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At least 91 records · Page 5

PROTECT: Production and Reuse of Thermally Efficient Ceramic Thermal Protection Systems

PROTECT (Production and Reuse Of Thermally Efficient Ceramic TPS) is a NASA Early Career Initiative focused on developing the next generation of reusable ceramic thermal protection systems (TPS). This project addresses key challenges in TPS design, including temperature capability, thermal stability, and refurbishment time, by integrating novel material development with predictive modeling. Leveraging enhanced capabilities in NASA’s Porous Microstructure Analysis (PuMA) software, PROTECT introduces new modeling tools to predict the thermal and mechanical behavior of fibrous ceramic materials. These tools enable accurate prediction of performance metrics such as thermal conductivity and structural integrity, reducing reliance on costly physical testing. Preliminary advances in these areas will be presented. To support model validation, PROTECT is building a comprehensive database of raw material properties using advanced characterization techniques, including micro computed tomography (CT) scanning in collaboration with the University of Illinois Urbana-Champaign (UIUC). The presentation will detail the sampling workflows and analysis methods used to generate this detailed microstructural data and how it is used to develop improved models in PuMA. This multi-center collaboration, spanning NASA (JSC, ARC, KSC, GRC), Oak Ridge National Laboratory, UIUC, and SpaceX, is developing tailored TPS solutions for LEO, lunar, and Martian missions. By bridging heritage systems with the demands of modern spaceflight, PROTECT contributes to the advancement of reusable TPS technologies for future exploration missions.

Propulsion, Refractory, and Coating Materials↗

PROTECT: Production and Reuse of Thermally Efficient Ceramic Thermal Protection Systems

PROTECT (Production and Reuse Of Thermally Efficient Ceramic TPS) is a NASA Early Career Initiative focused on developing the next generation of reusable ceramic thermal protection systems (TPS). This project addresses key challenges in TPS design, including temperature capability, thermal stability, and refurbishment time, by integrating novel material development with predictive modeling. Leveraging enhanced capabilities in NASA’s Porous Microstructure Analysis (PuMA) software, PROTECT introduces new modeling tools to predict the thermal and mechanical behavior of fibrous ceramic materials. These tools enable accurate prediction of performance metrics such as thermal conductivity and structural integrity, reducing reliance on costly physical testing. Preliminary advances in these areas will be presented. To support model validation, PROTECT is building a comprehensive database of raw material properties using advanced characterization techniques, including micro computed tomography (CT) scanning in collaboration with the University of Illinois Urbana-Champaign (UIUC). The presentation will detail the sampling workflows and analysis methods used to generate this detailed microstructural data and how it is used to develop improved models in PuMA. This multi-center collaboration, spanning NASA (JSC, ARC, KSC, GRC), Oak Ridge National Laboratory, UIUC, and SpaceX, is developing tailored TPS solutions for LEO, lunar, and Martian missions. By bridging heritage systems with the demands of modern spaceflight, PROTECT contributes to the advancement of reusable TPS technologies for future exploration missions.

Propulsion, Refractory, and Coating Materials↗

Earth Entry Requirements for Mars, Europa and Enceladus Sample Return Missions: A Thermal Protection System Perspective

This oral presentation will be given at the 13th International Planetary Probe Workshop on June 14th, 2016 and will cover the drivers for reliability and the challenges faced in selecting and designing the thermal protection system (TPS). In addition, an assessment is made on new emerging TPS related technologies that could help with designs to meet the planetary protection requirements to prevent backward (Earth) contamination by biohazardous samples.

Earth Entry↗

ISEP: A Joint SRAG/CCMC Collaboration to Improve Mitigation of Space Weather Effects on Crew Health in the Exo-LEO Era

The Space Radiation Analysis Group (SRAG) at Johnson Space Center (JSC) is tasked with monitoring changes to space weather and mitigating any resultant impacts to crew health and safety. As human spaceflight goals extend from Low-Earth Orbit (LEO) missions like the International Space Station (ISS) to the moon, Mars and beyond, SRAG will need to update their current approach for crew monitoring of and protection from radiation exposure due to energetic Solar Particle Events (ESPEs). Challenges faced in planning exo-LEO missions include the lack of protection from the Earth’s geomagnetic field employed by the ISS in addition to limited communication capability between the crew and the ground. In the event of an ESPE, the current ISS trajectory ensures that the vehicle is only traveling through fields of higher radiation exposure for a brief period of time; the Earth’s geomagnetic field prevents the penetration of the high-energy particles of concern throughout the majority of the orbit. Exo-LEO missions, on the other hand, require that the vehicle travel through free space, exposing vehicle and crew to the full impact of the ESPE. NASA has combined multiple approaches to resolve this radiation exposure issue. New vehicles are designed to take advantage of advances in particle transport modeling capabilities and shielding technology, allowing redistribution of mass throughout the vehicle to areas of thinner shielding when the energetic particle flux has increased to levels of concern. Although vehicle shielding is an important aspect of radiation exposure protection, there is a continued requirement to monitor and predict the space weather environment. To this end, SRAG maintains a console position in Mission Control with 24/7 mission support capability. In the event of increased solar activity, SRAG collaborates with the Flight Control Team (FCT) to determine if crew action (i.e., shelter) is required. During any increase in solar activity, the FCT needs three pieces of information to effectively decide the crew response in light of other required mission tasks: if an event (ESPE) will occur, how ‘intense’ an observed event will be, and how long will an observed event will last. An ideal alert system limits false alarms, therefore causing the crew to take action unnecessarily, without ignoring events that pose a hazard to the crew. SRAG’s current operational concept for ISS missions focuses on short-term forecasts, best described as ‘now-casting’. Console operators are in daily communication with the Space Weather Prediction Center (SWPC) for situational awareness purposes. When conditions exist that may lead to increased solar activity, operators receive notifications from SWPC. In the case of a well-connected ESPE, the console operator may only have on the order of minutes to several hours to notify the FCT of the event and provide a recommendation for crew action. As NASA shifts to exo-LEO missions, the increased time in free space as well as the reduced ability to communicate with the crew will force a transition in crew protection strategy that emphasizes improvments to both the accuracy and the lead time in forecasting capabilities.

Barzilla, Janet E.↗

Apollo experience report: Thermal protection subsystem

The Apollo command module was the first manned spacecraft to be designed to enter the atmosphere of the earth at lunar-return velocity, and the design of the thermal protection subsystem for the resulting entry environment presented a major technological challenge. Brief descriptions of the Apollo command module thermal design requirements and thermal protection configuration, and some highlights of the ground and flight testing used for design verification of the system are presented. Some of the significant events that occurred and decisions that were made during the program concerning the thermal protection subsystem are discussed.

Pavlosky, J. E.↗

Entry heating and thermal protection

The book provides a documentation of progress in entry heating and thermal protection as related to two very challenging and very dissimilar applications, viz., the Jovian atmospheric probe as a key element of the Galileo mission, and the Space Shuttle. The Jovian atmospheric probe presents what might be the ultimate challenge in terms of the severity of entry. Success of the Galileo probe depends upon a design based on computational analysis largely unverified by experiment. Topics of interest include methods for predicting off-stagnation-point flowfields for planetary entry probes, modeling of radiative heating in base region of Jovian entry probe, gas heating with pressure gradients for the Space Shuttle, external tank laminar and rarefied aeroheating, and a study of the aerothermal entry environment for the Galileo probe.

Olstad, W. B.↗

Shock interference prediction using direct simulation Monte Carlo

The shock interaction produced when an incident shock impinges on an inlet cowl lip is investigated for a cowl lip radius of 0.1 in. and flight conditions of Mach 15 and 35-km altitude. This problem is of interest in the design of hypersonic flight vehicles because the interference heating at the cowl lip surface from such a shock interaction is expected to be very high and the design of adequate thermal protection in this region will be challenging. Noncontinuum effects may be significant at this combination of altitude and small dimensions. If this is so, a computational solution based on the Navier-Stokes equations could significantly overpredict the surface heating on the cowl lip. Therefore, a kinetic theory solution technique, direct simulation Monte Carlo (DSMC), is used to predict the flowfield and surface heating. The details of modeling this problem and some preliminary results are presented. The same qualitative flow patterns are seen with DSMC and a continuum solution of the shock interference case, but the peak heating predicted with DSMC is somewhat lower.

Carlson, Ann B.↗

Space suits and life support systems for the exploration of Mars

The requirements and technologies needed for space suits to be used for the manned exploration of Mars are examined. Alternative concepts are proposed for both the space suit and the portable life support system (collectively called the Extravehicular Mobility Unit, or EMU) needed for Mars exploration. EMU system requirements are outlined. It is pointed out that the most fundamental difference between a Mars EMU and those that preceded it is that the design of a Mars EMU must be driven by science and permanent habitability requirements, while all prior EMU designs have been driven by engineering requirements. The EMU weight issues are discussed, and the system mass and mobility concerns are addressed, along with the backpack-to-body-weight ratio. The challenges of thermal and cosmic radiation protection, micrometeorite protection, and EMU system and crew heat rejection are dealt with briefly, as well as the physiological issues of pressure regulation and bacterial or contaminant isolation. A mathematical model is then presented for evaluation of candidate EMU designs and for concept optimization and selection. Lead technology issues are also discussed.

Kuznetz, Lawrence H.↗

Broadband IR Measurements for Modis Validation

The primary objective of this research was the development and deployment of autonomous shipboard systems for infrared measurement of ocean surface skin temperature (SST). The focus was on demonstrating long-term, all-weather capability and supplying calibrated skin SST to the MODIS Ocean Science Team (MOCEAN). A secondary objective was to investigate and account for environmental factors that affect in situ measurements of SST for validation of satellite products. We developed and extensively deployed the Calibrated, InfraRed, In situ Measurement System, or CIRIMS, for at-sea validation of satellite-derived SST. The design goals included autonomous operation at sea for up to 6 months and an accuracy of +/- 0.1 C. We used commercially available infrared pyrometers and a precision blackbody housed in a temperature-controlled enclosure. The sensors are calibrated at regular interval using a cylindro-cone target immersed in a temperature-controlled water bath, which allows the calibration points to follow the ocean surface temperature. An upward-looking pyrometer measures sky radiance in order to correct for the non-unity emissivity of water, which can introduce an error of up to 0.5 C. One of the most challenging aspects of the design was protection against the marine environment. A wide range of design strategies to provide accurate, all-weather measurements were investigated. The CIRIMS uses an infrared transparent window to completely protect the sensor and calibration blackbody from the marine environment. In order to evaluate the performance of this approach, the design incorporates the ability to make measurements with and without the window in the optical path.

Jessup, Andrew T.↗

Space radiation dosimetry in low-Earth orbit and beyond

Space radiation dosimetry presents one of the greatest challenges in the discipline of radiation protection. This is a result of both the highly complex nature of the radiation fields encountered in low-Earth orbit (LEO) and interplanetary space and of the constraints imposed by spaceflight on instrument design. This paper reviews the sources and composition of the space radiation environment in LEO as well as beyond the Earth's magnetosphere. A review of much of the dosimetric data that have been gathered over the last four decades of human space flight is presented. The different factors affecting the radiation exposures of astronauts and cosmonauts aboard the International Space Station (ISS) are emphasized. Measurements made aboard the Mir Orbital Station have highlighted the importance of both secondary particle production within the structure of spacecraft and the effect of shielding on both crew dose and dose equivalent. Roughly half the dose on ISS is expected to come from trapped protons and half from galactic cosmic rays (GCRs). The dearth of neutron measurements aboard LEO spacecraft and the difficulty inherent in making such measurements have led to large uncertainties in estimates of the neutron contribution to total dose equivalent. Except for a limited number of measurements made aboard the Apollo lunar missions, no crew dosimetry has been conducted beyond the Earth's magnetosphere. At the present time we are forced to rely on model-based estimates of crew dose and dose equivalent when planning for interplanetary missions, such as a mission to Mars. While space crews in LEO are unlikely to exceed the exposure limits recommended by such groups as the NCRP, dose equivalents of the same order as the recommended limits are likely over the course of a human mission to Mars. c2001 Elsevier Science B.V. All rights reserved.

short duration↗

High sustained +Gz acceleration: physiological adaptation to high-G tolerance

Since the early 1940s, a significant volume of research has been conducted in an effort to describe the impact of acute exposures to high-G acceleration on cardiovascular mechanisms responsible to maintaining cerebral perfusion and conscious in high performance aircraft pilots during aerial combat maneuvers. The value of understanding hemodynamic characteristics that underlie G-induced loss of consciousness has been instrumental in the evolution of optimal technology development (e.g., G-suits, positive pressure breathing, COMBAT EDGE, etc.) and pilot training (e.g., anti-G straining maneuvers). Although the emphasis of research has been placed on the development of protection against acute high +Gz acceleration effects, recent observations suggest that adaptation of cardiovascular mechanism associated with blood pressure regulation may contribute to a protective 'G-training' effect. Regular training at high G enhances G tolerance in humans, rats, guinea pigs, and dogs while prolonged layoff from exposure in high G profiles (G-layoff) can result in reduced G endurance. It seems probable that adaptations in physiological functions following chronically-repeated high G exposure (G training) or G-layoff could have significant impacts on performance during sustained high-G acceleration since protective technology such as G-suits and anit-G straining maneuvers are applied consistently during these periods of training. The purpose of this paper is to present a review of new data from three experiments that support the notion that repeated exposure on a regular basis to high sustained +Gz acceleration induces significant physiological adaptations which are associated with improved blood pressure regulation and subsequent protection of cerebral perfusion during orthostatic challenges.

Review, Tutorial↗

Automated Generation and Assessment of Autonomous Systems Test Cases

This slide presentation reviews some of the issues concerning verification and validation testing of autonomous spacecraft routinely culminates in the exploration of anomalous or faulted mission-like scenarios using the work involved during the Dawn mission's tests as examples. Prioritizing which scenarios to develop usually comes down to focusing on the most vulnerable areas and ensuring the best return on investment of test time. Rules-of-thumb strategies often come into play, such as injecting applicable anomalies prior to, during, and after system state changes; or, creating cases that ensure good safety-net algorithm coverage. Although experience and judgment in test selection can lead to high levels of confidence about the majority of a system's autonomy, it's likely that important test cases are overlooked. One method to fill in potential test coverage gaps is to automatically generate and execute test cases using algorithms that ensure desirable properties about the coverage. For example, generate cases for all possible fault monitors, and across all state change boundaries. Of course, the scope of coverage is determined by the test environment capabilities, where a faster-than-real-time, high-fidelity, software-only simulation would allow the broadest coverage. Even real-time systems that can be replicated and run in parallel, and that have reliable set-up and operations features provide an excellent resource for automated testing. Making detailed predictions for the outcome of such tests can be difficult, and when algorithmic means are employed to produce hundreds or even thousands of cases, generating predicts individually is impractical, and generating predicts with tools requires executable models of the design and environment that themselves require a complete test program. Therefore, evaluating the results of large number of mission scenario tests poses special challenges. A good approach to address this problem is to automatically score the results based on a range of metrics. Although the specific means of scoring depends highly on the application, the use of formal scoring - metrics has high value in identifying and prioritizing anomalies, and in presenting an overall picture of the state of the test program. In this paper we present a case study based on automatic generation and assessment of faulted test runs for the Dawn mission, and discuss its role in optimizing the allocation of resources for completing the test program.

Testing challenges↗

A Hypothesis on Biological Protection from Space Radiation Through the Use of New Therapeutic Gases

Radiation exposure to astronauts could be a significant obstacle for long duration manned space exploration because of current uncertainties regarding the extent of biological effects. Furthermore, concepts for protective shielding also pose a technically challenging issue due to the nature of cosmic radiation and current mass and power constraints with modern exploration technology. The concern regarding exposure to cosmic radiation is the biological damage it induces. As damage is associated with increased oxidative stress, it is important and would be enabling to mitigate and/or prevent oxidative stress prior to the development of clinical symptoms and disease. This paper hypothesizes a "systems biology" approach in which a combination of chemical and biological mitigation techniques are used conjunctively. It proposes using new, therapeutic, medical gases as both chemical radioprotectors for radical scavenging and biological signaling molecules for management of the body s response to exposure. From reviewing radiochemistry of water, biological effects of CO, H2, NO, and H2S gas, and mechanisms of radiation biology, it is concluded that this approach may have great therapeutic potential for radiation exposure. Furthermore, it also appears to have similar potential for curtailing the pathogenesis of other diseases in which oxidative stress has been implicated including, cardiovascular disease, cancer, chronic inflammatory disease, hypertension, ischemia/reperfusion injury, acute respiratory distress syndrome, parkinson s and alzheimer s disease, cataracts, and aging

Schoenfeld, Michael P.↗

A Hypothesis on Biological Protection from Space Radiation Through the Use of New Therapeutic Gases as Medical Counter Measures

Radiation exposure to astronauts could be a significant obstacle for long duration manned space exploration because of current uncertainties regarding the extent of biological effects. Furthermore, concepts for protective shielding also pose a technically challenging issue due to the nature of cosmic radiation and current mass and power constraints with modern exploration technology. The concern regarding exposure to cosmic radiation is the biological damage it induces. As damage is associated with increased oxidative stress, it is important and would be enabling to mitigate and/or prevent oxidative stress prior to the development of clinical symptoms and disease. This paper hypothesizes a "systems biology" approach in which a combination of chemical and biological mitigation techniques are used conjunctively. It proposes using new, therapeutic, medical gases as both chemical radioprotectors for radical scavenging and biological signaling molecules for management of the body s response to exposure. From reviewing radiochemistry of water, biological effects of CO, H2, NO, and H2S gas, and mechanisms of radiation biology, it is concluded that this approach may have great therapeutic potential for radiation exposure. Furthermore, it also appears to have similar potential for curtailing the pathogenesis of other diseases in which oxidative stress has been implicated including cardiovascular disease, cancer, chronic inflammatory disease, hypertension, ischemia/reperfusion injury, acute respiratory distress syndrome, Parkinson s and Alzheimer s disease, cataracts, and aging.

Schoenfeld, Michael P.↗

A Hypothesis on Biological Protection from Space Radiation Through the Use of New Therapeutic Gases

Radiation exposure to astronauts could be a significant obstacle for long duration manned space exploration because of current uncertainties regarding the extent of biological effects. Furthermore, concepts for protective shielding also pose a technically challenging issue due to the nature of cosmic radiation and current mass and power constraints with modern exploration technology. The concern regarding exposure to cosmic radiation is the biological damage it induces. As damage is associated with increased oxidative stress, it is important and would be enabling to mitigate and/or prevent oxidative stress prior to the development of clinical symptoms and disease. This paper hypothesizes a "systems biology" approach in which a combination of chemical and biological mitigation techniques are used conjunctively. It proposes using new, therapeutic, medical gases as both chemical radioprotectors for radical scavenging and biological signaling molecules for management of the body s response to exposure. From reviewing radiochemistry of water, biological effects of CO, H2, NO, and H2S gas, and mechanisms of radiation biology, it is concluded that this approach may have great therapeutic potential for radiation exposure. Furthermore, it also appears to have similar potential for curtailing the pathogenesis of other diseases in which oxidative stress has been implicated including cardiovascular disease, cancer, chronic inflammatory disease, hypertension, ischemia/reperfusion injury, acute respiratory distress syndrome, Parkinson s and Alzheimer s disease, cataracts, and aging.

Schoenfeld, Michael P.↗

A Hypothesis on Biological Protection from Space Radiation Through the Use of New Therapeutic Gases as Medical Counter Measures

Exposure to astronauts could be a significant obstacle for long duration manned space exploration because of current uncertainties regarding the extent of biological effects. Furthermore, concepts for protective shielding also pose a technically challenging issue due to the nature of cosmic radiation and current mass and power constraints with modern exploration technology. As biological damage from exposure is associated with increased oxidative stress, it would be enabling to mitigate and/or prevent stress prior to the development of clinical symptoms and disease. This paper hypothesizes a "systems biology" approach in which a combination of chemical and biological mitigation techniques are used conjunctively. It proposes using new, therapeutic, medical gases as both chemical radioprotectors for radical scavenging and biological promoters for management of the body s response to exposure. From reviewing radiochemistry of water, biological effects of CO, H2, NO, and H2S gas, and mechanisms of radiation biology, it is concluded that this approach may have great therapeutic potential for exposure. Furthermore, it also appears to have potential for curtailing the pathogenesis of other diseases in which oxidative stress has been implicated including cardiovascular disease, cancer, chronic inflammatory disease, hypertension, ischemia/reperfusion injury, acute respiratory distress syndrome, Parkinson s and Alzheimer s disease, cataracts, and aging.

Schoenfeld, Michael P.↗

NASA's Fire Information for Resource Management System (FIRMS): Near Real-Time Global Fire Monitoring Using Data from MODIS and VIIRS

NASA's Fire Information for Resource Management System (FIRMS) provides near-real time active fire / hotspot products from MODIS and VIIRS to users in over 160 countries. The goal of FIRMS is to meet the needs of natural resource and protected area managers that face considerable challenges in obtaining timely satellite-derived information on fires burning within and around their management area. FIRMS has been reliably providing active fire / hotspot data in easy to use formats since its inception in 2006. Fire information is provided through a web map interface, email alerts, a web mapping service, and a range of downloadable files (SHP, CSV, KML and JSON). FIRMS data are used directly by end users and by brokers who take the data and add value to it before re-distributing it.FIRMS was initially developed by the University of Maryland in 2006; it was funded by the United Nations FAO and NASA's Applied sciences program under a NASA ROSES call. In 2012 FIRMS became integrated in to NASA's Land Atmosphere Near real-time Capability for EOS (LANCE); a virtual system that leverages NASAs existing science processing capabilities to deliver NRT data from ten instruments within 3 hours of satellite overpass. This presentation will describe the FIRMS system, provide an overview of the system, briefly describe some of the known applications and describe plans to further integrate the data in to NASA's Global Imagery Browse Services (GIBS) public mapping services and Worldview website.

active fire/hotspots↗

Handling Emergency Management in [an] Object Oriented Modeling Environment

It has been understood that protection of a nation from extreme disasters is a challenging task. Impacts of extreme disasters on a nation's critical infrastructures, economy and society could be devastating. A protection plan itself would not be sufficient when a disaster strikes. Hence, there is a need for a holistic approach to establish more resilient infrastructures to withstand extreme disasters. A resilient infrastructure can be defined as a system or facility that is able to withstand damage, but if affected, can be readily and cost-effectively restored. The key issue to establish resilient infrastructures is to incorporate existing protection plans with comprehensive preparedness actions to respond, recover and restore as quickly as possible, and to minimize extreme disaster impacts. Although national organizations will respond to a disaster, extreme disasters need to be handled mostly by local emergency management departments. Since emergency management departments have to deal with complex systems, they have to have a manageable plan and efficient organizational structures to coordinate all these systems. A strong organizational structure is the key in responding fast before and during disasters, and recovering quickly after disasters. In this study, the entire emergency management is viewed as an enterprise and modelled through enterprise management approach. Managing an enterprise or a large complex system is a very challenging task. It is critical for an enterprise to respond to challenges in a timely manner with quick decision making. This study addresses the problem of handling emergency management at regional level in an object oriented modelling environment developed by use of TopEase software. Emergency Operation Plan of the City of Hampton, Virginia, has been incorporated into TopEase for analysis. The methodology used in this study has been supported by a case study on critical infrastructure resiliency in Hampton Roads.

Tokgoz, Berna Eren↗