Countdown Clocks Ticking Toward Friday Launch

The countdown to the final flight of Endeavour is under way at Kennedy Space Station and the astronauts destined to launch on the historic mission have arrived at NASA's shuttle homeport.

Some 150 to 200 engineers were called to their stations in Firing Room 4 of the Launch Control Center and countdown clocks began ticking backward at 2 p.m.

Soaring in four T-38 training jets, mission Commander Mark Kelly and his five crewmates made a high-speed fly-over of Endeavour at launch pad 39A before touching down on Runway 33 at the Shuttle Landing Facility.

"We got a chance to take a look at the orbiter as we flew over first the field and then over the pad. It’s great to see Endeavour all ready to go again," Kelly said. "Endeavour has had a pretty amazing career. It’s been flying now for 18 years. This is going to be Endeavour’s 25th flight, and me and my crew are excited to be a part of it."

Seen in this photo, the crew includes (left to right) mission specialists Greg Chamitoff and Andrew "Drew" Feustel, mission commander Mark Kelly, pilot Gregory "Box" Johnson and mission specialists Michael Fincke and Robert Vittori. Vittori is a European Space Agency astronaut.

A hoard of 75 journalists and a couple dozen family members were at the apron on the south end of the runway to greet the crew. Some of the family members wore black T-shirts that had 'Endeavour' and '134' on the front and the astronauts' autographs in silver pen on the back. The NASA designation for the shuttle's 134th flight is STS-134.

Engineers on Wednesday will load liquid hydrogen and liquid oxygen into the shuttle's fuel cell system and then on Thursday evening, the Rotating Service Structure will be backed away from the shuttle at the pad. External tank propellant-loading operations are scheduled to begin at 6:22 a.m. Friday. Liftoff remains scheduled for 3:47 p.m.