Venera 7 - Wikipedia

Soviet lander mission to Venus (1970) Venera 7

Reproduction of the Venera 7 lander at the Sergei Pavlovich Korolyov Museum of Cosmonautics
Mission type	Venus lander
Operator	Lavochkin
COSPAR ID	1970-060A
SATCAT no.	4489
Mission duration	Cruise: 3 months and 28 days Lander: 23 minutes
Spacecraft properties
Spacecraft	3MV No. 630
Manufacturer	Lavochkin
Launch mass	1,180 kg (2,600 lb)[1]
Landing mass	500 kg (1,100 lb)
Start of mission
Launch date	17 August 1970, 05:38:22 (1970-08-17UTC05:38:22Z) UTC[1]
Rocket	Molniya-M
Launch site	Baikonur 31/6
End of mission
Last contact	15 December 1970, 06:00 (1970-12-15UTC07Z) UTC
Orbital parameters
Reference system	Heliocentric
Perihelion altitude	0.69 AU (103 million km)
Aphelion altitude	1.01 AU (151 million km)
Inclination	2.0°
Period	287 days
Venus lander
Landing date	15 December 1970, 05:37:10 UTC
Landing site	5°S 351°E / 5°S 351°E / -5; 351
Instruments COP-18-4M GS-4 ITD DOW-1M
Seal of Venera 7 Venera program← Venera 6Kosmos 359 →

Venera 7 (Russian: Венера-7, lit. 'Venus 7') was a Soviet spacecraft, part of the Venera series of probes to Venus. When it landed on the Venusian surface on 15 December 1970, it became the first spacecraft to execute a successful soft landing on another planet and the first to transmit data from there back to Earth.[2][3]

Design

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The lander was designed to be able to survive pressure of up to 18 megapascals (2,600 psi) and temperatures of 580 °C (1,076 °F).[4] This was much greater than what was expected to be encountered but significant uncertainties as to the surface temperatures and pressure of Venus resulted in the designers opting for a large margin of error.[4] This degree of hardening limited the amount of mass available for scientific instruments both on the probe itself and the interplanetary bus.[4] The interplanetary bus carried a solar-wind charged-particle detector and a cosmic-ray detector.[5] On the lander were temperature and pressure sensors as well as an accelerometer to measure atmospheric density.[4] The probe also carried a radar altimeter.[4]

Launch

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The probe was launched from Earth on 17 August 1970, at 05:38 UTC. It consisted of an interplanetary bus, based on the 3MV system, and a lander.[6] During the flight to Venus, two in-course corrections were made using the bus's on-board KDU-414 engine.[6]

Landing

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Venera 7 entered the atmosphere of Venus on 15 December 1970.[6] The lander remained attached to the interplanetary bus during the initial stages of atmospheric entry[6] to allow the bus to cool the lander to −8 °C (18 °F) for as long as possible.[6] The lander was ejected once atmospheric buffeting broke the interplanetary bus's lock-on with Earth.[6] The parachute opened at a height of 60 kilometres (37 mi), and atmospheric testing began with results showing the atmosphere to be 97% carbon dioxide.[6] The parachute was initially reefed down to 1.8 square metres (19 sq ft), opening to 2.5 square metres (27 sq ft) 13 minutes later, after the reefing line melted as designed.[4] Six minutes after the unreefing, the parachute started to fail, resulting in a descent more rapid than planned.[4][6] The parachute eventually failed completely, and the probe entered a period of freefall.[4] As a result, the lander struck the surface of Venus at about 16.5 m/s (59 km/h; 37 mph) at 05:37:10 UTC.[6] The landing coordinates are 5°S 351°E / 5°S 351°E / -5; 351.[7]

The probe appeared to go silent on impact,[6] but recording tapes kept rolling.[8] A few weeks later, upon review of the tapes by radio astronomer Oleg Rzhiga, another 23 minutes of very weak signals were found on them.[8][9] The spacecraft had landed on Venus, and probably bounced onto its side, leaving the medium gain antenna aimed incorrectly for proper signal transmission to Earth.[8]

The probe transmitted information to Earth for 53 minutes, which included about 20 minutes from the surface.[10] It was found that the temperature at the surface of Venus was 475 ± 20 °C (887 ± 36 °F).[6][10] Using this temperature and models of the atmosphere, a pressure of 9.0 ± 1.5 MPa (1,310 ± 220 psi) was calculated.[11] From the spacecraft's rapid halt (from falling to stationary inside 0.2 second), it was possible to conclude that the craft had hit a solid surface with low levels of dust.[11]

The probe provided information about the surface of Venus that could not be seen through its thick atmospheric veil. The spacecraft confirmed that humans cannot survive on the surface of Venus. It excluded the possibility that there is any liquid water on the planet.[10][6]

See also

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Spaceflight portal

• List of missions to Venus
• Timeline of artificial satellites and space probes

References

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Citations

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1. ^ a b Siddiqi 2018, p. 93.
2. ^ "Science: Onward from Venus". Time. 8 February 1971. Archived from the original on 21 December 2008. Retrieved 2 January 2013.
3. ^ Siddiqi 2018, pp. 1, 3.
4. ^ a b c d e f g h W. T. Huntress; M. Y. Marov (2011). Soviet Robots in the Solar System: Mission Technologies and Discoveries. Springer New York. pp. 235–240. ISBN 978-1-4419-7897-4.
5. ^ "Venera 7". nssdc.gsfc.nasa.gov. NASA. Archived from the original on 11 April 2019. Retrieved 6 October 2019.
6. ^ a b c d e f g h i j k l Reeves 1994, pp. 211–215.
7. ^ P. Moore (2000). "Table 5-5, Missions to Venus, 1961–2000. Landing near Navka Planitia". The Data Book of Astronomy (1st ed.). CRC Press. p. 92. Bibcode:2000dba..book.....M. ISBN 978-0-750-30620-1.
8. ^ a b c L. Klaes (1993). "The Soviets and Venus, Part 1". Archived from the original on 29 September 2015. Retrieved 29 September 2015.
9. ^ B. Harvey (2007). Russian Planetary Exploration: History, Development, Legacy and Prospects. Springer. p. 114. ISBN 978-0-387-46343-8.
10. ^ a b c "Итоги работы станции "Венера-7"". Galspace (in Russian).
11. ^ a b P. Ulivi; D. M. Harland (2007). Robotic Exploration of the Solar System Part I: The Golden Age 1957–1982. Springer. pp. 97–99. ISBN 978-0-387-49326-8.

Bibliography

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• Reeves, Robert (1994). The Superpower Space Race: An Explosive Rivalry Through the Solar System. New York, NY: Plenum Press. ISBN 978-0-306-44768-6.
• Siddiqi, Asif A. (2018). Beyond Earth: A Chronicle of Deep Space Exploration, 1958–2016 (PDF). NASA SP (Second ed.). Washington, DC: NASA History Program Office. ISBN 978-1-62683-042-4. LCCN 2017059404. SP2018-4041.

External links

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• Venera 7 Archived 11 April 2019 at the Wayback Machine NASA NSSDC Master Catalog Data
• Plumbing the Atmosphere of Venus

v t e Venera program
Flybys	Venera 1 Venera 2
Orbiters	Venera 15 Venera 16
Descent probes	Venera 3 Venera 4 Venera 5 Venera 6 Venera 7
Landers	Venera 8 Venera 9 Venera 10 Venera 11 Venera 12 Venera 13 Venera 14
Failed launches	Tyazhely Sputnik Venera 2MV-1 No.1 Venera 2MV-1 No.2 Venera 2MV-2 No.1 Kosmos 21 Venera 3MV-1 No.2 Kosmos 27 Kosmos 96 Kosmos 167 Kosmos 359 Kosmos 482 Venera 1964A
Future missions	Venera-D

v t e Spacecraft missions to Venus
Active missions	Flybys Solar Orbiter‡ (en route)
Past missions	Orbiters Magellan Pioneer Venus Orbiter Venera 9 10 15 16 Venus Express Akatsuki Flybys Venera 1† Mariner 2 Zond 1† Venera 2† Mariner 5 10‡ Venera 11 12 13 14 Vega 1 2 Galileo‡ Cassini–Huygens‡ MESSENGER‡ IKAROS Shin-en† Parker Solar Probe‡ BepiColombo‡ Jupiter Icy Moons Explorer‡ Descent probes Venera 3† 4 5 6 Pioneer Venus Multiprobe Landers Venera 7 8 9 10 11 12 13 14 Vega 1 2 Pioneer Venus Small Probes Balloon probes Vega 1 2 Failed launches Tyazhely Sputnik Mariner 1 2MV-1 No.1 2MV-1 No.2 2MV-2 No.1 Kosmos 21 3MV-1 No.2 Kosmos 27 96 167 482
Planned missions	Orbiters Venus Orbiter Mission (2028) VERITAS (2031) EnVision (2031) Flybys Dragonfly‡ (2028) MBR Explorer‡ (2028) Tianwen-4‡ (2030) Descent probes Venus Life Finder (2026-2027) DAVINCI (2031–2032)
Proposed missions	Dedicated missions Venera-D Flybys Uranus Orbiter and Probe‡
Cancelled or not developed	AREE European Venus Explorer CUVE HAVOC HOVER Inspiration Mars Laplace-P Mercury-P TMK-Mavr VAMP Venus Orbiting Imaging Radar Vesta VICI VISAGE VISE VOICE VOX Zephyr
Program overviews	Venera 3MV Mariner Pioneer Venus Vega
Related	Colonization Observations and explorations List of artificial objects on Venus List of missions Manned Venus flyby Terraforming VeSpR
Missions are ordered by launch date. † indicates failure en route or before any data returned. ‡ indicates use of the planet as a gravity assist en route to another destination.

v t e ← 1969Orbital launches in 19701971 →
Kosmos 318 OPS 6531 Intelsat III F-6 Kosmos 319 Kosmos 320 Kosmos 321 Kosmos 322 ITOS-1 Australis-OSCAR 5 DS-P1-I No.6 SERT-2 E-8-5 No.405 Kosmos 323 Ohsumi OPS 0054 Molniya-1 No.17 Kosmos 324 Kosmos 325 OPS 0440 OPS 3402 Wika Mika Kosmos 326 Meteor No.14 Kosmos 327 NATO 2A Kosmos 328 Kosmos 329 Kosmos 330 Nimbus 4 Topo-1 Kosmos 331 OPS 7033 OPS 7044 Kosmos 332 Apollo 13 Kosmos 333 OPS 2863 Intelsat III F-7 Kosmos 334 Dong Fang Hong 1 Kosmos 335 Kosmos 336 Kosmos 337 Kosmos 338 Kosmos 339 Kosmos 340 Kosmos 341 Kosmos 342 Kosmos 343 Meteor No.13 Kosmos 344 Kosmos 345 OPS 4720 OPS 8520 DS-P1-Yu No.36 Soyuz 9 Kosmos 346 STV-3 Kosmos 347 Kosmos 348 Kosmos 349 OPS 5346 Meteor-M No.17 OPS 6820 Molniya-1 No.21 Kosmos 350 Kosmos 351 Unnamed Kosmos 352 Kosmos 353 Zenit-4 No.75 OPS 4324 Intelsat III F-8 Kosmos 354 Interkosmos 3 Kosmos 355 Kosmos 356 Venera 7 OPS 7874 Skynet 1B Kosmos 357 Kosmos 358 Kosmos 359 Kosmos 359 OPS 8329 Transit O-19 Kosmos 360 OPS 7329 Orba X-2 OPS 0203 Kosmos 361 Luna 16 Kosmos 362 Kosmos 363 Kosmos 364 MS-F1 Kosmos 365 Molniya-1 No.19 Kosmos 366 Kosmos 367 Kosmos 368 Nauka No.3 Kosmos 369 Kosmos 370 Kosmos 371 Interkosmos 4 Meteor-M No.16 Kosmos 372 Kosmos 373 Zond 8 Kosmos 374 OPS 7568 Kosmos 375 Kosmos 376 OPS 5960 OFO RM-1 Luna 17 (Lunokhod 1) Kosmos 377 Kosmos 378 OPS 4992 OPS 6829 Kosmos 379 Kosmos 380 Molniya-1 No.23 OAO-B Kosmos 381 Kosmos 382 Kosmos 383 Kosmos 384 Nauka No.2 NOAA-1 CEPI Uhuru Kosmos 385 Peole Kosmos 386 Kosmos 387 Kosmos 388 Kosmos 389 DS-P1-M No.1 Molniya-1 No.22
Payloads are separated by bullets ( · ), launches by pipes ( | ). Crewed flights are indicated in underline. Uncatalogued launch failures are listed in italics. Payloads deployed from other spacecraft are denoted in (brackets).