Seven astronauts on a fix-it job continued installing parts on the Hubble Space Telescope on Monday. For the long-distance service run, Space Shuttle Atlantis crew members grabbed the 19-year-old observatory and work on it while orbiting 350 miles above Earth. The first in-person Hubble visit since 2002 featured five spacewalks, including one Sunday that lasted eight hours.

The job, which has been harder than NASA engineers expected, includes fixing a burned-out camera, replacing two gyroscopes and installing a new instrument designed to detect faint light from faraway quasars (star-like objects). Space mechanics brought 180 specially designed tools, which they use while wearing gloves that are a bit like oven mitts. They work in zero gravity, which means a dropped tool or part could float into the $10-billion telescope and damage the delicate instrument. Stuck screws and bolts have complicated their tasks.

Hubble has spent nearly two decades in Earth's orbit, capturing snapshots of the distant universe that help astronomers, physicists and other scientists understand our solar system. Without routine maintenance, it slowly breaks down in the harsh environment of space. Thanks to this mission, it will be more powerful than ever and should keep going until at least 2014 -- when NASA plans to launch a large new observatory that will orbit about a million miles from Earth.
In one of the current trip's easiest duties, spacewalkers attached a kind of ring to Hubble so a future unmanned spacecraft can dock with the telescope to yank it out of orbit when its long, productive life finally ends.

Astronaut says: "From orbit: My spacewalk was amazing, we had some tough problems, but through them all, the view of our precious planet was beautiful." -- Mike Massimino (@)Astro_Mike), via Twitter on May 16

NASA specialist says: "Every day has been hold-your-breath." -- Dave Leckrone, project scientist

Why is it named Hubble? The giant space telescope is named for a trailblazing U.S. astronomer, Edwin P. Hubble, who lived from 1889 to 1953. NASA's website says: "Edwin Hubble transformed our understanding of the universe. His spirit of discovery lives on today in the Hubble Space Telescope."