The Mariner program was conducted by the American space agency NASA to explore other planets. Between 1962 and late 1973, NASA's Jet Propulsion Laboratory (JPL) designed and built 10 robotic interplanetary probes named Mariner to explore the inner Solar System – visiting the planets Venus, Mars and Mercury for the first time, and returning to Venus and Mars for additional close observations.
The Venera program was a series of space probes developed by the Soviet Union between 1961 and 1984 to gather information about the planet Venus.
The Pioneer Venus project was part of the Pioneer program consisting of two spacecraft, the Pioneer Venus Orbiter and the Pioneer Venus Multiprobe, launched to Venus in 1978. The program was managed by NASA's Ames Research Center.
Giotto was a European robotic spacecraft mission from the European Space Agency. The spacecraft flew by and studied Halley's Comet and in doing so became the first spacecraft to make close up observations of a comet. On 13 March 1986, the spacecraft succeeded in approaching Halley's nucleus at a distance of 596 kilometers. It was named after the Early Italian Renaissance painter Giotto di Bondone. He had observed Halley's Comet in 1301 and was inspired to depict it as the star of Bethlehem in his painting Adoration of the Magi in the Scrovegni Chapel.
Vega 1 was a Soviet space probe, part of the Vega program. The spacecraft was a development of the earlier Venera craft. They were designed by Babakin Space Centre and constructed as 5VK by Lavochkin at Khimki. The name VeGa (ВеГа) combines the first two letters from the Russian words for Venus and Halley.
The Vega program was a series of Venus missions that also took advantage of the appearance of comet 1P/Halley in 1986. Vega 1 and Vega 2 were uncrewed spacecraft launched in a cooperative effort among the Soviet Union and Austria, Bulgaria, France, Hungary, the German Democratic Republic, Poland, Czechoslovakia, and the Federal Republic of Germany in December 1984. They had a two-part mission to investigate Venus and also flyby Halley's Comet.
Venera 16 was a spacecraft sent to Venus by the Soviet Union. This uncrewed orbiter was to map the surface of Venus using high resolution imaging systems. The spacecraft was identical to Venera 15 and based on modifications to the earlier Venera space probes. The latest data from the spacecraft were received on June 13, 1985, when it responded to the signal sent from Earth for Vega 1.
The Venera 11 was a Soviet uncrewed space mission which was part of the Venera program to explore the planet Venus. Venera 11 was launched on 9 September 1978 at 03:25:39 UTC.
The Venera 12 was an uncrewed Soviet space mission designed to explore the planet Venus. Venera 12 was launched on 14 September 1978 at 02:25:13 UTC.
Venera 9, manufacturer's designation: 4V-1 No. 660, 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). The orbiter was the first spacecraft to orbit Venus, while the lander was the first to return images from the surface of another planet.
Venera 10, or 4V-1 No. 661, was a Soviet uncrewed space mission to Venus. It consisted of an orbiter and a lander. It was launched on June 14, 1975, 03:00:31 UTC and had a mass of 5033 kg (11096 lb).
Venera 6, or 2V (V-69) No.331, was a Soviet spacecraft, launched towards Venus to obtain atmospheric data. It had an on-orbit dry mass of 1,130 kg (2,490 lb).
The Comet Rendezvous Asteroid Flyby (CRAF) was a cancelled plan for a NASA-led exploratory mission designed by the Jet Propulsion Laboratory during the mid-to-late 1980s and early 1990s, that planned to send a spacecraft to encounter an asteroid, and then to rendezvous with a comet and fly alongside it for nearly three years. The project was eventually canceled when it went over budget; most of the money still left was redirected to its twin spacecraft, Cassini–Huygens, destined for Saturn, so it could survive Congressional budget cutbacks. Most of CRAF's scientific objectives were later accomplished by the smaller NASA spacecraft Stardust and Deep Impact, and by ESA's flagship Rosetta mission.
Venera 4, also designated 4V-1 No.310, was a probe in the Soviet Venera program for the exploration of Venus. The probe comprised a lander, designed to enter the Venusian atmosphere and parachute to the surface, and a carrier/flyby spacecraft, which carried the lander to Venus and served as a communications relay for it.
Venera 8 was a probe in the Soviet Venera program for the exploration of Venus and was the second robotic space probe to conduct a successful landing on the surface of Venus.
Venera 13 was part of the Soviet Venera program meant to explore Venus.
Venera 14 was a probe in the Soviet Venera program for the exploration of Venus.
Observations of the planet Venus include those in antiquity, telescopic observations, and from visiting spacecraft. Spacecraft have performed various flybys, orbits, and landings on Venus, including balloon probes that floated in the atmosphere of Venus. Study of the planet is aided by its relatively close proximity to the Earth, compared to other planets, but the surface of Venus is obscured by an atmosphere opaque to visible light.
Venera-D is a proposed Russian space mission to Venus that would include an orbiter and a lander to be launched in 2031. The orbiter's prime objective is to perform observations with the use of a radar. The lander, based on the Venera design, would be capable of operating for a long duration on the planet's surface. The "D" in Venera-D stands for "dolgozhivuschaya," which means "long lasting" in Russian.
A replica of the Vega spacecraft displayed at the Udvar-Hazy Center, Virginia, US | |
Names | Venera–Halley 2 |
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Mission type | Venus/Halley exploration |
Operator | Soviet space program |
COSPAR ID | 1984-128A 1984-128E 1984-128F |
SATCAT no. | 15449 15856 15857 |
Mission duration | Lander: 56 minutes Balloon: 2 days Flyby: 2 years, 3 months and 3 days |
Spacecraft properties | |
Spacecraft | 5VK No. 902 |
Spacecraft type | 5VK |
Manufacturer | NPO Lavochkin |
Launch mass | 4,840 kg (10,670 lb) [1] |
Landing mass | 1,520 kg (3,350 lb) |
Dimensions | 2.7 m × 2.3 m × 5.7 m (8.9 ft × 7.5 ft × 18.7 ft) (lander) |
Start of mission | |
Launch date | December 21, 1984 , 09:13:52 UTC [1] |
Rocket | Proton-K/D |
Launch site | Baikonur 200/40 |
Contractor | Khrunichev |
End of mission | |
Last contact | March 24, 1987 [1] |
Orbital parameters | |
Reference system | Heliocentric |
Eccentricity | 0.17 |
Perihelion altitude | 0.70 AU |
Aphelion altitude | 0.98 AU |
Inclination | 51.5° |
Period | 281 days |
Flyby of Venus | |
Closest approach | June 15, 1985 |
Distance | 24,500 km (15,200 mi) |
Venus atmospheric probe | |
Spacecraft component | Vega 2 Balloon |
Atmospheric entry | 02:06:04,June 15,1985 |
Venus lander | |
Spacecraft component | Vega 2 Lander |
Landing date | 03:00:50,June 15,1985 |
Landing site | |
Flyby of 1P/Halley | |
Closest approach | March 9,1986 |
Distance | ~8,030 km (4,990 mi) |
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Vega 2 (along with Vega 1) was a Soviet space probe part of the Vega program to explore Halley's comet and Venus. The spacecraft was a development of the earlier Venera craft. The name VeGa (ВеГа) combines the first two letters of the Russian words for Venus (Венера:"Venera") and Halley (Галлея:"Galleya"). They were designed by Babakin Space Centre and constructed as 5VK by Lavochkin at Khimki. The craft was powered by large twin solar panels. Instruments included an antenna dish,cameras,spectrometer,infrared sounder,magnetometers (MISCHA) and plasma probes. The 4,840 kilograms (10,670 lb) craft was launched on top of a Proton-K from Baikonur Cosmodrome,Tyuratam,Kazakh SSR. Both Vega 1 and 2 were three-axis stabilized spacecraft. The spacecraft were equipped with a dual bumper shield for dust protection from Halley's Comet.
The descent module arrived at Venus on 15 June 1985,two days after being released from the Vega 2 flyby probe. The module,a 1,500 kilograms (3,300 lb),240 centimetres (7.9 ft) diameter sphere,contained a surface lander and a balloon explorer. The flyby probe performed a gravitational assist maneuver using Venus,and continued its mission to intercept the comet. [2]
The surface lander was identical to that of Vega 1 as well as the previous six Venera missions. The objective of the probe was the study of the atmosphere and the exposed surface of the planet. The scientific payload included a UV spectrometer,temperature and pressure sensors,a water concentration meter,a gas-phase chromatograph,an X-ray spectrometer,a mass spectrometer,and a surface sampling device. Several of these scientific tools (the UV spectrometer,the mass spectrograph,and the devices to measure pressure and temperature) were developed in collaboration with French scientists. [2] Since the probe made a nighttime landing,no images were taken.
The Vega 2 lander touched down at 03:00:50 UT on 15 June 1985 at around 7°08′S177°40′E / 7.14°S 177.67°E ,in the northern region of Aphrodite Terra. The altitude of the touchdown site was 0.1 kilometres (330 ft) above the planetary mean radius. The measured pressure at the landing site was 91 atm and the temperature was 736 K (463 °C;865 °F). The surface sample was found to be an anorthosite–troctolite rock,rarely found on Earth,but present in the lunar highlands,leading to the conclusion that the area was probably the oldest explored by any Venera vehicle. It transmitted data from the surface for 56 minutes. [3]
The Vega 2 Lander/Balloon capsule entered the Venusian atmosphere (125 kilometres [78 mi] altitude) at 02:06:04 UT (Earth received time;Moscow time 05:06:04) on 15 June 1985 at roughly 11 kilometres per second (6.8 mi/s). At approximately 2:06:19 UT the parachute attached to the landing craft cap opened at an altitude of 64 kilometres (40 mi). The cap and parachute were released 15 seconds later at 63 kilometres (39 mi) altitude. The balloon package was pulled out of its compartment by parachute 40 seconds later at 61 kilometres (38 mi) altitude,at 7.45 degrees S,179.8 degrees east. A second parachute opened at an altitude of 55 kilometres (34 mi),200 seconds after entry,extracting the furled balloon.
The balloon was inflated 100 seconds later at 54 kilometres (34 mi) and the parachute and inflation system were jettisoned. The ballast was jettisoned when the balloon reached roughly 50 kilometres (31 mi) and the balloon floated back to a stable height between 53 and 54 kilometres (33 and 34 mi) some 15 to 25 minutes after entry. The mean stable height was 53.6 kilometres (33.3 mi),with a pressure of 535 millibars (535 hPa) and a temperature of 308–316 K (35–43 °C;95–109 °F) in the middle,most active layer of the Venus three-tiered cloud system. The balloon drifted westward in the zonal wind flow with an average speed of about 66 metres per second (220 ft/s) at nearly constant latitude. The probe crossed the terminator from night to day at 9:10 UT on 16 June after traversing 7,400 kilometres (4,600 mi). The probe continued to operate in the daytime until the final transmission was received at 00:38 UT on 17 June from 7.5 S,76.3 E after a total traverse distance of 11,100 kilometres (6,900 mi). It is not known how much further the balloon traveled after the final communication. [3]
After their encounters,the Vegas' motherships were redirected by Venus' gravity to intercept Halley's Comet.
The spacecraft initiated its encounter on March 7,1986,by taking 100 photos of the comet from a distance of 14,000,000 kilometres (8,700,000 mi).
Vega 2 made its closest approach at 07:20 UT on March 9,1986,at 8,030 kilometres (4,990 mi). The data intensive examination of the comet covered only the three hours around closest approach. They were intended to measure the physical parameters of the nucleus,such as dimensions,shape,temperature and surface properties,as well as to study the structure and dynamics of the coma,the gas composition close to the nucleus,the dust particles' composition and mass distribution as functions of distance to the nucleus and the cometary-solar wind interaction.
During the encounter,Vega 2 took 700 images of the comet,with better resolution than those from the twin Vega 1,partly due to the presence of less dust outside the coma at the time. Yet Vega 2 recorded an 80% power loss during the encounter as compared to Vega 1's 40%.
After further imaging sessions on 10 and 11 March 1986,Vega 2 finished its primary mission.
A 6 million kilometer distant flyby of 2101 Adonis was considered,however,Vega 2 didn't have enough fuel left to make the necessary orbital changes for the flyby. [4] Instead the Vega probes took the opportunity to measure the dust as they passed through the orbits of 72P/Denning–Fujikawa,Biela's Comet and 289P/Blanpain. [4]
Contact with Vega 2 was lost on 24 March 1987. [4] Vega 1 had previously exhausted its attitude control propellant on 30 January 1987. [4]
Vega 2 is currently in heliocentric orbit,with perihelion of 0.70 AU,aphelion of 0.98 AU,eccentricity of 0.17,inclination of 2.3 degrees and orbital period of 281 days. [ citation needed ]
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