Short answers, pulled from the story.
Mariner 2 launched on the 27th of August 1962 at 1:53 AM EST. The mission followed a failed launch attempt by its sister spacecraft Mariner 1 which was destroyed shortly after liftoff due to guidance errors.
Mariner 2 flew aboard an Atlas-Agena rocket system after engineers switched from the planned Atlas-Centaur vehicle. This operational booster allowed the probe to escape Earth's gravity and begin its journey toward Venus.
The Mariner 2 spacecraft weighed approximately 340 kilograms during flight operations. Non-experimental systems consumed about 150 kilograms while solar panels extended to reach heights of roughly 2.6 meters once deployed.
Mariner 2 measured the high temperature atmosphere of Venus at approximately 480 Kelvin. Microwave radiometer results confirmed this finding by showing limb darkening with cooler temperatures near the edge and higher temperatures at the center.
No detectable magnetic field existed near Venus according to data collected by Mariner 2. The magnetometer detected persistent interplanetary magnetic fields but found no trends or fluctuations indicating a planetary magnetic field like that surrounding Earth.