When the atmosphere of Venus was approached, a capsule weighing 405 kg (893 lb) and containing scientific instruments was jettisoned from the main spacecraft.

The spacecraft also carried a medallion bearing the State Coat of Arms of the Soviet Union and a bas-relief of Lenin to the night side of Venus.

Knowing the atmosphere was extremely dense, the parachutes were also made smaller so the capsule would reach its full crush depth before running out of power (as Venera 4 had done).

The probe entered the nightside atmosphere at 06:01 UTC and when the velocity slowed to 210 m/s the parachute deployed and transmissions to Earth began.

The photometer detected a light level of 250 watts per square meter and confirmed the high temperatures, pressures, and carbon dioxide composition of the atmosphere found by Venera 4.