Goals: Mariner 2 was designed to fly by Venus and send back information on the planet's atmosphere and surface.
Accomplishments: Mariner 2 was the first successful mission to another planet by any country. Launched just 36 days after the failure of its twin, Mariner 1, it flew by Venus as planned at a range of 34,762 km (21,600 miles), scanning the planet's atmosphere and surface for 42 minutes.
The spacecraft showed that surface temperature on Venus was at least 797 degrees Fahrenheit (425 degrees Celsius) on both the day and night sides, hot enough to melt lead. It also showed that Venus rotates in the opposite direction from most planets in our solar system, has an atmosphere mostly of carbon dioxide with very high pressure at the planet's surface, continuous cloud cover and no detectable magnetic field. It also found the solar wind streams continuously and that the density of cosmic dust between planets is much lower than it is near Earth.
27 Aug 1962: Launch
14 Dec 1962: Venus Flyby
3 Jan 1963: Contact Lost
Mission Type: Flyby
Launch Vehicle: Atlas-Agena B (no. 6 / Atlas D no. 179 / Agena B no. 6902)
Launch Site: Cape Canaveral, United States, Launch Complex 12
NASA Center: Jet Propulsion Laboratory
Spacecraft Mass: 203.6 kg
Spacecraft Instruments: 1) microwave radiometer; 2) infrared radiometer; 3) fluxgate magnetometer; 4) cosmic dust detector; 5) solar plasma spectrometer and 6) energetic particle detectors
Spacecraft Power: 220.0 W
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/
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 km 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 797 degrees Fahrenheit (425 degrees Celsius) 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 km above the surface. The spacecraft detected no discernible 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.