In 1990 the Hubble Space Telescope was launched, putting into orbit one of the most remarkable scientific instruments that has ever existed.

But initially the mission ran into problems, including a flawed mirror that meant the first images from Hubble were blurry.

Nasa astronaut Kathryn Sullivan was one of the five crew members who launched the Hubble.

Witness History: The stories of our times told by the people who were there.