Guidance, Navigation & Control Support for Ares Launch Vehicles

Dynamic Concepts, Inc. supports the GN&C design and development of NASA’s Ares Launch Vehicles – Ares I, Ares I-X and Ares V. Ares I is an in-line, two-stage rocket being designed to carry astronauts into orbit using the Orion crew vehicle. Ares I-X is the first test flight for the Ares Launch Vehicle program and is scheduled for launch in 2009. Ares V is the “heavy lifter” and will serve as NASA’s primary vehicle for delivery of large-scale hardware to space. The Exploration Launch Projects Office located at NASA’s Marshall Space Center (MSFC) is responsible for the new Project Constellation mission vehicles which will replace the Shuttle fleet.

Dynamic Concepts, Inc. has team members embedded within MSFC’s EV40 Flight Mechanics & Analysis Division to support modeling, simulation and analysis related to Ares Launch Vehicle GN&C systems. DCI’s modeling, simulation and analysis efforts for Ares I GN&C include: pre-launch gyrocompassing, trajectory integration, liftoff dynamics, ascent flight control system including load relief options, flexible body effects, rigid body ascent load indicators, separation dynamics, failure & abort scenarios, senor/effector/stacking alignments, and re-entry footprints. DCI’s modeling, simulation and analysis efforts for Ares I-X (test flight vehicle) GN&C involved developing an independent, non-linear, time-domain simulation for comparison and verification purposes including Monte Carlo simulation analysis. DCI’s modeling, simulation and analysis efforts for Ares V has focused on trajectory integration and re-entry footprints.

Specific examples of EV40 GN&C efforts are DCI’s support to the separation team in modeling and analyzing the Ares I trajectory and dynamics during liftoff and stage separation. The results from the liftoff analysis are being used in the design of the launch tower for Ares I, to ensure that the vehicle does not contact the tower during ascent. The stage separation analysis estimates the probability of re-contact between stages during separation for multiple vehicle design proposals. Re-contact during liftoff or staging can lead to mission failure.

Ares 1 First Stage (gray) / Upper Stage (black) separation event. The Upper Stage J-2X nozzle has to exit out of the First Stage without re-contact.

Dynamic Concepts, Inc. is also involved in analyses in the areas of Ares I failures and aborts. In the presence of TVC actuator failures and booster malfunctions, the resulting vehicle dynamics have been investigated to determine the need and required reaction time for vehicle aborts. In addition, abort triggers that make use of Ares I GN&C outputs have been devised to initiate an abort sequence in the event of off-nominal vehicle trajectories. Engineering based animations of staging and abort dynamics are available on the animations page.

Dynamic Concepts, Inc. personnel are also involved in the development of the Ares I navigation system in support of MSFC’s Guidance, Navigation, and Mission Analysis Branch (EV42). More specifically, DCI supports the following navigation tasks: design and development of Ares I inertial navigation algorithms, avionics procurement, development of instrument models, measurement conditioning algorithms for critical separation timing and sensor redundancy, and the development of navigation system performance and vehicle requirements at the integrated vehicle and element levels.