Venera 12

Infobox_Spacecraft
Name = Venera 12


Caption = Venera 11 lander
Organization = USSR
Major_Contractors =
Mission_Type = Flyby and Lander
Satellite_Of = Venus
Flyby_Date = December 19 1978
Launch = 14 September, 1978 02:25:13 UTC
Launch_Vehicle = Proton Booster Plus Upper Stage and Escape Stages
Decay =
Mission_Duration =
NSSDC_ID = 1978-086A
Webpage =
Mass = 4940 kg
Power =
Orbital_elements =
Semimajor_Axis =
Eccentricity =
Inclination =
Orbital_Period =
Apoapsis =
Periapsis = 6.62 RV (flight platform)
Orbits =

The Venera 12 ( _ru. Венера-12) was an USSR unmanned space mission to explore the planet Venus. Venera 12 was launched on 14 September, 1978 at 02:25:13 UTC. Separating from its flight platform on December 19, 1978, the lander entered the Venus atmosphere two days later at 11.2 km/s. During the descent, it employed aerodynamic braking followed by parachute braking and ending with atmospheric braking. It made a soft landing on the surface at 06:30 Moscow time on 21 December after a descent time of approximately 1 hour. The touchdown speed was 7-8 m/s. Landing coordinates are Venus coords and quad cat|7|S|294|E. It transmitted data to the flight platform for 110 minutes after touchdown until the flight platform moved out of range. Identical instruments were carried on Venera 11 and 12.

Flight platform

Venera 12 flight platform carried solar wind detectors, ionosphere electron instruments and two gamma ray burst detectors - the Soviet-built KONUS and the French-built SIGNE 2. The SIGNE 2 detectors were simultaneously flown on Venera 12 and Prognoz 7 to allow triangulation of gamma ray sources. Venera 12 used its ultraviolet spectrometer to study Comet Bradfield on 13 February, 1980.

List of flight platform instruments and experiments:
* 30-166 nm Extreme UV Spectrometer
* Compound Plasma Spectrometer
* KONUS Gamma-Ray Burst Detector
* SNEG Gamma-Ray Burst Detector
* Magnetometer
* 4 Semiconductor Counters
* 2 Gas-Discharge Counters
* 4 Scintillation Counters
* Hemispherical Proton Telescope

The mission ended in April, 1980.

Lander

The Venera 12 descent craft carried instruments designed to study the detailed chemical composition of the atmosphere, the nature of the clouds, and the thermal balance of the atmosphere.Among the instruments on board was a gas chromatograph to measure the composition of the Venus atmosphere, instruments to study scattered solar radiation and soil composition, and a device named Groza which was designed to measure atmospheric electrical discharges. Results reported included evidence of lightning and thunder, a high Ar³⁶/Ar⁴⁰ ratio, and the discovery of carbon monoxide at low altitudes.Both Venera 11 and Venera 12 had landers with two cameras, each designed for color imaging. Each failed to return images when the lens covers did not separate after landing due to a design flaw.

List of lander experiments and instruments:
* Backscatter Nephelometer
* Mass Spectrometer
* Gas Chromatograph
* X-Ray Fluorospectrometer
* 360° Scanning Photometer
* Spectrometer (430-1170 nm)
* Microphone/Anemometer
* Low-Frequency Radio Sensor
* 4 Thermometers
* 3 Barometer
* Accelerometer
* PROP-V Penetrometer
* Soil Analysis Device
* 2 Color Cameras