The escape stage entered parking orbit but the main engine cut off just 0.8 s after ignition due to cavitation in the oxidiser pump and pump failure.. The payload attached together with escape stage remained in Earth orbit.

The booster launched into a beautiful clear sky, and it could be followed by the naked eye for four minutes after launch. The third stage reached earth parking orbit, but the fourth stage didn't ignite. It was at first believed a radio antenna did not deploy from the interior of the stage, and it did not receive the ignition commands. Therefore the Soviet Union has successfully orbited a record eight-tonne 'Big Zero' into orbit. The State Commission meets two hours after the launch, and argues whether to make the launch public or not, and how to announce it. Glushko proposes the following language for a public announcement: 'with the objective of developing larger spacecraft, a payload was successfully orbited which provided on the first revolution the necessary telemetry'. Korolev and the others want to minimize any statement, to prevent speculation that it was a reconnaissance satellite or a failed manned launch. Kamanin's conclusion - the rocket didn't reach Venus, but it did demonstrated a new rocket that could deliver an 8 tonne thermonuclear warhead anywhere on the planet. The commission heads back to Moscow.

Venera 1 was the first spacecraft to fly by Venus. The 6424 kg assembly was launched first into a 229 x 282 km parking orbit, then boosted toward Venus by the restartable Molniya upper stage. On 19 February, 7 days after launch, at a distance of about two million km from Earth, contact with the spacecraft was lost. On May 19 and 20, 1961, Venera 1 passed within 100,000 km of Venus and entered a heliocentric orbit. This failure resulted in only the following objectives being met: checking of methods of setting space objects on an interplanetary course; checking of extra-long-range communications with and control of the space station; more accurate calculation of the dimension of the solar system; a number of physical investigations in space. Additional Details: here....

Attempt to launch a probe towards Mars. The launch went well, but the fourth stage motor burnt for only 45s of the planned 240s. The stage remained in Earth orbit. However Kamanin notes that it was good that the launch of the basic vehicle was a success - it gave the visiting female cosmonauts confidence in the rocket they will have to ride.

Mariner 2 was the first spacecraft to successfully flyby another planet. It was a backup for the Mariner 1 mission which failed shortly after launch to Venus. After launch and termination of the Agena first burn, the Agena-Mariner was in a 118 km altitude Earth parking orbit. The Agena second burn injected the Mariner 2 spacecraft into a geocentric escape hyperbola at 26 minutes 3 seconds after lift-off. Solar panel extension was completed about 44 minutes after launch. On 29 August 1962 cruise science experiments were turned on. A midcourse maneuver was initiated at 22:49:00 GMT on 4 September and completed at 2:45:25 GMT 5 September. On 8 September at 17:50 GMT the spacecraft suddenly lost its attitude control, which was restored by the gyroscopes 3 minutes later. The cause was unknown but may have been a collision with a small object. On October 31 the output from one solar panel deteriorated abruptly, and the science cruise instruments were turned off. A week later the panel resumed normal function and instruments were turned back on. The panel permanently failed on 15 November, but Mariner 2 was close enough to the Sun that one panel could supply adequate power. On December 14 the radiometers were turned on. Mariner 2 approached Venus from 30 degrees above the dark side of the planet, and passed below the planet at its closest distance of 34,773 km at 19:59:28 GMT 14 December 1962. After encounter, cruise mode resumed. Spacecraft perihelion occurred on 27 December at a distance of 105,464,560 km. The last transmission from Mariner 2 was received on 3 January 1963 at 07:00 GMT. Mariner 2 remains in heliocentric orbit. Scientific discoveries made by Mariner 2 included a slow retrograde rotation rate for Venus, hot surface temperatures and high surface pressures, a predominantly carbon dioxide atmosphere, continuous cloud cover with a top altitude of about 60 km, and no detectable magnetic field. It was also shown that in interplanetary space the solar wind streams continuously and the cosmic dust density is much lower than the near-Earth region. Improved estimates of Venus' mass and the value of the astronomical unit were made.

Mars probe intended to make a soft landing on Mars. Although the escape stage and payload reached orbit, the strong third stage vibrations shook a fuse loose from its mount in the main nozzle of the escape stage Block L's engine. The engine could not be ignited and remained in Earth orbit. It decayed about two months after insertion.

Venera 2 was launched towards the planet Venus and carried a TV system and scientific instruments. On February 27, 1966, the spacecraft passed Venus at a distance of 24,000 km and entered a heliocentric orbit. The spacecraft system had ceased to operate before the planet was reached and returned no data.

Venera 3 was launched towards the planet Venus. The mission was to land on the Venusian surface. The entry vehicle contained a radio communication system, scientific instruments, electrical power sources, and medallions bearing the coat of arms of the U.S.S.R. The station impacted Venus on March 1, 1966. However, the communications systems had failed before planetary data could be returned.

Venera 4 was successfully launched towards the planet Venus with the announced mission of direct atmospheric studies. On October 18, 1967, the descent vehicle entered the Venusian atmosphere. Signals were returned by the spacecraft, which deployed a parachute after braking to subsonic velocity in the Venusian atmosphere, until it reached an altitude of 24.96 km.

Mariner 5 flew by Venus on October 19, 1967 at an altitude of 3,990 kilometres. With more sensitive instruments than its predecessor Mariner 2, Mariner 5 was able to shed new light on the hot, cloud-covered planet and on conditions in interplanetary space. Operations of Mariner 5 ended in November 1967. The spacecraft instruments measured both interplanetary and Venusian magnetic fields, charged particles, and plasmas, as well as the radio refractivity and UV emissions of the Venusian atmosphere.

Suggestions for the cause of the failure included incorrect soldering of wires in multiple pin plugs, wrong attachments of the plugs to the pyrotechnic connectors, or a mix-up of the pyrotechnic connectors during assembly.. Investigation of the upper atmosphere and outer space.

Venera 5 is launched at 9:26 Moscow time from LC-31 in -23 deg C temperatures. All proceeds according to plan. Afterwards Kamanin meets Babakin. Venera 6 is planned for launch in 10 January. He also plans two moon landings in 1969 and two in 1970 of soil sample return spacecraft. Kamanin does not believe America can achieve a manned moon landing in 1969, and therefore that Babakin has a very good chance of stealing their thunder.

Meanwhile Venera 5 was launched from its parking orbit towards Venus to obtain atmospheric data. The spacecraft was very similar to Venera 4 although it was of a stronger design. When the atmosphere of Venus was approached, a capsule weighing 405 kg and containing scientific instruments was jettisoned from the main spacecraft. During satellite descent towards the surface of Venus, a parachute opened to slow the rate of descent. For 53 min on May 16, 1969, while the capsule was suspended from the parachute, data from the Venusian atmosphere were returned. The spacecraft also carried a medallion bearing the coat of arms of the U.S.S.R. and a bas-relief of V.I. Lenin to the night side of Venus.

Venera 6 was launched towards Venus to obtain atmospheric data. When the atmosphere of Venus was approached, a capsule weighing 405 kg was jettisoned from the main spacecraft. This capsule contained scientific instruments. During descent towards the surface of Venus, a parachute opened to slow the rate of descent. For 51 min on May 17, 1969, while the capsule was suspended from the parachute, data from the Venusian atmosphere were returned. The spacecraft also carried a medallion bearing the coat of arms of the U.S.S.R. and a bas-relief of V.I. Lenin to the night side of Venus.

Venera 7 was launched from an earth parking orbit towards Venus to study the Venusian atmosphere and other phenomena of the planet. Venera 7 entered the atmosphere of Venus on December 15, 1970, and a landing capsule was jettisoned. After aerodynamic braking, a parachute system was deployed. The capsule antenna was extended, and signals were returned for 35 min. Another 23 min of very weak signals were received after the spacecraft landed on Venus. The capsule was the first man-made object to return data after landing on another planet.

Venus atmospheric probe. The spacecraft took 117 days to reach Venus, entering the atmosphere on 22 July 1972. Descent speed was reduced from 41,696 km/hr to about 900 km/hr by aerobraking. The 2.5 meter diameter parachute opened at an altitude of 60 km, and a refrigeration system was used to cool the interior components. Venera 8 transmitted data during the descent and continued to send back data for 50 minutes after landing. The probe confirmed the earlier data on the high Venus surface temperature and pressure returned by Venera 7, and also measured the light level as being suitable for surface photography, finding it to be similar to the amount of light on Earth on an overcast day.

Combined Venus orbiter/lander mission. After separation of the lander, the orbiter spacecraft entered Venus orbit and acted as a communications relay for the lander and explored cloud layers and atmospheric parameters. On October 20, 1975, the Descent Craft was separated from the Orbiter, and landing was made with the sun near zenith at 05:13 GMT on October 22. The Descent Craft included a system of circulating fluid to distribute the heat load. This system, plus precooling prior to entry, permitted operation of the spacecraft for 53 min after landing. The landing was about 2,200 km from the Venera 10 landing site. Preliminary results indicated: (A) clouds 30-40 km thick with bases at 30-35 km altitude, (B) atmospheric constituents including HCl, HF, Br, and I, (C) surface pressure about 90 (earth) atmospheres, (D) surface temperature 485 deg C, (E) light levels comparable to those at earth midlatitudes on a cloudy summer day, and (F) successful TV photography showing shadows, no apparent dust in the air, and a variety of 30-40 cm rocks which were not eroded. Venera 9 and 10 were the first probes to send back black and white pictures from the Venusian surface. They were supposed to make 360 degree panoramic shots, but on both landers one of two camera covers failed to come off, restricting their field of view to 180 degrees. Parameters are for Venus orbit.

The orbiter spacecraft entered Venus orbit and was separated from the lander on October 23, 1975. The lander touched down with the sun near zenith, at 05:17 GMT, 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, and a compressible, metal, doughnut-shaped, landing cushion. The landing was about 2,200 km distant from Venera 9. Preliminary results provided: (A) profile of altitude (km)/pressure (earth atmospheres) / temperature (deg C) of 42/3.3/158, 15/37/363, and 0/92/465, (B) successful TV photography showing large pancake rocks with lava or other weathered rocks in between, and (C) surface wind speed of 3.5 m/s. Venera 9 and 10 were the first probes to send back black and white pictures from the Venusian surface. They were supposed to make 360 degree panoramic shots, but on both landers one of two camera covers failed to come off, restricting their field of view to 180 degrees.

The Pioneer Venus Orbiter was inserted into an elliptical orbit around Venus on December 4, 1978. After entering orbit around Venus in 1978, the spacecraft returned global maps of the planet's clouds, atmosphere and ionosphere, measurements of the atmosphere-solar wind interaction, and radar maps of 93 percent of the planet's surface. Additionally, the vehicle made use of several opportunities to make systematic UV observations of several comets. From Venus orbit insertion to July 1980, periapsis was held between 142 and 253 km (at 17 degrees north latitude) to facilitate radar and ionospheric measurements. The spacecraft was in a 24 hour orbit with an apoapsis of 66,900 km. Thereafter, the periapsis was allowed to rise (to 2290 km at maximum) and then fall, to conserve fuel. In 1991 the Radar Mapper was reactivated to investigate previously inaccessible southern portions of the planet. In May 1992 Pioneer Venus began the final phase of its mission, in which the periapsis was held between 150 and 250 km until the fuel ran out and atmospheric entry destroyed the spacecraft. With a planned primary mission duration of only eight months, the spacecraft remained in operation until October 8, 1992 when it finally burned up in Venus' atmosphere after running out of propellant.

The Pioneer Venus Multiprobe consisted of a bus which carried one large and three small `atmospheric probes. The large probe was released on November 16, 1978 and the three small probes on November 20. All four probes entered the Venus atmosphere on December 9, followed by the bus. The small probes were each targeted at different parts of the planet and were named accordingly. The North probe entered the atmosphere at about 60 degrees north latitude on the day side. The night probe entered on the night side. The day probe entered well into the day side, and was the only one of the four probes which continued to send radio signals back after impact, for over an hour. With no heat shield or parachute, the bus survived and made measurements only to about 110 km altitude before burning up. It afforded the only direct view of the upper Venus atmosphere, as the probes did not begin making direct measurements until they had decelerated lower in the atmosphere.

Venera 11 was part of a two-spacecraft mission to study Venus and the interplanetary medium. Each of the two spacecraft, Venera 11 and Venera 12, consisted of a flight platform and a lander probe. Identical instruments were carried on both spacecraft. Venera 11 was launched into a 177 x 205 km, 51.5 degree inclination earth orbit from which it was propelled into a 3.5 month Venus transfer orbit. 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 approximately 34,000 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. The Venera 11 descent craft separated from its flight platform on December 23, 1978 and entered the Venus atmosphere two days later at 11.2 km/sec. 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 approximately 1 hour. The touchdown speed was 7-8 m/s.

Both Venera 11 and 12 landers failed to return colour television views of the surface and perform soil analysis experiments. All of the camera protective covers failed to eject after landing (the cause was not established) The soil drilling experiment was apparently damaged by a leak in the soil collection device, the interior of which was exposed to the high Venusian atmospheric pressure. The leak had probably formed during the descent phase because the lander was less aerodynamically stable than had been thought.

Two further experiments on the lander failed as well. Results reported included evidence of lightning and thunder, a high Ar36/Ar40 ratio, and the discovery of carbon monoxide at low altitudes.

Venera 12 was part of a two-spacecraft mission to study Venus and the interplanetary medium. Each of the two spacecraft, Venera 11 and Venera 12, consisted of a flight platform and a lander probe. Identical instruments were carried on both spacecraft. Venera 12 was launched into a 177 x 205 km, 51.5 degree inclination Earth orbit from which it was propelled into a 3.5 month Venus transfer orbit which involved two mid-course corrections, on 21 September and 14 December. After ejection of the lander probe on 19 December, two days before encounter, the flight platform continued on past Venus in a heliocentric orbit. Near encounter with Venus occurred on December 21, 1978, at approximately 34,000 km altitude. The flight platform acted as a data relay for the descent craft for 110 minutes until it flew out of range and returned to its own measurements on interplanetary space. The Venera 12 descent craft entered the Venus atmosphere at 11.2 km/sec two days after separation from the flight bus. 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.

Both Venera 11 and 12 landers failed to return colour television views of the surface and perform soil analysis experiments. All of the camera protective covers failed to eject after landing (the cause was not established) The soil drilling experiment was apparently damaged by a leak in the soil collection device, the interior of which was exposed to the high Venusian atmospheric pressure. The leak had probably formed during the descent phase because the lander was less aerodynamically stable than had been thought. Therefore the landing gear of the following two landers (Venera-13/14) were equipped with tooth-shaped stabilisers.

Results reported included evidence of lightning and thunder, a high Ar36/Ar40 ratio, and the discovery of carbon monoxide at low altitudes.

The Venera-12 flyby bus continued in solar orbit and successfully used its Soviet-French ultraviolet spectrometer to study Comet Bradfield on 13 February 1980 (one year and two months after its Venus encounter). At that time the spacecraft was 190,373,790 km from Earth.

Venera 13 and 14 were identical spacecraft built to take advantage of the 1981 Venus launch opportunity and launched 5 days apart. After launch and a four month cruise to Venus, the descent vehicle separated and plunged into the Venus atmosphere on 1 March 1982. As it flew by Venus the bus acted as a data relay for the brief life of the descent vehicle, and then continued on into a heliocentric orbit. After the descent vehicle braked to subsonic speed a parachute was deployed. At an altitude of 47 km the parachute was released and simple airbraking was used the rest of the way to the surface. Venera 13 landed about 950 km northeast of Venera 14 at 7 deg 30 min S, 303 E, just east of the eastern extension of an elevated region known as Phoebe Regio. The area was composed of bedrock outcrops surrounded by dark, fine-grained soil. After landing an imaging panorama was started and a mechanical drilling arm reached to the surface and obtained a sample, which was deposited in a hermetically sealed chamber, maintained at 30 degrees C and a pressure of about .05 atmospheres. The composition of the sample, as determined by the X-ray flourescence spectrometer, put it in the class of weakly differentiated melanocratic alkaline gabbroids. The lander survived for 127 minutes (the planned design life was 32 minutes) in an environment with a temperature of 457 degrees C and a pressure of 84 Earth atmospheres. The bus carried instruments built by Austrian and French specialists, as well as Soviet scientific equipment.

Venera 13 and 14 were identical spacecraft built to take advantage of the 1981 Venus launch opportunity and launched 5 days apart. After launch and a four month cruise to Venus, the descent vehicle separated and plunged into the Venus atmosphere on 5 March 1982. As it flew by Venus the bus acted as a data relay for the brief life of the descent vehicle, and then continued on into a heliocentric orbit. The parachute of the descent vehicle opened after the lander reached subsonic speed. At an altitude of about 50 km the parachute was released and simple airbraking was used the rest of the way to the surface. Venera 14 landed about 950 km southwest of Venera 13 near the eastern flank of Phoebe Regio at 13 deg 15 min S by 310 E on a basaltic plain. After landing an imaging panorama was started It has been reported that the surface analysis arm accidentally landed on one of the ejected camera covers and therefore didn't send back any data on the Venusian soil. This is visible in photographs sent back. On the other hand, the official account very specifically states that the mechanical drilling arm obtained a sample, which was deposited in a hermetically sealed chamber, maintained at 30 degrees C and a pressure of about .05 atmospheres. The composition of the sample was determined by the X-ray flourescence spectrometer, showing it to be similar to oceanic tholeiitic basalts. The lander survived for 57 minutes (the planned design life was 32 minutes) in an environment with a temperature of 465 degrees C and a pressure of 94 Earth atmospheres.

Venera 15 was part of a two spacecraft mission (along with Venera 16) designed to use side-looking radar mappers to study the surface properties of Venus. The two spacecraft were inserted into Venus orbit a day apart with their orbital planes shifted by an angle of approximately 4 degrees relative to one another. This made it possible to reimage an area if necessary. Each spacecraft was in a nearly polar orbit with a periapsis at 62 N latitude. Together, the two spacecraft imaged the area from the north pole down to about 30 degrees N latitude over the 8 months of mapping operations. Data is for Venus orbit.

Venus radar mapper; entered Venus orbit 10/14/83. Venera 16 was part of a two spacecraft mission (along with Venera 15) designed to use side-looking radar mappers to study the surface properties of Venus. The two spacecraft were inserted into Venus orbit a day apart with their orbital planes shifted by an angle of approximately 4 degrees relative to one another. This made it possible to reimage an area if necessary. Each spacecraft was in a nearly polar orbit with a periapsis at 62 N latitude. Together, the two spacecraft imaged the area from the north pole down to about 30 degrees N latitude over the 8 months of mapping operations.

Investigations of the planet Venus and Halley's Comet. The APV-V plasma antenna did not deploy until the first mid-course correction burn. Deployed lander and balloon at Venus on June 19 1985. Rendezvoused with comet Halley on March 6, 1986. Fitted with scientific apparatus and equipment built in the USSR, Austria, Bulgaria, Hungary, German Democratic Republic, Poland, France, Federal Republic of Germany and C zechoslovakia.

Investigations of the planet Venus and Halley's Comet. The APV-V plasma antenna did not deploy until the first mid-course correction burn. Deployed lander and balloon at Venus on June 14, 1985. The surface experiments of the lander failed to send back data because they were inadvertently switched on at an altitude of 20 km. Apparently high winds activated a G-force sensor that was to automatically switch on the surface package after the jolt of touchdown. The bus continued in heliocentric orbit and rendezvoused with comet Halley on March 9, 1986. The images of the comet were nearly lost when a television sensor failed shortly before the flyby. A back-up sensor was activated just in time. Fitted with scientific apparatus and equipment built in the USSR, Austria, Bulgaria, Hungary, German Democratic Republic, Poland, France, Federal Republic of Germany and C zechoslovakia.

SAR radar imaging of the Venusian surface, gravitational field mapping. The Magellan spacecraft was deployed from shuttle STS-30 on May 5, 1989, arrived at Venus on August 10, 1990 and was inserted into a near-polar elliptical orbit with a periapsis altitude of 294 km at 9.5 deg. N. The primary objectives of the Magellan mission were to map the surface of Venus with a synthetic aperture radar (SAR) and to determine the topographic relief of the planet. At the completion of radar mapping 98% of the surface was imaged at resolutions better than 100 m, and many areas were imaged multiple times. The mission was divided up into 'cycles', each cycle lasted 243 days (the time necessary for Venus to rotate once under the Magellan orbit - i.e. the time necessary for Magellan to 'see' the entire surface once.) The mission proceeded as follows: 10 Aug 1990 - Venus orbit insertion and spacecraft checkout;15 Sep 1990 - Cycle 1: Radar mapping (left-looking); 15 May 1991 - Cycle 2: Radar mapping (right-looking); 15 Jan 1992 - Cycle 3: Radar mapping (left-looking); 14 Sep 1992 - Cycle 4: Gravity data acquisition; 24 May 1993 - Aerobraking to circular orbit; 3 Aug 1993 - Cycle 5: Gravity data acquisition; 30 Aug 1994 - Windmill experiment; 12 Oct 1994 - Loss of radio signal; 13 Oct 1994 - Loss of spacecraft. A total of 4225 usable SAR imaging orbits was obtained by Magellan. Magellan showed an Earth-sized planet with no evidence of Earth-like plate tectonics. At least 85% of the surface is covered with volcanic flows, the remainder by highly deformed mountain belts. Even with the high surface temperature (475 C) and high atmospheric pressure (92 bars), the complete lack of water makes erosion a negligibly slow process, and surface features can persist for hundreds of millions of years. Some surface modification in the form of wind streaks was observed. Over 80% of Venus lies within 1 km of the mean radius of 6051.84 km. The mean surface age is estimated to be about 500 million years. A major unanswered question concerns whether the entire surface was covered in a series of large events 500 million years ago, or if it has been covered slowly over time. The gravity field of Venus is highly correlated with the surface topography, which indicates the mechanism of topographic support is unlike the Earth, and may be controlled by processes deep in the interior. Details of the global tectonics on Venus were still unresolved.

Launch delayed from October 26. The Soyuz placed the probe and Fregat upper stage into a 30 km x 190 km x 51.6 deg orbit around the earth. At apogee the Fregat stage made a 50 m/s maneuver to circularize the orbit. At the appropriate moment in this parking orbit, the Fregat fired again, then separated from the now Venus-bound probe at 05:11 GMT. Venus Express passed lunar orbit on November 10 at 10:10 GMT and went into a 0.702 AU x 0.993 AU x 0.26 deg inclination solar orbit. It was to brake itself into a 250 km x 326,550 km x 89.7 deg orbit around Venus on 11 April 2006 at 08:40 GMT. Two maneuvers would put in its final 24-hour Venus orbit of 282 x 66,911 km x 90.0 deg on 30 April. This was selected to synchronise the satellite with tracking stations on earth, while the planet slowly revolves below its perigee point over the following several months.