My guess, after a quick google search: https://www1.grc.nasa.gov/facilities/erb/turbo/#small-engine-components-compressor-test-facility https://www1.grc.nasa.go

My guess, after a quick google search: https://www1.grc.nasa.gov/facilities/erb/turbo/#small-engine-components-compressor-test-facility https://www1.grc.nasa.gov/facilities/erb/turbo/#small-engine... The signs on the top of each section says "air 40 psig" and "ref. air 10 psig", and this matches the capabilities described in the link: "The compressor can draw air from either an atmospheric intake, a 40-psig pressure source, or 10-psig refrigerated air system". The image also has GRC in its file name. (It might be a complete miss, though)