NASA Halts Shuttle Stacking Operation

An operation aimed at connecting Atlantis and an external tank was put on hold this morning after engineers ran into trouble hooking up a liquid hydrogen feedline that routes fuel to the shuttle's three main engines.

The mating operation inside the Vehicle Assembly Building came to a halt when problems cropped up with an umbilical guidepin used to link the tank's 17-inch liquid hydrogen feedline with the orbiter's main propulsion system.

The feedline is on the left aft side of the tank and connects with the system through a tile- covered door on the belly of the shuttle orbiter. Click to enlarge the NASA photo above and you can see the umbilical that connects the pipe with the orbiter main propulsion system on the lower right side of the tank. Then click the enlarged image to make the image even bigger.

A guidepin within the umbilical is used to mate the feedline with the main propulsion system; then it is pulled out of an external tank side hole.

More at www.floridatoday.com