On December 4, 1993, Space Shuttle Endeavour roared into orbit on the most nerve-wracking repair job in NASA history. Their target - the Hubble Space Telescope, a school-bus-sized observatory worth $1.5 billion that had a tiny problem. Its main mirror had been ground slightly too flat, making every photo it sent back look blurry, like glasses with the wrong prescription. Scientists had built the greatest telescope of all time, and it could not see straight.
For five days in a row, astronauts Story Musgrave, Jeffrey Hoffman, Kathryn Thornton, and Tom Akers took turns floating outside the shuttle in spacesuits, performing the longest series of spacewalks ever attempted. They wrestled with stuck bolts, installed new gyroscopes, swapped out solar panels, and most importantly, fitted Hubble with corrective optics called COSTAR - basically giving the telescope a pair of contact lenses the size of a refrigerator.
When NASA powered Hubble back up, mission control burst into cheers. The blur was gone. Suddenly Hubble could see distant galaxies, baby stars being born inside glowing nebulae, and the rings of dying suns. Photos like the Pillars of Creation became famous around the world. Hubble has now sent back more than 1.5 million images and helped scientists figure out how old the universe is, around 13.8 billion years. None of that would exist without the brave astronauts who climbed out of Endeavour and gave a giant space eye its sight back.
