A technician checks the mirror on the Wide Field Camera 3 or WFC3 that will be installed on NASA's Hubble Space Telescope.

In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center, a technician checks the pick-off mirror on the Wide Field Camera 3, or WFC3, that will be installed on NASA's Hubble Space Telescope. WFC3 is part of the payload on space shuttle Atlantis' STS-125 mission for the fifth and final Hubble servicing flight to Hubble. As Hubble enters the last stage of its life, WFC3 will be Hubble's next evolutionary step, allowing Hubble to peer ever further into the mysteries of the cosmos. WFC3 will study a diverse range of objects and phenomena, from young and extremely distant galaxies, to much more nearby stellar systems, to objects within our very own solar system. WFC3 will take the place of Wide Field Planetary Camera 2, which astronauts will bring back to Earth aboard the shuttle. Launch of Atlantis is targeted at 1:34 a.m. EDT Oct. 8. Photo credit: NASA/Amanda Diller