At about the two minute mark (approximately 130 and 132 seconds) in the liftoff of the STS-122 mission on Thursday, February 7, 2008, three pieces of foam insulation or other types of debris were seen falling off the external tank.

It was not determined if these pieces hit the shuttle or not.

Other debris, probably ice, was also seen falling off the external tank later in the launch, however, the debris falling off at around two minutes after liftoff are the ones most likely to have caused damage, it they had indeed hit the shuttle.

In any case, a complete inspection of the shuttle is required by NASA and will be performed today and tomorrow as the shuttle approaches and begins its rendezvous, proximity operations, and docking phases with the International Space Station.

Thus, on Friday, flight day 2, the NASA astronauts will be spending much of their work day using a laser-tipped inspection pole (called the orbiter boom sensor system, OBSS), which is fixed onto the end of the Canadian robotic arm, to examine the space shuttle’s wings and nose cap area.

They are first inspecting the starboard (right side while facing the craft) side of the shuttle. Later, the astronauts will inspect the nose cap area, and, lastly, the port (left) side of the shuttle.

These areas are covered with the thermal protection system (TPS), including the reinforced carbon carbon (RCC) panels that cover the most sensitive areas of the shuttle, the nose cap and the wing's leading edges. 

The shuttle’s robotic arm is officially called the remote manipulator system (RMS), also known as the Canadarm.

Why was the boom added? Read on.