Courtesy of NASA's National Space Science Data Center
On-orbit dry mass:
Venera 4 was launched from a Tyazheliy Sputnik (67-058B) towards the planet
Venus with the announced mission of direct atmospheric studies. On October
18, 1967, the spacecraft entered the Venusian atmosphere and released two
thermometers, a barameter, a radio altimeter, and atmospheric density gauge,
11 gas analyzers, and two radio transmitters operating in the DM waveband.
The main bus, which had carried the capsule to Venus, included a
magnetometer, cosmic ray detectors, hydrogen and oxygen indicators, and
charged particle traps. Signals were returned by the spacecraft, which
braked and then deployed a parachute system after entering the Venusian
atmosphere, until it reached an altitude of 24.96 kilometers.