Vega 2The Soviet Union’s unmanned space probe Vega 2 makes its closest approach to the nucleus of Halley’s Comet, within 5,000 miles of the comet’s icy core. Hundreds of photos are taken and transmitted back to Earth, along with analysis of the dust and gas surrounding the comet. Within a week, Vega 2’s mission is complete, and the probe is allowed to fall into an orbit around the sun as Halley continues to speed back toward the outer solar system.