CAPE CANAVERAL, Fla. -- Damaged heat shields on the Endeavour's underbelly have NASA engineers concerned about the health of the space shuttle.
The heat shields are designed to protect the craft when it re-enters the extreme temperatures of the earth's atmosphere.
Seven places on the shuttle were damaged during the launch on Monday- though engineers have already cleared 5 of those spots because they don't pose any significant threat.
The astronauts will take a closer look at the 2 remaining places tomorrow- and if those places are enough of a problem, they'll have to do what's called a focused inspection in space.
NASA takes any damage to those heat shields very seriously since they were a contributing factor to the Columbia Shuttle Disaster of 2003 which killed seven astronauts.