Space Shuttle Discovery launched into orbit 30 years ago today with the Hubble Space Telescope in its payload bay.

Charlie Bolden, who served as pilot for the STS-31 shuttle mission, remembers the five-day spaceflight like it was yesterday. “What stands out most vividly in my mind is all things that didn’t go right,” Bolden recalled in an interview.

It’s true. Although astronomers would not discover that the Hubble Space Telescope had a serious problem with its mirror until a few weeks after Discovery landed, the deployment mission was not without difficulties itself. The crew came within minutes of embarking on an emergency spacewalk and even had contingency plans to bring Hubble back to Earth if needed.