Launched in 2004, Rosetta made history as the first spacecraft to orbit a comet, escorting 67P/Churyumov-Gerasimenko for two years and deploying the Philae lander before deliberately impacting the comet's surface in 2016.

Launched in 1962, Mariner 2 became the first spacecraft to successfully fly by another planet when it passed within 34,773 kilometers of Venus and confirmed the planet's extremely hot surface temperature and pressure.

Launched in 1972, Pioneer 10 became the first spacecraft to cross the asteroid belt, visit Jupiter, and leave the Solar System, sending its final signal in 2003 after traveling over 7.6 billion miles.