The DLR Institute for Planetary Research provides a radiometer and a camera for the MASCOT Lander, which is being developed in cooperation with the French space agency CNES. MASCOT is part of the scientific payload of JAXA’s Hayabusa II mission, which will investigate the near Earth asteroid 1999JU3 in 2018, to bring back samples in 2020. Apart from the camera and radiometer, MASCOT is equipped with a spectrometer and magnetometer. The measurements to be performed will characterize the asteroid on small scales in situ, and help to choose a site for sample collection.
The MASCOT radiometer MARA measures the radiometric flux emitted from the asteroid’s surface in 6 different infrared bands (Figure 1). Two long-pass channels are used to determine the surface brightness temperature, while 4 bandpass channels will determine the spectral characteristics of the surface. A comparison with spectra measured in the laboratory will then allow for a characterization of surface materials and the asteroid’s composition.
Figure 1: Sensorhead of the MASCOT radiometer (MARA) with the aperture cover removed (on the right hand side of the picture). The sensor head houses 6 thermopile sensors, each equipped with its own infrared filter to determine the radiometric flux at different wavelengths.
Figure 2: Interior of a thermopile sensor. The black absorber surface has a diameter of 0.5 mm. A temperature sensor to determine the temperature of the sensor housing is located to the left of the absorber.