Ready for Takeoff: Astronauts Prepare for a Mission

The crew of the Space Shuttle Atlantis leave the Operations and Checkout Building and prepare to board the "Astro Van," which will take them to Launch Pad 39A. (NASA TV)

The crew of the Space Shuttle Atlantis leave the Operations and Checkout Building and prepare to board the "Astro Van," which will take them to Launch Pad 39A. (NASA TV)

Atlantis fueling has been underway for several hours, and the official weather forecast remains an optimistic 70 percent chance of acceptable conditions for launch, scheduled to occur at 2:28 p.m. from Launch Pad 39A at NASA's Kennedy Space Center. (NASA TV)

Astronauts take a few minutes to consider the sheer size of the Shuttle that will take them to the International Space Station.  (NASA TV)

Cool air is pumped into the jackets to control temperatures prior to launch in the white room. When in the spaceship, each astronaut's body temperature is regulated by a liquid cooling system. (NASA TV)

Astronauts don their spacesuits and ride the elevator to the top of the Shuttle. Only one or two astronauts can ride up at a time; others wait in the white room at the foot of the Shuttle. (NASA TV)

Each astronaut is strapped into his chair very carefully. Because they will be strapped info for several hours prior to launch time, ensuring comfort is a crucial step.  (NASA TV)

Close-out crew members standing on the upright Shuttle adjust seat belts and other gear for the astronauts, who are strapped into their seats several hours prior to take off.  (NASA TV)

Close-out crew members standing on the upright Shuttle adjust seat belts and other gear for the astronauts, who are strapped into their seats several hours prior to take off.  (NASA TV)

With preparations complete, Space Shuttle Atlantis sits on the launchpad, ready for lift-off.  (NASA TV)