Venera 1

Venera 1, also known as Venera-1 or sometimes referred to as Sputnik 8 in its launch configuration, was a Soviet Venus probe launched in 1961. It was the first probe launched towards another planet by any nation. Its primary mission objective was to fly by Venus and transmit data about the planet and the interplanetary environment.

Launched on February 12, 1961, from Baikonur Cosmodrome using a Molniya rocket, Venera 1 initially entered Earth orbit before being placed on a trajectory towards Venus. The probe was equipped with instruments to measure solar wind, cosmic rays, magnetic fields, and micrometeorites. It also carried a magnetometer and plasma traps.

Telemetry was received for the first few days of the mission, confirming the probe's initial trajectory and deployment of its solar panels. However, after about a week, contact with Venera 1 was lost. It is believed that a malfunction in its orientation system caused the solar panels to lose alignment with the sun, leading to battery depletion and subsequent communication failure.

Although the mission ultimately failed in its primary objective of returning data from Venus, Venera 1 remains a significant milestone in space exploration history. It demonstrated the Soviet Union's capability to launch a probe to another planet and provided valuable experience for future interplanetary missions. Based on trajectory calculations, Venera 1 passed within approximately 100,000 kilometers (62,000 miles) of Venus on May 19–20, 1961, and entered a heliocentric orbit.