How the Space Shuttle completed a final, daring Hubble repair 15 years ago

The Hubble Space Telescope continues to operate to this day in part due to the work performed 15 years ago by the crew of STS-125. Dubbed Hubble Servicing Mission 4 (HSM 4), scientists knew this would be their final chance to use the space shuttle to visit and upgrade the orbiting laboratory. As we look back on the mission, the question remains whether or not Hubble will be visited or repaired again. More

(Source: NASASpaceFlight.com - May 21)