Mission Type: Flyby
Launch Vehicle: Atlas-Centaur (AC-19 / Atlas 3C no. 5105C / Centaur D-1A)
Launch Site: Cape Canaveral, USA / launch complex 36A°
NASA Center: Jet Propulsion Laboratory
Spacecraft Mass: 411.8
Spacecraft Instruments: 1) imaging system (two TV cameras); 2) infrared spectrometer; 3) ultraviolet spectrometer; 4) infrared radiometer; 5) celestial mechanics experiment; and 6) S-band occultation experiment
Spacecraft Dimensions: octagonal frame: 138.4 cm diagonally, 45.7 cm deep; deployed solar panels (tip to tip): 5.7 m; height: 3.35 m
Spacecraft Power: 4 solar panels and a 1200 W-hr rechargeable silver-zinc battery for backup power
Maximum Power: 800 W near Earth, 449 W at Mars
Antenna Diameter: 1 m diameter (high-gain parabolic antenna)
S-Band Data Rate: Channel A (engineering data): 8 1/3 or 33 1/3 bps; Channel B (scientific data): 66 2/3 or 270 bps; Channel C (science data): 16,200 bps
Maximum Data Rate: 16,200 bps (channel C, science data)
Project Manager: Harris M. Schurmeier
Principal Scientists: Dr. John A. Stallkamp (Project Scientist)
Total Cost: total research, development, launch, and support costs for the Mariner series (Mariners 1 through 10): $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.
Identical to Mariner 6, Mariner 7 had a similar mission of flying by Mars. After Mariner 6 had returned intriguing photos of Mars's south polar cap, controllers reprogrammed Mariner 7's control system to increase the number of scans of the south pole from 25 to 33.
Following a perfect midcourse correction on the way to Mars on 8 April 1969, on 30 July 1969, just 7 hours before Mariner 6 was scheduled to fly by Mars, the deep space tracking station at Johannesburg, South Africa, lost contact with the spacecraft's high-gain antenna. One of two stations in Madrid, Spain, was diverted from its original mission of tracking Pioneer 8 and joined the search for Mariner 7. Fortunately, the Pioneer station at Goldstone in California's Mojave Desert picked up faint signals from the spacecraft. Controllers sent commands to Mariner 7 to switch to the low-gain antenna, which worked well afterwards.
Despite problems with positional calibration, Mariner 7 recorded 93 far-encounter and 33 near-encounter images of the planet, showing heavily cratered terrain very similar to images recorded by Mariner 6. The closest approach to Mars was at 05:00:49 UT on 5 August 1969, at a distance of 3,430 kilometers. Oddly, despite the high resolution of 300 meters, Mariner 7 found the center of Hellas to be devoid of craters.
The spacecraft found a pressure of 3.5 millibars and a temperature of -90°F at 59° south latitude and 28° east longitude in the Hellespontus region, suggesting that this area was elevated about 6 kilometers above the average terrain. One photo from Mariner 7 showed the moon Phobos. Although surface features were not visible, the picture clearly showed the moon to be irregularly shaped.