While Americans squabble about politics here on earth, way above them the space shuttle Atlantis’ astronauts are engaging in a risky space walk to repair the Hubble Space Telescope — a high-tech repair with high stakes risks:

John Grunsfeld and Drew Feustel are on a six-and-a-half hour spacewalk to replace Hubble’s interplanetary camera with a new one that will allow it to look deeper into the universe. They will also replace a science data computer that failed last September and install a device to capture the telescope for de-orbit at the end of its life.

This is the first of five scheduled spacewalks to service Hubble and keep it operating for at least five more years. The telescope has been in orbit since 1990 and this is the fifth and final flight to make upgrades and repairs to it.

The mission is more dangerous than others because the telescope is sharing an orbit with lots of debris left behind by satellite collisions and rocket launches.

Missions to the telescope can also be riskier because astronauts only have the supplies they carry with them. But with missions to the International Space Station, the station can support a stranded crew for up to three months.

A TV report puts it into perspective:
http://www.youtube.com/watch?v=F0lpbK_rTD0&eurl=http%3A%2F%2Fnews.google.com%2Fnwshp%3Fclient%3Dfirefox-a%26rls%3Dorg.mozilla%3Aen-US%3Aofficial%26hl%3Den%26tab%3Dwn&feature=player_embedded
The Christian Science Monitor says this will be the astronauts’ Things To Do List:

• Replace the telescope’s wide-field and planetary camera. The duo will pull WFPC 2 out of Hubble, stow it, replace it with WFPC 3. WFPC 2 has generated some of Hubble’s most memorable images. And it took the first of what will be three so-called deep-field surveys of the universe — a look back at the universe when it was less than 2 billion years old. WFPC 3 will play a key role in survey No. 3. The survey is expected to capture images of the universe when it was only about 500 million years old.

• Replace a balky computer that acts as Hubble’s Grand Central Station for data. The computer — the Science Instrument Command and Data Handling Unit — routes commands from the ground to the telescope and ships engineering and science data back to Earth. This, plus the upgrade to the wide-field camera, are two of five jobs that represent the least the astronauts must accomplish to earn high-fives when they get back.

• Install new latches on some of the doors to the telescope’s interior to speed the work on later repair spacewalks.

• As a “get ahead” task, Grunsfeld and Feustel also will install a soft-capture device on Hubble. This gives a spacecraft several years a spot it can use to grab the telescope and drag it to an orbit that would allow for its final spectacle — a fiery demise as it reenters Earth’ atmosphere.

NPR has some details on the repairs so far:

The Hubble Space Telescope got to welcome back an old friend Thursday morning when astronaut John Grunsfeld floated out of space shuttle Atlantis to start repair work on the 19-year-old observatory, which is resting in the shuttle’s open payload bay.

“This is fantastic,” exclaimed Grunsfeld as he exited the hatch in his bulky spacesuit, telling his partner, Andrew Feustel, a first-time spacewalker, “You’re going to love it, Drew.”

Grunsfeld, an astrophysicist who has used the telescope to do research, has been a Hubble repairman on two previous shuttle missions. The spacewalkers are giving Hubble a more powerful camera and replacing a data-handling computer during the first of the mission’s five planned spacewalks.

Image is NASA image off NASA website