Between 1961 and 1984 the Soviet Union sent 18 probes to Venus, and the planet crushed, cooked, and blinded them one after another. This episode traces the extreme trial and error of the Venera program, starting with engineers who as late as 1964 were still building buoyancy systems in case a probe splashed into a Venusian ocean. It covers the failed flybys of Venera 1 and 2, the first impact on another planet by Venera 3 in 1966, and the parachute probes Venera 4 through 6 that were crushed in the atmosphere while discovering it was overwhelmingly carbon dioxide.

The conversation explains how the American Mariner 5 used radio occultation to reveal surface pressures of 75 to 100 atmospheres, forcing the Soviets to retract the claim that Venera 4 reached the ground. That led to the brute-force titanium sphere of Venera 7, which crash-landed at 17 meters per second in 1970, toppled over, got stuck transmitting only temperature, and still became the first probe to send data from another planet’s surface. The episode follows the five-ton landers of Venera 9 through 14, the first surface photographs in 1975, the maddening lens cap failures, Venera 13’s record 127 minutes and first color images, and Venera 14’s hammer striking its own ejected lens cap. It closes with the synthetic aperture radar mapping of Venera 15 and 16 and the Vega balloon missions.

• How scientists derived 90 atmospheres of pressure from a single temperature reading of 465 degrees Celsius
• Why a gamma ray spectrometer could analyze Venusian soil without touching it
• How phase change materials and crush rings kept five-ton landers alive
• Why thermal expansion fused the metal lens caps shut on Venera 11 and 12
• How 8-centimeter radar wavelengths pierced sulfuric acid clouds to map the northern hemisphere