Technicians begin the modal survey testing on the top part of the Ares I-X center after sensors were placed on the stack.

In high bay 4 of the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida, technicians begin the modal survey testing on the top part of the Ares I-X (center) after sensors were placed on the stack. The top consists of the launch abort tower, crew module, service module and spacecraft adaptor. Shakers will impose random loads/vibrations to determine the flight test vehicle’s first several bending modes and the strategically located sensors throughout the stacks will measure the amount, acceleration and direction of movement. The purpose of the testing is to confirm that Ares I-X will behave as predicted as it lifts off the pad and powers through the initial stage of flight in a demonstration flight later this year. Photo credit: NASA/Jack Pfaller