The space shuttle Atlantis took up its position Wednesday close to the Hubble Space Telescope, nearing the end of a chase that began almost two days earlier.

Atlantis is preparing for its robot arm to grab hold of the orbiting telescope at 12:54 p.m. ET. The operation is a delicate dance for the shuttle crew, involving periodic firings of the shuttle's thrusters to align it with the space telescope -- all of this taking place about 350 miles above Earth.

Goddard Space Flight Center in Greenbelt, Maryland, is commanding the telescope to stow its two high-gain antennas and close a door to protect Hubble's sensitive equipment and mirror. Ultimately, the shuttle will maneuver to within 35 feet of the telescope before capturing it and pulling it into the cargo bay for repairs.

Atlantis launched Monday afternoon for NASA's fifth and final repair visit to the telescope. It has been seven years since NASA's last mission to service the Hubble, which was designed to go about three years between fixes.

NASA canceled an Atlantis mission to extend Hubble's operational life in January 2004 because the trip was considered too risky in the wake of the 2003 space shuttle Columbia disaster, which killed seven astronauts. That accident was blamed on a hole punched in the front of the wing by debris during liftoff. But public pressure and steps taken to increase shuttle safety led the space agency to reconsider.

A survey of Atlantis' outer body after launch revealed that four tiles on the right side have "some dings" in them, flight director Tony Ceccacci said Tuesday. "To me, I'm not the tile expert, but they looked very minor," he said. Ceccacci said tile experts will examine the dings, which are on the wing. Space shuttle Endeavour is on standby in the unlikely event that NASA would need to rescue the Atlantis crew members during their 11-day mission.

Source: CNN