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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 595 records · Page 33
All sourcesNASA NTRSDOE OSTI
NASA NTRS2014

Cubesat Application for Planetary Entry (CAPE) Missions: Micro-Reentry Capsule (MIRCA)

The Cubesat Application for Planetary Entry Missions (CAPE) concept describes a high-performing Cubesat system which includes a propulsion module and miniaturized technologies capable of surviving atmospheric entry heating, while reliably transmitting scientific and engineering data. The Micro Return Capsule (MIRCA) is CAPEs first planetary entry probe flight prototype. Within this context, this paper briefly describes CAPEs configuration and typical operational scenario, and summarizes ongoing work on the design and basic aerodynamic characteristics of the prototype MIRCA vehicle. CAPE not only opens the door to new planetary mission capabilities, it also offers relatively low-cost opportunities especially suitable to university participation.

micro-return capsule↗
NASA NTRS2014

Woven Thermal Protection System (WTPS) a Novel Approach to Meet NASA's Most Demanding Reentry Missions

NASA's future robotic missions to Venus and outer planets, namely, Saturn, Uranus, Neptune, result in extremely high entry conditions that exceed the capabilities of current mid-density ablators (PICA or Avcoat). Therefore mission planners assume the use of a fully dense carbon phenolic heat shield similar to what was flown on Pioneer Venus and Galileo. Carbon phenolic (CP) is a robust Thermal Protection System (TPS) however its high density and thermal conductivity constrain mission planners to steep entries, high heat fluxes, pressures and short entry durations, in order for CP to be feasible from a mass perspective. The high entry conditions pose certification challenges in existing ground based test facilities. In 2012 the Game Changing Development Program in NASA's Space Technology Mission Directorate funded NASA ARC to investigate the feasibility of a Woven Thermal Protection System (WTPS) to meet the needs of NASA's most challenging entry missions. This presentation will summarize maturation of the WTPS project.

carbon phenolic↗
NASA NTRS2015

Entry Descent and Landing Workshop Proceedings: Inflatable Reentry Vehicle Experiment-3 (IRVE-3) Project Overview & Instrumentation - Volume 1

Entry mass at Mars is limited by the payload size that can be carried by a rigid capsule that can fit inside the launch vehicle fairing. Landing altitude at Mars is limited by ballistic coefficient (mass per area) of entry body. Inflatable technologies allow payload to use full diameter of launch fairing, and deploy larger aeroshell before atmospheric interface, landing more payload at a higher altitude. Also useful for return of large payloads from Low Earth Orbit (LEO).

Dillman, Robert↗
NASA NTRS2017

Oblate-Earth Effects on the Calculation of Ec During Spacecraft Reentry

The bulge in the Earth at its equator has been shown to lead to a clustering of natural decays biased to occur towards the equator and away from the orbit's extreme latitudes. Such clustering must be considered when predicting the Expectation of Casualty (Ec) during a natural decay, because of the corresponding clustering of the human population in the lower latitudes. This study expands upon prior work, and formalizes in a single empirical equation the correction that must be made to the calculation of the average exposed population density as a result of this effect. The equation is represented as a function of ballistic number and inclination of the entering spacecraft over the credible range of ballistic numbers.

Bacon, John B.↗
NASA NTRS2017

Oblate-Earth Effects on the Calculation of Ec During Spacecraft Reentry

The bulge in the Earth at its equator has been shown to lead to a clustering of natural decays biased to occur towards the equator and away from the orbit's extreme latitudes. Such clustering must be considered when predicting the Expectation of Casualty (Ec) during a natural decay because of the clustering of the human population in the same lower latitudes. This study expands upon prior work, and formalizes the correction that must be made to the calculation of the average exposed population density as a result of this effect. Although a generic equation can be derived from this work to approximate the effects of gravitational and atmospheric perturbations on a final decay, such an equation averages certain important subtleties in achieving a best fit over all conditions. The authors recommend that direct simulation be used to calculate the true Ec for any specific entry as a more accurate method. A generic equation is provided, represented as a function of ballistic number and inclination of the entering spacecraft over the credible range of ballistic numbers.

Bacon, John B.↗
NASA NTRS2017

Oblate-Earth Effects on the Calculation of Ec During Spacecraft Reentry

The bulge in the Earth at its equator has been shown to lead to a clustering of natural decays biased to occur towards the equator and away from the orbit's extreme latitudes. Such clustering must be considered when predicting the Expectation of Casualty (Ec) during a natural decay, because of the corresponding clustering of the human population in the lower latitudes. This study expands upon prior work, and formalizes in a single empirical equation the correction that must be made to the calculation of the average exposed population density as a result of this effect. The equation is represented as a function of ballistic number and inclination of the entering spacecraft over the credible range of ballistic numbers.

Bacon, John B.↗
NASA NTRSDate not supplied

Pyrolysis Rate and Yield Strength Reduction in Carbon Fiber and Glass Fiber Composites under Reentry Heating Conditions

The behavior of composite materials, specifically carbon fiber-reinforced polymer (CFRP) and glass fiber-reinforced polymer (GFRP), under re-entry conditions poses a problem for orbital debris re-entry risk modeling. Since these materials pyrolyze rather than melt and their different components demise at different rates, modeling their destruction to determine ground impact risk is complex. Modern spacecraft are using these materials in ever-greater quantities owing to their superior strength-to -weight characteristics, and this has required that the orbital debris community improve its understanding of how these materials demise on re-entry.

Benton R Greene↗
NASA NTRSDate not supplied

Scale Resolving Simulations of Viking '75 Reentry Capsule Wake Flow

Scale resolving simulations of static wake tests of the '75 Viking capsule have been performed using two unstructured grid flow solvers, US3D and PyFR. Simulations with several resolutions have been performed at varying Mach numbers with the aim of solver validation for capsule wake flows as well as establishing simulation best practices.

Rathakrishnan Bhaskaran↗
NASA NTRSDate not supplied

Scale Resolving Simulations of Viking '75 Reentry Capsule Wake Flow

Scale resolving simulations of static wake tests of the '75 Viking capsule have been performed using two unstructured grid flow solvers, US3D and PyFR. Simulations with several resolutions have been performed at varying Mach numbers with the aim of solver validation for capsule wake flows as well as establishing simulation best practices.

Rathakrishnan Bhaskaran↗
NASA NTRSDate not supplied

Scale-Resolving Simulations of Viking '75 Reentry Capsule Wake Flow

Scale resolving simulations of static wake tests of the '75 Viking capsule have been performed using two unstructured grid flow solvers, US3D and PyFR. Simulations with several resolutions have been performed at varying Mach numbers with the aim of solver validation for capsule wake flows as well as establishing simulation best practices.

Rathakrishnan Bhaskaran↗