Courtesy of the Jet Propulsion Laboratory and NASA's National Space Science Data Center
Once past Mars, Mariner 4 journeyed on to the far side of the Sun before returning to the vicinity of Earth again in 1967. Nearly out of power by then, engineers decided to use the aging craft for a series of operational and telemetry tests to improve their knowledge of the technologies that would be needed for future interplanetary spacecraft. All operations of the spacecraft ceased on December 20, 1967.
Mariner 4 was launched November 28, 1964, on a 228-day mission to Mars. The spacecraft passed Mars at a distance of 9,868 kilometers (6,118 miles), recording and transmitting to Earth the first close-up picture of the red planet. In 22 pictures, Mariner's TV camera scanned about one percent of the Martian surface, revealing ancient craters of varying size. (Courtesy NASA/JPL)
Mariner IV Mars Encounter Imaging Geometry
Mariner IV was the fourth in a series of spacecraft used for planetary exploration in a flyby mode and the first spacecraft to succesfully image a planet. It was launched on 28 November 1964 by an Atlas/Agena rocket and flew by Mars on July 15, 1965.
The total data returned by the mission was 5.2 million bits including 21 pictures
plus 21 lines of a 22nd picture and took more than a week to transmit to earth
with the 8.33 bps transmission rate of the spacecraft. The images returned showed
a Moon-like cratered terrain (which later Mariner IX showed was not typical for
Mars, but only for the more ancient region imaged by Mariner IV). Though not as
good looking as images returned by later missions these 22 images are mankind's
first images taken by a planetary spacecraft and have great historical value.
(Courtesy A. Tayfun Oner)