Small-Scale Simulation Chamber for Space Environment Survivability Testing

Abstract

A vacuum chamber was designed that simulates the space environment to facilitate tests of material modification due to space environment interactions. Critical environmental elements to be simulated include an ultrahigh vacuum, a far ultraviolet (FUV)/ultraviolet/VIS/NIR solar spectrum, an electron plasma flux, temperature extremes, and long duration exposure. To simulate the solar electromagnetic spectrum (EMS), a solar simulator was used with a range 200-2000 nm. A Krypton lamp provides surrogate radiation for the prominent FUV hydrogen Lyman- α120-nm emission not produced by the solar simulator. A monoenergetic electron flood gun (20-15 keV) provides a controlled electron flux. Electron and EMS incident fluxes of up to four times sun equivalent intensities at 95% uniformity across the full 100- cm2 sample surface are possible to reduce the exposure time for accelerated testing. A temperature range from 100 to 450 K is achieved using an attached cryogenic reservoir and resistance heaters. The versatile sample holder and radiation mask allow for cost-effective, customizable investigations of multiple small-scale samples under diverse conditions. In situ monitoring capabilities allow measurements to be taken at frequent intervals during the course of the exposure cycle, while the samples are still under vacuum. An automated data acquisition system monitors and records the temperature, pressure, electron, and EMS fluxes. Calibrated reflectivity, absorptivity, and emissivity of the samples can be measured using in situ integrating sphere and IR absorptivity/emissivity probes.