The story

The space shuttle Atlantis crew completed its first spacewalk to upgrade the Hubble Space Telescope, a daylong act of grueling labor that featured the replacement and installation of key instruments.

Astronauts John Grunsfeld and Drew Feustel removed the Wide Field and Planetary Camera 2 and swapped it out with an updated model, a device that "will allow the telescope to take large-scale, clear and detailed photos over a wide range of colors," NASA said.

But they had a tough time removing a bolt in that task, an issue that caused some concern for colleagues on the ground. They eventually released it. Read full article »

CNN's John Zarrella and Kim Segal contributed to this report

All About NASA • Space Shuttle Atlantis