ROLIS (Rosetta Lander Imaging System) is one of the two imaging
systems carried by the Rosetta’s Lander Philae. Consisting of a miniaturized CCD
camera, ROLIS will operate as a descent imager, acquiring imagery of the landing
site on comet 67P/Churyumov-Gerasimenko with increasing spatial resolution.
After touchdown ROLIS will focus at an object distance of 30 cm, taking pictures
of the comet’s surface below the Lander. Multispectral imaging is achieved through
an illumination device consisting of four arrays of monochromatic light emitting
diodes working in the 470-, 530-, 640-, and 870-nm spectral bands. The drill sample
sites, as well as the Alpha X-Ray Spectrometer (APXS) target locations, will be
imaged to provide context for the measurements performed by the in situ analyzers.
After the drilling operation, the borehole will be inspected to study its morphology
and to search for signs of stratification. Taking advantage of the Lander’s rotation
capability, stereo image pairs will be acquired, which will facilitate the mapping
and identification of surface structures.