Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. It has the longest rotation period of any planet in the Solar System and rotates in the opposite direction to most other planets, it does not have any natural satellites. It is named after the Roman goddess of beauty, it is the second-brightest natural object in the night sky after the Moon, reaching an apparent magnitude of −4.6 – bright enough to cast shadows at night and visible to the naked eye in broad daylight. Orbiting within Earth's orbit, Venus is an inferior planet and never appears to venture far from the Sun. Venus is a terrestrial planet and is sometimes called Earth's "sister planet" because of their similar size, proximity to the Sun, bulk composition, it is radically different from Earth in other respects. It has the densest atmosphere of the four terrestrial planets, consisting of more than 96% carbon dioxide; the atmospheric pressure at the planet's surface is 92 times that of Earth, or the pressure found 900 m underwater on Earth.
Venus is by far the hottest planet in the Solar System, with a mean surface temperature of 735 K though Mercury is closer to the Sun. Venus is shrouded by an opaque layer of reflective clouds of sulfuric acid, preventing its surface from being seen from space in visible light, it may have had water oceans in the past, but these would have vaporized as the temperature rose due to a runaway greenhouse effect. The water has photodissociated, the free hydrogen has been swept into interplanetary space by the solar wind because of the lack of a planetary magnetic field. Venus's surface is a dry desertscape interspersed with slab-like rocks and is periodically resurfaced by volcanism; as one of the brightest objects in the sky, Venus has been a major fixture in human culture for as long as records have existed. It has been made sacred to gods of many cultures, has been a prime inspiration for writers and poets as the morning star and evening star. Venus was the first planet to have its motions plotted across the sky, as early as the second millennium BC.
As the planet with the closest approach to Earth, Venus has been a prime target for early interplanetary exploration. It was the first planet beyond Earth visited by a spacecraft, the first to be landed on. Venus's thick clouds render observation of its surface impossible in visible light, the first detailed maps did not emerge until the arrival of the Magellan orbiter in 1991. Plans have been proposed for rovers or more complex missions, but they are hindered by Venus's hostile surface conditions. Venus is one of the four terrestrial planets in the Solar System, meaning that it is a rocky body like Earth, it is similar to Earth in size and mass, is described as Earth's "sister" or "twin". The diameter of Venus is 12,103.6 km —only 638.4 km less than Earth's—and its mass is 81.5% of Earth's. Conditions on the Venusian surface differ radically from those on Earth because its dense atmosphere is 96.5% carbon dioxide, with most of the remaining 3.5% being nitrogen. The Venusian surface was a subject of speculation until some of its secrets were revealed by planetary science in the 20th century.
Venera landers in 1975 and 1982 returned images of a surface covered in sediment and angular rocks. The surface was mapped in detail by Magellan in 1990–91; the ground shows evidence of extensive volcanism, the sulfur in the atmosphere may indicate that there have been recent eruptions. About 80% of the Venusian surface is covered by smooth, volcanic plains, consisting of 70% plains with wrinkle ridges and 10% smooth or lobate plains. Two highland "continents" make up the rest of its surface area, one lying in the planet's northern hemisphere and the other just south of the equator; the northern continent is called Ishtar Terra after Ishtar, the Babylonian goddess of love, is about the size of Australia. Maxwell Montes, the highest mountain on Venus, lies on Ishtar Terra, its peak is 11 km above the Venusian average surface elevation. The southern continent is called Aphrodite Terra, after the Greek goddess of love, is the larger of the two highland regions at the size of South America. A network of fractures and faults covers much of this area.
The absence of evidence of lava flow accompanying any of the visible calderas remains an enigma. The planet has few impact craters, demonstrating that the surface is young 300–600 million years old. Venus has some unique surface features in addition to the impact craters and valleys found on rocky planets. Among these are flat-topped volcanic features called "farra", which look somewhat like pancakes and range in size from 20 to 50 km across, from 100 to 1,000 m high; these features are volcanic in origin. Most Venusian surface features are named after mythological women. Exceptions are Maxwell Montes, named after James Clerk Maxwell, highland regions Alpha Regio, Beta Regio, Ovda Regio; the latter three features were named before the current system was adopted by the International Astronomical Union, the body which oversees planetary nomenclature. The longitudes of physical features on Venus are expressed relative to its prime meridian; the original prime meridian passed through the radar-bright spot at the centre o
The Venera 11 was a Soviet unmanned space mission part of the Venera program to explore the planet Venus. Venera 11 was launched on 9 September 1978 at 03:25:39 UTC. Separating from its flight platform on December 23, 1978 the lander entered the Venus atmosphere two days on December 25 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 06:24 Moscow time on 25 December after a descent time of 1 hour. The touchdown speed was 7 to 8 m/s. Information was transmitted to the flight platform for retransmittal to earth until it moved out of range 95 minutes after touchdown. Landing coordinates are 14°S 299°E. After ejection of the lander probe, the flight platform continued on past Venus in a heliocentric orbit. Near encounter with Venus occurred on December 25, 1978, at 35,000 km altitude; the flight platform acted as a data relay for the descent craft for 95 minutes until it flew out of range and returned its own measurements on interplanetary space.
Venera 11 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 flown on Venera 12 and Prognoz 7 to allow triangulation of gamma ray sources. Before and after Venus flyby, Venera 11 and Venera 12 yielded detailed time-profiles for 143 gamma-ray bursts, resulting in the first catalog of such events; the last gamma-ray burst reported by Venera 11 occurred on January 27, 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 telescopeThe mission ended in February, 1980. Venera 11 is in heliocentric orbit, with perihelion of 0.69 AU, aphelion of 1.01 AU, eccentricity of 0.19, inclination of 2.3 degrees and orbital period of 284 days.
The lander carried instruments to study the temperature and atmospheric and soil chemical composition. A device called. Both Venera 11 and Venera 12 had landers with two cameras, each designed for color imaging, though Soviet literature does not mention them; each failed to return images when the lens covers did not separate after landing due to a design flaw. The soil analyzer failed. A gas chromatograph was on board to measure the composition of the Venus atmosphere, as well as instruments to study scattered solar radiation. Results reported included evidence of lightning and thunder, a high Ar36/Ar40 ratio, the discovery of carbon monoxide at low altitudes. List of lander experiments and instruments: List of missions to Venus Timeline of artificial satellites and space probes Venera 11 & Venera 12 Experiments on Venera 11 Has detail on each experiment/instrument. Drilling into the Surface of Venus
The Venera series space probes were developed by the Soviet Union between 1961 and 1984 to gather data from Venus, Venera being the Russian name for Venus. As with some of the Soviet Union's other planetary probes, the versions were launched in pairs with a second vehicle launched soon after the first. Ten probes from the Venera series landed on Venus and transmitted data from the surface of Venus, including the two Vega program and Venera-Halley probes. In addition, thirteen Venera probes transmitted data from the atmosphere of Venus. Among other results, probes of the series became the first human-made devices to enter the atmosphere of another planet, to make a soft landing on another planet, to return images from the planetary surface, to perform high-resolution radar mapping studies of Venus; the latter probes in the Venera series carried out their mission, providing the first direct observations of the surface of Venus. Since the surface conditions on Venus are extreme, the probes only survived on the surface for durations varying between 23 minutes up to about 2 hours.
The first Soviet attempt at a flyby probe to Venus was launched on February 4, 1961, but failed to leave Earth orbit. In keeping with the Soviet policy at that time of not announcing details of failed missions, the launch was announced under the name Tyazhely Sputnik, it is known as Venera 1VA. Venera 1 and Venera 2 were intended to fly past Venus without entering orbit. Venera 1 was launched on February 12, 1961. Telemetry on the probe failed seven days after launch, it remains in heliocentric orbit. Venera 2 launched on November 12, 1965, but suffered a telemetry failure after leaving Earth orbit. Several other failed attempts at Venus flyby probes were launched by the Soviet Union in the early 1960s, but were not announced as planetary missions at the time, hence did not receive the "Venera" designation; the Venera 3 to 6 probes were similar. Weighing one ton, launched by the Molniya-type booster rocket, they included a cruise "bus" and a spherical atmospheric entry probe; the probes were optimised for atmospheric measurements, but not equipped with any special landing apparatus.
Although it was hoped they would reach the surface still functioning, the first probes failed immediately, thereby disabling data transmission to Earth. Venera 3 became the first human-made object to impact another planet's surface as it crash-landed on March 1, 1966. However, as the spacecraft's dataprobes had failed upon atmospheric penetration, no data from within the Venusian boundary were retrieved from the mission. On 18 October 1967, Venera 4 became the first spacecraft to measure the atmosphere of another planet. While the Soviet Union claimed the craft reached the surface intact, re-analysis including atmospheric occultation data from the American Mariner 5 spacecraft that flew by Venus the day after its arrival demonstrated that Venus's surface pressure was 75-100 atmospheres, much higher than Venera 4's 25 atm hull strength, the claim was retracted. Realizing the ships would be crushed before reaching the surface, the Soviets launched Venera 5 and Venera 6 as atmospheric probes. Designed to jettison nearly half their payload prior to entering the planet's atmosphere, these craft recorded 53 and 51 minutes of data while descending by parachute before their batteries failed.
The Venera 7 probe was the first one designed to survive Venus surface conditions and to make a soft landing. Massively overbuilt to ensure survival, it had few experiments on board, scientific output from the mission was further limited due to an internal switchboard failure which stuck in the "transmit temperature" position. Still, the control scientists succeeded in extrapolating the pressure from the temperature data with 465 °C, which resulted from the first direct surface measurements; the Doppler measurements of the Venera 4 to 7 probes were the first evidence of the existence of high-speed zonal winds in the Venusian atmosphere. Venera 7's parachute failed shortly before landing close to the surface, it toppled over, but survived. Due to the resultant antenna misalignment, the radio signal was weak, but was detected for 23 more minutes before its batteries expired. Thus, it became, on 15 December 1970, the first human-made probe to transmit data from the surface of Venus. Venera 8 was equipped with an extended set of scientific instruments for studying the surface.
The cruise bus of Venera 7 and 8 was similar to that of earlier ones, with the design ascending to the Zond 3 mission. The lander landed in sunlight, it had no camera. It transmitted data for an hour; the Venera 9 to 12 probes were of a different design. They weighed five tons and were launched by the powerful Proton booster, they included a transfer and relay bus that had engines to brake into Venus orbit and to serve as receiver and relay for the entry probe's transmissions. The entry probe was attached to the top of the bus in a spherical heat shield; the probes were optimized for surface operations with an unusual looking design that included a spherical compartment to protect the electronics from atmospheric pressure and heat for as
Venera 10, or 4V-1 No. 661, was a Soviet unmanned space mission to Venus. It consisted of a lander, it had a mass of 5033 kg. The orbiter entered Venus orbit on October 23, 1975, its mission was to serve as a communications relay for the lander and to explore cloud layers and atmospheric parameters with several instruments and experiments: 1.6-2.8 μm IR Spectrometer 8-28 μm IR Radiometer 352 nm UV Photometer 2 Photopolarimeters 300-800 nm Spectrometer Lyman-α 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 detectorThe 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, mounted on top was a 2.4 meter sphere which held the landers.
To reach Venus, the spacecraft traveled in a heliocentric orbit from Earth to the planet 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. On October 23, 1975, this spacecraft was separated from the Orbiter, landing was made with the sun near zenith, at 0517 UT, on October 25. A system of circulating fluid was used to distribute the heat load; this system, plus precooling prior to entry, permitted operation of the spacecraft for 65 min after landing. During descent, heat dissipation and deceleration were accomplished sequentially by protective hemispheric shells, three parachutes, a disk-shaped drag brake, a compressible, doughnut-shaped, landing cushion, it landed near the border area between Beta Regio and Hyndla Regio, three days after the touchdown of, 2200 km from Venera 9. Venera 10 measured a surface windspeed of 3.5 m/s. Other measurements included atmospheric pressure at various heights, temperature, surface light levels.
Venera 10 was the second probe to send back black and white television pictures from the Venusian surface. Venera 10 photographs showed lava rocks of pancake shape with lava or other weathered rocks in between. Planned 360 degree panoramic pictures could not be taken because, as with Venera 9, one of two camera lens covers failed to come off, limiting pictures to 180 degrees; the lander communicated with Earth using the Venera 10 orbiter as a communication relay. Lander Payload: Temperature and pressure sensors Accelerometer Visible / IR photometer - IOV-75 Backscatter and multi-angle nephelometers - MNV-75 P-11 Mass spectrometer - MAV-75 Panoramic telephotometers Anemometer - ISV-75 Gamma-ray spectrometer - GS-12V Gamma ray densitometer - RP-75 Radio Doppler experiment List of missions to Venus Timeline of artificial satellites and space probes
Gagarin's Start is a launch site at Baikonur Cosmodrome in Kazakhstan, used for the Soviet space program and now managed by Roscosmos. The launchpad for the world's first human spaceflight made by Yuri Gagarin on Vostok 1 in 1961, the site was referred to as Site No.1 as the first one of its kind. It is sometimes referred to as NIIP-5 LC1, Baikonur LC1 or GIK-5 LC1. On 17 March 1954 the Council of Ministers ordered several ministries to select a site for a proving ground to test the R-7 rocket by 1 January 1955. A special reconnaissance commission considered several possible geographic regions and selected Tyuratam in the Kazakh SSR; this selection was approved on 12 February 1955 by the Council of Ministers, with a completion of construction targeted for 1958. Work on the construction of Site No.1 began on 20 July 1955 by military engineers. Day and night more than 60 powerful trucks worked at the site. During winter explosives were utilized. By the end of October 1956 all primary building and installation of infrastructure for R-7 tests was completed.
The Installation and Testing Building named "Site No.2" was built and a special railway completed from there to Site No.1 where the launch pad for the rocket was located. By April 1957 all remaining work was completed and the site was ready for launches; the R-7 missile made its maiden voyage from LC-1 on 15 May 1957. On 4 October 1957 the pad was used to launch the world's first artificial satellite, Sputnik 1. Manned spaceflights launched from the site include Yuri Gagarin's flight, Valentina Tereshkova's flight, numerous other human spaceflight missions, including all Soviet and Russian manned spaceflights to Mir; the pad was used to launch Luna program spacecraft, Mars probe program spacecraft, Venera program spacecraft, many Cosmos satellites and others. From 1957 through 1966 the site hosted ready-to-launch strategic nuclear ICBMs in addition to spacecraft launches; the 500th launch from this site was of Soyuz TMA-18M on 2 September 2015. In 1961, the growing launch schedule of the Soviet space program resulted in the opening of a sister pad at Baikonur, LC-31/6.
LC-1 has been the primary facility for manned launches, with occasional Soyuz flights from LC-31/6. LC-1 was damaged several times by booster explosions during the early years; as of 2016, the most recent accident to occur on or around the pad was the attempted launch of Soyuz T-10-1 in September 1983 ended disastrously when the booster caught fire during prelaunch preparations and exploded, causing severe damage that left LC-1 inoperable for a year. According to the Russian State Owned Sputnik, Gagarin's Start is supposed to be decommissioned by the end of 2019 due to the upcoming decommission of the Soyuz-FG Launch Vehicle, but again according to the same article there could be some difficulties with the decommission, because LC-31/6 might not be able to handle all planned launches in 2020. Baikonur Cosmodrome Site 31 Cape Canaveral Air Force Station Launch Complex 14, the equivalent for the United States' first manned spaceflights J. K. Golovanov, M. "Korolev: Facts and myths", Nauka, 1994, ISBN 5-02-000822-2.
ISBN 5-217-02942-0. I. Ostashev, Korolyov, 2001.. Korolev. Yangel." - M. I. Kuznetsk, Voronezh: IPF "Voronezh", 1997, ISBN 5-89981-117-X. Notes of a military engineer" - Rjazhsky A. A. 2004, SC. first, the publishing house of the "Heroes of the Fatherland" ISBN 5-91017-018-X. "Rocket and space feat Baikonur" - Vladimir Порошков, the "Patriot" publishers 2007. ISBN 5-7030-0969-3 "Unknown Baikonur" - edited by B. I. Posysaeva, M.: "globe", 2001. ISBN 5-8155-0051-8 "Bank of the Universe" - edited by Boltenko A. C. Kiev, 2014. Publishing house "Phoenix", ISBN 978-966-136-169-9
Venera 4 designated 1V s/n 310 was a probe in the Soviet Venera program for the exploration of Venus. The probe comprised an entry probe, designed to enter the Venus atmosphere and parachute to the surface, a carrier/flyby spacecraft, which carried the entry probe to Venus and served as a communications relay for the entry probe. In 1967 it was the first successful probe to perform in-place analysis of the environment of another planet, it may have been the first probe to land on another planet, with the fate of its predecessor Venera 3 being unclear. Venera 4 provided the first chemical analysis of the Venusian atmosphere, showing it to be carbon dioxide with a few percent of nitrogen and below one percent of oxygen and water vapors; the station detected no radiation field. The outer atmospheric layer contained little hydrogen and no atomic oxygen; the probe sent the first direct measurements proving that Venus was hot, that its atmosphere was far denser than expected, that it had lost most of its water long ago.
The main carrier spacecraft 4 stood 3.5 metres high, its solar panels spanned 4 metres and had an area of 2.5 square metres. The carrier spacecraft included a 2-meter long magnetometer, an ion detector, a cosmic ray detector and an ultraviolet spectrometer capable of detecting hydrogen and oxygen gases; the devices were intended to operate until entry into the Venusian atmosphere. At that juncture, the station was designed to release the probe disintegrate; the rear part of the carrier spacecraft contained a liquid-fuel thruster capable of correcting the flight course. The flight program was planned to include two significant course corrections, for which purpose the station could receive and execute up to 127 different commands sent from the Earth; the front part of the carrier spacecraft contained a nearly spherical landing capsule 1 metre in diameter and weighing 383 kilograms. Compared to previous Venera probes, the capsule contained an improved heat shield which could withstand temperatures up to 11,000 °C.
Instead of the previous liquid-based cooling design, a simpler and more reliable gas system was installed. The durability of the capsule was checked by exposing it to high temperatures and accelerations using three unique testing installations; the heat resistance was checked in a high-temperature vacuum system emulating the upper layers of the atmosphere. The capsule was pressurized up to 25 atmospheres, it was subjected to accelerations of up to 450 g in a centrifuge. The centrifuge test caused cracking of electronic components and cable brackets, which were replaced shortly before launch; the timing for launch was rather tight, so as not to miss the launch window—the days of the year when the path to the destination planet from Earth is energetically least demanding. The capsule could float in case of a water landing. Considering the possibility of such a landing, its designers made the lock of the capsule using sugar; the capsule contained a newly developed vibration-damping system, its parachute could resist temperatures up to 450 °C.
The capsule contained an altimeter, thermal control, a parachute and equipment for making atmospheric measurements. The latter included a thermometer, hydrometer, altimeter and a set of gas analysis instruments; the data were sent by two transmitters at a rate of 1 bit/s. The transmitters were activated by the parachute deployment as soon as the outside pressure reached 0.6 standard atmospheres, thought to occur at the altitude about 26 kilometres above the surface of the planet. The signals were received including the Jodrell Bank Observatory; the capsule was equipped with a rechargeable battery with a capacity sufficient for 100 minutes of powering the measurement and transmitter systems. To avoid becoming discharged during the flight to Venus, the battery was kept charged using the solar panels of the carrier spacecraft. Before the launch, the entire Venera 4 station was sterilized to prevent possible biological contamination of Venus. Two nominally identical 4V-1 probes were launched in June 1967.
The first probe, Venera 4, was launched on 12 June by a Molniya-M carrier rocket flying from the Baikonur Cosmodrome. A course correction was performed on 29 July. Although two such corrections had been planned, the first one was accurate enough and therefore the second correction was canceled. On 18 October 1967, the spacecraft entered the Venusian atmosphere with an estimated landing place near 19°N 38°E; the second probe, Kosmos 167, was failed to depart low Earth orbit. During entry into the Venusian atmosphere, the heat shield temperature rose to 11,000 °C and at one point the cabin deceleration reached 300 G; the descent lasted 93 minutes. The capsule deployed its parachute at an altitude of about 52 kilometres, started sending data on pressure and gas composition back to Earth; the temperature control kept the inside of the capsule at −8 °C. The temperature at 52 km was recorded as 33 °C, the pressure as less than 1 standard atmosphere. At the end of the 26-km descent, the temperature reached 262 °C and pressure increased to 22 standard atmospheres, the signal transmission terminated.
The atmospheric compo