Thermospheric far infrared emission was measured by a rocket borne, helium cooled grating spectrometer in the wavelength region 45&mgr;m to 125&mgr;m. The rocket was launched on March 16, 1977 at 2304 CET from Andoya, Norway, during a moderate geomagnetic disturbance. First spectral measurements of 63 &mgr;m atomic oxygen fine structure transition were obtained in the altitude regime 90--180 km. No other emissions were found in the spectral range covered at altitudes above 130 km. The minimum detectable radiance was below 2⋅10-11W/cm2sr. Radiometric measurements of CO2 15&mgr;m band emission were made by the same instrument in the altitude range 102-140 km.