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 soft land on another planet and the first to transmit data from there back to Earth.[1][2]
![]() Reproduction of the Venera 7 lander at the Sergei Pavlovich Korolyov Museum of Cosmonautics | |||||||||||
Mission type | Venus lander | ||||||||||
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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 (1970-08-17UTC05:38:22Z) UTC | ||||||||||
Rocket | Molniya 8K78M | ||||||||||
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 astronomical units (103,000,000 km) | ||||||||||
Aphelion altitude | 1.01 astronomical units (151,000,000 km) | ||||||||||
Inclination | 2.0° | ||||||||||
Period | 287 days | ||||||||||
Venus lander | |||||||||||
Landing date | 15 December 1970, 05:37:10 UTC | ||||||||||
Landing site | 5°S 351°E | ||||||||||
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![]() Seal of Venera 7 Venera Kosmos 359 → |
The lander was designed to be able to survive pressure of up to 180 bars (18,000 kPa) (2,610 psi) and temperatures of 580 °C (1,076 °F).[3] This was significantly 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.[3] The degree of hardening added mass to the probe which limited the amount of mass available for scientific instruments both on the probe itself and the interplanetary bus.[3] The interplanetary bus carried a solar wind charged particle detector and a cosmic ray detector.[4] On the lander there were temperature and pressure sensors as well as an accelerometer to measure atmospheric density.[5] The probe also carried a radar altimeter.[5]
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' on-board KDU-414 engine.[6]
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 (17 °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 km, 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 meters, opening to 2.5 square meters 13 minutes later, when the reefing line melted as designed.[5] Six minutes after the unreefing, the parachute started to fail, resulting in a descent more rapid than planned.[5][6] The parachute eventually failed completely, and the probe entered a period of freefall.[5] 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.[7]
The probe appeared to go silent on impact,[6] but recording tapes kept rolling.[8] A few weeks later, upon a review of the tapes by the 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 °C (887 °F) ± 20 °C.[6][10] Using the temperature, and models of the atmosphere, a pressure of 9.0 MPa (1,300 psi) ± 1.5 MPa was calculated.[11] From the spacecraft's rapid halt (from falling to stationary inside 0.2 seconds), 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, which could not be seen through a thick veil of atmosphere. 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]
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Descent probes | |
Landers | |
Failed launches |
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Future missions |
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Spacecraft missions to Venus | |||||||||||||
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Active missions |
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Past missions |
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Program overviews |
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Related |
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← 1969 · Orbital launches in 1970 · 1971 → | |
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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). |