*** Welcome to piglix ***

Mariner 9

Mariner 9
Mariner09.jpg
The Mariner 9 spacecraft
Mission type Mars orbiter
Operator NASA / JPL
COSPAR ID 1971-051A
SATCAT no. 5261
Mission duration 1 year, 4 months, 27 days
Spacecraft properties
Manufacturer Jet Propulsion Laboratory
Launch mass 997.9 kilograms (2,200 lb)
Dry mass 558.8 kilograms (1,232 lb)
Power 500 watts
Start of mission
Launch date May 30, 1971, 22:23:04 (1971-05-30UTC22:23:04Z) UTC
Rocket Atlas SLV-3C Centaur-D
Launch site Cape Canaveral LC-36B
End of mission
Disposal Decommissioned
Deactivated October 27, 1972 (1972-10-28)
Orbital parameters
Reference system Areocentric
Periareion 1,650 kilometres (1,030 mi)
Apoareion 16,860 kilometres (10,480 mi)
Inclination 64.4°
Period 719.47 minutes
Mars orbiter
Orbital insertion November 14, 1971, 00:42:00 UTC

Mariner 9 (Mariner Mars '71 / Mariner-I) was an unmanned NASA space probe that contributed greatly to the exploration of Mars and was part of the Mariner program. Mariner 9 was launched toward Mars on May 30, 1971 from Cape Canaveral Air Force Station and reached the planet on November 14 of the same year, becoming the first spacecraft to orbit another planet – only narrowly beating the Soviets' Mars 2 and Mars 3, which both arrived within a month. After months of dust storms it managed to send back clear pictures of the surface.

Mariner 9 returned 7329 images over the course of its mission, which concluded in October 1972.

Mariner 9 was designed to continue the atmospheric studies begun by Mariner 6 and 7, and to map over 70% of the Martian surface from the lowest altitude (1,500 kilometers (930 mi)) and at the highest resolutions (from 1 kilometer per pixel to 100 meters per pixel) of any Mars mission up to that point. An infrared radiometer was included to detect heat sources in search of evidence of volcanic activity. It was to study temporal changes in the Martian atmosphere and surface. Mars' two moons were also to be analyzed. Mariner 9 more than met its objectives.

Under original plans, a dual mission was to be flown like Mariners 6-7, however the launch failure of Mariner 8 ruined this scheme and forced NASA planners to fall back on a simpler one-probe mission. NASA still held out hope that another Mariner probe and Atlas-Centaur could be readied before the 1971 Mars launch window closed. A few logistical problems emerged, including the lack of an available Centaur payload shroud of the correct configuration for the Mariner probes, however there was a shroud in NASA's inventory which could be modified. Convair also had an available Centaur stage on hand and could have an Atlas readied in time, but the idea was ultimately abandoned for lack of funding.

Mariner 9 was mated to Atlas-Centaur AC-23 on May 9 with investigation into Mariner 8's failure ongoing. The malfunction was traced to a problem in the Centaur's pitch control servoamplifier and because it was not clear if the spacecraft itself had been responsible, RFI testing was conducted on Mariner 9 to ensure the probe was not releasing interference that could cause problems with the Centaur's electronics. All testing came back negative and on May 22, a tested and verified rate gyro package arrived from Convair and was installed in the Centaur.


...
Wikipedia

...