Atlantis and seven astronauts blasted off from Cape Canaveral in Florida on Nasa's final trip to Hubble, which was delayed by seven months.
About 30,000 people jammed into the Kennedy Space Centre for the launch of Nasa's fifth and final trip to Hubble, launched 19 years ago.
The stakes, as well as the dangers, are higher since astronauts last visited in 2002.
Space has become more littered with junk at Hubble's altitude because of satellite collisions and break-ups, and Nasa now knows all too well how much damage can be done at lift-off by a piece of fuel-tank foam.
Columbia was brought down by the damage on February 1, 2003, when it disintegrated over Texas during re-entry into the Earth's atmosphere, with the loss of all seven crew members.
Atlantis and its crew were supposed to fly to Hubble last autumn, but the telescope broke down.
The shuttle should arrive at the orbiting observatory on Wednesday. The billion-dollar repair job will feature five spacewalks.
Astronauts will install new cameras, batteries and gyroscopes, and attempt to fix two broken scientific instruments.
Another shuttle is on a launch pad and ready to lift off on a rescue mission if Atlantis is seriously damaged during the 11-day flight.Reuse content