High resolution slit spectroscopy of Stardust

Michael Winter, Ecole Centrale Paris, Chatenay-Malabry, France
Surface temperatures of the STARDUST heat shield and plasma emission spectra during re-entry and estimates of vibrational and rotational temperature of the main molecular radiators CN and N2+ were determined from the emission of post shock and surface radiation during the Stardust re-entry which was detected during an observation mission initiated by NASA aboard the NASA DC-8 airborne observatory. A conventional spectrometer in a Cerny Turner configuration (f=300mm, grating 600 l/mm) was fed by fiber optics with light collected by a small mirror telescope. A wavelength range from 324 nm to 456 nm was covered with a pixel resolution of 0.08 nm. Data was taken during 30 s around the point of maximum heating until the capsule left the observed region with a measurement frequency of 5 Hz. The emission of CN as a major erosion product as well as N2+ and different atoms could be monitored successfully during that time. Planck temperatures as a measure for the heat shield t emperatures as well as rotational and vibrational temperatures of CN and N2+ were extracted along the visible trajectory.