Scientists have long puzzled over why Venus appears to be such an unstable, polluted version of Earth. Today, NASA announced it had approved two missions to study this turbulent world.
DAVINCI+ will examine the planet’s toxic atmosphere while VERITAS will map its surface and search for any sign that it once hosted water.
Venera 1 and 2
In February 1961, the inaugural of 16 Venera probes to visit Venus began its journey. The 1VA spacecraft, attached to an 8K78 rocket and known as Molniya after the communication satellites which regularly launched it was designed by OKB-1 under Chief Designer Sergei Korolev.
An umbrella-like antenna measuring 2.4 meters in diameter was used for communications with Earth; commands were uploaded at one bit per second. To aid reentry, a slow-sprang down parachute assisted the main parachute when necessary.
Venera 5 and 6
On May 16 and 17, 1969, two Soviet Venera spacecraft safely landed on Venus. Although their images were partially obscured by its hostile atmosphere, their findings revealed a harsh alien planet devoid of life and damped romantic hopes that life existed there.
The orbiters examined Venusian clouds with high-resolution radar systems and conducted investigations of its interior with various instruments – cosmic ray detectors, solar wind charged particle analyzers, UV photometers etc – that included cosmic ray detectors.
Venera 8
Soviet Venera 13 and 14 lander-bus spacecrafts successfully landed on Venus in March 1982, transmitting TV photography while gathering data about temperature, pressure, light levels and cloud cover conditions on the planet surface.
Surveying its atmosphere through gas composition measurement, gamma-ray spectroscopy and electric discharges were among their goals. Their lander featured drill, surface sampler, seismometer and drogue parachute; prior to atmospheric entry the capsule used drogue parachute for slow descent with main antenna operating for 50 minutes post landing.
Venera 11 and 12
Venera 11 and 12, the final Soviet probes to land on Venus, successfully mapped its surface using hyperbolic trajectories designed to keep radio contact long enough for imaging to take place.
Both landers successfully sent back color TV views of Venusian surfaces but were unable to perform soil analysis experiments due to high Venusian pressures; additionally a lens cap failed to eject after landing due to excessive rotation and oscillation.
Both Venera 11 and 12 were equipped with flyby buses which relayed telemetry back to Earth.
Pioneer 1 and 2
Pioneer Venus launched two spacecraft: an orbiter and multiprobe bus. The orbiter entered an elliptical orbit around Venus while the multiprobe bus launched four entry probes – one large probe and three small ones.
The Pioneer Venus Orbiter provided accurate readings on Venus atmospheric temperature and density as well as discovering spectral windows on its night side. Instruments aboard this craft measured lightning strikes as well as cloud components like sulfur. A radar altimeter captured 98% of Venus surface area.
Venera 13 and 14
Venera 13 and 14 completed a four month cruise and returned after showing a panoramic view of Venus’ surface rocks.
This lander used an optical-mechanical camera to take two panoramas of Mars’ rocky surface and included an optical-mechanical camera for images taken by an optical-mechanical camera and two panoramas were captured using UV grating monochromator, electron and proton spectrometers, drill & soil delivery devices as well as pressure and temperature instruments.
The bus served as an information relay while flying by Venus in its heliocentric orbit.
Venera 15 and 16
Venera 15 and 16 conducted an eight-month radar scan of Venus using radar, producing images (radar swathes) and height profiles that were combined into a mosaic map of its northern hemisphere.
Venera 13 arrived on Venus on March 1, 1982, with Venera 14 following four days later. Both landers used color cameras and drills to measure compressibility of Venusian soil.
Soviet flyby buses and lander probes revealed Venus to be a dry planet with vast plains, towering volcanoes, intricate fault systems, mysterious lightning activity in its atmosphere and strange weather patterns.
Mariner 5
Mariner 5 was part of NASA’s Mariner series of spacecraft and featured an array of experiments designed to study Venus’ atmosphere. An octagonal magnesium frame held electronics, cabling, a midcourse propulsion system and attitude control gas supplies.
Mariner 5 encountered Venus for its initial encounter in January 1967 and used radio occultation experiments to detect surface temperatures and pressures up to 980 degrees Fahrenheit with 75 to 100 Earth atmospheres of density. Unfortunately, attempts between April and November 1968 to recover Mariner 5 proved futile.