Intensified Low-Resolution Optical Spectroscopy of the Stardust Sample Return Capsule Entry

The radiation emitted by the Stardust sample return capsule during reentry into Earth's atmosphere on 15 January 2006 was measured with a staring airborne intensified camera, equipped with an objective transmission grating. The instrumental setup was designed to provide low-resolution spectra of the capsule's radiation, even if other instruments would fail in tracking the object. Spectra were recorded at the video frame rate of 30 Hz. The spectra covered the range of 380-860 nm, with a dispersion of 2.3 nm/pixel and a full-width-at-half-maximum resolution of 7 nm. Fully calibrated results, to an absolute precision of similar to 17%, are presented for the time period from 09:57:17 to 09:57:43 Coordinated Universal Time, averaged over periods of 1 s. The data provided records of the CN band intensity detected throughout flight (unsaturated), the continuum emission (partially saturated), and the shock plasma emissions of oxygen and nitrogen during peak heating (partially saturated). A spectrum of wake radiation is also presented.