Modern space exploration missions, such as planetary exploration of Mars, have significantly different tribological concerns compared to conditions faced by mechanical devices in satellites. Space lubricants have traditionally implied extremely low vapor pressure, but limited performance in boundary lubrication. Mars devices on the other hand are subjected to heavier loads, while operating in an atmosphere composed of CO2 at <1 kPa. Ionic liquids are synthetic fluids with inherently low vapor pressure that are known to readily form boundary films under severe conditions. In our recent work, an ionic liquid designed as lubricant base fluid formed highly effective boundary films composed of silicate when evaluated in air. These boundary films include oxygen, which can possibly be supplied by the atmosphere or by the lubricant itself. In this work, we employ tribotesting in CO2, and N2, and perform surface analysis to evaluate the effect of oxygen supply on boundary film formation.