Mariner Mars 9 stereophotogrammetry

Discussion of the equipment and orbital specifications of the Mariner Mars 9 spacecraft - a Martian orbiter which was placed in orbit on Nov. 14, 1971, for an expected 50-year stay and has made possible a practically 100% photographic coverage of the planet's surface. The orbit has a nominal 12-hr period, a nominal periapsis of 1300 km, and a nominal apoapsis of 18,000 km. Many of the outstanding topographic features of the planet have been covered by the convergent stereopairs carried by the orbiter. Theoretical considerations are set forth concerning the necessary instrument orientation and rotation requirements to achieve such performance levels in this extraterrestrial application of photogrammetry. The photogrammetric method used in this mission is assessed as useful in the evaluation of outstanding Martian features such as the mammoth volcano of the Nix Olympica region.