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Vega 2

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Vega - Venus Missions

Vega - Venus Missions

NASA

Key Dates:

  • 12.21.84: Launch
  • 06.15.85: End of Venus Mission
  • 03.11.86: End of Comet Mission
  • Status: Mission Complete

Scientific Instruments:

Lander
  1. Malakhit mass spectrometer
  2. Sigma-3 gas chromatograph
  3. VM-4 hygrometer
  4. GS-15-SCV gamma-ray spectrometer
  5. UV spectrometer
  6. BDRP-AM25 x-ray fluorescence spectrometer and drill
  7. ISAV nephelometer/scatterometer
  8. Temperature and pressure sensors
  9. IFP aerosol analyzer
Balloon
  1. temperature and pressure sensors
  2. vertical wind anemometer
  3. nephelometer
  4. light level/lighting detector
Bus
  1. imaging system
  2. infrared spectrometer
  3. ultraviolet, visible, infrared imaging spectrometer
  4. shield penetration detector
  5. dust detectors
  6. dust mass spectrometer
  7. neutral gas mass spectrometer
  8. plasma energy analyzer
  9. energetic-particle analyzer
  10. magnetometer
  11. wave and plasma analyzers

Fast facts:

  • Nation: USSR (103)
  • Objective(s): Venus atmospheric entry and landing, Halley's Comet flyby
  • Spacecraft: 5VK (no. 902)
  • Spacecraft Mass: c. 4,920 kg
  • Mission Design and Management: NPO Lavochkin
  • Launch Vehicle: 8K82K + Blok DM (Proton-K no. 329-01 / Blok DM no. 11L)
  • Launch Date and Time: 21 December 1984 / 09:13:52 UT
  • Launch Site: NIIP-5 / launch site 200P

Mission Results:

The Vega project was an ambitious deep space Soviet mission with three major goals: to place advanced lander modules on the surface of Venus, to deploy balloons (two each) in the Venusian atmosphere, and, by using Venusian gravity, to fly the remaining buses past the Comet Halley. It was a cooperative effort among the Soviet Union (who provided the spacecraft and launch vehicle) and Austria, Bulgaria, Hungary, the German Democratic Republic (East Germany), Poland, Czechoslovakia, France, and the Federal Republic of Germany (West Germany).
Vega 1's sister spacecraft Vega 2 essentially performed a near-identical mission to its twin.

On 15 June 1985 the main lander probe set down without problems at 03:00:50 UT in the northern region of Aphrodite, about 1,500 kilometers southeast of Vega. Landing coordinates were 6.45 degrees south latitude and 181.08 degrees longitude. The spacecraft transmitted from the surface for 57 minutes.

The Vega 2 lander had better luck at being able to collect and investigate a soil sample than her sister, Vega 1. It identified an anorthosite-troctolite rock, rarely found on Earth, but present in the lunar highlands. According to the lander's data. The area was probably the oldest explored by any Venera vehicle. Unfortunately, the mass spectrometer did not return any data.

Vega 2 released its balloon upon entry into the atmosphere. The balloon flew through the Venusian atmosphere, collecting data like its twin, and survived for 46.5 hours of data transmission.

After releasing its lander, the flyby probe continued on its flight to Comet Halley. The spacecraft initiated its encounter on 7 March 1986 by taking 100 photos of the comet from a distance of 14 million kilometers. Vega 2's closest approach to Halley was at 07:20 UT two days later when the spacecraft was traveling at a speed of 76.8 kilometers per second (slightly lower than Vega 1's 79.2 kilometers per second).

During the encounter, Vega 2 took 700 images of the comet -- of much better resolution than those from the spacecraft's twin, partly due to the presence of less dust outside of the coma during this transit. Ironically, Vega 2 sustained an 80-percent power loss during the encounter (as compared to Vega 1's 40 percent).

Seven instruments between the two spacecraft were partially damaged, although no instrument on both was incapacitated. After further imaging sessions on 10 and 11 March 1986, Vega 2 finished its primary mission and headed out into heliocentric orbit.

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