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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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This paper describes the use of Smoothed Particle Hydrodynamics (SPH) to simulate the water flow from the rainbird nozzle system used in the sound suppression system during pad abort and nominal launch. The simulations help determine if water from rainbird nozzles will impinge on the rocket nozzles and other sensitive ground support elements.
NASA Ames is a key contributor in Orion heatshield development, aerothermodynamics and aerodynamic and launch abort system modeling of the Artemis generation spacecrafts. This talk will provide an overview and highlights of various present and past activities that ARC staff has been contributing to the program.
In order to achieve the Artemis I mission objectives to human-rate the Orion spacecraft even under off-nominal conditions, trajectories were developed to handle contingency scenarios: alternate missions for contingencies before or during the Trans-Lunar Injection burn, recoveries to return Orion to the nominal trajectory after a delayed or partial burn, and abort trajectories to return the spacecraft to Earth after a critical failure. In addition, disposal trajectories were generated for situations where recovery was not an option. Details are given on the trajectory characteristics, solution families, the generation of the trajectories, and operations considerations.
This paper presents an analysis of a guidance method which uses a reference trajectory. The four state variables needed to prescribe the trajectory are used as follows : Velocity is made the independent variable, and the errors in the rate-of-climb, acceleration, and range variables away from the reference are used to govern the lift. A linearized form of the motion equations is used to show that this represents a third-order control system. First- and second- order control terms (rate of climb and acceleration inputs) are shown to determine the entry corridor depth by stabilizing the trajectory so that the vehicle does not skip back out of the atmosphere or does not exceed a specified acceleration limit. The destabilizing effect that range input (the third-order control term) can have is illustrated and the results indicate that a low value of range input gain must be used at the high supercircular velocities while larger values of range input gain can be used at lower velocities. The usable corridor depth and range capability with this guidance system are demonstrated for a lifting capsule (L/D = 0.5). The practical applications of this system are illustrated with a fixed trim configuration wherein roll angle is used to command the desired lift. The results show that the guidance system requires only one reference trajectory for abort entry conditions as well as for entry conditions near the design values.
In accordance with the basic design concepts of the Mercury Capsule, the manual and automatic control systems were developed to provide a redundant and integrated method of controlling the capsule attitude. The systems were designed to meet the requirements of ballistic and orbital flight, for normal and abort missions. Since the orbital mission includes all modes of control, it will serve as a basis for the system description.
Problems involved in manned lunar missions, discussing the round trip flight, lunar landing and surface operations, crew survival and abort techniques
Space system design optimization based on mission and human requirements as they pertain to acceleration, discussing boost, abort, earth entry and restricting of accelerations
Manual space navigation computer to provide backup guidance capability under abort conditions during advanced manned space missions
The static stability and axial force characteristics of an upper stage Saturn 1B/Apollo model were investigated in a series of wind tunnel tests at Mach numbers between 1. 93 and 8. 05. This report presents and analyzes the results of these small-scale studies. Test procedures and models are described, and consideration of boundary layer characteristics and violated modeling rules yields an assessment of the validity of the data. Four basic models provided evaluation of the basic launch vehicle characteristics, as well as the effects of two modes of mission abort and jettison of the launch escape system. The launch configuration experienced sudden, strong changes in stability derivatives and axial force coefficients near Mach 5. No similar changes were observed on the other configurations. Effects of Reynolds number, Mach number and boundary layer trips were obtained for each shape. The faired curves are believed to be valid for full-scale flight of the Saturn 1B/Apollo upper stage.
Aerodynamic damping and oscillatory stability in pitch and yaw of Gemini abort and reentry configurations at transonic and supersonic speeds
DOD Gemini experiment D-12 astronaut maneuvering unit /AMU/ design, detailing propulsion, flight control, oxygen and power supply, abort-alarm and communications
Secondary or abort mission maximized subject to primary mission constraints by variational treatment of optimal branched trajectories
Failure analyses on some aborted missions due to static electricity
Abort guidance system for Apollo lunar module
Secondary or abort mission maximized subject to primary mission constraints by variational treatment of optimal branched trajectories
Aborted flight of Apollo 13 lunar landing mission caused by power loss in main electrical circuit
Mission-payload and safety-abort analyses for reusable space shuttles with multimission capability - Vol. 8
Malfunctions defining impending abort situation for Saturn 5 launch trajectory to attain contingency orbit