NSSDCA ID: 2004-006C-02
Mission Name: PhilaeThe Rosetta Lander Imaging System (ROLIS) is a CCD imager designed to return images of the landing site on the comet nucleus before and after Philae has landed. The primary scientific objective is to use the images to help characterize the landing site and study the morphology and mineralogy of the surface. ROLIS will also be used to image the sampling sites around the lander, both before and after sampling, to look into the boreholes produced by the drill to look for changes with depth, and to observe the evolution of the surface as the comet approaches the Sun.
ROLIS is located on the balcony of the Philae lander oriented in a downward-looking direction. The imager will be about 31 cm above the surface of the comet after landing. ROLIS will also acquire images of the landing site and its vicinity shortly before touch down during the descent phase. ROLIS is comprised of two parts, the camera head, ROLIS-D and the digital electronics subsystem, ROLIS-IME, which controls the camera and is located inside the lander body.
The camera head has dimensions of 9.0 x 6.3 x 8.6 cm and a mass of about 0.4 kg. It consists of a 1024 x 1024 pixel frame-transfer CCD and bi-modal optics which allow a wide angle (75 degree) view of the surface during the descent and a narrower angle (50 degree) view after landing. At the nominal 31 cm distance the field of view will be roughly 30 x 30 cm with a resolution of 0.3 mm/pixel. The camera has four color channels: blue, green, red, and infrared. Illumination of the surface is provided by four independent arrays of light emitting diodes (LEDs) irradiating through the visible and near IR, in spectral bands centered at about 470, 530, 640 and 870 nm, respectively, and with a FWHM of about 100 nm. The lander body can rotate, affording views of all sides of the landing site. The imager is designed for operating temperatures of -150 to +30 degrees C, allowing it to operate at distances of 3.0 to 1.8 AU from the Sun.
The ROLIS-IME (Imaging main Electronics) controls the operations of the camera as well as those of the CIVA experiment. Wavelet transformation data compression (>1:10) is used for both instruments.
The ROLIS experiment is designed to achieve its primary goals during the descent phase and within a few days after landing, at a heliocentric distance of 3 AU. The expected extended mission will allow observations of the evolution of the comet's surface as it approaches the Sun and heats up.
Mass: 0.4 kg
Questions and comments about this experiment can be directed to: Dr. David R. Williams
Name | Role | Original Affiliation | |
---|---|---|---|
Dr. Harald Michaelis | General Contact | harald.mihaelis@dlr.de | |
Dr. Stefano Mottola | Principal Investigator | stefano.mottola@dlr.de |