The space shuttle Endeavour successfully docked with the International Space Station Friday afternoon and appeared in good shape, NASA officials said, despite finding that ice particles may have gouged the tile near the starboard side door.

In this image from NASA TV, the shuttle Endeavour, bottom, docks with the International Space Station on Friday.
(NASA TV/Associated Press)

The damage appeared to be only minimal, John Shannon, chair of the mission management team, said at a press conference in Cape Canaveral, Fla.

"What the team is hypothesizing right now is that you have a piece of ice that gouged that tile, broke up and rolled up along this vehicle," Shannon said.

Radar images showing smaller white spots "downstream" of a larger particle were likely smaller pieces that broke away, he said.

On flight day five, which is Sunday, the crew aboard the shuttle is scheduled to circle the damaged area with an orbital boom to get a closer look.

Earlier Friday, the Endeavour team checked for damage, believing that three pieces of insulation — possibly foam — struck the shuttle's exterior during liftoff. Foam damage has been a worry for NASA since a chunk pierced the space shuttle Columbia's left wing on Feb. 1, 2003, causing it to break up upon re-entry.

Debris 'looked more like ice than foam'

At a later press conference in Cape Canaveral, however, Shannon said the particles they were tracking "looked more like ice than foam."

The focused inspection planned for Sunday is an extra precaution.

"We perked up our ears a bit because ice is much denser than foam and could do much more damage on tile … so that was interesting," Shannon said.

NASA TV broadcast Endeavour's arrival to the International Space Station, cutting away minutes before to show a picture of the space station crew.

"The hosts are awaiting the arrival of the guests," the commentator said.

The shuttle docks at right angles to the space station, so a tube pointing "up" from the cargo bay [if Endeavour was on the ground] links to a similar tube on the station. Once sealed, the tubes acted as a conduit through which seven shuttle crew members — including Canadian Dave Williams — were able to enter the station.

The shuttle was a little late, arriving at 2:02 p.m. ET, rather than the forecast 1:53 p.m. ET, about 365 kilometres above the South Pacific. The shuttle will stay linked to the station for seven to 10 days.

Before the docking, pilot Charles Hobaugh and Cmdr. Scott Kelly made the shuttle backflip so the space-station crew could shoot images of the heat shield, which were sent to NASA for damage checks.

With files from the Associated Press