Near-infrared Spectroscopy of the Stardust Sample Return Capsule Entry: Detection of Carbon
Journal of Spacecraft and Rockets
American Institute of Aeronautics and Astronautics
The 1069 nm line of atomic carbon was detected in radiation emitted during the 15 January 2006 reentry of the Stardust sample return capsule. In time-averaged data, the corresponding weaker lines in the range of 960–966 nm were also present. The spectra covered the wavelength range from 930 to 1075 nm at a spectral full-width-at-halfmaximum resolution of 1.6 nm. The integrated 1069 nm line intensity decreased from 737 44 W=m2=nm=sr at 80.7 km altitude (09:57:16.5 Universal Time) to 432 44 W=m2=nm=sr at 70.9 km altitude (09:57:24.5 Universal Time). At the same time, the 1011 nm blend of nitrogen lines increased from 2110 29 to 5378 42 W=m2=nm=sr. Absolute calibration errors add to these values a systematic uncertainty of about 20%. The capsule’s heat shield consisted of a phenol-impregnated carbon ablator. Hence, the intensity of the carbon-atom line emission is a measure of the ablation rate during descent, but it also depends on the details of carbon-atom ablation and the excitation in the shock layer.
Taylor, M.J., and P. Jenniskens, Near-infrared spectroscopy of the Stardust Sample Return Capsule entry: detection of carbon, J. Spacecraft and Rockets, 47, 6, 878, 2010.