Venera 9

Venera 9 (Венера-9), manufacturer's designation: 4V-1 No. 660, was a Soviet uncrewed space mission to Venus. It consisted of an orbiter and a lander. It was launched on June 8, 1975, at 02:38:00 UTC and had a mass of . The orbiter was the first spacecraft to orbit Venus, while the lander was the first to return images from the surface of another planet. The orbiter entered Venus orbit on October 20, 1975. Its mission was to act as a communications relay for the lander and to explore cloud layers and atmospheric parameters with several instruments and experiments. It performed 17 survey missions from October 26, 1975, to December 25, 1975. The orbiter consisted of a cylinder with two solar panel wings and a high gain parabolic antenna attached to the curved surface. A bell-shaped unit holding propulsion systems was attached to the bottom of the cylinder, and mounted on top was a sphere which held the lander. The instruments composing the orbiter included: 1.6–2.8 μm IR spectrometer 8–28 μm IR radiometer 352 nm UV photometer 2 photo-polarimeters (335–800 nm) 300–800 nm spectrometer Lyman-α (alpha) H/D spectrometer Bistatic radar mapping CM, DM radio occultations Triaxial Magnetometer 345–380 nm UV camera 355–445 nm camera 6 electrostatic analyzers 2 modulation ion traps Low-energy proton / alpha detector Low-energy electron detector 3 semiconductor counters 2 gas-discharge counters Cherenkov detector The lander was encased in a spherical shell before landing to help protect it from the heat of entry as it slowed from to . This sphere was then separated with explosive bolts and a three-domed parachute was deployed which slowed the lander further to at an altitude of above the planet. The descent through the cloud layer took about 20 minutes, during which time the lander took measurements of the atmosphere and radioed the information to the orbiter. To minimize lander damage in the hot atmosphere, the parachute was released at an altitude of , and the ring-shaped aerodynamic shield provided braking.