Hubble Space Telescope

The Hubble Space Telescope, launched in 1990, overcame a famously flawed mirror—fixed during one of the most dramatic spacewalks ever—to capture over 1.5 million observations, fundamentally altering astronomy. It proved the universe's expansion is accelerating, earning a Nobel Prize, and revealed galaxies forming just 500 million years after the Big Bang, a discovery 30% older than the previous record. Hubble's images became cultural icons, making the public care about the cosmos more than any other mission, surpassing even Voyager 1 in public engagement.