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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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At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Composite flexible insulation for thermal protection of space vehicles

A composite flexible blanket insulation (CFBI) system considered for use as a thermal protection system for space vehicles is described. This flexible composite insulation system consists of an outer layer of silicon carbide fabric, followed by alumina mat insulation, and alternating layers of aluminized polyimide film and aluminoborosilicate scrim fabric. A potential application of this composite insulation would be as a thermal protection system for the aerobrake of the Aeroassist Space Transfer Vehicle (ASTV). It would also apply to other space vehicles subject to high convective and radiative heating during atmospheric entry. The thermal performance of this composite insulation as exposed to a simulated atmospheric entry environment in a plasma arc test facility is described. Other thermophysical properties which affect the thermal response of this system are also described. Analytical modeling describing the thermal performance of this composite insulation is included. It shows that this composite insulation is effective as a thermal protection system at total heating rates up to 30.6 W/sq cm.

Kourtides, Demetrius A.↗
NASA NTRS2022

A Rideshare Tensegrity Rover Concept to Explore Titan’s Lands and Oceans

The Tension Adjustable Network for Deploying Entry Membrane (TANDEM) concept is a phase II NASA Innovative Advanced Concepts (NIAC) project. One of the goals for this project was to extend the application of tensegrity-based rovers to a rideshare concept for a Titan mission. This report provides preliminary details of the TANDEM concept for Titan. System analyses of the entry vehicle were performed and compared to data from the Huygens mission to Titan. The entry aeroshell was based on Huygens and Stardust aeroshells. Modeling, simulation and design of the tensegrity deployment were performed using a nonlinear optimization form-finding algorithm. Lastly, a neuroevolution-based machine learning control strategy was applied, which produced efficient rolling locomotion gaits.

tensegrity↗
NASA NTRS1993

Aerothermodynamic performance and thermal protection design for blunt re-entry bodies at L/D = 0.3

Aerodynamic heating and thermal protection design analyses were performed for three blunt re-entry bodies at an L/D = 0.3 returning from low earth orbit. These configurations consisted of a scaled up Apollo command module, a Viking re-entry vehicle, and an Aeroassist Flight Experiment (AFE) aerobrake, each with a maximum diameter of 4.42 m. The aerothermodynamic analysis determined the equilibrium stagnation point heating rate and heat load for nominal and 3-sigma re-entry trajectories and the distribution of heating along the pitch and yaw planes for each of the vehicles at the time of highest heat flux. Using the predicted heating rates and heating distributions, a Thermal Protection System (TPS) design with flight certified materials was tailored for each of the configurations. Results indicated that the heating to the corner of the Viking aeroshell would exceed current limits of reusable tile material. Also, the maximum heating for the AFE would be 15 percent greater than the maximum heating for the Apollo flying the same trajectory. TPS designs showed no significant advantage in TPS weight between the different vehicles; however, heat-shield areal density comparisons showed the Apollo configuration to be the most efficient in terms of TPS weight.

Caram, Jose M.↗
NASA NTRS1989

A predictive guidance algorithm for Mars entry

This report presents the derivation, logic, and performance of a Mars entry guidance algorithm for the Mars Rover Sample Return Mission. This algorithm guides the Mars entry vehicle along an equilibrium glide trajectory designed to satisfy a set of equality and inequality constraints at chute deploy. An equilibrium glide assumption permits analytic prediction of terminal state conditions and eliminates the need for determining numeric state sensitivities. Trajectory deviations due to dispersions or uncertainties in Martian atmosphere, vehicle aerodynamics, or entry interface conditions are accommodated simply by predicting the compensating equilibrium glide profile and achieving this profile with the available lift control. This Mars Predictive Equilibrium Glide guidance scheme was tested on a range of vehicle configurations with a variety of aerodynamic, atmosphere, and trajectory dispersions with a high degree of success.

Tigges, M. A.↗
NASA NTRS1991

Composite flexible insulation for thermal protection of space vehicles

A composite flexible blanket insulation (CFBI) system considered for use as a thermal protection system for space vehicles is described. This flexible composite insulation system consists of an outer layer of silicon carbide fabric, followed by alumina mat insulation, and alternating layers of aluminized polyimide film and aluminoborosilicate scrim fabric. A potential application of this composite insulation would be as a thermal protection system for the aerobrake of the aeroassist space transfer vehicle (ASTV). It would also apply to other space vehicles subject to high convective and radiative heating during atmospheric entry. The thermal performance of this composite insulation as exposed to a simulated atmospheric entry environment in a plasma arc test facility is described. Other thermophysical properties which affect the thermal response of this composite insulation is included. It shows that this composite insulation is effective as a thermal protection system at total heating rates up to 30.6 W/sq cm.

Kourtides, Demetrius A.↗
NASA NTRS1992

Composite flexible insulation for thermal protection of space vehicles

A composite flexible blanket insulation (CFBI) system considered for use as a thermal protection system for space vehicles is described. This flexible composite insulation system consists of an outer layer of silicon carbide fabric, followed by alumina mat insulation, and alternating layers of aluminized polyimide film and aluminoborosilicate scrim fabric. A potential application of this composite insulation would be as a thermal protection system for the aerobrake of the aeroassist space transfer vehicle (ASTV). It would also apply to other space vehicles subject to high convective and radiative heating during atmospheric entry. The thermal performance of this composite insulation as exposed to a simulated atmospheric entry environment in a plasma arc test facility is described. Other thermophysical properties which affect the thermal response of this composite insulation is included. It shows that this composite insulation is effective as a thermal protection system at total heating rates up to 30.6 W/sq cm.

Kourtides, Demetrius A.↗
NASA NTRS2020

InSight Entry, Descent and Landing Pre-Flight Performance Predictions

On November 26, 2018, the Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) lander successfully touched down on the surface of Mars. Over its seven-plus year development, NASA Langley Research Center’s (LaRC) Program to Optimize Simulated Trajectories II (POST2) was used to assess the mission’s Entry, Descent and Landing (EDL) vehicle system performance against related requirements across the full range of possible environmental and spacecraft conditions. Much of the simulation code was derived from the Phoenix mission, for which this vehicle is very similar. The InSight six degree-of-freedom simulation included models for Mars atmosphere, gravity and digital elevation maps of the landing location. Additionally, vehicle specific aerodynamic, parachute, engine, navigation sensor, flight software and landing radar models were also included. A set of dispersions for each model, as well as for additional simulation input parameters, were also included in order to provide a statistical, Monte Carlo prediction of the EDL system performance. An overview of the pre-flight performance assessments completed, including the various simulation campaigns used, will be provided. Ultimately, this work was critical in the assessment of readiness for InSight launch. A brief description of the use of this simulation in support of flight operations is also discussed.

Robert W Maddock↗
NASA NTRS1976

Entry into outer planet environments. II - Performance of volume reflecting hyperpure silica heat shields

The performance of hyperpure silica heat shields that backscatter incident radiation in the depths of the material, i.e., a volume reflecting heat shield, is mapped for probes entering the atmospheres of Saturn and Uranus. Three models of each atmosphere are considered; the warm, nominal, and cool models. The most recent thermophysical and optical properties of hyperpure silica are employed. Detailed incident radiative spectra and the effects of ablation on radiative and convective heating obtained from benchmark flowfield solutions are used. In-depth material response is examined and results are presented in terms of the peak rear-face temperature as a function of initial thickness for each atmosphere. Results are compared with carbon phenolic heat-shield requirements.

Howe, J. T.↗
NASA NTRS2013

Mars Science Laboratory Entry, Descent and Landing System Overview

The Mars Science Laboratory project recently places the Curiosity rove on the surface of Mars. With the success of the landing system, the performance envelope of entry, descent and landing capabilities has been extended over the previous state of the art. This paper will present an overview to the MSL entry, descent and landing system design and preliminary flight performance results.

MSL↗
NASA NTRS2014

Atmospheric Entry Studies for Uranus

To better understand the technology requirements for a Uranus atmospheric entry probe, an internal NASA study was conducted. The main objectives for this study were: (1) to determine the entry trade space through parametric studies; and (2) to identify entry technologies that could be used to enable a mission that would meet at least the Tier 1 science objectives described in the Decadal Survey. The paper describes two different approaches to the planet: 1) direct ballistic entry 2) aerocapture followed by direct entry of probe. For direct ballistic entry the trajectory analyses were performed for a range of entry flight path angles and ballistic coefficients. The larger size probes was also considered in an attempt to enable Tier 2 science objectives. For aerocapture analysis a single case was studied to demonstrate feasibility and benefits with this option. A summary of all of the above analyses, including factors that constrain allowable entry trajectories, is presented

Atmospheric entry↗
NASA NTRS1990

Reach performance while wearing the Space Shuttle launch and entry suit during exposure to launch accelerations

A crew of four veteran astronaut/pilots were subjected to sustained linear accelerations of up to 3G(x) in order to quantify crew reach performance while wearing the currently used Launch and Entry Suit (LES). Photogrammetric techniques were used to quantify magnitudes of reach in any direction while subjects rode a centrifuge. Subjects exhibited small changes of reach capability in the +x (forward) direction which ranged from an improvement of 2.04 cm to a decrease of 14.4 cm while reach performance in the +z (overhead) direction was improved in three of four subjects, indicating that any task which could be accomplished under exposure to 1G(x) could definitely be done at 3G(x). The data from this experiment demonstrated that Shuttle crews in training can expect to maintain all of the overhead reach capability evident in good simulator runs and suffer only moderate degradation in the forward reach performance during the launch phase of an actual Shuttle mission.

Bagian, James P.↗
NASA NTRS1994

Experimental investigation of nozzle/plume aerodynamics at hypersonic speeds

Much of the work involved the Ames 16-Inch Shock Tunnel facility. The facility was reactivated and upgraded, a data acquisition system was configured and upgraded several times, several facility calibrations were performed and test entries with a wedge model with hydrogen injection and a full scramjet combustor model, with hydrogen injection, were performed. Extensive CFD modeling of the flow in the facility was done. This includes modeling of the unsteady flow in the driver and driven tubes and steady flow modeling of the nozzle flow. Other modeling efforts include simulations of non-equilibrium flows and turbulence, plasmas, light gas guns and the use of non-ideal gas equations of state. New experimental techniques to improve the performance of gas guns, shock tubes and tunnels and scramjet combustors were conceived and studied computationally. Ways to improve scramjet engine performance using steady and pulsed detonation waves were also studied computationally. A number of studies were performed on the operation of the ram accelerator, including investigations of in-tube gasdynamic heating and the use of high explosives to raise the velocity capability of the device.

Bogdanoff, David W.↗