Image: As dawn breaks over the Space Coast of Florida, space shuttle Atlantis stands poised for launch. Photo credit: NASA TV
"We have a good ECO system and we are ready to fly," says STS-122 Launch Director Doug Lyons.
Once the filling of space shuttle Atlantis' external fuel tank with 500,000 gallons of liquid oxygen and liquid hydrogen was completed, the engine cut-off sensors under went further successful testing. Fueling of the tank took approximately three hours and began at 5:21 a.m. The countdown is now in a scheduled hold that will last two and a half hours, and the Final Inspection Team is conducting its top-to-bottom check of the vehicle.
There are four engine cut-off, or ECO, sensors inside the liquid hydrogen section of the tank. The sensors are part of several systems that protect the shuttle's main engines by triggering them to shut down if fuel runs unexpectedly low.
Liftoff is scheduled for 2:45 p.m. EST, which is the middle of the 10-minute launch window. The timing is precise so Atlantis can catch up and dock with the International Space Station.
Forecasters expect a cold front to move over Kennedy around launch time, bringing with it clouds and storms, resulting in only a 30-percent chance of good weather for liftoff. Further, there is a possibility that the front may stall over Central Florida, providing only slightly better chances for acceptable weather for launch attempts on Friday or Saturday.
NASA has strict flight rules for weather that include limits on cloud height, storms in the area and clouds that could produce lightning. The criteria are set in part by the conditions a shuttle would need if it has to make an emergency landing soon after liftoff.
The good news for Atlantis and crew is that no technical issues are reported.
NASA astronaut Steve Frick commands a crew of six, including Pilot Alan Poindexter and Mission Specialists Leland Melvin, Rex Walheim, Stanley Love and the European Space Agency's Hans Schlegel and Leopold Eyharts. This is the first spaceflight for Poindexter, Love and Melvin.
During the 11-day mission, the crew's prime objective is to attach the European Space Agency's Columbus Laboratory to the International Space Station, adding to the station's size and capabilities.
Expedition 16 Flight Engineer Daniel Tani, who arrived at the station aboard Discovery in October, will return to Earth with the Atlantis crew as Eyharts takes his place on the station.
