Mariner 2:
NASA brought the Mariner R-2 spacecraft out of storage and launched it just 36 days after the failure of Mariner 1. Mariner 2, as it was known after launch, was equipped with an identical complement of instrumentation to that of its predecessor (see
Mariner 1).
The mission proved to be the first fully successful interplanetary mission performed by any nation. After a midcourse correction on 4 September, the spacecraft flew by Venus at a range of 34,762 kilometers on 14 December 1962. During a 42-minute scan of the planet, Mariner 2 gathered significant data on the Venusian atmosphere and surface
before continuing on to heliocentric orbit.
NASA maintained contact until 07:00 UT on 3 January 1963, when the spacecraft was 87.4
million kilometers from Earth, a new record for a deep space probe. The data returned
showed that the surface temperature on Venus was at least 425°C with minimal differentiation between the day and night sides of the
planet. Mariner 2 also found that there was a dense cloud layer that extended from 56 to 80
kilometers above the surface. The spacecraft detected no discernable planetary magnetic
field; this lack is partly explained by the great distance of the flyby.
After this successful mission, NASA elected to stand down the third
spacecraft in the series (Mariner R-3), scheduled for the 1964 launch window.
Mariner 2's success was celebrated with a float in the 1963 Tournament of Roses Parade (right).
