Mission Type: Orbiter
Launch Vehicle: Atlas-Centaur (AC-23 / Atlas 3C no. 5404C / Centaur D-1A)
NASA Center: Jet Propulsion Laboratory
Spacecraft Mass: 998 kg at launch, about 560 kg in Mars orbit
Spacecraft Instruments: 1) imaging system; 2) ultraviolet spectrometer; 3) infrared spectrometer; 4) infrared radiometer; 5) S-band occultation experiment; and 6) celestial mechanics experiment
Spacecraft Dimensions: Octagonal frame 45.7 cm deep and 138.4 cm across a diagonal. Each pair of the two pair of solar panels spanned 6.89 m from tip to tip. Overall spacecraft height was 2.28 m.
Spacecraft Power: 4 solar panels, with power stored in a 20-amp-hr nickel-cadmium battery
Maximum Power: 800 W at Earth, 500 W at Mars
Antenna Diameter: 1 m (high-gain)
S-Band Data Rate: 16, 8, 4, 2, and 1 kbit/s using two tracks at a time
Total Cost: total research, development, launch, and support costs for the Mariner series of spacecraft (Mariners 1 through 10) was approximately $554 million.
Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, Monographs in Aerospace History No. 24, by Asif A. Siddiqi
National Space Science Data Center, http://nssdc.gsfc.nasa.gov/
Solar System Log by Andrew Wilson, published 1987 by Jane's Publishing Co. Ltd.
Mariner 9 was the second in the pair of identical spacecraft launched in 1971 to orbit Mars. The first spacecraft, Mariner 8, failed to reach Earth orbit.
Based on a wide octagonal structure, these vehicles used a bipropellant propulsion system with a fixed thrust of 136 kilograms for orbital insertion around Mars. All scientific instrumentation on the spacecraft was mounted on a movable scan platform underneath the main bodies. The span of the spacecraft over its extended solar panels was 6.9 meters.
Following an en route midcourse correction on 5 June 1971, Mariner 9 ignited its main engine for 915.6 seconds on 14 November 1971 at 00:18 UT, becoming the first human-made object to enter orbit around a planet other than Earth. Initial orbital parameters were 1,398 x 17,916 kilometers at 64.3° inclination.
The primary goal of the mission was to map about 70 percent of the surface during the first three months of operation. The dedicated imaging mission began in late November, but because of the major dust storm at the planet during this time, photos taken prior to about mid-January 1972 did not show great detail. Once the dust storm had subsided, Mariner 9 began to return spectacular photos of the deeply pitted Martian landscape, showing for the first time such features as the great system of parallel rilles stretching more than 1,700 kilometers across Mare Sirenum.
The vast amount of incoming data countered the notion that Mars was geologically inert. There was some speculation on the possibility of water having existed on the surface during an earlier period, but the spacecraft data could not provide any conclusive proof.
By February 1972, the spacecraft had identified about 20 volcanoes, one of which, later named Olympus Mons, dwarfed any similar feature on Earth. Olympus Mons, part of Nix Olympica-a "great volcanic pile" possibly formed by the eruption of hot magma from the planet's interior-is 25 kilometers high and has a base with a diameter of 600 kilometers. On 11 February 1972, NASA announced that Mariner 9 had achieved all its goals. By the time of last contact at 22:32 UT on 27 October 1972, the spacecraft had mapped 85 percent of the planet at a resolution of 1 to 2 kilometers, returning 7,329 photos.