave portions of the electromagnetic spectrum to monitor and study Earth resources. The Marshall Space Flight Center had program management responsibility for the development of Skylab hardware and experiments.