Goals: The ambitious twin-spacecraft Vega project aimed to deliver advanced lander modules on Venus, study the planet's atmosphere with balloons and then fly on for a close encounter with comet Halley.
Accomplishments: Both Vega 2 and its twin Vega 1 were tremendously successful. Vega 2's balloons drifted a third of the way around Venus, collecting valuable atmospheric data. The balloon measured temperatures 6.5°C (11.7°F) lower than did the Vega 1 balloon. Vega 2's set down 1,500 km (932 miles) SE of the Vega 1 lander, on a surface that was surprisingly smooth for the region. Unlike its twin, this lander performed soil analysis successfully, reporting a type of rock that is rare on Earth but found in lunar highlands.