Mission Type: Flyby, Lander
Launch Vehicle: 8K82K + Blok DM (Proton-K no. 325-02 / Blok DM no. 12L)
Launch Site: NIIP-5 / launch site 200P, Tyuratam (Baikonur Cosmodrome), USSR
Spacecraft Mass: 4,920 kg
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 and 9) IFP aerosol analyzer
Balloon: 1) temperature and pressure sensors; 2) vertical wind anemometer; 3) nephelometer and 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) APV-V plasma energy analyzer; 9) energetic-particle analyzer; 10) magnetometer and 11) wave and plasma analyzers
Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, Monographs in Aerospace History No. 24, by Asif A. Siddiqi
National Space Science Data Center, http://nssdc.gsfc.nasa.gov/
Solar System Log by Andrew Wilson, published 1987 by Jane's Publishing Co. Ltd
Vega 2 was the sister spacecraft to Vega 1 and essentially performed a near-identical mission to its twin.
The main lander probe set down without problems at 03:00:50 UT on 15 June 1985 in the northern region of Aphrodite, about 1,500 kilometers southeast of
Vega. Landing coordinates were 6.45° south latitude and 181.08° longitude. The spacecraft transmitted from the surface for 57 minutes.
Unlike its twin, the Vega 2 lander was able to collect and investigate a soil sample; the experiment 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. The mass spectrometer did not return any data.
The balloon, released upon entry into the atmosphere, 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.