Moses says the good news is that the shuttle isn't going fast enough at 10 seconds into the launch for a debris strike to be a problem. "I can't even begin to speculate on what it might be. We will let the experts figure it out and do a trajectory analysis to see where it came from," Moses said.
The astronauts spent the night using the orbital boom attached to the space shuttles robotic arm to examine Endeavour inch by inch to see if any signs of damage could be detected on the orbiter's fragile heat shield. Nothing immediately popped out at anyone during the scan, according to Moses.
Endeavour is chasing the International Space Station and will catch up to it later tonight, then rendezvous and dock after the shuttle performs it's spectacular somersault to allow the space station astronauts to photograph the shuttle's belly.
This mission, designated STS-123, is one of a dozen that remain on NASA's shuttle manifest. All remaining shuttle flights, except for one to repair the Hubble Space Telescope, are dedicated to finishing construction of the space station.
Inside Endeavour's cargo bay are parts of a large laboratory called Kibo, built by the Japanese space agency. Japanese astronaut Takao Doi, who flew on a shuttle mission back in 1997, is on board to oversee the assembly of the Kibo lab.
In addition, Endeavour's crew will install a Canadian-made two-armed robot nicknamed Dextre that can move around to different parts of the space station.
There are five spacewalks on the schedule for Endeavour's flight. Astronauts Richard Linnehan, Michael Foreman, Garrett Reisman and Robert Behnken will divide up the outside work.
The mission commander is Dominic Gorie, who is making his fourth flight. Beside him on the flight deck is pilot Gregory Johnson, who has waited nearly 10 years for his first flight.
There will be something of a Musical Chairs game on this flight, as there have been on past space station missions. Reisman will stay behind as a member of the space station crew. His seat on the ride home will be taken by French Gen. Leopold Eyeharts, who was delivered to the station by the Shuttle Atlantis six weeks ago.
NASA and its international space agency partners are managing traffic on orbit. A new European-made robotic cargo ship, known as the Automated Transfer Vehicle or ATV, was launched from French Guiana, Saturday. It will hover in orbit until Endeavour has left and then dock with the station.
After the shuttles are retired, the space station will have to rely on the European ATV, plus Russian Soyuz and Progress spacecraft, for supplies and new crew members.
The next generation of American piloted ships, known as Orion, will not begin flying until the middle of the next decade. The last space shuttle flight, STS-133, is tentatively scheduled for the middle of 2010.