(CNN) -- A survey of space shuttle Atlantis' outer body has revealed that four tiles on the right side have "some dings" in them, the flight director said Tuesday.
Space shuttle Atlantis launched from Florida Monday on its way to the Hubble telescope.
"As we were going through the surveys we did see probably about 21 inches in all ... four tiles with some dings in them," Tony Ceccacci told reporters.
"To me, I'm not the tile expert, but they looked very minor."
He said tile experts will examine the dings, which are on the wing.
Ceccacci said an "event" occurred around 103 seconds into Monday's launch.
He said NASA is looking into what may have caused the nicks. Debris that fell off the external fuel tank during liftoff has been the culprit on previous flights. Watch Ceccacci describe the damage »
Atlantis launched Monday afternoon for NASA's fifth and final repair visit to the Hubble Space Telescope, with which it is scheduled to rendezvous on Wednesday.
It has been seven years since NASA's last mission to service the Hubble, which was designed to go only 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 Columbia tragedy, which killed seven astronauts.
That disaster was blamed on a hole punched in the front of the wing by debris during liftoff. Watch Atlantis lift off on Hubble mission »
But public pressure and steps taken to increase shuttle safety led the U.S. space agency to reconsider.
Space shuttle Endeavour is on standby at the Kennedy Space Center in Florida in the unlikely event that NASA will need to rescue the Atlantis crew members during their 11-day mission.