Directly adjacent to the area where the CEV mockup was being detailed (note the
decal sheet a bit below center) was a
remote manipulator system robotic arm.
The tour guide said that this remote manipulator system was originally designed
and built for the Dextre robotic Hubble servicing mission (in the wake of the
Columbia disaster, the then-planned manned Hubble servicing mission was deemed
too dangerous and was replaced with a robotic mission). After MDA
(the same company which produced the Special Purpose Dexterous Manipulator arm
for the ISS) completed manufacturing the arm, the robotic mission was replaced
with the originally-planned manned mission, rendering the arm surplus. The arm
was awaiting use in some future project.