Steel pieces that make up most of Ares I-X are clustered in High Bay 4 of the assembly building. The five cylinders represent the interstage and upper stage of Ares I; the final piece is the dart-shaped mock-up of the crew capsule.Since this first test flight of Ares I will not reach orbit, the fifth segment of the vehicle’s rocket booster isn’t needed. Engineers created a dummy version of the segment, which will hold the avionics module that guides the rocket’s flight.
A system designed to control rotational forces on the rocket lies under a blanket that is visible through a hatch in the interstage.Ares I-X has more than 700 sensors that will measure temperature and multiple forces on the rocket during all phases of its flight; some of the most critical sensors, such as those that gauge air pressure and speed, are at the top of the dart-shaped fifth stack, near the simulated rocket nozzles of the launch abort system.Wires run down the walls of the simulated crew module; when the rocket is finished, they will connect sensors in the module to data recorders that reside in the avionics module (not shown).A yellow framework known as the “birdcage” surrounds and supports the fifth stack as massive cranes lift it and mate it with its counterpart cylinder. It will take weeks for engineers to stack the rocket’s pieces together. When fully assembled, Ares I-X will stand 99 meters tall and vary from 3.7 to 5.5 meters in diameter; it will weigh more than 800,000 kilograms when fueled.