On this date, November 13, 1971 the Mariner 9 spacecraft became the first artificial satellite to orbit another planet. Launched on May 30, 1971, the satellite took just over five months to reach Mars and narrowly beat two Russian spacecraft (Mars 2 and Mars 3) by a month to reach Mars orbit. Mariner 9 took 7,329 images of the Red planet before retiring a year later in October 1972. Mariner 9 was packed with technology and weighed more than its two predecessors (Mariner 6 and 7) combined. Despite carrying an impressive array of cameras and sensing technology, when Mariner 9 arrived at Mars, Mars was in the midst of a massive dust storm, blanketing much of the planet. While this unexpected development delayed the first images of Mars, it validated the usefulness of a satellite in orbit and pointed out the need for surface exploration of the planet.
The word satellite comes from the Latin word satelles (satellitem is the closest Latin form) meaning an attendant, follower, courtier or life-guard. The great German mathematician and astronomer Johannes Kepler is credited as the first to use satellite to describe a moon around a planet. The first use of satellite to indicate a man-made object was 1936, over twenty years before the Russians actually accomplished it with the launch in October 1957 of the satellite Sputnik.
The Mariner 9 program paved the way for the Rover programs to follow, just as the earlier Mariner 6 and 7 flybys paved the way for the Mariner 9 orbit.
Images of the Mariner 9 satellite and launch courtesy NASA, in the public domain.