Space Shuttle Endeavour Lifts Off

The 22nd flight to the International Space Station, STS-118 will be the first flight for Endeavour since 2002.

Space Shuttle Endeavour during liftoff. Photo courtesy: NASA

(CAPE CANAVERAL, Fla.) - It's launch day at NASA's Kennedy Space Center in Florida, where Space Shuttle Endeavour and her crew of seven astronauts are undergoing final preparations for the STS-118 mission to the International Space Station.

Endeavour's orange external tank is being loaded with 500,000 gallons of liquid oxygen and hydrogen.

This process, called "tanking," takes about three hours to complete. The propellant levels in the tank will be continuously "topped off" during the remainder of today's countdown.

All systems onboard the space shuttle are functioning normally this morning, and there's only a 20 percent chance of weather prohibiting a liftoff at 6:36 p.m. EDT.

Mission STS-118 will be the first for Mission Specialist Barbara Morgan, the teacher-turned-astronaut whose association with NASA began more than 20 years ago.

First Lady Laura Bush called Morgan Tuesday morning to offer congratulations "one schoolteacher to another," and to thank her for her commitment to the space program and to education.

The 22nd flight to the International Space Station, STS-118 will be the first flight for Endeavour since 2002.

Launch remains on target for tonight at 6:36 PM EDT.