Context Camera Investigation on board the Mars Reconnaissance Orbiter

TLDR

The Context Camera (CTX) on the Mars Reconnaissance Orbiter is a facility instrument built by Malin Space Science Systems and the MARCI team, with a 12 % data return (~3 Tb) that covers roughly 9 % of Mars at 6 m/pixel, and its ground system builds on nine years of Mars Global Surveyor MOC experience. CTX’s purpose is to provide context imagery for other MRO instruments, to observe features of interest to NASA’s Mars Exploration Program, and to conduct a scientific investigation of Martian geology, geomorphology, and meteorology led by the MARCI team. The instrument comprises a 350 mm f/3.25 Schmidt telescope with a 5.7° field of view, a 5000‑element CCD covering 500–700 nm with 7 µm pixels, delivering ~6 m/pixel resolution, and its raw data are compressed on board before transmission to Earth. CTX first acquired images of Mars on 24 March 2006 during instrument checkout.

Abstract

The Context Camera (CTX) on the Mars Reconnaissance Orbiter (MRO) is a Facility Instrument (i.e., government‐furnished equipment operated by a science team not responsible for design and fabrication) designed, built, and operated by Malin Space Science Systems and the MRO Mars Color Imager team (MARCI). CTX will (1) provide context images for data acquired by other MRO instruments, (2) observe features of interest to NASA's Mars Exploration Program (e.g., candidate landing sites), and (3) conduct a scientific investigation, led by the MARCI team, of geologic, geomorphic, and meteorological processes on Mars. CTX consists of a digital electronics assembly; a 350 mm f/3.25 Schmidt‐type telescope of catadioptric optical design with a 5.7° field of view, providing a ∼30‐km‐wide swath from ∼290 km altitude; and a 5000‐element CCD with a band pass of 500–700 nm and 7 μ m pixels, giving ∼6 m/pixel spatial resolution from MRO's nearly circular, nearly polar mapping orbit. Raw data are transferred to the MRO spacecraft flight computer for processing (e.g., data compression) before transmission to Earth. The ground data system and operations are based on 9 years of Mars Global Surveyor Mars Orbiter Camera on‐orbit experience. CTX has been allocated 12% of the total MRO data return, or about ≥3 terabits for the nominal mission. This data volume would cover ∼9% of Mars at 6 m/pixel, but overlapping images (for stereo, mosaics, and observation of changes and meteorological events) will reduce this area. CTX acquired its first (instrument checkout) images of Mars on 24 March 2006.