The Ares I-X ascent development flight test will provide significant data and understanding to be used in the design and development of the Ares I. Although the vehicles are not identical, they are enough alike to meet the mission objectives and support Ares I development. The number one primary objective is to demonstrate control of a vehicle dynamically similar to the Ares I using Ares I relevant flight control algorithms.
This objective will be met because the flight control system architecture, including the gain and phase stabilization, is similar for Ares I-X and Ares I, and the same GN&C team is working on both vehicles. Differences in structural dynamics and sensor placement related to flight control will be accounted for and incorporated during post-flight analysis of the data using the design and analysis tools and models that were used prior to flight.
The second primary objective is to perform an in-flight separation/staging event between the first and upper stage. Although the Ares I and Ares I-X staging scenarios are different, the data acquired during Ares I-X will help engineers evaluate the basic kinematics of staging for this class of vehicle, the timing of the staging sequence, the effectiveness of the BDMs, the FS thrust side load at staging, and pyroshock and debris transport properties.
The third primary objective is to demonstrate assembly and recovery of a new Ares I-like FS element at KSC. Although not discussed in this paper, Ares I-X provides the initial opportunity for processing, stacking, assembly, and recovery operations at KSC with a FS similar to Ares I.
The fourth primary objective is to demonstrate FS separation sequencing and quantify FS atmospheric entry dynamics and parachute performance. While there are some deficiencies in modeling all aspects of staging with different separation planes for Ares I-X and Ares I, this flight test demonstration will exercise a FS tumble, initiation of parachute deployment, deceleration using prototype Ares I main parachutes, and separation of the FS nozzle extension. Furthermore, flight data will be acquired to assess the models used to develop the FS atmospheric descent dynamics.
The fifth primary objective is to characterize the magnitude of integrated vehicle roll torque throughout FS Flight. Pure vehicle roll torque data are expected to be obtained by incorporating small periods of time throughout ascent when the roll control system will not be active.
Finally, while it was not originally conceived as a primary flight test objective, the potential for FS thrust oscillation (identified during Ares I design and analysis) will be addressed on Ares I-X by relocating and adding DFI to characterize the nature of the thrust oscillation for its four- segment RSRM.
In addition to the five primary objectives, there are six secondary objectives. They include (1) quantifying the effectiveness of the FS booster deceleration motors, (2) characterizing the induced environments and loads on the flight test vehicle during the ascent flight phase, (3) demonstrating a procedure to determine the vehicle’s pre-launch geodetic orientation vector for initializing the flight control system, (4) characterizing induced loads on the launch vehicle on the launch pad, (5), assessing potential Ares I access locations in the Vehicle Assembly Building and on the pad, and (6)validating FS electrical umbilical performance.
Ares I-X has sufficient similitude with Ares I to meet all five primary objectives and all six secondary objectives. Ares I-X data will be used to validate tools and models being used in Ares I design and analysis and will be available in time to be incorporated into the Ares I design before its critical design review scheduled for 2011
