Space Flight Support

Space Flight Support

AMA personnel have been directly involved with LaRC Systems Analysis and Concepts Directorate (SACD) and other NASA agencies in the area of flight mission support, planning, and development. AMA's involvement has crossed all design phases.

Mars Odyssey

Mars Odyssey is part of NASA's Mars Exploration Program, a long-term robotic exploration of the red planet. Odyssey's primary science mission is the mapping of the amount and distribution of chemical elements and minerals across the Martian surface. The mission will also record radiation in low Mars orbit to determine the risk for any future human exploration of Mars.

AMA served as a member of the NASA Langley Research Center's flight operation team on this mission and provided several capabilities: Aero Database: AMA supported the development of the aero-database for the spacecraft. The database was used to conduct preflight simulations and to develop a thermal model for the solar arrays. During flight operations, the database was used in performing various mission analyses. AeroBraking Analysis: AMA performed analyses on the aerodynamic data during the aerobraking phase of the mission. Comparisons were made with the accelerometer read-outs and aerodynamics predictions based on the spacecraft attitude obtained from the IMU data. The comparison was used to determine any anomalies in spacecraft attitude during aerobraking and provide database updates as applicable.

GRACE

The Gravity Recovery and Climate Experiment (GRACE) is the first NASA Earth Science Pathfinder (ESSP) mission. Its mission is to map variations in the Earth's gravity field over the next five years to help track water movement on and beneath the Earth's surface. GRACE actually consists of two identical spacecraft flying in synchronized polar orbit. Measurements of the distance between the two satellites, using both global positioning and a microwave ranging system, will create the maps of the Earth's gravity fields. This mission will provide an efficient and cost effective mapping method with unprecedented precision.

AMA provided an active role in several areas for the GRACE project:

  • Satellite design based on an aero-thermal analysis. FREEMOL, the tool used, was itself developed by AMA. FREEMOL can predict the aerodynamic forces and torques acting on the spacecraft as a function of attitude, altitude, solar geometry and satellite surface properties. It has been successfully used with the PAMS satellite test unit and now with GRACE.
  • Mission profile design including orbit lifetime and station keeping between the two GRACE satellites. AMA used SK (Station Keeping) tool to obtain approximate fuel budgets as a function of differential ballistic coefficients of the satellites.
  • Design support and independent verification and validation of the attitude and orbit control system (AOCS) including several modes of the satellite, such as Science and Safe.
  • Simulation support to the AOCS sub-system using tools such as MATLAB and SIMULINK integrated with spacecraft dynamics and aero-thermal analysis. Prediction models for fuel consumption and power requirements were created.

Mars Exploration Rover

The Mars Exploration Rover(MER) mission is the latest of NASA's Mars Exploration Program projects to take aim at red planet. The mission calls for twin rovers (Spirit and Opportunity) to explore locations on opposite sides of Mars. Armed with a host of scientific instruments including cameras and spectrometers, the rovers' primary objective is to study specific geological features (e.g. rocks and soils) in order to uncover clues as to the history of water on the planet. One of the real mission challenges in safely landing the rovers on the surface. Referred to as entry, descent, and landing (EDL), this phase of the mission calls for a parachute and aeroshell to decelerate the lander through the Martian atmosphere. Once sufficiently near the surface, retro-rockets are fired to further slow the lander before airbags are deployed to soften the lander's impact.

For the MER program, AMA provided both engineering and visualization expertise.

  • Multi-body Dynamics: development of multi-body dynamics models for simulation of parachute deployment, aeroshell jettison, lander payout, and retro-rocket firing.
  • Modeling: development and integration of simulation models to address aerodynamics, mass properties, atmospheric characteristics, and line properties.
  • Simulation Reconciliation: identification and resolution of modeling discrepancies through the comparative, simulation analysis of two independently developed EDL simulation tools.
  • Aerodynamics: reconcilliation of entry configuration aerodynamic models using reconstructed flight data.
  • Reconstruction Visualization: data integration and simulation for the reconstruction of the EDL phase of the mission.
  • High Resolution Animations: Actual mission data from the Spirit rover EDL was used for an animation to provide a realistic reconstruction of the descent and landing sequence. View the Mars Rover "Spirit" Animation.

ARES

As a part of the Mars Scout 2007 activity, NASA LaRC and its team proposed the Aerial Regional-scale Environmental Survey of Mars mission (ARES). NASA picked ARES as one of the four Step I winners. The ARES mission delivers an atmospheric flight system to Mars with a spacecraft derived from Genesis heritage, and an entry and descent system derived from Mars Pathfinder and Mars Exploration Rover. The atmospheric flight system is comprised of a science payload and an airplane suitable for flight at Mars.

As a member of the ARES team, AMA had several roles:

  • Multibody Dynamics: Understand and simulate the multibody dynamics of the Entry, Descent, and Deployment. This includes the dynamics of the entry body, parachute, heatshield separation and airplane separation. AMA is using the commercial ADAMS software as the heart of the multi-body solver.
  • Trajectory Optimization: Using the genetic algorithm tools developed at AMA, optimize the fly-by trajectory to maximize communication between the airplane and the fly-by carrier vehicle.

 

Mars Odyssey

 

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