Venera 9 (Russian: Венера-9, lit. 'Venus-9'), manufacturer's designation: 4V-1 No. 660,[3] was a Soviet uncrewed space mission to Venus. It consisted of an orbiter and a lander. It was launched on June 8, 1975, at 02:38:00 UTC and had a mass of 4,936 kilograms (10,882 lb).[4] The orbiter was the first spacecraft to orbit Venus, while the lander was the first to return images from the surface of another planet.[5]
![]() Artist's conception of Venera 9 landed on Venus | |
Mission type | Venus orbiter / lander |
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Operator | Lavochkin |
COSPAR ID | 1975-050A 1975-050D |
SATCAT no. | 7915 8411 |
Mission duration | Orbiter: 158 days Lander: 53 minutes Launch to last contact: 292 days |
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 (1975-06-08UTC02:38) UTC[1] |
Rocket | Proton-K/D[1] |
Launch site | Baikonur 81/24 |
End of mission | |
Last contact | Orbiter primary mission: March 22, 1976 (1976-03-23)[2] Lander: October 22, 1975 (1975-10-23) |
Orbital parameters | |
Reference system | Cytherocentric |
Eccentricity | 0.89002 |
Pericytherion altitude | 7,625 km (4,738 mi) |
Apocytherion altitude | 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 / 31.01; 291.64 (near Beta Regio) |
![]() Stamp of Venera 9 Venera |
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The orbiter entered Venus orbit on October 20, 1975. Its mission was to act as a communications relay for the lander and to explore cloud layers and atmospheric parameters with several instruments and experiments. It performed 17 survey missions from October 26, 1975, to December 25, 1975.
The 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, and mounted on top was a 2.4-metre (7.9 ft) sphere which held the lander.
The instruments composing the orbiter included:[6]
The lander was encased in a spherical shell before landing to help protect it from the heat of entry as it slowed from 10.7 km/s to 150 m/s. This sphere was then separated with explosive bolts and a three-domed parachute was deployed which slowed the lander further to 50 m/s at an altitude of 63 km above the planet.[7]
The descent through the cloud layer took about 20 minutes, during which time the lander took measurements of the atmosphere and radioed the information to the orbiter.[7] To minimize lander damage in the hot atmosphere, the parachute was released at an altitude of 50 km, and the ring-shaped aerodynamic shield provided braking. The Venusian atmosphere is so dense near the surface that this shield provided a descent rate of 7 m/s as the lander touched down.[7] The landing device, a hollow ring surrounding the lower part of the lander, was partly crushed upon touchdown to take up most of the landing impact.[7]
On October 20, 1975, the lander spacecraft separated from the orbiter, and landing was made with the Sun near zenith at 05:13 UTC on October 22. Venera 9 landed within a 150 km (93 mi) radius of 31.01°N 291.64°E / 31.01; 291.64, near Beta Regio, on a steep (20°) slope covered with boulders (suspected to be the slope of the tectonic rift valley, Aikhylu Chasma). The entry sphere weighed 1,560 kg (3,440 lb) and the surface payload was 660 kg (1,455 lb).[8]
It was the first spacecraft to return an image from the surface of another planet. Many of the instruments began working immediately after touchdown and the cameras were operational 2 minutes later. These instruments revealed a smooth surface with numerous stones. The lander measured a light level of 14,000 lux, similar to that of Earth in full daylight but no direct sunshine.[7]
A system of circulating fluid was used to distribute the heat load. This system, plus pre-cooling prior to entry, permitted operation of the lander for 53 minutes after landing, at which time radio contact with the orbiter was lost as the orbiter moved out of radio range.[6] During descent, heat dissipation and deceleration were accomplished sequentially by protective hemispheric shells, three parachutes, a disc-shaped drag brake, and a compressible, metal, doughnut-shaped landing cushion. The landing was about 2,200 km (1,400 mi) from the Venera 10 landing site.
Venera 9 measured clouds that were 30–40 km (19–25 mi) thick with bases at 30–35 km (19–22 mi) altitude. It also measured 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. Venera 9 was the first probe to send back television pictures (black and white) from the Venusian surface, showing no shadows, no apparent dust in the air, and a variety of 30 to 40 cm (12 to 16 in) rocks which were not eroded. Planned 360-degree panoramic pictures could not be taken because one of two camera lens covers failed to come off, limiting pictures to 180 degrees. This failure recurred with Venera 10.
The lander payload was as follows:[6]
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← 1974 · Orbital launches in 1975 · 1976 → | |
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Soyuz 17 | Kosmos 702 | Kosmos 703 | Landsat 2 | Kosmos 704 | Kosmos 705 | Kosmos 706 | Kosmos 707 | Molniya-2-12 | Starlette | SMS-2 | Kosmos 708 | Kosmos 709 | Intelsat IV F-6 | Taiyo | Kosmos 710 | Kosmos 711 · Kosmos 712 · Kosmos 713 · Kosmos 714 · Kosmos 715 · Kosmos 716 · Kosmos 717 · Kosmos 718 | OPS 2439 | Kosmos 719 | Kosmos 720 | Kosmos 721 · Nauka-5KSA No.4 | Kosmos 722 | Interkosmos 13 | Meteor-M No.31 | Kosmos 723 | Soyuz 7K-T No.39 | Kosmos 724 | Kosmos 725 | GEOS-3 | Kosmos 726 | RM-20 | Molniya-3 No.12 | Kosmos 727 | Kosmos 728 | OPS 4883 | Aryabhata | Kosmos 729 | Kosmos 730 | Molniya-1-29 | Explorer 53 | Anik A3 | Polluz · Castor | OPS 9435 · OPS 9436 | Kosmos 731 · Nauka-9KS No.2 | Intelsat IV F-1 | OPS 6226 | Soyuz 18 | Kosmos 732 · Kosmos 733 · Kosmos 734 · Kosmos 735 · Kosmos 736 · Kosmos 737 · Kosmos 738 · Kosmos 739 | Kosmos 740 | Kosmos 741 | DS-U3-IK No.5 | Kosmos 742 | Molniya-1 No.24 · SRET-2 | Venera 9 | OPS 6381 · P-226-1 | Nimbus 6 | Kosmos 743 | Venera 10 | OPS 4966 | Kosmos 744 | OSO-8 | Kosmos 745 | Kosmos 746 | Kosmos 747 | Kosmos 748 | Kosmos 749 | Molniya-2-13 | Meteor-2 No.1 | Apollo-Soyuz | DM-2 | Kosmos 750 | Kosmos 751 | Kosmos 752 | Ji Shu Shiyan Weixing 1 | Kosmos 753 | Cos-B | Kosmos 754 | Kosmos 755 | Viking 1 | Kosmos 756 | Symphonie 2 | Kosmos 757 | Molniya-1-31 | Kosmos 758 | Molniya-2-14 | Kiku 1 | Viking 2 | Kosmos 759 | Kosmos 760 | Kosmos 761 · Kosmos 762 · Kosmos 763 · Kosmos 764 · Kosmos 765 · Kosmos 766 · Kosmos 767 · Kosmos 768 | Meteor-M No.28 | Kosmos 769 | Kosmos 770 | Kosmos 771 | Intelsat IVA F-1 | Aura | Kosmos 772 | Kosmos 773 | Kosmos 774 | Explorer 54 | Kosmos 775 | OPS 5499 | Triad 2 | E-8-5M No.412 | GOES 1 | Kosmos 776 | Kosmos 777 | Kosmos 778 | Kosmos 779 | Molniya-3 No.13 | Soyuz 20 | Explorer 55 | Kosmos 780 | Kosmos 781 | Kosmos 782 | Fanhui Shi Weixing 2 | Kosmos 783 | Kosmos 784 | OPS 4428 · OPS 5547 | DAD-A · DAD-B | Interkosmos 14 | Kosmos 785 | Satcom 1 | OPS 3165 | Ji Shu Shiyan Weixing 2 | Kosmos 786 | Molniya-2-15 | Unnamed | Prognoz 4 | Gran' No.11L | Meteor No.38 | Molniya-3 No.15 | |
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). |