Astronaut Kathryn Thornton works with instruments while on a spacewalk. A small part of Earth is visible behind her on the right.)
NASA

In this image from Dec. 8, 1993, astronaut Kathryn C. Thornton works with equipment during a spacewalk. The spacewalk was part of an 11-day mission, Servicing Mission 1, to service the Hubble Space Telescope. Shortly after Hubble was launched in 1990, NASA discovered a flaw in the observatory’s primary mirror that affected the clarity of the telescope’s early images. Fortunately, Hubble’s design allowed astronauts to perform repairs, replace parts, and update its technology with new instruments while in orbit.

Watch an exclusive interview with Thornton, where she shares a firsthand account of the groundbreaking mission, unveiling the challenges, triumphs, and the incredible journey that revitalized Hubble.

Image credit: NASA