ED09-0284-23 NASA Langley Research Center researcher Glen Sachse pours liquid nitrogen in a dewar used to keep the infrared detectors of the Differential Absorption CO Measurement instrument cold. Developed at NASA Langley, the instrument is installed on NASA's DC-8 airborne laboratory and will be used to measure carbon monoxide, methane, and nitrous oxide concentrations during the Operation Ice Bridge mission to Antarctica. September 29, 2009 NASA Photo / Tom Tschida NASA Identifier: 392885main_ED09-0284-23_full_full