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Rocket Sled Parachute Design Verification

This test architecture helps verify parachute designs for Mars and Earth applications that are too large to fit inside existing wind tunnels. NASA’s Jet Propulsion Laboratory, Pasadena, California Historically, parachutes have been load-tested by various methods including release from an aircraft, deploying in a wind tunnel, dragging through water, and shooting out of an air cannon. Each type of testing has its own advantages and drawbacks. Due to the loading mechanics particular to parachutes deploying in a very thin atmosphere, none of the testing methods was appropriate for testing the next generation of Mars’ full-scale parachutes.

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Reynolds-Averaged Navier-Stokes Integration for Shock Noise (RISN)

Langley Research Center, Hampton, Virginia Reynolds-averaged Navier-Stokes (RANS) Integration for Shock- Noise (RISN) is a computer program that evaluates acoustic analogies to predict jet noise. Jet noise is due to turbulence from the chaotic flow within the exhaust of a rocket or air-breathing jet engine. The source of jet noise is the turbulent mixing of the exhaust, screech (tones) due to a feedback loop between the semi-periodic shock cells and the nozzle, and broadband shockassociated noise due to the interaction of the turbulence with the shock cells. Acoustic analogies are rearrangements of the Navier-Stokes equations into a left-hand-side propagation operator and a right-hand-side equivalent noise source. RISN is capable of predicting the noise spectrum from all source components within supersonic offdesign jets. Furthermore, the noise from three-dimensional and axisymmetric nozzles can be predicted as long as a steady RANS solution is present. RISN predictions are based upon integrations of computational fluid dynamic solutions. Predictions consist of the spectral density at observers positioned around the nozzle exit.

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Regeneratively Cooled Porous Media Jacket

Cooling jackets were developed comprising impermeable inner and outer walls. Lyndon B. Johnson Space Center, Houston, Texas A non-toxic nitrous oxide fuel blend (NOFB) monopropellant with a high adiabatic flame temperature reaching and probably exceeding 3,450 K and a very high thermal decomposition limit (>390 °C) is under development. To design an optimal rocket engine that can handle the high adiabatic temperature during continuous rocket thruster operations, a regeneratively cooled rocket engine is desirable, but the regenerative jacket temperatures must remain well below the monopropellant’s thermal decomposition limit. In fact, the entire engine during operation should ideally remain well below the thermal ignition limit so that heat soak-back cannot potentially decompose the monopropellant following an engine restart.

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Multi-Pulse Motor (MPM) Designed for Use with Electric Solid Propellants

The solid rocket motor can be electrically pulsed a number of times to produce a required thrust or impulse bit. Marshall Space Flight Center, Alabama The multi-pulse motor is a solid-propellant rocket motor that is able to produce a number of pulses for various thrust levels (5 to 30 pulses and thrusts between 0.25 and 1.5 N, depending on electric power delivery system) and can be turned on and off through the application of electrical power.

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Adaptive Augmenting Control

Marshall Space Flight Center, Alabama Adaptive augmenting control (AAC) is a forward gain, multiplicative adaptive algorithm for launch vehicle flight control that meets three summary-level design objectives: Do no harm — return to baseline control design when not needed; respond to errors in the ability of the vehicle to track commands to increase performance; and respond to undesirable parasitic dynamics (e.g., control-structure interaction) to maintain stability.

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Daily Mesoscale Sea Surface Salinity from Evaporation and Precipitation

This model leads to a method for deriving sea surface salinity from evaporation and precipitation data at improved resolution. NASA’s Jet Propulsion Laboratory, Pasadena, California Quantification of salinity is hampered by the lack of time and space resolution of existing measurements and models. At present, skin salinity measurements are available every few days with limited spatial resolution. Daily skin salinity products are full of gaps, which some applications can’t tolerate. Modeled salinity derived in the ocean mixed layer differs from remote sensing data of ocean skin layer salinity to a large extent for certain regions. The cool skin is a conductive layer in the upper few millimeters of the ocean within which transport of salt is dominated by vertical diffusion under the condition of weak to moderate winds. A technique to derive ocean skin layer salinity from satellite-based data for daily and 101 to 102 km scales was developed.

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Software for Inferring the Aerosol Water and Soot Fractions from Remote Sensing Measurements

The technique uses the aerosol real refractive index. Langley Research Center, Hampton, Virginia Aerosol water content and soot concentrations are important components of aerosol forcing. Aerosols contain varying amounts of water depending upon their aerosol hygroscopicity, and anthropogenic aerosols are among the most hygroscopic aerosols; hence, it is important to properly model aerosol hygroscopic effects when computing the effect of anthropogenic aerosols upon the climate system. Soot is the dominant absorbing particulate, and atmospheric soot originates exclusively from fossil fuel burning and biomass burning.

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