Soviet (Венера) Venera Space Program 1970-1982: Venera 7-14

The Soviet Venus “Venera” Space Program 1970 – 1982 Venera Missions 7-14

Table of Contents

1. Overview
2. Appendix 1 Figure 1.1 Venera 13 lander 1.2 Basic Venera Data/Further Reading 1.3 Communication Duration Analysis 1.4 Tool/Experiment Inventory 1.5 : DATASHEETS “Venera 7-14” (English) published by Lavochkin (manufacturer) translated by David Grunwald

1. Overview

From 1970 to 1982, the Soviet Union launched 7 orbital landers to the Venusian surface.   This paper is an overview of these missions. To be sure, the Venera program (Venus in Russian) was part of the Cold War “space race” and it may be that political considerations played a role in the lander launch times and the mission objectives.  Finally, it may be interesting to note the cost and benefits of such a program in social, political and economic dimensions.

The Venera program, meaning “Venus” in Russian, is a fascinating piece of Cold War history and not covered extensively in the West.  Many people don’t realize that the Soviet Union was sending data and color pictures back to earth from the Venusian surface.  It had never been done before, and has never been done since.

Venus travel is frought with heat, time, space and distance challenges.  Launch dates and landing dates will inform about the total time in transit which may impact equipment due to radiation exposure, heat, movement, fluid/lubricant evaporation and lack of water.  Further investigation of the correlation may yield important insight into the routes taken and the effect on equipment.  The equipment itself, and the effects of the journeys may yield useful information about the nature of space travel.  Certainly, the multiple lens failures on Venera 11, 12 can be a useful reminder of the importance of planning for failures and recovery.  In this way, the failures and attempts to address are key to addressing the testing cycles in spacecraft

In an effort to reach Venus, the spacecrafts experienced many failures including crash landing on to the surface.  It appears that by Venera 7, the Soviets had developed a method to launch consistently and learn from earlier failures.  A cycle of continuous adaptation based on data confirmation and trial and error commenced.   New equipment requirements also drove change.  For example, the increase use of scientific equipment resulted in a change out of cadmium-nickel batteries for lead-zinc which were charged by solar batteries 15 days before landing.(1)

Each mission had added to the understanding of Venus and had important design implications.  According to the Lavochkin manufacturer, experiments on Venera 7 were a result of findings from Venera 5 and 6 missions.  The wind speeds were calculated at 1.5 m/s which apparently factored into the redesign of the landers.  It is interesting to note that atmospheric pressure was also major concern.  Also, the surface operation requirement seems to have been set a 30 minutes as early as Venera 7.   The parachute/braking system improvements were also factored as time of the descent vehicle played a key role in operations.  In an extremely hot environment, every second counted.

The Lavochkin site states “based on these accepted conditions, a fundamentally new lander was designed. It had to withstand pressure six times higher than the Venera-5 and Venera- landers.  Another requirement was that the lander had to work on the surface at maximum pressure for at least 30 minutes.”(2)

Sometimes landers were sent as pairs or had different flight plans.  Unlike earlier missions, Venera 8 was programmed to land on the day side of Venus (light).  Atmospheric and temperature confirmation made by Venera 7 led to adjustments in the thickness of the instrument compartment in the Venera 8 mission.(3)  Venera 8 confirmed clouds in the atmosphere and sufficient sunlight for photographs.  Important adjustments were made to the antenna (narrow pattern) and landing considerations to enhance radio communication between the orbiter and earth.  Venera 8 provided the first measurements of the surface regolith of Venus, and a profile of the cloud layer, including detection of sulfuric acid, was made.(4) The Venera Missions 9 and 10 were complete redesigns based on the errors of Venera 7 and 8.   In addition to compartment designs, heat control mechanisms were implemented after freeing up weight by reducing the weight of the landing gear.  Beryllium shells were installed along with heat accumulators.(5)

According the Lavochkin data sheet, the Venera 9 and 10 landers separated from their orbiters 2 days prior to landing on the Venusian surface.  The reasons for this procedure was not entirely clear.

Venera 11 and 12 repeated the paths taken by 8 and 9.  Before and after Venus flyby, Venera 11 and Venera 12 yielded detailed time-profiles for 143 gamma ray bursts, resulting in the first ever catalog of such events.  Also, the exclusion of the three-dome main parachute used in the Venera 9-10 missions reduced the descent time by 15 minutes.(6)  This is yet another way to accommodate the heat and provide for time for the instruments to relay valuable information from the planet surface.

Changes in design appeared to correlate to longer lander time on the planet; however, this was not conclusive as design times for the later probes (Venera 13,14) record a design intention of 32 minutes which Venera 13 exceeded by a 100%.  This discrepancy has never been fully explained as both models were recorded as identical.  This can mean other factors, including spacecraft construction, materials and travel routes/landing experiences may have differed.  Isolating the differences between Venera 13 and 14 would offer a valuable insight into performance variances in space travel.

According to the Lavochkin website, “the landing sites were chosen in such a way as to determine the nature of the relief and rocks of the most typical geological and morphological provinces of the planet.”(7)

The standard mean between the durations was 32.62 minutes and the overall operations mean 72.5 minutes on the venusian surface.    The Soviets needed to address the problem of extreme heat (~872 degrees) which is hot enough to melt lead.   How did the Soviets beat the heat?  Sources are not clear.  Early missions utilized heat load distribution and pre-cooling.  There appears to have been tradeoffs made between pre-cooling (Venera 7 -8° C, Venera 8 -15° C) and building for withstanding atmospheric pressure.   Between the 7 and 8 missions the atmospheric pressure design was reduced from 180 atmospheric pressures to 105.  Venera 9 and 10 (1975) was cooled to -10° C before separating from the bus, and the interior temperature rose to 60° C after an hour on the surface. Mission lifetime was limited by loss of radio contact, not thermal failure.   These early Soviet experiences appear to have driven the recent U.S. testing at NASA’s Glenn Research Center with the usage of silicon carbide semiconductor integrated circuits to function for extended periods in high heat environments.

For Venera 9 and 10, the core of the descent vehicle was a spherical titanium hull about 80 cm in diameter. It was formed in several sections, bolted and sealed with gold-wire gaskets. That was covered in a 12 cm layer of thermal insulation (a composite honeycomb material) and a thin outer skin of titanium. The pressure hull was lined inside with insulation, possibly layers of fiberglass and metal foil. A large thermal accumulator of lithium nitrate trihydrate and a circulating fan distributed and absorbed excess heat.

In later missions, Soviet engineers had developed new heat-resistant materials and electronics that were comfortable in this working environment. Exotic lubricants, based on molybdenum disulphide and microscopic metal flakes, were designed to function at high pressures and temperatures up to 1000° C.

Over 12 years of exploration, 9.6 hours spent on the planet surface, with the mean time spent per mission of 72 minutes and 30 seconds.  The maximun time spent was 127 minutes (Venera 13) with the shortest time 5 minutes, 38 seconds (Venera 7).

Interesting questions remain.  Venera 13 and 14 were identical spacecraft, both designed to work 32 minutes.  And while both transmitted over the design limit, Venera 13 continued to work twice as long – in fact the longest duration of all Venera spacecraft) in a similar landing area around 591 miles apart – east of Phoebe Regio region.  Both craft landed within 2 days of each other the only other difference being the land time 3:57UTC and 7:00UTC respectively.

(1) http://www.laspace.ru/projects/planets/venera-7/  Автоматическая межпланетная     станция «Венера-7» trans. by David Grunwald

(2) ibid

(3)  https://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=1972-021A 9/23/2017

(4) http://www.laspace.ru/projects/planets/venera-8/ станция «Венера-8» trans. by David Grunw

(5) ibid

(6) http://www.laspace.ru/projects/planets/venus13-14/ Автоматическая межпланетная станция «Венера-13-14» trans. by David Grunwald

(7) ibid

Appendix:

1.1 Venera 13 Lander.  The design was similar to the earlier Venera 9-12 landers

1.2 The following table shows basic information available on the Venera missions.  The eight Venera mission 7-14 provide some data on the communication duration.

1.3 Duration data analyzing communication duration using Python’s pandas module for computation.

With Python’s  datetime module, determining time of travel is easy.   The travel times differ which in itself can be an interesting study.

from datetime import datetime

Venera7 = datetime(1970, 12, 15) – datetime(1970, 8, 17) V7_days = Venera7.days print(“Venera 7 – Days in transit: %d ” % V7_days)

Venera8 = datetime(1972, 7, 22) – datetime(1972, 3, 27) V8_days = Venera8.days print(“Venera 8 – Days in transit: %d ” % V8_days)

Venera9 = datetime(1975, 10, 22) – datetime(1975, 6, 8) V9_days = Venera9.days print(“Venera 9 – Days in transit: %d ” % V9_days)

Venera10 = datetime(1975, 10, 25) – datetime(1975, 6, 14) V10_days = Venera10.days print(“Venera 10 – Days in transit: %d ” % V10_days)

Venera11 = datetime(1978, 12, 25) – datetime(1978, 9, 9) V11_days = Venera11.days print(“Venera 11 – Days in transit: %d ” % V11_days)

Venera12 = datetime(1978, 12, 15) – datetime(1978, 9, 14) V12_days = Venera12.days print(“Venera 12 – Days in transit: %d ” % V12_days)

Venera13 = datetime(1982, 3, 1) – datetime(1981, 10, 30) V13_days = Venera13.days print(“Venera 13 – Days in transit: %d ” % V13_days)

Venera14 = datetime(1982, 3, 3) – datetime(1981, 11, 4) V14_days = Venera14.days print(“Venera 14 – Days in transit: %d ” % V14_days)

total_travel_days = V7_days + V8_days + V9_days + V10_days + V11_days + V12_days + V13_days + V14_days

print(“Total travel days for all missions: %d” % total_travel_days)

Venera 7 – Days in transit: 120 Venera 8 – Days in transit: 117 Venera 9 – Days in transit: 136 Venera 10 – Days in transit: 133 Venera 11 – Days in transit: 107 Venera 12 – Days in transit: 92 Venera 13 – Days in transit: 122 Venera 14 – Days in transit: 119 Total travel days for all missions: 946

The availability of .kml files and the Magellan mapping of Venus offer the researcher an ability to study the surface and the Venera missions closely.     The instrumented data from the Venera landings has yet to be made publically available.   Analysis of this data will be useful in framing questions and promoting a deeper understanding of planetary exploration.

Further Reading:

Maps

https://planetarynames.wr.usgs.gov/Feature/673;jsessionid=4CC38903EAD54A764112DFDB59A78747

https://developers.google.com/kml/documentation/kml_tut

https://www.google.com/maps/d/u/0/  (Bell Regio)

https://www.nasa.gov/press-release/nasa-glenn-demonstrates-electronics-for-longer-venus-surface-missions

Pictures

http://mentallandscape.com/C_CatalogVenus.htm  (Don Mitchell)

https://www.space.com/18551-venera-13.html

Overview

http://mentallandscape.com/V_Venus.htm

Python (Data Science Tools)

Python’s pandas and numpy/SciPy modules.  Wes McKinney’s book “Python for Data Analysis” is currently being revised for a second edition (available October 2017).  http://shop.oreilly.com/product/0636920023784.do

1.4 Venera 7-14 Tool/Experiment Inventory on Landers

Venera 7

temerature (surface) 887 F atmospheric 97% carbon dioxide

Venera 8

temperature pressure light sensors altimeter gamma ray spectrometer gas analyzer radio transmitters (one or two?)

Lander Payload:

Temperature and pressure sensors – ITD Accelerometer – DOU-1M Photometers – IOV-72 Ammonia analyser – IAV-72 Gamma ray spectrometer – GS-4 Radar altimeter Radio Doppler experiment

Venera 9 (first photographs transmitted from surface)

cloud measurements atmospheric chemicals including hydrochloric acid, hydrofluoric acid, bromine and iodine. Other measurements included surface pressure of about 9,100 kilopascals (90 atm), temperature of 485 °C (905 °F), and surface light levels comparable to those at Earth mid-latitudes on a cloudy summer day.

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 (2, with lamps) Anemometer – ISV-75 Gamma-ray spectrometer – GS-12V Gamma-ray densitometer – RP-75

Venera 10

windspeeds atmospheric pressure at various heights, temperature, and surface light levels.

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 (2, with lamps) Anemometer – ISV-75 Gamma ray spectrometer – GS-12V Gamma ray densitometer – RP-75 Radio Doppler experiment

Venera 11

temperature and atmospheric and soil chemical composition.

Lander Payload:

Backscatter Nephelometer Mass spectrometer – MKh-6411 Gas chromatograph – Sigma X-Ray fluorospectrometer 360° Scanning photometer – IOAV Spectrometer (430–1170 nm) Microphone/anemometer Low-frequency radio sensor 4 Thermometers 3 Barometers Accelerometer – Bizon Penetrometer – PrOP-V Soil analysis device 2 Color cameras Small solar batteries – MSB

Venera 12

Included 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.

Lander Payload:

Groza (lightening detector) carbon monoxide at low levels thunder Backscatter nephelometer Mass spectrometer – MKh-6411 Gas chromatograph – Sigma X-Ray fluorospectrometer 360° scanning photometer – IOAV Spectrometer (430–1170 nm) Microphone / anemometer Low-Frequency radio sensor (thunder) 4 Thermometers 3 Barometers Accelerometer – Bizon Penetrometer – PrOP-V Soil Analysis Device 2 Color Cameras Small solar batteries – MSB

Venera 13 (design similar to 9-12) (color photographs)

The descent lander was a hermetically-sealed pressure vessel, which contained most of the instrumentation and electronics, mounted on a ring-shaped landing platform and topped by an antenna.

Included instruments to take chemical and isotopic measurements, monitor the spectrum of scattered sunlight, and record electric discharges during its descent phase through the Venusian atmosphere. The spacecraft utilized a camera system, an X-ray fluorescence spectrometer, a screw drill and surface sampler, a dynamic penetrometer, and a seismometer to conduct investigations on the surface.

Lander Payload: (hermetically sealed)

Accelerometer, Impact Analysis – Bison-M Thermometers, Barometers – ITD Spectrometer / Directional Photometer – IOAV-2 Ultraviolet Photometer Mass Spectrometer – MKh-6411 Penetrometer / Soil ohmmeter – PrOP-V Chemical Redox Indicator – Kontrast 2 Color Telephotometer Cameras – TFZL-077 Gas Chromatograph – Sigma-2 Radio / Seismometer – Groza-2 Nephelometer – MNV-78-2 Hydrometer – VM-3R X-Ray Fluorescence Spectrometer (Aerosol) – BDRA-1V X-Ray Fluorescence Spectrometer (Soil) – Arakhis-2 Soil Drilling Apparatus – GZU VB-02 Stabilized Oscillator / Doppler Radio Small solar batteries – MSB

NOTE Venera 13, 14 landers are hermetically sealed.

Venera 14 (color photographs)

It carried instruments to take chemical and isotopic measurements, monitor the spectrum of scattered sunlight, and record electric discharges during its descent phase through the Venusian atmosphere. The spacecraft utilized a camera system, an X-ray fluorescence spectrometer, a screw drill and surface sampler, a dynamic penetrometer, and a seismometer to conduct investigations on the surface.

Lander Payload:

Accelerometer, Impact analysis – Bison-M Thermometers, Barometers – ITD Spectrometer / Directional Photometer – IOAV-2 Ultraviolet Photometer Mass spectrometer – MKh-6411 Penetrometer / Soil ohmmeter – PrOP-V Chemical Redox indicator – Kontrast 2 color telephotometer cameras – TFZL-077 Gas chromatograph – Sigma-2 Radio / Microphone / Seismometer – Groza-2 Nephelometer – MNV-78-2 Hydrometer – VM-3R X-Ray Fluorescence Spectrometer (Aerosol) – BDRA-1V X-Ray Fluorescence Spectrometer (Soil) – Arakhis-2 Soil Drilling Apparatus – GZU VB-02 Stabilized Oscillator / Doppler Radio Small solar batteries – MSB

NOTE Venera 13, 14 landers are hermetically sealed.

1.5 : DATASHEETS “Venera 7-14” (English) published by Lavochkin (manufacturer)

Manufacturer Data Sheets (Lavochkin) information (in Russian).  English translations by David Grunwald.

Lavochkin information (in Russian)

http://www.laspace.ru/projects/planets/venera-7/ http://www.laspace.ru/projects/planets/venera-8/ http://www.laspace.ru/projects/planets/venus9-10/ http://www.laspace.ru/projects/planets/venus11-12/ http://www.laspace.ru/projects/planets/venus13-14/

Venera 7   http://www.laspace.ru/projects/planets/venera-7/ The Venus 7 lander reached the surface of Venus for the first time in the history of the world.  The spacecraft landed on the dark side of the planet.(1)   The unmanned station, Venera 7, was developed from the (earlier) Venera 4, 5 and 6 probes.

Based on the flight results of the Venera-5 and Venera-6 probes, which completed the measurements at an altitude of about 20 km above the mean surface level, calculations were made of pressure and temperature estimates at the level of the average surface of Venus, which amounted to Temperature = 500 ° C (932 F) and (atmospheric Pressure = 100 (earth) atmospheres.

Unlike previous expeditions, the main launch goal in 1970 was landing on the surface of the planet.  The wind speed at the surface of Venus was calculated at 1.5 m/s.

Based on these accepted conditions, a fundamentally new lander was designed. It had to withstand pressure six times higher than the Venera-5 and Venera- landers.  Another requirement was that the lander had to work on the surface at maximum pressure for at least 30 minutes.

To withstand such pressure, the body of the descent vehicle was manufactured not from the aluminum-magnesium alloy AMG 6, as in the previous Venera landers, but from titanium able to withstand external pressures of 180 (earth) atmospheres.

Thermal insulation of the lower hemisphere was made of glass fiber (fiberglass), and the upper hemisphere – from glass wool (glass wool enduction), which filled the cells of the glass. To reduce the overloads that affect the equipment when the device comes into contact with the planet’s surface, a cushioning device (амортизационное устройство) was installed.

High atmospheric pressure made it possible to replace the two-stage parachute system with a single-stage one with a conical shaped cone shaped parachute measuring 2.8 m².  This is slightly more than the area of ​​the dome of the brake parachute on the “Venus-4”.     The parachute was made from the domestic-manufactured material.   To ensure sufficient strength, the canopy of the parachute was made of 4 layers of fabric. After burning out the nitron, the air permeability of the dome was ensured, ensuring its reliable functioning. Accordingly, the automation of the parachute system was changed.

The composition of scientific equipment was completely changed. In addition, a new radio altimeter was installed to measure altitudes in the range of 25-1 km.

In connection with the change in the composition of scientific equipment in the descent vehicle and the operation of the cyclogram, it was necessary to increase the capacity of the battery. Instead of cadmium-nickel, a lead-zinc battery was installed.  15 days before the approach to Venus, on command from Earth, it was charged by solar batteries.

In connection with the increase in the weight of the descent vehicle by almost 100 kg, compared with the descent vehicles of the “Venus-5,6″, it was necessary to simplify the orbital compartment as much as possible.  All scientific equipment was removed except for the counter of cosmic particles. But even after that, the mass of the whole apparatus (1180 kg) was 50 kg more than the mass of earlier”Venus-5,6”, and therefore exceeded the capabilities of the carrier Molniya 8K78M. The carrying capacity of the carrier could be increased by refining the booster tanks (it received the designation of NVL (upper stage), which made it possible to add 140 kg of fuel.

Mission type	Venus lander
Operator	Lavochkin
COSPAR ID	1970-060A
SATCAT no.	4489
Mission duration	Travel: 120 days Lander: 23 minutes
Spacecraft properties
Spacecraft	4V-1 No. 630
Manufacturer	Lavochkin
Launch mass	1,180 kilograms (2,600 lb)
Landing mass	500 kilograms (1,100 lb)
Start of mission
Launch date	17 August 1970, 05:38:22 UTC
Rocket	MolniyaHYPERLINK “https://en.wikipedia.org/wiki/Molniya-M” 8K78M
Launch site	Baikonur 31/6
End of mission
Last contact	15 December 1970, 06:00 UTC
Orbital parameters
Reference system	Heliocentric
Perihelion	0.69 AU
Apohelion	1.01 AU
Inclination	2.0°
Period	287 days
Venus lander
Landing date	15 December 1970, 05:37:10 UTC
Landing site	5°S 351°E

Data Sheet Wikipedia

* translated by David Grunwald from manufacturer Lavochkin data sheet for the Venera program.

Footnotes:

(1) Venera 7 measured the temperature, confirming that the dark side of Venus was basically as hot as the “day” side.  Because of its thick CO2 atmosphere and slow rotation, Venus maintains an average temperature of around 460 °C (860 °F) whether it is “day” or “night”.   It takes Venus 243 days to do one complete revolution.   A “day” on Venus is longer than its year.   Venus has a “retrograde” rotation, compared to its orbit around the Sun. Unlike the other major planets, Venus rotates in a slow clockwise direction (from east to west).

Venera 8   http://www.laspace.ru/projects/planets/venera-8/ The unmanned spacecraft “Venera-8” almost completely repeated the aims and objectives of the earlier flight of probe “Venera-7”. Based on the results of the Venera-7 flight, the Venusian atmosphere model was adjusted, which allowed the design of the Venera descent vehicle to be made for real conditions with marginal changes. Instead of a design pressure of 150 atmospheres, a design 105 atmospheres were used, and instead of 540 °C (1004 °F), the reading 493 °C (919.4 °F) was used in calculations. Reduction of the maximum values ​​of temperature and pressure of the Venusian atmosphere made it possible to reduce the wall thickness of the instrument compartment of the Venera-8 spacecraft compared to Venus-7.

In the lower part of the compartment, the wall thickness was reduced from 25 to 12 mm, and at the top – from 8.7 to 5.7 mm, which made it possible to reduce the weight of the landing gear by 38.5 kg. To improve the thermal conditions of the equipment, beryllium shells were installed on the inside of the titanium hull of the descent vehicle, heat accumulators (аккумуляторы тепла) were installed, and fiberglass-lining pads were inserted into the hull of the instrument compartment at the frame attachment points.(1)

Since the landing of the Venus-7 lander, there were strong signal fluctuations caused by the lack of fixation of the lander on the surface and a relatively narrow antenna pattern (± 45 °), Also, landing on the daytime side (на освещенную сторону) caused difficulties with radio communications (the angle between the direction to Earth and the local vertical will be 30-50 °).  The antenna-feeder system was refined.

The main helical antenna worked only in the descending section, and after landing, an additional antenna was ejected from the lander. The case of this antenna was made in the form of a flat washer with four folding petals, so that one of its flat sides should actually lie on the surface of Venus.

This was to ensure a fairly good orientation of the funnel-shaped antenna pattern relative to the local vertical. After landing, it is thrown out of the parachute compartment. The petals open and do not allow the antenna to stand on the edges. At the ends of the disk are emitters, and the gravitational switch installed inside it after fixing the antenna turns on the gamma radiation the upper side.

In order to determine the illumination of the planet’s surface, which is necessary for photographing the surface of the planet on the descent vehicles of the next generation, scientific equipment in the descent vehicle was supplemented with an IOV 72 photometer.

Taking into account the new tasks, the ballistic flight scheme of the Venera-8 spacecraft changed.  Unlike the earlier space stations “Venera-4, 5, 6, 7”, the descent vehicle had to land on the day side of the planet.

The orbiter of the spacecraft “Venera-8” remained unchanged.

Mission type	Venus lander
Operator	Lavochkin
COSPAR ID	1972-021A
SATCAT no.	5912
Mission duration	Travel: 117 days Lander: 50 minutes
Spacecraft properties
Spacecraft	4V-1 No.670
Manufacturer	Lavochkin
Launch mass	1,184 kilograms (2,610 lb)
Landing mass	495 kilograms (1,091 lb)
Start of mission
Launch date	27 March 1972, 04:15:01 UTC
Rocket	MolniyaHYPERLINK “https://en.wikipedia.org/wiki/Molniya-M”-M/MVL
Launch site	Baikonur 31/6
End of mission
Last contact	22 July 1972
Orbital parameters
Reference system	Geocentric
Semi-major axis	6,591 kilometres (4,095 mi)
Eccentricity	0.03732
Perigee	194 kilometres (121 mi)
Apogee	246 kilometres (153 mi)
Inclination	51.7°
Period	88.9 minutes
Epoch	27 March 1972
Venus lander
Landing date	22 July 1972, 09:32 UTC
Landing site	10.70°S 335.25°E

Data Sheet Wikipedia

Footnotes:

(1) The element beryllium is a grey metal that is stronger than steel and lighter than aluminum. Its physical properties of great strength-to-weight, high melting point, excellent thermal stability and conductivity, reflectivity, and transparency to X-rays make it an essential material in the aerospace, telecommunications, information technology, defense, medical, and nuclear industries source: https://www.osha.gov/SLTC/beryllium/ published United States Department of Labor  9/23/2017

Venera 9 and 10  http://www.laspace.ru/projects/planets/venus9-10/

Venera 9’s orbiter was the first spacecraft to orbit Venus, while the lander was the first to return images from the surface of another planet.

In the flight with “Venus-9” and “Venus-10” two trajectory corrections were carried out. Two days before the flight to Venus, the descent vehicles were separated from their spacecraft (orbiter).  On October 22, 1975 the descent vehicle station “Venus-9” entered the atmosphere of the planet at an angle of 20-23 °. After the descent – first on a parachute, and then using a brake aerodynamic shield – the lander made a soft landing on the side of Venus, illuminated by the Sun, but invisible from the Earth. During the descent, scientific measurements of the atmosphere were carried out, including the measurement of cloud layers, which were then immediately transferred to the orbiter.   2 minutes after landing, the transfer of the television panorama began.   These were the world’s first photographs transmitted from the surface of another planet.

The image was obtained in visible light with a telephotometer – a system, according to the principle of action resembling a mechanical television. The landing site of “Venus-9” was a scattering of rather large stones. The age of the surface of this type cannot be very old (106-107 years) and, consequently, Venus is a geologically active planet. Instruments for measuring the density of surface rocks and the content of natural radioactive elements in them were installed on Venera-9 and Venera-10. 1.4 Image from Venera 9

The orbiter “Venus-9”, braking at the pericentre of the approach trajectory, entered the orbit of  Venus for a period of ~ 48 hours.  On October 23, 1975, the orbital and descent vehicle of the spacecraft Venera-10 was separated and the orbital compartment was moved into a flight trajectory.

On October 25, 1975, the descent vehicle of the unmanned Venera-10 spacecraft made a soft landing on the illuminated side (day) of the planet at 2200 km from the landing point of Venera-9. In the landing areas, the temperature and pressure at the surface were 460 ° C (860 ° F) and 90 atm (atmospheric pressure).  Television images of the surface of Venus were transmitted from the descent vehicle (lander) to the Earth. The operating time of the lander on the surface of Venus was 65 minutes. The orbital compartment of Venera-10, meanwhile, also went into orbit around Venus.

After the separation, the spacecraft were then transferred to flight trajectories, and then put into orbits as satellites of the planet. To transmit scientific information, the necessary ballistic scheme was implemented, which provided the required distances, and the mutual position of the orbital compartment with the landers. The information received by each lander was transmitted to its orbital module, which had by that time become WIS (ИСВ), and relayed (the information) to Earth.

Both orbital vehicles, after completing work with the descent vehicles (landers), conducted complex studies of the planet Venus and near-planetary space, including photographing the cloud cover.

Venera 9

Mission type	Venus orbiter / lander
Operator	Lavochkin
COSPAR ID	1975-050A 1975-050D
SATCAT no.	7915 8411
Mission duration	Orbiter: 158 days Lander: 53 minutes
Spacecraft properties
Spacecraft	4V-1 No. 660
Manufacturer	Lavochkin
Launch mass	4,936 kg (10,882 lb)
Landing mass	1,560 kg (3,440 lb)
Payload mass	660 kg (1,455 lb)
Start of mission
Launch date	June 8, 1975, 02:38 UTC[1]
Rocket	Proton-K/D[1]
Launch site	Baikonur 81/24
End of mission
Last contact	Orbiter: March 26, 1976 Lander: October 22, 1975
Orbital parameters
Reference system	Cytherocentric
Eccentricity	0.89002
Pericytherion	7,625 km (4,738 mi)
Apocytherion	118,072 km (73,367 mi)
Inclination	29.5 degrees
Period	48.3 hours
Venus orbiter
Spacecraft component	Orbiter
Orbital insertion	October 20, 1975
Venus lander
Spacecraft component	Lander
Landing date	October 22, 1975, 05:13 UTC
Landing site	31.01°N 291.64°E (near Beta Regio)

Data Sheet Wikipedia

Venera 10

Mission type	Venus orbiter / lander
Operator	Lavochkin
COSPAR ID	1975-054A 1975-054D
SATCAT no.	7947 8423
Mission duration	Travel: 4 months and 9 days Orbiter: 144 days Lander: 65 minutes
Spacecraft properties
Spacecraft type	4V-1 No. 661
Manufacturer	Lavochkin
Launch mass	5,033 kg (11,096 lb)
BOL mass	2,230 kg (4,920 lb)
Landing mass	1,560 kg (3,440 lb)
Dimensions	2.7 m × 2.3 m × 5.7 m (8.9 ft × 7.5 ft × 18.7 ft)
Start of mission
Launch date	June 14, 1975, 03:00:31 UTC
Rocket	Proton with upper and escape stages
Launch site	Baikonur 81/24
End of mission
Last contact	March 26, 1976
Orbital parameters
Reference system	Cytherocentric
Eccentricity	0.8798
Pericytherion	1,620 kilometers (1,010 mi)
Apocytherion	113,900 kilometers (70,800 mi)
Inclination	29.5°
Period	49.4 hours
Revolution no.	71
Venus orbiter
Orbital insertion	October 23, 1975
Venus lander
Spacecraft component	Venera 10 descent craft
Landing date	02:17, October 25, 1975
Landing site	15.42°N 291.51°E (near Beta Regio)

Data Sheet Wikipedia

Venera 11-12     http://www.laspace.ru/projects/planets/venus11-12/ In connection with the change in the ballistic conditions for flight to Venus in 1978, a flying-landing scheme was chosen. Until the moment of landing of the descent vehicle, the ballistic flight scheme of the spacecraft completely repeated the scheme of the earlier spacecraft flight (“Venera-9” and “Venera-10”).

After passing the stages of launching to the reference orbit of the satellite and starting from it in the direction of Venus, the series was displayed on the incoming trajectory of the first half-circle (the range of flight was less than 180 degrees).

At the time of landing, the orbiter made a partial flight of Venus, during which the information was received from the lander, while the minimum distance from the surface of Venus was 35,000 km.

The duration of the flight was 107 days.

The lander entered the atmosphere of Venus at a speed of 11.2 km / s. With a decrease to an altitude of 62-67 km and a decrease in the value of the overload to a value of nx = -2, a parachute system was introduced. A parachute system with an area of ​​1.4 m2 and a parachute for evacuation of the upper hemisphere of the lander with an area of ​​6 m2 were successively triggered.

The parachute descent was carried out within 10-14 seconds, after which the PVU command disconnects (using pyrotechnic devices) the hemispheres of the heat shield. Due to aerodynamic influence, the upper hemisphere was separated from the spacecraft by a parachute, and a 24-m2 brake parachute was introduced. At this moment, the telemetry system of the descent vehicle and scientific instruments were switched on.

In the region of the lower boundary of the cloud layer at a height of 46-48 km, the brake parachute was separated, and further descent of the lander was carried with the aerodynamic brake shield. The descent stage on the brake flap ended with a landing on the surface. Depending on the pressure of the atmosphere at the landing site, the estimated landing speed of the vehicle is 7.3-8.5 m / sec, and the total time of descent was 58-70 minutes ..

Since the three-dome main parachute with an area of ​​180 m2 was excluded from the parachute system, the total time of descent of the lander in the atmosphere decreased in comparison with the “Venus-9, 10” by 15 minutes.

After a soft landing on the surface, and 32 seconds after reaching the contact, simultaneous operation of the soil sampling device and telephotometers began. The transmission of a television image, alternating with inserts of telemetric information and a digital array with the results of soil analysis, continued until the radio was lost.

Upon completion of the main task of the expedition – the research of Venus – the orbiter continued flight in heliocentric orbit, transmitting scientific information about the interplanetary space to earth.

Venera 11

Operator	Soviet Academy of Sciences
COSPAR ID	1978-084A 1978-084D
SATCAT no.	11020 11027
Mission duration	Travel: 3 months and 16 days Lander: 95 minutes
Spacecraft properties
Spacecraft	4V-1
Spacecraft type	4V-1 No. 360
Bus	4MV
Launch mass	4,940 kg (10,890 lb)
BOL mass	4,715 kg (10,395 lb)
Landing mass	760 kg (1,680 lb)
Dimensions	2.7 m × 2.3 m × 5.7 m (8.9 ft × 7.5 ft × 18.7 ft)
Start of mission
Launch date	September 9, 1978, 03:25:39 UTC
Rocket	Proton-K/D-1 8K82K
Launch site	Baikonur 81/23
Orbital parameters
Reference system	Geocentric
Regime	Low Earth
Semi-major axis	6,569 kilometers (4,082 mi)
Eccentricity	0.0312
Perigee	177 kilometres (110 mi)
Apogee	205 kilometres (127 mi)
Inclination	51.5°
Flyby of Venus
Spacecraft component	Venera 11 flight platform
Closest approach	25 December 1978
Distance	~35,000 kilometers (22,000 mi)
Venus lander
Spacecraft component	Venera 11 descent craft
Landing date	25 December 1978, 03:24
Landing site	14°SHYPERLINK “https://tools.wmflabs.org/geohack/geohack.php?pagename=Venera_11&params=14_S_299_E_globe:Venus” HYPERLINK “https://tools.wmflabs.org/geohack/geohack.php?pagename=Venera_11&params=14_S_299_E_globe:Venus”299°E (near Phoebe Regio)

Data Sheet Wikipedia Venera 12

Mission type	Venus flyby / lander
Operator	Soviet Academy of Sciences
COSPAR ID	1978-086A 1978-086C
SATCAT no.	11025 12028
Mission duration	Travel: 3 months and 6 days Lander: 110 minutes
Spacecraft properties
Spacecraft type	4V-1
Bus	4MV
Launch mass	4,940 kg (10,890 lb)
Dry mass	1,600 kg (3,500 lb)
Dimensions	2.3 m × 2.7 m × 5.7 m (7.5 ft × 8.9 ft × 18.7 ft)
Start of mission
Launch date	September 14, 1978, 02:25:13 UTC
Rocket	Proton-K/D-1 8K82K
Launch site	Baikonur 81/23
Orbital parameters
Reference system	Geocentric
Regime	Low Earth
Semi-major axis	6,569 kilometres (4,082 mi)
Perigee	177 kilometres (110 mi)
Apogee	205 kilometres (127 mi)
Inclination	51.5°
Flyby of Venus
Spacecraft component	Venera 12 flight platform
Closest approach	19 December 1978
Distance	35,000 km (22,000 mi)
Venus lander
Spacecraft component	Venera 12 descent module
Landing date	21 December 1978, 03:30
Landing site	7°SHYPERLINK “https://tools.wmflabs.org/geohack/geohack.php?pagename=Venera_12&params=7_S_294_E_globe:Venus” HYPERLINK “https://tools.wmflabs.org/geohack/geohack.php?pagename=Venera_12&params=7_S_294_E_globe:Venus”294°E

Data Sheet Wikipedia

Venera 13-14  http://www.laspace.ru/projects/planets/venus13-14/

For the expeditions of the space vehicles of the  Venera 13-14 series, a flight-landing scheme was chosen.  A detailed description of the flight scheme was given in the section of Venera Spacecraft.

Differences were in the duration of the flight (for the Venera 13-14 series it was just over 120 days) and the sequence of operations performed by the on-board equipment after landing. The work of the soil sampling device started, just like in the previous expedition, 32 seconds after reaching the surface, and the work of the telephotometers – within a 4-minute delay. The first four minutes were dedicated to broadcasting information from other scientific instruments and telemetry about the operation of the GZU, and then the transmission of the panorama of the surface of Venus continued until the radio connection was terminated.(1)

The Venera orbiter continued to fly along the heliocentric orbit, transmitting to the Earth scientific information about interplanetary space.

Despite the fact that the Venera 13-14 series was in many respects identical to its predecessors (“Venera-11, -12”), 18 experimental operations were tested to verify all changes. Only 39 types of tests were planned for checking the operation of resetting the telephotometer caps. But in reality, 78 tests were conducted. Before the launch, the lander was heated to 450 degrees, and then dropped from the altitude, simulating thereby landing on the surface of Venus. And only after that testing, the lid was installed. The tests were carried out to the verge of failure. As a result, with an estimated availability of new nodes ~ 7.5, a reserve of 20.5 was obtained. With this reserve it was already possible to fly.

Selecting a damper on the landing gear and checking the theoretical calculations required numerous test of the spacecraft’s landing gear in the wind tunnel.

Both spacecraft of the 4B1M series (Venera-13, -14 spacecraft) successfully passed comprehensive ground tests and were launched from the Baikonur cosmodrome in the autumn of 1981.

As mentioned, the launch of two identical devices was planned to increase the overall reliability of the mission, but also to study the surface of Venus from two different regions of the planet.(2)

The landing sites were chosen in such a way as to determine the nature of the relief and rocks of the most typical geological and morphological provinces of the planet.

Footnotes:

(1) Despite the testing mentioned by the manufacturer, both 13 and 14 experiences issues related to lenses. For Venera 13 the quartz camera windows were covered by lens caps which popped off after descent.  On Venera 14, the fallen lens cap blocked the soil probe.

(2)  Venera 13 landed in 7.5°S 303°E (east of Phoebe Regio), and Venera 14, 13°15′S 310°0′E (east of Phoebe Regio).  These two sites are 591 miles from each other.

Venera 13

Mission type	Venus flyby / lander
Operator	Soviet Academy of Sciences
COSPAR ID	1981-106A 1981-106D
SATCAT no.	12927 15599
Mission duration	Travel: 5 months Lander: 127 minutes
Spacecraft properties
Spacecraft type	4V-1 no.760
Manufacturer	NPO HYPERLINK “https://en.wikipedia.org/wiki/NPO_Lavochkin”Lavochkin
Launch mass	4,397.85 kilograms (9,695.6 lb)
Landing mass	760 kg (1,680 lb)
Dry mass	1,643.72 kg (3,623.8 lb)
Dimensions	2.7 m × 2.3 m × 2.7 m (8.9 ft × 7.5 ft × 8.9 ft)
Start of mission
Launch date	October 30, 1981, 06:04:00 UTC
Rocket	Proton-K/D-1 8K82K
Launch site	Baikonur 200/40
Orbital parameters
Reference system	Heliocentric
Eccentricity	0.17
Perihelion	0.70 AU
Apohelion	0.99 AU
Inclination	2.3 degrees
Period	285 days
Flyby of Venus
Spacecraft component	Venera 13 flight platform
Closest approach	March 1, 1982
Distance	~36,000 kilometres (22,000 mi)
Venus lander
Spacecraft component	Venera 13 descent craft
Landing date	03:57:21, March 1, 1982
Landing site	7.5°S 303°E (east of Phoebe Regio)

Venera 14

Mission type	Venus flyby / lander
Operator	Soviet Academy of Sciences
COSPAR ID	1981-110A 1981-110D
SATCAT no.	12939 15600
Mission duration	Travel: 4 months and 1 day Lander: 57 minutes
Spacecraft properties
Spacecraft type	4V-1 No. 761
Manufacturer	NPO HYPERLINK “https://en.wikipedia.org/wiki/NPO_Lavochkin”Lavochkin
Launch mass	4,394.5 kg (9,688 lb)
Landing mass	760 kilograms (1,680 lb)
Dry mass	1,632.71 kilograms (3,599.5 lb)
Dimensions	2.7 m × 2.3 m × 5.7 m (8.9 ft × 7.5 ft × 18.7 ft)
Start of mission
Launch date	November 4, 1981, 05:31:00 UTC
Rocket	Proton-K/D-1
Launch site	Baikonur 200/39
Orbital parameters
Reference system	Heliocentric
Eccentricity	0.17
Perihelion	0.71 Astronomical units
Apohelion	0.99 Astronomical units
Inclination	2.3 degrees
Period	286 days
Flyby of Venus
Spacecraft component	Venera 14 flight platform
Closest approach	March 5, 1982
Distance	26,050 km (16,190 mi)
Venus lander
Spacecraft component	Venera 14 descent craft
Landing date	March 3, 1982, 07:00:10 UTC
Landing site	13°15′SHYPERLINK “https://tools.wmflabs.org/geohack/geohack.php?pagename=Venera_14&params=13_15_S_310_0_E_globe:Venus” HYPERLINK “https://tools.wmflabs.org/geohack/geohack.php?pagename=Venera_14&params=13_15_S_310_0_E_globe:Venus”310°0′E (east of Phoebe Regio)

Data Sheet Wikipedia

 

 

 

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