VIRTIS: Visible Infrared Thermal Imaging Spectrometer for the Rosetta mission

摘要

Abstract: The visible infrared thermal imaging spectrometer(VIRTIS) is one of the principal payloads to belaunched in 2003 on ESA's Rosetta spacecraft. Itsprimary scientific objective s are to map the surfaceof the comet Wirtanen, monitor its temperature, andidentify the solids and gaseous species on the nucleusand in the coma. VIRTIS will also collet data on twoasteroids, one of which has been identified asMimistrobell. The data is collected remotely using amapping spectrometer co-boresighted with a highspectral resolution spectrometer. The mapper consistsof a Shafer telescope matched to an Offner gratingspectrometer capable of gathering high spatial, mediumspectral resolution image cubes in the 0.25 to 5 $mu@mwaveband. The high spectral resolution spectrometeruses an echelle grating and a cross dispersing prism toachieve resolving powers of 1200 to 300 in the 1.9 to 5$mu@m band. Both sub-systems are passively cooled to130 K and use two Sterling cycle coolers to enable twoHgCdTe detector arrays to operate at 70 K. The mapperalso uses a silicon back-side illuminated detectorarray to cover the ultra-violet to near-infraredoptical band. !6