New Horizons

New Horizons' 2015 flyby of Pluto revealed a geologically active world 4.8 billion kilometers from Earth, capturing nitrogen ice glaciers and a 1,000-kilometer-wide heart-shaped plain. Its speed of 14 kilometers per second made it faster than the typical deep-space probe by 30%, and it outperforms #5 Cassini-Huygens in redefining a planetary body's complexity at the solar system's edge despite a 90% lower payload mass. The mission cost just $780 million, a bargain that delivered 50 gigabits of data on Pluto's five moons, including direct evidence of cryovolcanism.