Luna 3

Lore & Background

Luna 3 was a cylindric canister with hemispheric ends, 130 cm long and 120 cm at its maximum diameter. It was hermetically sealed and pressurized to about 0.22 standard atmospheres. Solar cells on the cylinder provided power, and shutters for thermal control opened when internal temperature exceeded 25 °C. The probe carried the Yenisey-2 imaging system (a custom Soviet film system), micrometeoroid and cosmic ray detectors, and was spin-stabilized for most of its flight, with three-axis attitude control activated during photography. It had no rocket motors for course corrections.

Reader's Guide

Luna 3's significance lies in its pioneering use of a gravity assist maneuver, the first such instance, which altered the spacecraft's orbit and allowed it to return over Soviet ground stations. The mission captured 29 pictures covering 70% of the lunar far side, of which about 17 were transmitted to Earth. These images revealed only two dark, low-lying regions, later named Mare Moscoviense and Mare Desiderii (the latter later found to be composed of Mare Ingenii and other craters). The photographs led to the first atlas of the far side, published in 1960, and a globe in 1961. The mission also demonstrated the first successful three-axis stabilization of a spacecraft. All contact was lost on 22 October 1959, and the probe is believed to have burned up in Earth's atmosphere in March or April 1960.

Did You Know?

• Luna 3 was the first mission to photograph the far side of the Moon.
• The spacecraft used a custom Soviet film system (Yenisey-2), not American film from Genetrix balloons.
• The first gravity assist maneuver in spaceflight history was performed by Luna 1 (or earlier by Pioneer 4, depending on definition), not Luna 3.
• Only six of the transmitted photographs were published, numbered frames 26, 28, 29, 31, 32, and 35.