The Endeavor astronauts will conduct an inspection at the eight sites where the heat protection tiles fell

The first spacewalk in the Endeavor mission has been completed, but an unplanned task may be added to one of the following spacewalks: gluing patches in place of the fallen tiles

Astronauts Drew Feustel and Greg Chaimtoff completed a spacewalk that lasted six hours and 19 minutes. They successfully installed antennas for the external wireless communication system, routing cables, installed handles to hold future astronauts and power cables.
Due to a problem with the carbon dioxide system in Chaimtoff's space suit, the flight controllers shortened the mission by ten minutes. There is no evidence that the carbon dioxide levels in the suit increased. However, one of the sub-tasks, removing a shield against micro-meteorites and connecting some power points, was postponed to another time.
It was the first spacewalk on mission STS-134, the 245th spacewalk performed by American astronauts. Meanwhile, astronauts Greg Johnson and Roberto Vittori continued to transfer equipment and supplies from the Endeavor to the space station.

And in the meantime, NASA is preparing another mission for the spacewalkers - plugging holes in the protective tile system that protects the astronauts from heating up upon entering the atmosphere, as happened to the shuttle Columbia.

Endeavor arrived at the space station on Wednesday, and before docking it performed a rollover maneuver that allowed station crew members to get close-up images of the thermal protection system to ensure the shuttle would not be damaged during re-entry into the atmosphere.
It turns out that in eight areas there is a fear of damage to these black tiles, some of them very close to two of the three landing wheels - the front and the right rear wheel. As you get closer to the door where the landing gear is stored, this draws the attention of the mission managers. Three of them look very large.
The mission managers requested a closer inspection of these areas using the robotic arms of the station and the shuttle. If it is proven that there is damage, the crew members have the ability to make small repairs in the space, and in particular, plugging these holes with a special material.