Venera 10

Lore & Background

The orbiter entered Venus orbit on October 23, 1975, and served as a communications relay for the lander while exploring cloud layers and atmospheric parameters with a suite of instruments including an IR spectrometer, UV photometer, magnetometer, and multiple cameras. The orbiter consisted of a cylinder with two solar panel wings and a high-gain parabolic antenna, with a bell-shaped propulsion unit and a 2.4-meter sphere holding the landers. It traveled in a heliocentric orbit with perihelion of 0.72 AU, apohelion of 1.02 AU, eccentricity of 0.17, inclination of 2.3 degrees, and orbital period of 294 days.

The lander separated from the orbiter on October 23, 1975, and touched down with the sun near zenith at 05:17 UT on October 25. It landed near the border area between Beta Regio and Hyndla Regio, three days after and 2200 km from Venera 9. A system of circulating fluid distributed heat load, allowing operation for 65 minutes after landing. During descent, heat dissipation and deceleration were accomplished by protective hemispheric shells, three parachutes, a disk-shaped drag brake, and a compressible metal doughnut-shaped landing cushion. The lander measured surface windspeed of 3.5 m/s, atmospheric pressure at various heights, temperature, and surface light levels. Photographs showed lava rocks of pancake shape with lava or other weathered rocks in between; planned 360-degree panoramic pictures were limited to 180 degrees because one of two camera lens covers failed to come off.

Reader's Guide

Venera 10 was a significant Soviet mission that advanced understanding of Venus's surface and atmosphere. As the second probe to return black-and-white television pictures from the Venusian surface, it provided direct visual evidence of the planet's geology, revealing pancake-shaped lava rocks and weathered terrain. Its lander operated for 65 minutes after touchdown, transmitting data on surface windspeed, pressure, temperature, and light levels. The orbiter's extensive instrument suite, including spectrometers, photometers, and a magnetometer, contributed to studies of cloud layers and atmospheric composition. The mission demonstrated the Soviet capability to deliver a lander to Venus and relay data via an orbiter, building on the achievements of Venera 9. The failure of one camera lens cover limited panoramic imaging but did not diminish the mission's value in planetary science.

Did You Know?

• Venera 10 was launched on June 14, 1975, at 03:00:31 UTC with a mass of 5033 kg.
• The lander touched down on October 25, 1975, near the border between Beta Regio and Hyndla Regio.
• It measured a surface windspeed of 3.5 m/s on Venus.
• One of two camera lens covers failed to come off, limiting panoramic pictures to 180 degrees.