Hubble Space Telescope

Launched in 1990 with a famously flawed mirror — then fixed by astronauts in one of the most dramatic spacewalks ever — Hubble has captured over 1.5 million observations and fundamentally changed our understanding of the universe. It proved the universe's expansion is accelerating (earning a Nobel Prize), revealed galaxies forming just 500 million years after the Big Bang, and produced images so beautiful they've become cultural icons. Hubble didn't just observe the cosmos — it made the public care about it.