Understanding the phenomenology of the interaction of the space environment with organic composite spacecraft surfaces is both interesting science and important to the longevity of our space assets. The importance of this understanding has been made even more critical by the desire to use new, organic composite materials whose lower weight and higher stiffness will make it possible to orbit larger payloads. Inconsistencies between ground simulation and space test data clearly indicate that our understanding of the interaction phenomenology is inadequate. Preliminary research carried out by the Phillips Laboratory has demonstrated that the simultaneous interaction of all of the space environmental factors is often required to obtain agreement between ground- and space-test data. This paper describes the test equipment designed by Phillips Laboratory to subject composite materials to a simulated low-earth-orbit environment consisting of simultaneous fluxes of hyperthermal neutral oxygen atoms, energetic electrons, vacuum ultraviolet light, and hypervelocity-particle impacts characteristic of space debris and micrometeorites. Preliminary results of studies of the combined effects of fluxes of atomic oxygen and electrons on polysulfone resins and composites, and an evaluation of impact damage to polysulfone resins and composites from small aluminum particles traveling at velocities up to 6 km/s, are presented. The need for testing standards and methods for measuring space environmental effects is assessed.