Base flow investigation of the Apollo AS-202 Command Module

NASA Astrophysics Data System (ADS)

Walpot, Louis M. G.; Wright, Michael J.; Noeding, Peter; Schrijer, Ferry

2012-01-01

A major contributor to the overall vehicle mass of re-entry vehicles is the afterbody thermal protection system. This is due to the large acreage (equal or bigger than that of the forebody) to be protected. The present predictive capabilities for base flows are comparatively lower than those for windward flowfields and offer therefore a substantial potential for improving the design of future re-entry vehicles. To that end, it is essential to address the accuracy of high fidelity CFD tools exercised in the US and EU, which motivates a thorough investigation of the present status of hypersonic flight afterbody heating. This paper addresses the predictive capabilities of afterbody flow fields of re-entry vehicles investigated in the frame of the NATO/RTO-RTG-043 task group. First, the verification of base flow topologies on the basis of available wind-tunnel results performed under controlled supersonic conditions (i.e. cold flows devoid of reactive effects) is performed. Such tests address the detailed characterization of the base flow with particular emphasis on separation/reattachment and their relation to Mach number effects. The tests have been performed on an Apollo-like re-entry capsule configuration. Second, the tools validated in the frame of the previous effort are exercised and appraised against flight-test data collected during the Apollo AS-202 re-entry.

Predicting Boundary-Layer Transition on Space-Shuttle Re-Entry

NASA Technical Reports Server (NTRS)

Berry, Scott; Horvath, Tom; Merski, Ron; Liechty, Derek; Greene, Frank; Bibb, Karen; Buck, Greg; Hamilton, Harris; Weilmuenster, Jim; Campbell, Chuck;

Improvements to NASA's Debris Assessment Software

NASA Technical Reports Server (NTRS)

Opiela, J.; Johnson, Nicholas L.

2007-01-01

NASA's Debris Assessment Software (DAS) has been substantially revised and expanded. DAS is designed to assist NASA programs in performing orbital debris assessments, as described in NASA s Guidelines and Assessment Procedures for Limiting Orbital Debris. The extensive upgrade of DAS was undertaken to reflect changes in the debris mitigation guidelines, to incorporate recommendations from DAS users, and to take advantage of recent software capabilities for greater user utility. DAS 2.0 includes an updated environment model and enhanced orbital propagators and reentry-survivability models. The ORDEM96 debris environment model has been replaced by ORDEM2000 in DAS 2.0, which is also designed to accept anticipated revisions to the environment definition. Numerous upgrades have also been applied to the assessment of human casualty potential due to reentering debris. Routines derived from the Object Reentry Survival Analysis Tool, Version 6 (ORSAT 6), determine which objects are assessed to survive reentry, and the resulting risk of human casualty is calculated directly based upon the orbital inclination and a future world population database. When evaluating reentry risks, the user may enter up to 200 unique hardware components for each launched object, in up to four nested levels. This last feature allows the software to more accurately model components that are exposed below the initial breakup altitude. The new DAS 2.0 provides an updated set of tools for users to assess their mission s compliance with the NASA Safety Standard and does so with a clear and easy-to-understand interface. The new native Microsoft Windows graphical user interface (GUI) is a vast improvement over the previous DOS-based interface. In the new version, functions are more-clearly laid out, and the GUI includes the standard Windows-style Help functions. The underlying routines within the DAS code are also improved.

Reentry trajectory optimization based on a multistage pseudospectral method.

PubMed

Zhao, Jiang; Zhou, Rui; Jin, Xuelian

2014-01-01

Of the many direct numerical methods, the pseudospectral method serves as an effective tool to solve the reentry trajectory optimization for hypersonic vehicles. However, the traditional pseudospectral method is time-consuming due to large number of discretization points. For the purpose of autonomous and adaptive reentry guidance, the research herein presents a multistage trajectory control strategy based on the pseudospectral method, capable of dealing with the unexpected situations in reentry flight. The strategy typically includes two subproblems: the trajectory estimation and trajectory refining. In each processing stage, the proposed method generates a specified range of trajectory with the transition of the flight state. The full glide trajectory consists of several optimal trajectory sequences. The newly focused geographic constraints in actual flight are discussed thereafter. Numerical examples of free-space flight, target transition flight, and threat avoidance flight are used to show the feasible application of multistage pseudospectral method in reentry trajectory optimization.

Reentry Trajectory Optimization Based on a Multistage Pseudospectral Method

PubMed Central

Zhou, Rui; Jin, Xuelian

2014-01-01

Of the many direct numerical methods, the pseudospectral method serves as an effective tool to solve the reentry trajectory optimization for hypersonic vehicles. However, the traditional pseudospectral method is time-consuming due to large number of discretization points. For the purpose of autonomous and adaptive reentry guidance, the research herein presents a multistage trajectory control strategy based on the pseudospectral method, capable of dealing with the unexpected situations in reentry flight. The strategy typically includes two subproblems: the trajectory estimation and trajectory refining. In each processing stage, the proposed method generates a specified range of trajectory with the transition of the flight state. The full glide trajectory consists of several optimal trajectory sequences. The newly focused geographic constraints in actual flight are discussed thereafter. Numerical examples of free-space flight, target transition flight, and threat avoidance flight are used to show the feasible application of multistage pseudospectral method in reentry trajectory optimization. PMID:24574929

Genesis Reentry Observations and Data Analysis

NASA Technical Reports Server (NTRS)

Suggs, R. M.; Swift, W. R.

2005-01-01

The Genesis spacecraft reentry represented a unique opportunity to observe a "calibrated meteor" from northern Nevada. Knowing its speed, mass, composition, and precise trajectory made it a good subject to test some of the algorithms used to determine meteoroid mass from observed brightness. It was also a good test of an inexpensive set of cameras that could be deployed to observe future shuttle reentries. The utility of consumer-grade video cameras was evident during the STS-107 accident investigation, and the Genesis reentry gave us the opportunity to specify and test commercially available cameras that could be used during future reentries. This Technical Memorandum describes the video observations and their analysis, compares the results with a simple photometric model, describes the forward scatter radar experiment, and lists lessons learned from the expedition and implications for the Stardust reentry in January 2006 as well as future shuttle reentries.

Analysis of reentry into the White Sands Missile Range (WSMR) for the LifeSat mission

NASA Technical Reports Server (NTRS)

Hametz, M.; Roszman, L.; Snow, F.; Cooley, J.

1993-01-01

This study investigates the reentry of the LifeSat vehicles into the WSMR. The LifeSat mission consists of two reusable reentry satellites, each carrying a removable payload module, which scientists will use to study long-term effects of microgravity, Van Allen belt radiation, and galactic cosmic rays on living organisms. A series of missions is planned for both low-Earth circular orbits and highly elliptic orbits. To recover the payload module with the specimens intact, a soft parachute landing and recovery at the WSMR is planned. This analysis examines operational issues surrounding the reentry scenario to assess the feasibility of the reentry.

"Our commonality is our past:" a qualitative analysis of re-entry community health workers' meaningful experiences.

PubMed

Bedell, Precious; Wilson, John L; White, Ann Marie; Morse, Diane S

Re-entry community health workers (CHWs) are individuals who connect diverse community residents at risk for chronic health issues such as Hepatitis C virus and cardiovascular disease with post-prison healthcare and re-entry services. While the utilization of CHWs has been documented in other marginalized populations, there is little knowledge surrounding the work of re-entry CHWs with individuals released from incarceration. Specifically, CHWs' experiences and perceptions of the uniqueness of their efforts to link individuals to healthcare have not been documented systematically. This study explored what is meaningful to formerly incarcerated CHWs as they work with released individuals. The authors conducted a qualitative thematic analysis of twelve meaningful experiences written by re-entry CHWs employed by the Transitions Clinic Network who attended a CHW training program during a conference in San Francisco, CA. Study participants were encouraged to recount meaningful CHW experiences and motivations for working with re-entry populations in a manner consistent with journal-based qualitative analysis techniques. Narratives were coded using an iterative process and subsequently organized according to themes in ATLAS.ti. Study personnel came to consensus with coding and major themes. The narratives highlighted thought processes and meaning related to re-entry CHWs' work helping patients navigate complex social services for successful re-integration. Six major themes emerged from the analysis: advocacy and support, empathy relating to a personal history of incarceration, giving back, professional satisfaction and responsibilities, resiliency and educational advancement, and experiences of social inequities related to race. Re-entry CHWs described former incarceration, employment, and social justice as sources of meaning for assisting justice-involved individuals receive effective, efficient, and high-quality healthcare. Health clinics for individuals released from incarceration provide a unique setting that links high risk patients to needed care and professionalizes career opportunities for formerly incarcerated re-entry CHWs. The commonality of past correctional involvement is a strong indicator of the meaning and perceived effectiveness re-entry CHWs find in working with individuals leaving prison. Expansion of reimbursable visits with re-entry CHWs in transitions clinics designed for re-entering individuals is worthy of further consideration.

Inadvertent Earth Reentry Breakup Analysis for the New Horizons Mission

NASA Technical Reports Server (NTRS)

Ling, Lisa M.; Salama, Ahmed; Ivanov, Mark; McRonald, Angus

2007-01-01

The New Horizons (NH) spacecraft was launched in January 2006 aboard an Atlas V launch vehicle, in a mission to explore Pluto, its moons, and other bodies in the Kuiper Belt. The NH spacecraft is powered by a Radioisotope Thermoelectric Generator (RTG) which encases multiple General Purpose Heat Source (GPHS) modules. Thus, a pre-launch vehicle breakup analysis for an inadvertent atmospheric reentry in the event of a launch failure was required to assess aerospace nuclear safety and for launch contingency planning. This paper addresses potential accidental Earth reentries analyzed at the Jet Propulsion Laboratory (JPL) which may arise during the ascent to parking orbit, resulting in a suborbital reentry, as well as a departure from parking orbit, resulting in an orbital reentry.

'What on earth can this possibly mean'? French reentry courts and experts' risk assessment.

PubMed

Herzog-Evans, Martine

2016-01-01

Against the backdrop of ten years of punitive criminal justice policies, the number of cases in which risk assessments by psychiatrist experts are mandatory has considerably increased in France. Because of complex and deeply ingrained cultural factors, most experts and academics oppose the use of actuarial or other structured judgement tools, which they assimilate to these policy changes. Parallel to this, the reentry judges in charge of making release and other community sentence decisions have maintained a strong rehabilitative and desistance-focused culture. Drawing on interviews with these judges and experts, the author wanted to assess the judges' expectations of experts' reports, their opinion on actuarial tools, and how they perceived experts and their aptitude to assess risk. The study showed that French reentry judges manage to keep experts' conclusions at bay when they do not fit with their desistance goals, as they can draw upon their own expertise and that of probation services. They do not have much faith in the professionalism and methodology of experts, and would like them to better demonstrate how they reach their conclusions. Moreover, criminogenic needs assessment would be much more useful to them than static risk assessment, which raises the issue as to why this is not the French probation services' role. Reentry judges who never encountered a report which uses a structured tool are influenced by the French ideological debate; those who have read such reports are unanimously in favour of such tools. It thus seems clear that they would like experts to be more strongly guided by science, but are not yet fully aware of what this entails. Copyright © 2015 Elsevier Ltd. All rights reserved.

New Horizons Launch Contingency Effort

NASA Astrophysics Data System (ADS)

Chang, Yale; Lear, Matthew H.; McGrath, Brian E.; Heyler, Gene A.; Takashima, Naruhisa; Owings, W. Donald

2007-01-01

On 19 January 2006 at 2:00 PM EST, the NASA New Horizons spacecraft (SC) was launched from the Cape Canaveral Air Force Station (CCAFS), FL, onboard an Atlas V 551/Centaur/STAR™ 48B launch vehicle (LV) on a mission to explore the Pluto Charon planetary system and possibly other Kuiper Belt Objects. It carried a single Radioisotope Thermoelectric Generator (RTG). As part of the joint NASA/US Department of Energy (DOE) safety effort, contingency plans were prepared to address the unlikely events of launch accidents leading to a near-pad impact, a suborbital reentry, an orbital reentry, or a heliocentric orbit. As the implementing organization. The Johns Hopkins University Applied Physics Laboratory (JHU/APL) had expanded roles in the New Horizons launch contingency effort over those for the Cassini mission and Mars Exploration Rovers missions. The expanded tasks included participation in the Radiological Control Center (RADCC) at the Kennedy Space Center (KSC), preparation of contingency plans, coordination of space tracking assets, improved aerodynamics characterization of the RTG's 18 General Purpose Heat Source (GPHS) modules, and development of spacecraft and RTG reentry breakup analysis tools. Other JHU/APL tasks were prediction of the Earth impact footprints (ElFs) for the GPHS modules released during the atmospheric reentry (for purposes of notification and recovery), prediction of the time of SC reentry from a potential orbital decay, pre-launch dissemination of ballistic coefficients of various possible reentry configurations, and launch support of an Emergency Operations Center (EOC) on the JHU/APL campus. For the New Horizons launch, JHU/APL personnel at the RADCC and at the EOC were ready to implement any real-time launch contingency activities. A successful New Horizons launch and interplanetary injection precluded any further contingency actions. The New Horizons launch contingency was an interagency effort by several organizations. This paper describes JHU/APL's roles and responsibilities in the launch contingency effort, and the specific tasks to fulfill those responsibilities. The overall effort contributed to mission safety and demonstrated successful cooperation between several agencies.

On-Ground Casualty Risk Reduction by Structural Design for Demise

NASA Astrophysics Data System (ADS)

Lemmens, Stijn; Krag, Holger; Funke, Quirin

In recent years, awareness concerning the risk posed by un-controlled re-entering spacecraft on ground has increased. Some re-entry events such as ESA's GOCE in 2013 and NASA's UARS appeared prominent in international media. Space agencies and nations, in cooperation within the Inter-Agency Space Debris Coordination Committee (IADC), have established a requirements to limited the on-ground risk for future missions. To meet the requirements, the amount of debris falling back on Earth has to be limited in number, mass and size. Design for demise (D4D) refers to all measures taken in the design of a space object to increase the potential for demise of the object and its components during re-entry. SCARAB (Spacecraft Atmospheric Re-entry and Break-Up) is ESA's high-fidelity tool which analyses the thermal and structural effects of atmospheric re-entry on spacecraft in a finite-element approach. For this study, a model of a representative satellite is developed in Scarab to serve as test-bed for D4D analysis on a structural level. The model is used as starting point for different D4D approaches based on increasing the exposure of the satellite components to the aero-thermal environment, as a way to speed up the demise. Statistical bootstrapping is applied to the resulting on-ground fragment lists in order to compare the different re-entry scenarios and to determine the uncertainties of the results. Moreover, the bootstrap results can be used to analyse the casualty risk estimator from a theoretical point of view. The risk reductions for the analysed D4D techniques are presented w.r.t. the reference scenario for the modelled representative satellite.

FLPP IXV Re-entry Vehicle, Transonic Characterisation Based on FOI T1500 Wind Tunnel Tests and CFD

NASA Astrophysics Data System (ADS)

Torngren, L.; Chiarelli, C.; Mareschi, V.; Tribot, J.-P.; Binetti, P.; Walloschek, T.

2009-01-01

The European Space Agency ESA, has engaged in 2004, the IXV project (Intermediate eXperimental Vehicle) which is part of the FLPP (Future Launcher Preparatory Programme) aiming at answering to critical technological issues, while supporting the future generation launchers and to improve in general European capabilities in the strategic field of atmospheric re-entry for space transportation, exploration and scientific applications. The IXV key mission and system objectives are the design, development, manufacturing, assembling and on-ground to in-flight verification of an autonomous European lifting and aerodynamically controlled re-entry system, integrating the critical re-entry technologies at the system level. The current IXV vehicle is a slender body type exhibiting rounded shape, thick body controlled by means of two control surfaces. The current mission is to perform an atmospheric re- entry ended by a safe recovery in supersonic regime. A potential extension of the flight domain down to the transonic regime was proposed to be analyzed. The objectives were to study the capability of the IXV for flying autonomously enabling a recovery of the vehicle by means of a subsonic parachute based DRS. The vehicle designed for the hypersonic speeds integrating a large base with only two control surfaces located close to the plane of symmetry is definitively not tuned for transonic ones. CFD done by Thales Alenia Space and wind tunnel activities involving FOI T1500 facility contributed to built up an Aerodynamic Data Base (AEDB) to be used as inputs for flying qualities analysis and re-entry simulations. The paper presents the main objectives of the transonic activities with emphasis on CFD and WTT including a description of the different prediction tools and discussing the main outcomes of the current data comparisons.

Lunar Return Reentry Thermal Analysis of a Generic Crew Exploration Vehicle Wall Structures

NASA Technical Reports Server (NTRS)

Ko, William L.; Tran, Van T.; Bowles, Jeff

2007-01-01

Thermostructural analysis was performed on generic crew exploration vehicle (GCEV) heat shielded wall structures subjected to reentry heating rates based on five potential lunar return reentry trajectories. The GCEV windward outer wall is fabricated with a graphite/epoxy composite honeycomb sandwich panel and the inner wall with an aluminum honeycomb sandwich panel. The outer wall is protected with an ablative Avcoat-5026-39H/CG thermal protection system (TPS). A virtual ablation method (a graphical approximation) developed earlier was further extended, and was used to estimate the ablation periods, ablation heat loads, and the TPS recession layer depths. It was found that up to 83 95 percent of the total reentry heat load was dissipated in the TPS ablation process, leaving a small amount (3-15 percent) of the remaining total reentry heat load to heat the virgin TPS and maintain the TPS surface at the ablation temperature, 1,200 F. The GCEV stagnation point TPS recession layer depths were estimated to be in the range of 0.280-0.910 in, and the allowable minimum stagnation point TPS thicknesses that could maintain the substructural composite sandwich wall at the limit temperature of 300 F were found to be in the range of 0.767-1.538 in. Based on results from the present analyses, the lunar return abort ballistic reentry was found to be quite attractive because it required less TPS weight than the lunar return direct, the lunar return skipping, or the low Earth orbit guided reentry, and only 11.6 percent more TPS weight than the low Earth orbit ballistic reentry that will encounter a considerable weight penalty to obtain the Earth orbit. The analysis also showed that the TPS weight required for the lunar return skipping reentry was much more than the TPS weight necessary for any of the other reentry trajectories considered.

Payload vehicle aerodynamic reentry analysis

NASA Astrophysics Data System (ADS)

Tong, Donald

An approach for analyzing the dynamic behavior of a cone-cylinder payload vehicle during reentry to insure proper deployment of the parachute system and recovery of the payload is presented. This analysis includes the study of an aerodynamic device that is useful in extending vehicle axial rotation through the maximum dynamic pressure region. Attention is given to vehicle configuration and reentry trajectory, the derivation of pitch static aerodynamics, the derivation of the pitch damping coefficient, pitching moment modeling, aerodynamic roll device modeling, and payload vehicle reentry dynamics. It is shown that the vehicle dynamics at parachute deployment are well within the design limit of the recovery system, thus ensuring successful payload recovery.

Thermal Analysis of Small Re-Entry Probe

NASA Technical Reports Server (NTRS)

Agrawal, Parul; Prabhu, Dinesh K.; Chen, Y. K.

2012-01-01

The Small Probe Reentry Investigation for TPS Engineering (SPRITE) concept was developed at NASA Ames Research Center to facilitate arc-jet testing of a fully instrumented prototype probe at flight scale. Besides demonstrating the feasibility of testing a flight-scale model and the capability of an on-board data acquisition system, another objective for this project was to investigate the capability of simulation tools to predict thermal environments of the probe/test article and its interior. This paper focuses on finite-element thermal analyses of the SPRITE probe during the arcjet tests. Several iterations were performed during the early design phase to provide critical design parameters and guidelines for testing. The thermal effects of ablation and pyrolysis were incorporated into the final higher-fidelity modeling approach by coupling the finite-element analyses with a two-dimensional thermal protection materials response code. Model predictions show good agreement with thermocouple data obtained during the arcjet test.

Optimum reentry trajectories of a lifting vehicle

NASA Technical Reports Server (NTRS)

Chern, J. S.; Vinh, N. X.

1980-01-01

Research results are presented of an investigation of the optimum maneuvers of advanced shuttle type spacecraft during reentry. The equations are formulated by means of modified Chapman variables resulting in a general set of equations for flight analysis which are exact for reentry and for flight in a vacuum. Four planar flight typical optimum manuevers are investigated. For three-dimensional flight the optimum trajectory for maximum cross range is discussed in detail. Techniques for calculating reentry footprints are presented.

Simulation-Based Analysis of Reentry Dynamics for the Sharp Atmospheric Entry Vehicle

NASA Technical Reports Server (NTRS)

Tillier, Clemens Emmanuel

1998-01-01

This thesis describes the analysis of the reentry dynamics of a high-performance lifting atmospheric entry vehicle through numerical simulation tools. The vehicle, named SHARP, is currently being developed by the Thermal Protection Materials and Systems branch of NASA Ames Research Center, Moffett Field, California. The goal of this project is to provide insight into trajectory tradeoffs and vehicle dynamics using simulation tools that are powerful, flexible, user-friendly and inexpensive. Implemented Using MATLAB and SIMULINK, these tools are developed with an eye towards further use in the conceptual design of the SHARP vehicle's trajectory and flight control systems. A trajectory simulator is used to quantify the entry capabilities of the vehicle subject to various operational constraints. Using an aerodynamic database computed by NASA and a model of the earth, the simulator generates the vehicle trajectory in three-dimensional space based on aerodynamic angle inputs. Requirements for entry along the SHARP aerothermal performance constraint are evaluated for different control strategies. Effect of vehicle mass on entry parameters is investigated, and the cross range capability of the vehicle is evaluated. Trajectory results are presented and interpreted. A six degree of freedom simulator builds on the trajectory simulator and provides attitude simulation for future entry controls development. A Newtonian aerodynamic model including control surfaces and a mass model are developed. A visualization tool for interpreting simulation results is described. Control surfaces are roughly sized. A simple controller is developed to fly the vehicle along its aerothermal performance constraint using aerodynamic flaps for control. This end-to-end demonstration proves the suitability of the 6-DOF simulator for future flight control system development. Finally, issues surrounding real-time simulation with hardware in the loop are discussed.

Social Support, Motivation, and the Process of Juvenile Reentry: An Exploratory Analysis of Desistance

ERIC Educational Resources Information Center

Panuccio, Elizabeth A.; Christian, Johnna; Martinez, Damian J.; Sullivan, Mercer L.

2012-01-01

Many scholarly works and studies have explored the experience of reentry and desistance for adult offenders, but fewer studies have focused on these processes among juvenile offenders. Using qualitative case studies of juveniles released from secure confinement, this study explores the desistance process during juvenile reentry by examining how…

Reentry Vehicle Flight Controls Design Guidelines: Dynamic Inversion

NASA Technical Reports Server (NTRS)

Ito, Daigoro; Georgie, Jennifer; Valasek, John; Ward, Donald T.

2002-01-01

This report addresses issues in developing a flight control design for vehicles operating across a broad flight regime and with highly nonlinear physical descriptions of motion. Specifically it addresses the need for reentry vehicles that could operate through reentry from space to controlled touchdown on Earth. The latter part of controlled descent is achieved by parachute or paraglider - or by all automatic or a human-controlled landing similar to that of the Orbiter. Since this report addresses the specific needs of human-carrying (not necessarily piloted) reentry vehicles, it deals with highly nonlinear equations of motion, and then-generated control systems must be robust across a very wide range of physics. Thus, this report deals almost exclusively with some form of dynamic inversion (DI). Two vital aspects of control theory - noninteracting control laws and the transformation of nonlinear systems into equivalent linear systems - are embodied in DI. Though there is no doubt that the mathematical tools and underlying theory are widely available, there are open issues as to the practicality of using DI as the only or primary design approach for reentry articles. This report provides a set of guidelines that can be used to determine the practical usefulness of the technique.

Application of a Near Infrared Imaging System for Thermographic Imaging of the Space Shuttle during Hypersonic Re-Entry

NASA Technical Reports Server (NTRS)

Zalameda, Joseph N.; Tietjen, Alan B.; Horvath, Thomas J.; Tomek, Deborah M.; Gibson, David M.; Taylor, Jeff C.; Tack, Steve; Bush, Brett C.; Mercer, C. David; Shea, Edward J.

2010-01-01

High resolution calibrated near infrared (NIR) imagery was obtained of the Space Shuttle s reentry during STS-119, STS-125, and STS-128 missions. The infrared imagery was collected using a US Navy NP-3D Orion aircraft using a long-range infrared optical package referred to as Cast Glance. The slant ranges between the Space Shuttle and Cast Glance were approximately 26-41 nautical miles at point of closest approach. The Hypersonic Thermodynamic Infrared Measurements (HYTHIRM) project was a NASA Langley led endeavor sponsored by the NASA Engineering Safety Center, the Space Shuttle Program Office and the NASA Aeronautics Research Mission Directorate to demonstrate a quantitative thermal imaging capability. HYTHIRM required several mission tools to acquire the imagery. These tools include pre-mission acquisition simulations of the Shuttle trajectory in relationship to the Cast Glance aircraft flight path, radiance modeling to predict the infrared response of the Shuttle, and post mission analysis tools to process the infrared imagery to quantitative temperature maps. The spatially resolved global thermal measurements made during the Shuttle s hypersonic reentry provides valuable flight data for reducing the uncertainty associated with present day ground-to-flight extrapolation techniques and current state-of-the-art empirical boundary-layer transition or turbulent heating prediction methods. Laminar and turbulent flight data is considered critical for the development of turbulence models supporting NASA s next-generation spacecraft. This paper will provide the motivation and details behind the use of an upgraded NIR imaging system used onboard a Navy Cast Glance aircraft and describe the characterizations and procedures performed to obtain quantitative temperature maps. A brief description and assessment will be provided of the previously used analog NIR camera along with image examples from Shuttle missions STS-121, STS-115, and solar tower test. These thermal observations confirmed the challenge of a long-range acquisition during re-entry. These challenges are due to unknown atmospheric conditions, image saturation, vibration etc. This provides the motivation for the use of a digital NIR sensor. The characterizations performed on the digital NIR sensor included radiometric, spatial, and spectral measurements using blackbody radiation sources and known targets. An assessment of the collected data for three Space Shuttle atmospheric re-entries, STS-119, STS-125, and STS-128, are provided along with a description of various events of interest captured using the digital NIR imaging system such as RCS firings and boundary layer transitions. Lastly the process used to convert the raw image counts to quantitative temperatures is presented along with comparisons to the Space Shuttle's onboard thermocouples.

Social reintegration of traumatic brain-injured: the French experience.

PubMed

Truelle, J-L; Wild, K Von; Onillon, M; Montreuil, M

2010-01-01

Traumatic Brain Injury (TBI) may lead to specific handicap, often hidden, mainly due to cognitive and behavioural sequelae. Social re-entry is a long-term, fluctuant and precarious process. The French experience will be illustrated by 6 initiatives answering to 6 challenges to do with TBI specificities:1. bridging the gap, between initial rehabilitation and community re-entry, via transitional units dealing with assessment, retraining, social/vocational orientation and follow-up. Today, there are 30 such units based on multidisciplinary teams.2. assessing recovery by TBI-specific and validated evaluation tools: EBIS holistic document, BNI Screening of higher cerebral functions, Glasgow outcome extended, and QOLIBRI, a TBI-specific quality of life tool.3. promoting specific re-entry programmes founded on limited medication, ecological neuro-psychological rehabilitation, exchange groups and workshops, violence prevention, continuity of care, environmental structuration, and "resocialisation".4. taking into account the "head injured family"5. facilitating recovery after sports-related concussion6. facing medico-legal consequences and compensation: In that perspective, we developed guidelines for TBI-specific expert appraisal, including mandatory neuro-psychological assessment, family interview and an annual forum gathering lawyers and health professionals.

New re-entry device for revascularization of chronic coronary total occlusions: preliminary single Japanese center experience.

PubMed

Tsuchikane, Etsuo; Kimura, Masashi; Suzuki, Takahiko; Habara, Maoto; Kurita, Tairo; Tanaka, Nobuyoshi; Nasu, Kenya; Ito, Tatsuya; Kinoshita, Yoshihisa; Wyman, R Michael

2012-08-01

Although retrograde approach for coronary chronic total occlusion (CTO) has been introduced, the procedure is still time and resource consuming. A simplified antegrade approach mightbe another resort. The aim of this study was to evaluate a new device designed to facilitate guidewire re-entry into the true lumen of a CTO from the adjacent subintimal space. Patients with CTO were entered into a prospective registry regardless of lesion characteristics. A new metal-tip catheter was used initially in primary use cases. If it created subintimal tracking, a new re-entry tool (a flat balloon with 2 exit ports offset by 180 degrees) was used as a platform to attempt guidewire penetration into the distal true lumen. In rescue use cases after unsuccessful conventional wiring, the re-entry procedure was subsequently attempted. In 11 CTO lesions attempted, device success was achieved in 8 cases (72.7%). Re-entry procedure success rate was higher in primary use cases (80%) compared to rescue use cases (33.3%). Retrograde approach was conducted immediately after unsuccessful antegrade procedure using this device in the other 3 cases and successful recanalization was achieved in all cases. All lesions were stented, resulting in TIMI 3 flow without major complications. A new coronary re-entry device may provide another strategic option in the antegrade approach to recanalize CTOs.

Space Debris Modeling at NASA

NASA Technical Reports Server (NTRS)

Johnson, Nicholas L.

2001-01-01

Since the Second European Conference on Space Debris in 1997, the Orbital Debris Program Office at the NASA Johnson Space Center has undertaken a major effort to update and improve the principal software tools employed to model the space debris environment and to evaluate mission risks. NASA's orbital debris engineering model, ORDEM, represents the current and near-term Earth orbital debris population from the largest spacecraft to the smallest debris in a manner which permits spacecraft engineers and experimenters to estimate the frequency and velocity with which a satellite may be struck by debris of different sizes. Using expanded databases and a new program design, ORDEM2000 provides a more accurate environment definition combined with a much broader array of output products in comparison with its predecessor, ORDEM96. Studies of the potential long-term space debris environment are now conducted with EVOLVE 4.0, which incorporates significant advances in debris characterization and breakup modeling. An adjunct to EVOLVE 4.0, GEO EVOLVE has been created to examine debris issues near the geosynchronous orbital regime. In support of NASA Safety Standard 1740.14, which establishes debris mitigation guidelines for all NASA space programs, a set of evaluation tools called the Debris Assessment Software (DAS) is specifically designed for program offices to determine whether they are in compliance with NASA debris mitigation guidelines. DAS 1.5 has recently been released with improved WINDOWS compatibility and graphics functions. DAS 2.0 will incorporate guideline changes in a forthcoming revision to NASA Safety Standard 1740.14. Whereas DAS contains a simplified model to calculate possible risks associated with satellite reentries, NASA's higher fidelity Object Reentry Survival Analysis Tool (ORSAT) has been upgraded to Version 5.0. With the growing awareness of the potential risks posed by uncontrolled satellite reentries to people and property on Earth, the application of both DAS and ORSAT has increased markedly in the past two years.

Finite-element reentry heat-transfer analysis of space shuttle Orbiter

NASA Technical Reports Server (NTRS)

Ko, William L.; Quinn, Robert D.; Gong, Leslie

1986-01-01

A structural performance and resizing (SPAR) finite-element thermal analysis computer program was used in the heat-transfer analysis of the space shuttle orbiter subjected to reentry aerodynamic heating. Three wing cross sections and one midfuselage cross section were selected for the thermal analysis. The predicted thermal protection system temperatures were found to agree well with flight-measured temperatures. The calculated aluminum structural temperatures also agreed reasonably well with the flight data from reentry to touchdown. The effects of internal radiation and of internal convection were found to be significant. The SPAR finite-element solutions agreed reasonably well with those obtained from the conventional finite-difference method.

Inflight thermodynamic properties

NASA Technical Reports Server (NTRS)

Brown, S. C.; Daniels, G. E.; Johnson, D. L.; Smith, O. E.

1973-01-01

The inflight thermodynamic parameters (temperature, pressure, and density) of the atmosphere are presented. Mean and extreme values of the thermodynamic parameters given here can be used in application of many aerospace problems, such as: (1) research and planning and engineering design of remote earth sensing systems; (2) vehicle design and development; and (3) vehicle trajectory analysis, dealing with vehicle thrust, dynamic pressure, aerodynamic drag, aerodynamic heating, vibration, structural and guidance limitations, and reentry analysis. Atmospheric density plays a very important role in most of the above problems. A subsection on reentry is presented, giving atmospheric models to be used for reentry heating, trajectory, etc., analysis.

Initial experience with a dedicated coronary re-entry device for revascularization of chronic total occlusions.

PubMed

Whitlow, Patrick L; Lombardi, William L; Araya, Mario; Michael Wyman, R; Torres, Humberto; Dauvergne, Christian; Tsuchikane, Etsuo; Lansky, Alexandra; Thompson, Craig A

2012-11-01

The aim of this registry was to evaluate a new device designed to facilitate antegrade guidewire re-entry into the true lumen of a chronic total coronary occlusion (CTO) from the adjacent subintimal space. Successful recanalization of CTOs results in clinical improvement in appropriately selected patients. CTO intervention is time- and resource-consuming, and a simplified approach enabling antegrade guidewire re-entry into the distal true lumen might improve success. Patients with CTO and ischemia were entered into a prospective registry regardless of lesion characteristics. If wire manipulation resulted in subintimal wire entrapment, a new re-entry tool (a 2.5-mm flat subintimal balloon with two exit ports offset by 180°) was used as a platform to attempt guidewire penetration into the distal true lumen. The primary endpoint assessed was successful device-guided re-entry. Standard techniques were then utilized to open the CTO. In 40 consecutive CTO lesions attempted, 19 resulted in subintimal wire entrapment (mean occlusion length 44 mm). Sixteen of these 19 were successfully crossed with an antegrade guidewire into the distal true lumen using the new device (84%). One patient with unsuccessful re-entry was subsequently recanalized with a retrograde technique. All crossed lesions were stented (17/17), resulting in TIMI 3 flow without major complications. Two cases were unsuccessful. One patient had a grade I coronary perforation requiring no treatment. A new device to recanalize CTOs complicated by subintimal wire entrapment can be used successfully by experienced operators. Further study of this coronary re-entry device is ongoing. Copyright © 2011 Wiley Periodicals, Inc.

Relational vulnerabilities of incarcerated and reentry mothers: therapeutic implications.

PubMed

Few-Demo, April L; Arditti, Joyce A

2014-11-01

A qualitative study involving a follow-up interview with 10 incarcerated and reentry mothers in rural southwest and central Virginia was conducted to explore the influence that women's close relationships have on their reentry experiences with their families. The Vulnerability Conceptual Model (VCM) was used to sensitize an examination of how incarcerated and reentry mothers negotiate relational vulnerabilities in the context of varying situational vulnerability. Grounded theory analysis revealed three themes that characterized relational vulnerabilities. Given our focus on close relationships and the potential of the VCM to identify opportunities for resilience and vulnerability, we highlighted the influence of ambiguous and ambivalent relationships and unresolved loss and grief due to relationship dissolution or the death of a parent, sibling, child, or intimate partner in the reentry process. The data revealed two types of reentry mothers with divergent trajectories for social reintegration. Implications of these types for therapeutic treatment approaches for reentry women are discussed. © The Author(s) 2013.

Parametric Study of Biconic Re-Entry Vehicles

NASA Technical Reports Server (NTRS)

Steele, Bryan; Banks, Daniel W.; Whitmore, Stephen A.

2007-01-01

An optimization based on hypersonic aerodynamic performance and volumetric efficiency was accomplished for a range of biconic configurations. Both axisymmetric and quasi-axisymmetric geometries (bent and flattened) were analyzed. The aerodynamic optimization wag based on hypersonic simple Incidence angle analysis tools. The range of configurations included those suitable for r lunar return trajectory with a lifting aerocapture at Earth and an overall volume that could support a nominal crew. The results yielded five configurations that had acceptable aerodynamic performance and met overall geometry and size limitations

Time-dependent solution for axisymmetric flow over a blunt body with ideal gas, CF4, or equilibrium air chemistry

NASA Technical Reports Server (NTRS)

Hamilton, H. H., II; Spall, J. R.

1986-01-01

A time-asymptotic method has been used to obtain steady-flow solutions for axisymmetric inviscid flow over several blunt bodies including spheres, paraboloids, ellipsoids, and spherically blunted cones. Comparisons with experimental data and results of other computational methods have demonstrated that accurate solutions can be obtained using this approach. The method should prove useful as an analysis tool for comparing with experimental data and for making engineering calculations for blunt reentry vehicles.

Time-dependent solution for axisymmetric flow over a blunt body with ideal gas, CF4, or equilibrium air chemistry

NASA Astrophysics Data System (ADS)

Hamilton, H. H., II; Spall, J. R.

1986-07-01

A time-asymptotic method has been used to obtain steady-flow solutions for axisymmetric inviscid flow over several blunt bodies including spheres, paraboloids, ellipsoids, and spherically blunted cones. Comparisons with experimental data and results of other computational methods have demonstrated that accurate solutions can be obtained using this approach. The method should prove useful as an analysis tool for comparing with experimental data and for making engineering calculations for blunt reentry vehicles.

Technology Combination Analysis Tool (TCAT) for Active Debris Removal

NASA Astrophysics Data System (ADS)

Chamot, B.; Richard, M.; Salmon, T.; Pisseloup, A.; Cougnet, C.; Axthelm, R.; Saunder, C.; Dupont, C.; Lequette, L.

2013-08-01

This paper present the work of the Swiss Space Center EPFL within the CNES-funded OTV-2 study. In order to find the most performant Active Debris Removal (ADR) mission architectures and technologies, a tool was developed in order to design and compare ADR spacecraft, and to plan ADR campaigns to remove large debris. Two types of architectures are considered to be efficient: the Chaser (single-debris spacecraft), the Mothership/ Kits (multiple-debris spacecraft). Both are able to perform controlled re-entry. The tool includes modules to optimise the launch dates and the order of capture, to design missions and spacecraft, and to select launch vehicles. The propulsion, power and structure subsystems are sized by the tool thanks to high-level parametric models whilst the other ones are defined by their mass and power consumption. Final results are still under investigation by the consortium but two concrete examples of the tool's outputs are presented in the paper.

Review of Orbiter Flight Boundary Layer Transition Data

NASA Technical Reports Server (NTRS)

Mcginley, Catherine B.; Berry, Scott A.; Kinder, Gerald R.; Barnell, maria; Wang, Kuo C.; Kirk, Benjamin S.

2006-01-01

In support of the Shuttle Return to Flight program, a tool was developed to predict when boundary layer transition would occur on the lower surface of the orbiter during reentry due to the presence of protuberances and cavities in the thermal protection system. This predictive tool was developed based on extensive wind tunnel tests conducted after the loss of the Space Shuttle Columbia. Recognizing that wind tunnels cannot simulate the exact conditions an orbiter encounters as it re-enters the atmosphere, a preliminary attempt was made to use the documented flight related damage and the orbiter transition times, as deduced from flight instrumentation, to calibrate the predictive tool. After flight STS-114, the Boundary Layer Transition Team decided that a more in-depth analysis of the historical flight data was needed to better determine the root causes of the occasional early transition times of some of the past shuttle flights. In this paper we discuss our methodology for the analysis, the various sources of shuttle damage information, the analysis of the flight thermocouple data, and how the results compare to the Boundary Layer Transition prediction tool designed for Return to Flight.

STS-107 Debris Characterization Using Re-entry Imaging

NASA Technical Reports Server (NTRS)

Raiche, George A.

2009-01-01

Analysis of amateur video of the early reentry phases of the Columbia accident is discussed. With poor video quality and little theoretical guidance, the analysis team estimated mass and acceleration ranges for the debris shedding events observed in the video. Camera calibration and optical performance issues are also described.

An Analysis of Ablation-Shield Requirements for Manned Reentry Vehicles

NASA Technical Reports Server (NTRS)

Roberts, Leonard

1960-01-01

The problem of sublimation of material and accumulation of heat in an ablation shield is analyzed and the results are applied to the reentry of manned vehicles into the earth's atmosphere. The parameters which control the amount of sublimation and the temperature distribution within the ablation shield are determined and presented in a manner useful for engineering calculation. It is shown that the total mass loss from the shield during reentry and the insulation requirements may be given very simply in terms of the maximum deceleration of the vehicle or the total reentry time.

Development and application of an empirical probability distribution for the prediction error of re-entry body maximum dynamic pressure

NASA Technical Reports Server (NTRS)

Lanzi, R. James; Vincent, Brett T.

1993-01-01

The relationship between actual and predicted re-entry maximum dynamic pressure is characterized using a probability density function and a cumulative distribution function derived from sounding rocket flight data. This paper explores the properties of this distribution and demonstrates applications of this data with observed sounding rocket re-entry body damage characteristics to assess probabilities of sustaining various levels of heating damage. The results from this paper effectively bridge the gap existing in sounding rocket reentry analysis between the known damage level/flight environment relationships and the predicted flight environment.

Social Reintegration of Traumatic Brain-Injured: The French Experience

PubMed Central

Truelle, J.-L.; Wild, K. Von; Onillon, M.; Montreuil, M.

2010-01-01

Traumatic Brain Injury (TBI) may lead to specific handicap, often hidden, mainly due to cognitive and behavioural sequelae. Social re-entry is a long-term, fluctuant and precarious process. The French experience will be illustrated by 6 initiatives answering to 6 challenges to do with TBI specificities: 1. bridging the gap, between initial rehabilitation and community re-entry, via transitional units dealing with assessment, retraining, social/vocational orientation and follow-up. Today, there are 30 such units based on multidisciplinary teams. 2. assessing recovery by TBI-specific and validated evaluation tools: EBIS holistic document, BNI Screening of higher cerebral functions, Glasgow outcome extended, and QOLIBRI, a TBI-specific quality of life tool. 3. promoting specific re-entry programmes founded on limited medication, ecological neuro-psychological rehabilitation, exchange groups and workshops, violence prevention, continuity of care, environmental structuration, and “resocialisation”. 4. taking into account the “head injured family” 5. facilitating recovery after sports-related concussion 6. facing medico-legal consequences and compensation: In that perspective, we developed guidelines for TBI-specific expert appraisal, including mandatory neuro-psychological assessment, family interview and an annual forum gathering lawyers and health professionals. PMID:22028740

Casualty Risk Assessment Controlled Re-Entry of EPS - Ariane 5ES - ATV Mission

NASA Astrophysics Data System (ADS)

Arnal, M.-H.; Laine, N.; Aussilhou, C.

2012-01-01

To fulfil its mission of compliance check to the French Space Operations Act, CNES has developed ELECTRA© tool in order to estimate casualty risk induced by a space activity (like rocket launch, controlled or un-controlled re-entry on Earth of a space object). This article describes the application of such a tool for the EPS controlled re-entry during the second Ariane 5E/S flight (Johannes Kepler mission has been launched in February 2011). EPS is the Ariane 5E/S upper composite which is de-orbited from a 260 km circular orbit after its main mission (release of the Automated Transfer Vehicle - ATV). After a brief description of the launcher, the ATV-mission and a description of all the failure cases taken into account in the mission design (which leads to "back-up scenarios" into the flight software program), the article will describe the steps which lead to the casualty risk assessment (in case of failure) with ELECTRA©. In particular, the presence on board of two propulsive means of de-orbiting (main engine of EPS, and 4 ACS longitudinal nozzles in case of main engine failure or exhaustion) leads to a low remaining casualty risk.

Convective Heating Predictions of Apollo IV Flight Data

NASA Technical Reports Server (NTRS)

White, Molly E.

2012-01-01

It has been more than 50 years since NASA engineers have attempted to design a manned space vehicle with the capability to return from beyond low Earth orbit. In this interval, our methodologies for designing the thermal protection system (TPS) to protect humans from the extremely high temperatures of re-entry have changed significantly. With these considerations in mind, we return to the Apollo IV (AS-501) flight data. This incredible data set allows us to assess the current tools and methodologies being used to design Orion MPCV. In particular, our ability to predict the aftbody separated region convective heating environments for MPCV is critical. The design uses reusable TPS in this area, whereas Apollo designers used ablative TPS which can withstand much more severe environments. This presentation will revisit the flight data, summarize the assumptions going into the analysis, present the results and draw conclusions regarding how accurately we can currently predict the heating in the aftbody separated region of a re-entry capsule.

Stochastic Simulation Tool for Aerospace Structural Analysis

NASA Technical Reports Server (NTRS)

Knight, Norman F.; Moore, David F.

2006-01-01

Stochastic simulation refers to incorporating the effects of design tolerances and uncertainties into the design analysis model and then determining their influence on the design. A high-level evaluation of one such stochastic simulation tool, the MSC.Robust Design tool by MSC.Software Corporation, has been conducted. This stochastic simulation tool provides structural analysts with a tool to interrogate their structural design based on their mathematical description of the design problem using finite element analysis methods. This tool leverages the analyst's prior investment in finite element model development of a particular design. The original finite element model is treated as the baseline structural analysis model for the stochastic simulations that are to be performed. A Monte Carlo approach is used by MSC.Robust Design to determine the effects of scatter in design input variables on response output parameters. The tool was not designed to provide a probabilistic assessment, but to assist engineers in understanding cause and effect. It is driven by a graphical-user interface and retains the engineer-in-the-loop strategy for design evaluation and improvement. The application problem for the evaluation is chosen to be a two-dimensional shell finite element model of a Space Shuttle wing leading-edge panel under re-entry aerodynamic loading. MSC.Robust Design adds value to the analysis effort by rapidly being able to identify design input variables whose variability causes the most influence in response output parameters.

Reentry Capsule for Sample Return from Asteroids in the Planetary Exploration Missions

NASA Astrophysics Data System (ADS)

Inatani, Yoshifumi

2018-04-01

For carrying sample from the bodies of interplanetary space, a wide range of knowledge of reentry technology is needed. HAYABUSA(MUSES-C) was an asteroid explorer returned to the earth after the 7 years of voyage, and its capsule reenters into the Earth’s atmosphere, which was a good example of reentry technology implemented to the flight vehicle. It performed a safe reentry flight and recovery. For the design of the capsule, many considerations were made due to its higher entry velocity and higher aerodynamic heating than those of normal reentry from the low earth orbit. Taking into account the required functions throughout the orbital flight, reentry flight, and descent/recovery phase, the capsule was deigned, tested, manufactured and flight demonstrated finally. The paper presents the concept of the design and qualification approach of the small space capsule of the asteroid sample and return mission. And presented are how the reentry flight was performed and a brief overview of the post flight analysis primarily for these design validation purposes and for the better understanding of the flight results.

Atmospheric reentry of the in-core thermionic SP-100 reactor system

NASA Technical Reports Server (NTRS)

Stamatelatos, M. G.; Barsell, A. W.; Harris, P. A.; Francisco, J.

1987-01-01

Presumed end-of-life atmospheric reentry of the GA SP-100 system was studied to assess dispersal feasibility and associated hazards. Reentry was studied by sequential use of an orbital trajectory and a heat analysis computer program. Two heating models were used. The first model assumed a thermal equilibrium condition between the stagnation point aerodynamic heating and the radiative cooling of the skin material surface. The second model allowed for infinite conductivity of the skin material. Four reentering configurations were studied representing stages of increased SP-100 breakup: (1) radiator, shield and reactor, (2) shield and reactor, (3) reactor with control drums, and (4) reactor without control drums. Each reentering configuration was started from a circular orbit at 116 km having an inertial velocity near Mach 25. The assumed failing criterion was the attainment of melting temperature of a critical system component. The reentry analysis revealed breakup of the vessel in the neighborhood of 61 km altitude and scattering of the fuel elements. Subsequent breakup of the fuel elements was not predicted. Oxidation of the niobium skin material was calculated to cause an increase in surface temperature of less than ten percent. The concept of thermite analogs for enhancing reactor reentry dispersal was assessed and found to be feasible in principle. A conservative worst-case hazards analysis was performed for radioactive and nonradioactive toxic SP-100 materials assumed to be dispersed during end-of-life reentry. The hazards associated with this phase of the SP-100 mission were calculated to be insignificant.

Circumferential and functional re-entry of in vivo slow-wave activity in the porcine small intestine.

PubMed

Angeli, T R; O'Grady, G; Du, P; Paskaranandavadivel, N; Pullan, A J; Bissett, I P; Cheng, L K

2013-05-01

Slow-waves modulate the pattern of small intestine contractions. However, the large-scale spatial organization of intestinal slow-wave pacesetting remains uncertain because most previous studies have had limited resolution. This study applied high-resolution (HR) mapping to evaluate intestinal pacesetting mechanisms and propagation patterns in vivo. HR serosal mapping was performed in anesthetized pigs using flexible arrays (256 electrodes; 32 × 8; 4 mm spacing), applied along the jejunum. Slow-wave propagation patterns, frequencies, and velocities were calculated. Slow-wave initiation sources were identified and analyzed by animation and isochronal activation mapping. Analysis comprised 32 recordings from nine pigs (mean duration 5.1 ± 3.9 min). Slow-wave propagation was analyzed, and a total of 26 sources of slow-wave initiation were observed and classified as focal pacemakers (31%), sites of functional re-entry (23%) and circumferential re-entry (35%), or indeterminate sources (11%). The mean frequencies of circumferential and functional re-entry were similar (17.0 ± 0.3 vs 17.2 ± 0.4 cycle min(-1) ; P = 0.5), and greater than that of focal pacemakers (12.7 ± 0.8 cycle min(-1) ; P < 0.001). Velocity was anisotropic (12.9 ± 0.7 mm s(-1) circumferential vs 9.0 ± 0.7 mm s(-1) longitudinal; P < 0.05), contributing to the onset and maintenance of re-entry. This study has shown multiple patterns of slow-wave initiation in the jejunum of anesthetized pigs. These results constitute the first description and analysis of circumferential re-entry in the gastrointestinal tract and functional re-entry in the in vivo small intestine. Re-entry can control the direction, pattern, and frequency of slow-wave propagation, and its occurrence and functional significance merit further investigation. © 2013 Blackwell Publishing Ltd.

Assessment on EXPERT Descent and Landing System Aerodynamics

NASA Astrophysics Data System (ADS)

Wong, H.; Muylaert, J.; Northey, D.; Riley, D.

2009-01-01

EXPERT is a re-entry vehicle designed for validation of aero-thermodynamic models, numerical schemes in Computational Fluid Dynamics codes and test facilities for measuring flight data under an Earth re-entry environment. This paper addresses the design for the descent and landing sequence for EXPERT. It includes the descent sequence, the choice of drogue and main parachutes, and the parachute deployment condition, which can be supersonic or subsonic. The analysis is based mainly on an engineering tool, PASDA, together with some hand calculations for parachute sizing and design. The tool consists of a detailed 6-DoF simulation performed with the aerodynamics database of the vehicle, an empirical wakes model and the International Standard Atmosphere database. The aerodynamics database for the vehicle is generated by DNW experimental data and CFD codes within the framework of an ESA contract to CIRA. The analysis will be presented in terms of altitude, velocity, accelerations, angle-of- attack, pitch angle and angle of rigging line. Discussion on the advantages and disadvantages of each parachute deployment condition is included in addition to some comparison with the available data based on a Monte-Carlo method from a Russian company, FSUE NIIPS. Sensitivity on wind speed to the performance of EXPERT is shown to be strong. Supersonic deployment of drogue shows a better performance in stability at the expense of a larger G-load than those from the subsonic deployment of drogue. Further optimization on the parachute design is necessary in order to fulfill all the EXPERT specifications.

Demystifying rotors and their place in clinical translation of atrial fibrillation mechanisms.

PubMed

Nattel, Stanley; Xiong, Feng; Aguilar, Martin

2017-09-01

Treatment of atrial fibrillation (AF), the most common arrhythmia in clinical practice, remains challenging. Improved understanding of underlying mechanisms is needed to improve therapy. Functional re-entry is central to AF maintenance. The first detailed, quantitative theory of functional re-entry, the 'leading circle' model, was developed 40 years ago. Subsequently, an alternative paradigm based on 'spiral waves' has evolved. Spiral-wave generators, or 'rotors', have been identified using advanced mapping methods in experimental and clinical AF. A central tool in the analysis of spiral-wave rotors is the phase transformation, allowing for easier visualization of rotors and tracking of 'phase singularity' points at the rotor tip. In contrast to leading circle theory, which is expressed in terms familiar to (and easily understood by) cardiologists, the ideas needed to understand rotors are much more theoretical and harder for clinicians to apply. In this Review, we summarize the basic notions of phase mapping and spiral-wave rotors, and the ways in which rotor sources might be involved in AF maintenance. We discuss competing observations about the role of spatially confined rotors, short-lived rotors clustered at the edge of fibrotic zones, endocardial-epicardial interactive breeder properties and transmural re-entry, as well as studies underway to resolve them. We conclude with consideration of the clinical relevance of the issues discussed and their potential implications for the management of patients with AF.

The FAA's Approach to Quality Assurance in the Flight Safety Analysis of Launch and Reentry Vehicles

NASA Astrophysics Data System (ADS)

Murray, Daniel P.; Weil, Andre

2010-09-01

The U.S. Federal Aviation Administration(FAA) Office of Commercial Space Transportation’s safety mission is to ensure protection of the public, property, and the national security and foreign policy interests of the United States during commercial launch and reentry activities. As part of this mission, the FAA issues licenses to the operators of launch and reentry vehicles who successfully demonstrate compliance with FAA regulations. To meet these regulations, vehicle operators submit an application that contains, among other things, flight safety analyses of their proposed missions. In the process of evaluating these submitted analyses, the FAA often conducts its own independent analyses, using input data from the submitted license application. These analyses are conducted according to approved procedures using industry developed tools. To assist in achieving the highest levels of quality in these independent analyses, the FAA has developed a quality assurance program that consists of multiple levels of review. These reviews rely on the work of multiple teams, as well as additional, independently performed work of support contractors. This paper describes the FAA’s quality assurance process for flight safety analyses. Members of the commercial space industry may find that elements of this process can be easily applied to their own analyses, improving the quality of the material they submit to the FAA in their license applications.

GOCE Re-Entry Predictions for the Italian Civil Protection Authorities

NASA Astrophysics Data System (ADS)

Pardini, Carmen; Anselmo, Luciano

2015-03-01

The uncommon nature of the GOCE reentry campaign, sharing an uncontrolled orbital decay with a finely controlled attitude along the atmospheric drag direction, made the reentry predictions for this satellite an interesting case study, especially because nobody was able to say a priori if and when the attitude control would have failed, leading to an unrestrained tumbling and a sudden variation of the orbital decay rate. As in previous cases, ISTI/CNR was in charge of reentry predictions for the Italian civil protection authorities, monitoring also the satellite decay in the frame of an international reentry campaign promoted by the Inter-Agency Space Debris Coordination Committee (IADC). Due to the peculiar nature of the GOCE reentry, the definition of reliable uncertainty windows was not easy, especially considering the critical use of this information for civil protection evaluations. However, after an initial period of test and analysis, reasonable and conservative criteria were elaborated and applied, with good and consistent results through the end of the reentry campaign. In the last three days of flight, reentries were simulated over Italy to obtain quite accurate ground tracks, debris swaths and air space crossing time windows associated with the critical passes over the national territory still included in the global uncertainty windows.

Who Comes Back? A Longitudinal Analysis of the Reentry Behavior of Exiting Teachers

ERIC Educational Resources Information Center

Grissom, Jason A.; Reininger, Michelle

2012-01-01

While a large literature examines the factors that lead teachers to leave teaching, few studies have examined what factors affect teachers' decisions to reenter the profession. Drawing on research on the role of family characteristics in predicting teacher work behavior, we examine predictors of reentry. We employ survival analysis of time to…

Development Of Metallic Thermal Protection System For The Expert Re-Entry Vehicle: Design Verification

NASA Astrophysics Data System (ADS)

Fatemi, Javad

2011-05-01

The thermal protection system of the EXPERT re-entry vehicle is subjected to accelerations, vibrations, acoustic and shock loads during launch and aero-heating loads and aerodynamic forces during re-entry. To fully understand the structural and thermomechanical performances of the TPS, heat transfer analysis, thermal stress analysis, and thermal buckling analysis must be performed. This requires complex three-dimensional thermal and structural models of the entire TPS including the insulation and sensors. Finite element (FE) methods are employed to assess the thermal and structural response of the TPS to the mechanical and aerothermal loads. The FE analyses results are used for the design verification and design improvement of the EXPERT thermal protection system.

Space Debris Alert System for Aviation

NASA Astrophysics Data System (ADS)

Sgobba, Tommaso

2013-09-01

Despite increasing efforts to accurately predict space debris re-entry, the exact time and location of re-entry is still very uncertain. Partially, this is due to a skipping effect uncontrolled spacecraft may experience as they enter the atmosphere at a shallow angle. Such effect difficult to model depends on atmospheric variations of density. When the bouncing off ends and atmospheric re-entry starts, the trajectory and the overall location of surviving fragments can be precisely predicted but the time to impact with ground, or to reach the airspace, becomes very short.Different is the case of a functional space system performing controlled re-entry. Suitable forecasts methods are available to clear air and maritime traffic from hazard areas (so-called traffic segregation).In US, following the Space Shuttle Columbia accident in 2003, a re-entry hazard areas location forecast system was putted in place for the specific case of major malfunction of a Reusable Launch Vehicles (RLV) at re-entry. The Shuttle Hazard Area to Aircraft Calculator (SHAAC) is a system based on ground equipment and software analyses and prediction tools, which require trained personnel and close coordination between the organization responsible for RLV operation (NASA for Shuttle) and the Federal Aviation Administration. The system very much relies on the operator's capability to determine that a major malfunction has occurred.This paper presents a US pending patent by the European Space Agency, which consists of a "smart fragment" using a GPS localizer together with pre- computed debris footprint area and direct broadcasting of such hazard areas.The risk for aviation from falling debris is very remote but catastrophic. Suspending flight over vast swath of airspace for every re-entering spacecraft or rocket upper stage, which is a weekly occurrence, would be extremely costly and disruptive.The Re-entry Direct Broadcasting Alert System (R- DBAS) is an original merging and evolution of the Re- entry Breakup Recorder (REBR) concept developed by The Aerospace Corporation, often called the black box of spacecraft, and of the Shuttle Hazard Area to Aircraft Calculator (SHAAC). Unlike the REBR, whichdownloads data via satellite link for later analysis, the R-DBAS is intended as a direct communication tool with the end user. As a spacecraft carrying R-DBAS re- enters into the atmosphere, it relays a message with the coordinates of the falling debris footprint area to anyone with a receiver and a display like laptop or iPad, warning them of the hazard.Much like the REBR, the R-DBAS is designed to release from its host vehicle when it experiences significant heat which melts the attachment point and closes the power circuit. Once activated, the R-DBAS determines its own location and computes the final coordinates of the preloaded debris footprint which is then broadcasted to anyone holding a receiver in the proximity of the hazard area.The R-DBAS is intended to provide precise information directly to the cockpit. An airplane would have about 5- 7 minutes to get out of the way. Being the hazard area 1,000-2000 km long but very narrow, 30 -70 km, an escape manoeuvre from the risky area can be readily performed or go on holding before crossing the hazard area.By equipping aircraft and other vulnerable systems with a simple receivers that can be attached to a common laptop, escape manoeuvres can be performed as in front of bad weather or shelter can be taken by people on ground.

Intermediate Experimental Vehicle, ESA Program IXV ATDB Tool and Aerothermodynamic Characterization

NASA Astrophysics Data System (ADS)

Mareschi, Vincenzo; Ferrarella, Daniela; Zaccagnino, Elio; Tribot, Jean-Pierre; Vallee, Jean-Jacques; Haya-Ramos, Rodrigo; Rufolo, Giuseppe; Mancuso, Salvatore

2011-05-01

In the complex domain of the space technologies and among the different applications available in Europe, a great interest has been placed since several years in the development of re-entry technologies. Among the different achievements obtained in that field it is to be recalled the experience of the Atmospheric Re-entry Vehicle flight in 1998 and a certain number of important investments per-formed at Agency and national levels like Hermes, MSTP, Festip, X-38, FLPP, TRP, GSTP, HSTS, AREV, Pre-X. IXV (Intermediate eXperimental V ehicle) builds on these past experiences and studies and it is conceived to be the next technological step forward with respect to ARD With respect to previous European ballistic or quasi- ballistic demonstrators, IXV will have an increased in- flight manoeuvrability and the planned mission will allow verifying the performances of the required technologies against a wider re-entry corridor. This will imply from the pure technological aspect to increase the level of engagement on critical technologies and disciplines like aerodynamics/aerothermodynamics, guidance, navigation, control, thermal protection materials and in flight measurements. In order to support the TPS design and the other sub- systems, an AeroThermodynamicDataBase Tool has been developed by Dassault Aviation and integrated by Thales Alenia Space with the Functional Engineering Simulator (used for GNC performances evaluation) in order to characterize the aerothermodynamic behaviour of the vehicle. This paper will describe: - The methodology used to develop the ATDB tool, based on the processing of CFD computations and WTT campaigns results. - The utilization of the ATDB tool, by means of its integration into the System process. - The methodology used for the aerothermal characterization of IXV.

Attitude Control Performance of IRVE-3

NASA Technical Reports Server (NTRS)

Dillman, Robert A.; Gsell, Valerie T.; Bowden, Ernest L.

2013-01-01

The Inflatable Reentry Vehicle Experiment 3 (IRVE-3) launched July 23, 2012, from NASA Wallops Flight Facility and successfully performed its mission, demonstrating both the survivability of a hypersonic inflatable aerodynamic decelerator in the reentry heating environment and the effect of an offset center of gravity on the aeroshell's flight L/D. The reentry vehicle separated from the launch vehicle, released and inflated its aeroshell, reoriented for atmospheric entry, and mechanically shifted its center of gravity before reaching atmospheric interface. Performance data from the entire mission was telemetered to the ground for analysis. This paper discusses the IRVE-3 mission scenario, reentry vehicle design, and as-flown performance of the attitude control system in the different phases of the mission.

Airborne Observation of the Hayabusa Sample Return Capsule Re-Entry

NASA Technical Reports Server (NTRS)

Grinstead, Jay H.; Jenniskens, Peter; Cassell, Alan M.; Albers, James; Winter, Michael W.

2011-01-01

NASA Ames Research Center and the SETI Institute collaborated on an effort to observe the Earth re-entry of the Japan Aerospace Exploration Agency's Hayabusa sample return capsule. Hayabusa was an asteroid exploration mission that retrieved a sample from the near-Earth asteroid Itokawa. Its sample return capsule re-entered over the Woomera Prohibited Area in southern Australia on June 13, 2010. Being only the third sample return mission following NASA's Genesis and Stardust missions, Hayabusa's return was a rare opportunity to collect aerothermal data from an atmospheric entry capsule returning at superorbital speeds. NASA deployed its DC-8 airborne laboratory and a team of international researchers to Australia for the re-entry. For approximately 70 seconds, spectroscopic and radiometric imaging instruments acquired images and spectra of the capsule, its wake, and destructive re-entry of the spacecraft bus. Once calibrated, spectra of the capsule will be interpreted to yield data for comparison with and validation of high fidelity and engineering simulation tools used for design and development of future atmospheric entry system technologies. A brief summary of the Hayabusa mission, the preflight preparations and observation mission planning, mission execution, and preliminary spectral data are documented.

Current Status on Radiation Modeling for the Hayabusa Re-entry

NASA Technical Reports Server (NTRS)

Winter, Michael W.; McDaniel, Ryan D.; Chen, Yih-Kang; Liu, Yen; Saunders, David

2011-01-01

On June 13, 2010 the Japanese Hayabusa capsule performed its reentry into the Earths atmosphere over Australia after a seven year journey to the asteroid Itokawa. The reentry was studied by numerous imaging and spectroscopic instruments onboard NASA's DC-8 Airborne Laboratory and from three sites on the ground, in order to measure surface and plasma radiation generated by the Hayabusa Sample Return Capsule (SRC). Post flight, the flow solutions were recomputed to include the whole flow field around the capsule at 11 points along the reentry trajectory using updated trajectory information. Again, material response was taken into account to obtain most reliable surface temperature information. These data will be used to compute thermal radiation of the glowing heat shield and plasma radiation by the shock/post-shock layer system to support analysis of the experimental observation data. For this purpose, lines of sight data are being extracted from the flow field volume grids and plasma radiation will be computed using NEQAIR [4] which is a line-by-line spectroscopic code with one-dimensional transport of radiation intensity. The procedures being used were already successfully applied to the analysis of the observation of the Stardust reentry [5].

Cassini launch contingency effort

NASA Astrophysics Data System (ADS)

Chang, Yale; O'Neil, John M.; McGrath, Brian E.; Heyler, Gene A.; Brenza, Pete T.

2002-01-01

On 15 October 1997 at 4:43 AM EDT, the Cassini spacecraft was successfully launched on a Titan IVB/Centaur on a mission to explore the Saturnian system. It carried three Radioisotope Thermoelectric Generators (RTGs) and 117 Light Weight Radioisotope Heater Units (LWRHUs). As part of the joint National Aeronautics and Space Administration (NASA)/U.S. Department of Energy (DoE) safety effort, a contingency plan was prepared to address the unlikely events of an accidental suborbital reentry or out-of-orbital reentry. The objective of the plan was to develop procedures to predict, within hours, the Earth impact footprints (EIFs) for the nuclear heat sources released during the atmospheric reentry. The footprint predictions would be used in subsequent notification and recovery efforts. As part of a multi-agency team, The Johns Hopkins University Applied Physics Laboratory (JHU/APL) had the responsibility to predict the EIFs of the heat sources after a reentry, given the heat sources' release conditions from the main spacecraft. (No ablation burn-through of the heat sources' aeroshells was expected, as a result of earlier testing.) JHU/APL's other role was to predict the time of reentry from a potential orbital decay. The tools used were a three degree-of-freedom trajectory code, a database of aerodynamic coefficients for the heat sources, secure links to obtain tracking data, and a high fidelity special perturbation orbit integrator code to predict time of spacecraft reentry from orbital decay. In the weeks and days prior to launch, all the codes and procedures were exercised. Notional EIFs were derived from hypothetical reentry conditions. EIFs predicted by JHU/APL were compared to those by JPL and US SPACECOM, and were found to be in good agreement. The reentry time from orbital decay for a booster rocket for the Russian Progress M-36 freighter, a cargo ship for the Mir space station, was predicted to within 5 minutes more than two hours before reentry. For the Cassini launch, JHU/APL's on-station real-time launch contingency activities were implemented. Live news from NASA Select TV of a successful Cassini launch and interplanetary injection precluded any further contingency actions. The Cassini launch contingency effort contributed to mission safety and demonstrated successful cooperation between several agencies. .

Aortic Dissection: Accurate Subintimal Flap Fenestration by Using a Reentry Catheter with Fluoroscopic Guidance-Initial Single-Institution Experience.

PubMed

Wolfschmidt, Franziska; Hassold, Nicole; Goltz, Jan Peter; Leyh, Rainer; Bley, Thorsten Alexander; Kickuth, Ralph

2015-09-01

To evaluate the feasibility, effectiveness, and safety of using a commercially available reentry catheter with fluoroscopic guidance to gain controlled target lumen reentry for fenestration in patients with aortic dissection. This retrospective study was approved by the local institutional review board; informed consent was waived. Between April 2009 and December 2013, 13 consecutive patients (10 men and three women; mean age, 51.2 years; range, 30.0-77.0 years; mean age of women, 47.0 years; range, 30.0-69.0 years; mean age of men, 52.4 years; range, 35.0-77.0 years) with aortic dissection and spinal (n = 4), renal (n = 7), mesenteric (n = 2), and/or iliofemoral (n = 9) malperfusion syndrome were included. All patients received target lumen reentry by means of balloon fenestration of the aortic dissection flap. A reentry catheter was used for fluoroscopically guided puncture of the target lumen. Technical success, clinical outcome, Stanford type of dissection, procedure time, number of fenestrations of the intimal flap per patient, necessity of additional aortic stent-graft implantation and/or placement of a bare metal stent, complications, and follow-up images were evaluated. Pre- and postinterventional systolic blood pressure gradients between the true lumen and the false lumen were compared (Wilcoxon signed-rank test). Safety of the reentry catheter maneuver was estimated with the Clopper-Pearson method. Use of the reentry catheter was technically successful in all 13 (100%) patients and clinically successful in 10 of 13 (77%) patients. Four patients had type A and nine had type B dissection. The mean clinical follow-up period was 14.2 months. Median procedure time was 71 minutes. In four patients, fenestration of the intimal flap was performed twice. Three patients underwent additional aortic stent grafting, four patients underwent placement of an iliofemoral stent, and one patient underwent placement of a carotid artery stent. Blood pressure gradients between the true lumen and the false lumen were significantly reduced (P = .0313). One patient who had a combination of syndromes died of multiorgan failure. The applied commercially available reentry catheter seems to be a reliable and safe tool that may be useful for gaining target lumen reentry with reasonably good clinical outcomes.

Orbital Debris Quarterly News. Volume 13; No. 1

NASA Technical Reports Server (NTRS)

Liou, J.-C. (Editor); Shoots, Debi (Editor)

2009-01-01

Topics discussed include: new debris from a decommissioned satellite with a nuclear power source; debris from the destruction of the Fengyun-1C meteorological satellite; quantitative analysis of the European Space Agency's Automated Transfer Vehicle 'Jules Verne' reentry event; microsatellite impact tests; solar cycle 24 predictions and other long-term projections and geosynchronus (GEO) environment for the Orbital Debris Engineering Model (ORDEM2008). Abstracts from the NASA Orbital Debris Program Office, examining satellite reentry risk assessments and statistical issues for uncontrolled reentry hazards, are also included.

Return to Flight Resource Reel 1 of 2

NASA Technical Reports Server (NTRS)

2005-01-01

A video presentation detailing the tests performed on the Space Shuttle Discovery in preparation for its return to flight is shown. The tests include: 1) Reinforced Carbon-Carbon (RCC) Impact Test Article; 2) RCC Foam Impact Testing; 3) Thermal Protection System (TPS) Ice Impact Testing featuring Justin Kerr, Project Engineer; 4) Wing Leading Edge Wireless Sensors featuring Karl Kiefer, President and CEO of Invocon, and Kevin Champaigne of Invocon; 5) TPS Repair Testing KC-135 Zero-G Environment featuring Soichi Noguchi, Mission Specialist; 6) TPS Extravehicular Activity Tool Demonstration; 7) TPS Repair Testing Vacuum Glove box; 8) TPS Repair Testing Human Thermal Vacuum Chamber; 9) TPS Reentry Testing Atmospheric Reentry Materials and Structures Evaluation Facility; 10) TPS Alternative Repair Concept; 11) Lora Bailey Lead Engineer for EVA Tools; 12) Reinforced Carbon-Carbon ATK Thiokol Plug Repair Animation; 13) 3-Percent Model Build-Up; and 14) Wind Tunnel Testing RCC Aging Research Ballistic Testing.

Emittance of TD-NiCr after simulated reentry

NASA Technical Reports Server (NTRS)

Clark, R. K.; Dicus, D. L.; Lisagor, W. B.

1978-01-01

The effects of simulated reentry heating on the emittance of TD-NiCr were investigated. Groups of specimens with three different preconditioning treatments were exposed to 6, 24, and 30 half-hour simulated reentry exposure cycles in a supersonic arc tunnel at each of three conditions intended to produce surface temperatures of 1255, 1365, and 1475 K. Emittance was determined at 1300 K on specimens which were preconditioned only and specimens after completion of reentry simulation exposure. Oxide morphology and chemistry were studied by scanning electron microscopy and X-ray diffraction analysis. A consistent relationship was established between oxide morphology and total normal emittance. Specimens with coarser textured oxides tended to have lower emittances than specimens with finer textured oxides.

A System Trade Study of Remote Infrared Imaging for Space Shuttle Reentry

NASA Technical Reports Server (NTRS)

Schwartz, Richard J.; Ross, Martin N.; Baize, Rosemary; Horvath, Thomas J.; Berry, Scott A.; Krasa, Paul W.

2008-01-01

A trade study reviewing the primary operational parameters concerning the deployment of imaging assets in support of the Hypersonic Thermodynamic Infrared Measurements (HYTHIRM) project was undertaken. The objective was to determine key variables and constraints for obtaining thermal images of the Space Shuttle orbiter during reentry. The trade study investigated the performance characteristics and operating environment of optical instrumentation that may be deployed during a HYTHIRM data collection mission, and specified contributions to the Point Spread Function. It also investigated the constraints that have to be considered in order to optimize deployment through the use of mission planning tools. These tools simulate the radiance modeling of the vehicle as well as the expected spatial resolution based on the Orbiter trajectory and placement of land based or airborne optical sensors for given Mach numbers. Lastly, this report focused on the tools and methodology that have to be in place for real-time mission planning in order to handle the myriad of variables such as trajectory ground track, weather, and instrumentation availability that may only be known in the hours prior to landing.

Nonlinear Transient Thermal Analysis by the Force-Derivative Method

NASA Technical Reports Server (NTRS)

Balakrishnan, Narayani V.; Hou, Gene

1997-01-01

High-speed vehicles such as the Space Shuttle Orbiter must withstand severe aerodynamic heating during reentry through the atmosphere. The Shuttle skin and substructure are constructed primarily of aluminum, which must be protected during reentry with a thermal protection system (TPS) from being overheated beyond the allowable temperature limit, so that the structural integrity is maintained for subsequent flights. High-temperature reusable surface insulation (HRSI), a popular choice of passive insulation system, typically absorbs the incoming radiative or convective heat at its surface and then re-radiates most of it to the atmosphere while conducting the smallest amount possible to the structure by virtue of its low diffusivity. In order to ensure a successful thermal performance of the Shuttle under a prescribed reentry flight profile, a preflight reentry heating thermal analysis of the Shuttle must be done. The surface temperature profile, the transient response of the HRSI interior, and the structural temperatures are all required to evaluate the functioning of the HRSI. Transient temperature distributions which identify the regions of high temperature gradients, are also required to compute the thermal loads for a structural thermal stress analysis. Furthermore, a nonlinear analysis is necessary to account for the temperature-dependent thermal properties of the HRSI as well as to model radiation losses.

The ESA/NASA Multi-Aircraft ATV-1 Re-Entry Campaign: Analysis of Airborne Intensified Video Observations from the NASA/JSC Experiment

NASA Technical Reports Server (NTRS)

Barker, Ed; Maley, Paul; Mulrooney, Mark; Beaulieu, Kevin

2009-01-01

In September 2008, a joint ESA/NASA multi-instrument airborne observing campaign was conducted over the Southern Pacific ocean. The objective was the acquisition of data to support detailed atmospheric re-entry analysis for the first flight of the European Automated Transfer Vehicle (ATV)-1. Skilled observers were deployed aboard two aircraft which were flown at 12.8 km altitude within visible range of the ATV-1 re-entry zone. The observers operated a suite of instruments with low-light-level detection sensitivity including still cameras, high speed and 30 fps video cameras, and spectrographs. The collected data has provided valuable information regarding the dynamic time evolution of the ATV-1 re-entry fragmentation. Specifically, the data has satisfied the primary mission objective of recording the explosion of ATV-1's primary fuel tank and thereby validating predictions regarding the tanks demise and the altitude of its occurrence. Furthermore, the data contains the brightness and trajectories of several hundred ATV-1 fragments. It is the analysis of these properties, as recorded by the particular instrument set sponsored by NASA/Johnson Space Center, which we present here.

Recording animal vocalizations from a UAV: bat echolocation during roost re-entry.

PubMed

Kloepper, Laura N; Kinniry, Morgan

2018-05-17

Unmanned aerial vehicles (UAVs) are rising in popularity for wildlife monitoring, but direct recordings of animal vocalizations have not yet been accomplished, likely due to the noise generated by the UAV. Echolocating bats, especially Tadarida brasiliensis, are good candidates for UAV recording due to their high-speed, high-altitude flight. Here, we use a UAV to record the signals of bats during morning roost re-entry. We designed a UAV to block the noise of the propellers from the receiving microphone, and report on the characteristics of bioacoustic recordings from a UAV. We report the first published characteristics of echolocation signals from bats during group flight and cave re-entry. We found changes in inter-individual time-frequency shape, suggesting that bats may use differences in call design when sensing in complex groups. Furthermore, our first documented successful recordings of animals in their natural habitat demonstrate that UAVs can be important tools for bioacoustic monitoring, and we discuss the ethical considerations for such monitoring.

Blunt Body Aerodynamics for Hypersonic Low Density Flows

NASA Technical Reports Server (NTRS)

Moss, James N.; Glass, Christopher E.; Greene, Francis A.

2006-01-01

Numerical simulations are performed for the Apollo capsule from the hypersonic rarefied to the continuum regimes. The focus is on flow conditions similar to those experienced by the Apollo 6 Command Module during the high altitude portion of its reentry. The present focus is to highlight some of the current activities that serve as a precursor for computational tool assessments that will be used to support the development of aerodynamic data bases for future capsule flight environments, particularly those for the Crew Exploration Vehicle (CEV). Results for aerodynamic forces and moments are presented that demonstrate their sensitivity to rarefaction; that is, free molecular to continuum conditions. Also, aerodynamic data are presented that shows their sensitivity to a range of reentry velocities, encompassing conditions that include reentry from low Earth orbit, lunar return, and Mars return velocities (7.7 to 15 km/s). The rarefied results obtained with direct simulation Monte Carlo (DSMC) codes are anchored in the continuum regime with data from Navier-Stokes simulations.

Virtual Reality Modelling Simulation of the Re-entry Motion of an Axialsymmetric Vehicle

NASA Astrophysics Data System (ADS)

Guidi, A.; Chu, Q.. P.; Mulder, J. A.

This work started during the stability analysis of the Delft Aerospace Re-entry Test demonstrator (DART) which is a small axisymmetric ballistic re-entry vehicle. The dynamic stability evaluation of an axisymmetric re-entry vehicle is especially concerned on the behaviour of its angle of attack during the flight through the atmosphere. The variation in the angle of attack is essential for prediction of the trajectory of the vehicle and for heating requirement of the structure of the vehicle. The concept of the total angle of attack and the windward meridian plane are introduced. The position of the centre of pressure can be a crucial point in the stability of the vehicle. Although the simpleness of an axisymmetric shape, the re-entry of such a vehicle is characterised by several complex phenomenologies that were analysed with the aid of the flight simulator and of a 3D virtual reality modeling simulator. Simulations were performed with a 25° AOA initial condition in order to simulate the response of the vehicle to a disturbance that may occur during the flight causing a variation in attitude from its Trim . Certain aspects of re-entry vehicle motion are conveniently described in the terms of Euler angles. Using the Eulerian angle it is possible to generate a tridimensional animation of the output of the Flight Simulator. This tridimensional analysis is of great importance in order to understand the mentioned complex motions. Furthermore with growing in computer power it is possible to generate online visualisation of the simulations. The output of the flight simulator was used in a software written in Virtual Reality Modelling Language (VRML). With VRML this software was possible the visualisation of the re-entry motion of the vehicle. With this option the animation can run on-line during the with the flight simulator and can be also easily published on the internet or send to other users in very small file size. (the VRLM simulation of the re-entry, can be seen at the official DART internet site: www.dart-project.com)

Thermo-Physics Technical Note No. 60: thermal analysis of SNAP 10A reactor core during atmospheric reentry and resulting core disintegration and fuel element separation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mouradian, E.M.

1966-02-16

A thermal analysis is carried out to determine the temperature distribution throughout a SNAP 10A reactor core, particularly in the vicinity of the grid plates, during atmospheric reentry. The transient temperatue distribution of the grid plate indicates when sufficient melting occurs so that fuel elements are free to be released and continue their descent individually.

Anticipating Father Reentry: A Qualitative Study of Children's and Mothers' Experiences

ERIC Educational Resources Information Center

Yocum, Annie; Nath, Sanjay

2011-01-01

Utilizing a grounded theory analysis of interviews with 17 children and their 8 mothers anticipating a father's prison release within 12 months, the authors propose a theory of participants' experiences, focused on the child-father aspects of reentry. Among other expectations, all participants wanted fathers to be involved with the children after…

Boundary Layer Transition Results From STS-114

NASA Technical Reports Server (NTRS)

Berry, Scott A.; Horvath, Thomas J.; Cassady, Amy M.; Kirk, Benjamin S.; Wang, K. C.; Hyatt, Andrew J.

2006-01-01

The tool for predicting the onset of boundary layer transition from damage to and/or repair of the thermal protection system developed in support of Shuttle Return to Flight is compared to the STS-114 flight results. The Boundary Layer Transition (BLT) Tool is part of a suite of tools that analyze the aerothermodynamic environment of the local thermal protection system to allow informed disposition of damage for making recommendations to fly as is or to repair. Using mission specific trajectory information and details of each damage site or repair, the expected time of transition onset is predicted to help determine the proper aerothermodynamic environment to use in the subsequent thermal and stress analysis of the local structure. The boundary layer transition criteria utilized for the tool was developed from ground-based measurements to account for the effect of both protuberances and cavities and has been calibrated against flight data. Computed local boundary layer edge conditions provided the means to correlate the experimental results and then to extrapolate to flight. During STS-114, the BLT Tool was utilized and was part of the decision making process to perform an extravehicular activity to remove the large gap fillers. The role of the BLT Tool during this mission, along with the supporting information that was acquired for the on-orbit analysis, is reviewed. Once the large gap fillers were removed, all remaining damage sites were cleared for reentry as is. Post-flight analysis of the transition onset time revealed excellent agreement with BLT Tool predictions.

CubeSat Material Limits For Design for Demise

NASA Technical Reports Server (NTRS)

Kelley, R. L.; Jarkey, D. R.

2014-01-01

The CubeSat form factor of nano-satellite (a satellite with a mass between one and ten kilograms) has grown in popularity due to their ease of construction and low development and launch costs. In particular, their use as student led payload design projects has increased due to the growing number of launch opportunities. CubeSats are often deployed as secondary or tertiary payloads on most US launch vehicles or they may be deployed from the ISS. The focus of this study will be on CubeSats launched from the ISS. From a space safety standpoint, the development and deployment processes for CubeSats differ significantly from that of most satellites. For large satellites, extensive design reviews and documentation are completed, including assessing requirements associated with reentry survivability. Typical CubeSat missions selected for ISS deployment have a less rigorous review process that may not evaluate aspects beyond overall design feasibility. CubeSat design teams often do not have the resources to ensure their design is compliant with reentry risk requirements. A study was conducted to examine methods to easily identify the maximum amount of a given material that can be used in the construction of a CubeSats without posing harm to persons on the ground. The results demonstrate that there is not a general equation or relationship that can be used for all materials; instead a limiting value must be defined for each unique material. In addition, the specific limits found for a number of generic materials that have been previously used as benchmarking materials for reentry survivability analysis tool comparison will be discussed.

CubeSat Material Limits for Design for Demise

NASA Technical Reports Server (NTRS)

Kelley, R. L.; Jarkey, D. R.

2014-01-01

The CubeSat form factor of nano-satellite (a satellite with a mass between one and ten kilograms) has grown in popularity due to their ease of construction and low development and launch costs. In particular, their use as student led payload design projects has increased due to the growing number of launch opportunities. CubeSats are often deployed as secondary or tertiary payloads on most US launch vehicles or they may be deployed from the ISS. The focus of this study will be on CubeSats launched from the ISS. From a space safety standpoint, the development and deployment processes for CubeSats differ significantly from that of most satellites. For large satellites, extensive design reviews and documentation are completed, including assessing requirements associated with re-entry survivability. Typical CubeSat missions selected for ISS deployment have a less rigorous review process that may not evaluate aspects beyond overall design feasibility. CubeSat design teams often do not have the resources to ensure their design is compliant with re-entry risk requirements. A study was conducted to examine methods to easily identify the maximum amount of a given material that can be used in the construction of a CubeSats without posing harm to persons on the ground. The results demonstrate that there is not a general equation or relationship that can be used for all materials; instead a limiting value must be defined for each unique material. In addition, the specific limits found for a number of generic materials that have been previously used as benchmarking materials for re-entry survivability analysis tool comparison will be discussed.

Young Men's Reentry after Incarceration: A Developmental Paradox

ERIC Educational Resources Information Center

Arditti, Joyce A.; Parkman, Tiffaney

2011-01-01

We apply a life course perspective to study young men's transition to adulthood within the context of their return to family after a period of incarceration. Our phenomenological analysis was based on 9 in-depth, semi-structured interviews with formerly incarcerated men between the age of 18 and 24. Our findings revealed that reentry was a…

14 CFR 435.35 - Acceptable reentry risk for reentry of a reentry vehicle.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Acceptable reentry risk for reentry of a reentry vehicle. 435.35 Section 435.35 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL... reentry vehicle, does not exceed acceptable risk for the conduct of an RLV mission as defined in...

14 CFR 435.35 - Acceptable reentry risk for reentry of a reentry vehicle.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Acceptable reentry risk for reentry of a reentry vehicle. 435.35 Section 435.35 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL... reentry vehicle, does not exceed acceptable risk for the conduct of an RLV mission as defined in...

14 CFR 435.35 - Acceptable reentry risk for reentry of a reentry vehicle.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Acceptable reentry risk for reentry of a reentry vehicle. 435.35 Section 435.35 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL... reentry vehicle, does not exceed acceptable risk for the conduct of an RLV mission as defined in...

14 CFR 435.35 - Acceptable reentry risk for reentry of a reentry vehicle.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Acceptable reentry risk for reentry of a reentry vehicle. 435.35 Section 435.35 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL... reentry vehicle, does not exceed acceptable risk for the conduct of an RLV mission as defined in...

14 CFR 435.35 - Acceptable reentry risk for reentry of a reentry vehicle.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Acceptable reentry risk for reentry of a reentry vehicle. 435.35 Section 435.35 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL... reentry vehicle, does not exceed acceptable risk for the conduct of an RLV mission as defined in...

PEP solar array definition study

NASA Technical Reports Server (NTRS)

1979-01-01

The conceptual design of a large, flexible, lightweight solar array is presented focusing on a solar array overview assessment, solar array blanket definition, structural-mechanical systems definition, and launch/reentry blanket protection features. The overview assessment includes a requirements and constraints review, the thermal environment assessment on the design selection, an evaluation of blanket integration sequence, a conceptual blanket/harness design, and a hot spot analysis considering the effects of shadowing and cell failures on overall array reliability. The solar array blanket definition includes the substrate design, hinge designs and blanket/harness flexibility assessment. The structural/mechanical systems definition includes an overall loads and deflection assessment, a frequency analysis of the deployed assembly, a components weights estimate, design of the blanket housing and tensioning mechanism. The launch/reentry blanket protection task includes assessment of solar cell/cover glass cushioning concepts during ascent and reentry flight condition.

Filament wound data base development, revision 1

NASA Technical Reports Server (NTRS)

Sharp, R. Scott; Braddock, William F.

1985-01-01

The objective was to update the present Space Shuttle Solid Rocket Booster (SRB) baseline reentry aerodynamic data base and to develop a new reentry data base for the filament wound case SRB along with individual protuberance increments. Lockheed's procedures for performing these tasks are discussed. Free fall of the SRBs after separation from the Space Shuttle Launch Vehicle is completely uncontrolled. However, the SRBs must decelerate to a velocity and attitude that is suitable for parachute deployment. To determine the SRB reentry trajectory parameters, including the rate of deceleration and attitude history during free-fall, engineers at Marshall Space Flight Center are using a six-degree-of-freedom computer program to predict dynamic behavior. Static stability aerodynamic coefficients are part of the information required for input into this computer program. Lockheed analyzed the existing reentry aerodynamic data tape (Data Tape 5) for the current steel case SRB. This analysis resulted in the development of Data Tape 7.

Thermal stress response of General Purpose Heat Source (GPHS) aeroshell material

NASA Technical Reports Server (NTRS)

Grinberg, I. M.; Hulbert, L. E.; Luce, R. G.

1980-01-01

A thermal stress test was conducted to determine the ability of the GPHS aeroshell 3 D FWPF material to maintain physical integrity when exposed to a severe heat flux such as would occur from prompt reentry of GPHS modules. The test was performed in the Giant Planetary Facility at NASA's Ames Research Center. Good agreement was obtained between the theoretical and experimental results for both temperature and strain time histories. No physical damage was observed in the test specimen. These results provide initial corroboration both of the analysis techniques and that the GPHS reentry member will survive the reentry thermal stress levels expected.

The Federal Workforce Development Program: An Analysis of Probationers and Characteristics Associated with and Predictive of Successful Reentry

ERIC Educational Resources Information Center

McNichols, Kelley B.

2012-01-01

With years of research focusing on soaring incarceration rates, the phenomena of prisoner reentry has been largely overlooked. The majority of incarcerated people will return to the community setting. In fact, millions of recently released offenders are on some form of community based supervision. Today, recidivism is a problem that plagues…

Reentry into Out-of-Home Care: Implications of Child Welfare Workers' Assessments of Risk and Safety

ERIC Educational Resources Information Center

Wells, Melissa; Correia, Melissa

2012-01-01

This longitudinal analysis examined predictors of reentry to foster care among children and youths who entered foster care between 2001 and 2007. Three sources of administrative data (Chapin Hall Center for Children longitudinal files, National Child Abuse and Neglect Data System, and structured decision making) from one state were used to assess…

The RN-BSN Bridge Course: Transitioning the Re-Entry Learner.

ERIC Educational Resources Information Center

Huston, Carol; Shovein, Julia; Damazo, Becky; Fox, Sherry

2001-01-01

A 6-week bridge course designed to ease the transition of registered nurses into baccalaureate degree programs focused on critical thinking, learning styles, professional roles, values clarification, time management, and career planning. It also oriented students to Web Course Tools, used for distance learning. Outcomes included role and campus…

Romance, recovery & community re-entry for criminal justice involved women: Conceptualizing and measuring intimate relationship factors and power

PubMed Central

Walt, Lisa C.; Hunter, Bronwyn; Salina, Doreen; Jason, Leonard

2015-01-01

Researchers have suggested that interpersonal relationships, particularly romantic relationships, may influence women’s attempts at substance abuse recovery and community re-entry after criminal justice system involvement. The present paper evaluates relational and power theories to conceptualize the influence of romantic partner and romantic relationship qualities on pathways in and out of substance abuse and crime. The paper then combines these conceptualizations with a complementary empirical analysis to describe an ongoing research project that longitudinally investigates these relational and power driven factors on women’s substance abuse recovery and community re-entry success among former substance abusing, recently criminally involved women. This paper is designed to encourage the integration of theory and empirical analysis by detailing how each of these concepts are operationalized and measured. Future research and clinical implications are also discussed. PMID:25750487

Plume-Free Stream Interaction Heating Effects During Orion Crew Module Reentry

NASA Technical Reports Server (NTRS)

Marichalar, J.; Lumpkin, F.; Boyles, K.

2012-01-01

During reentry of the Orion Crew Module (CM), vehicle attitude control will be performed by firing reaction control system (RCS) thrusters. Simulation of RCS plumes and their interaction with the oncoming flow has been difficult for the analysis community due to the large scarf angles of the RCS thrusters and the unsteady nature of the Orion capsule backshell environments. The model for the aerothermal database has thus relied on wind tunnel test data to capture the heating effects of thruster plume interactions with the freestream. These data are only valid for the continuum flow regime of the reentry trajectory. A Direct Simulation Monte Carlo (DSMC) analysis was performed to study the vehicle heating effects that result from the RCS thruster plume interaction with the oncoming freestream flow at high altitudes during Orion CM reentry. The study was performed with the DSMC Analysis Code (DAC). The inflow boundary conditions for the jets were obtained from Data Parallel Line Relaxation (DPLR) computational fluid dynamics (CFD) solutions. Simulations were performed for the roll, yaw, pitch-up and pitch-down jets at altitudes of 105 km, 125 km and 160 km as well as vacuum conditions. For comparison purposes (see Figure 1), the freestream conditions were based on previous DAC simulations performed without active RCS to populate the aerodynamic database for the Orion CM. Other inputs to the analysis included a constant Orbital reentry velocity of 7.5 km/s and angle of attack of 160 degrees. The results of the study showed that the interaction effects decrease quickly with increasing altitude. Also, jets with highly scarfed nozzles cause more severe heating compared to the nozzles with lower scarf angles. The difficulty of performing these simulations was based on the maximum number density and the ratio of number densities between the freestream and the plume for each simulation. The lowest altitude solutions required a substantial amount of computational resources (up to 1800 processors) to simulate approximately 2 billion molecules for the refined (adapted) solutions.

The Role of Counselling and Parental Encouragement on Re-Entry of Adolescents into Secondary Schools in Abia State, Nigeria

ERIC Educational Resources Information Center

Alika, Henrietta Ijeoma; Ohanaka, Blessing Ijeoma

2013-01-01

This paper examined the role of counselling, and parental encouragement on re-entry of adolescents into secondary school in Abia State, Nigeria. A total of 353 adolescents who re-entered school were selected from six secondary schools in the State through a simple random sampling technique. A validated questionnaire was used for data analysis.…

Thermal investigation of nuclear waste disposal in space

NASA Technical Reports Server (NTRS)

Wilkinson, C. L.

1981-01-01

A thermal analysis has been conducted to determine the allowable size and response of bare and shielded nuclear waste forms in both low earth orbit and at 0.85 astronomical units. Contingency conditions of re-entry with a 45 deg and 60 deg aeroshell are examined as well as re-entry of a spherical shielded waste form. A variety of shielded schemes were examined and the waste form thermal response for each determined. Two optimum configurations were selected. The thermal response of these two shielded waste configurations to indefinite exposure to ground conditions following controlled and uncontrolled re-entry is determined. In all cases the prime criterion is that waste containment must be maintained.

Electrophysiological and Structural Remodeling in Heart Failure Modulate Arrhythmogenesis. 2D Simulation Study

PubMed Central

Gomez, Juan F.; Cardona, Karen; Martinez, Laura; Saiz, Javier; Trenor, Beatriz

2014-01-01

Background Heart failure is operationally defined as the inability of the heart to maintain blood flow to meet the needs of the body and it is the final common pathway of various cardiac pathologies. Electrophysiological remodeling, intercellular uncoupling and a pro-fibrotic response have been identified as major arrhythmogenic factors in heart failure. Objective In this study we investigate vulnerability to reentry under heart failure conditions by incorporating established electrophysiological and anatomical remodeling using computer simulations. Methods The electrical activity of human transmural ventricular tissue (5 cm×5 cm) was simulated using the human ventricular action potential model Grandi et al. under control and heart failure conditions. The MacCannell et al. model was used to model fibroblast electrical activity, and their electrotonic interactions with myocytes. Selected degrees of diffuse fibrosis and variations in intercellular coupling were considered and the vulnerable window (VW) for reentry was evaluated following cross-field stimulation. Results No reentry was observed in normal conditions or in the presence of HF ionic remodeling. However, defined amount of fibrosis and/or cellular uncoupling were sufficient to elicit reentrant activity. Under conditions where reentry was generated, HF electrophysiological remodeling did not alter the width of the VW. However, intermediate fibrosis and cellular uncoupling significantly widened the VW. In addition, biphasic behavior was observed, as very high fibrotic content or very low tissue conductivity hampered the development of reentry. Detailed phase analysis of reentry dynamics revealed an increase of phase singularities with progressive fibrotic components. Conclusion Structural remodeling is a key factor in the genesis of vulnerability to reentry. A range of intermediate levels of fibrosis and intercellular uncoupling can combine to favor reentrant activity. PMID:25054335

Infra-red and vibration tests of hybrid ablative/ceramic matrix technological breadboards for earth re-entry thermal protection systems

NASA Astrophysics Data System (ADS)

Barcena, Jorge; Garmendia, Iñaki; Triantou, Kostoula; Mergia, Konstatina; Perez, Beatriz; Florez, Sonia; Pinaud, Gregory; Bouilly, Jean-Marc; Fischer, Wolfgang P. P.

2017-05-01

A new thermal protection system for atmospheric earth re-entry is proposed. This concept combines the advantages of both reusable and ablative materials to establish a new hybrid concept with advanced capabilities. The solution consists of the design and the integration of a dual shield resulting on the overlapping of an external thin ablative layer with a Ceramic Matrix Composite (CMC) thermo-structural core. This low density ablative material covers the relatively small heat peak encountered during re-entry the CMC is not able to bear. On the other hand the big advantage of the CMC based TPS is of great benefit which can deal with the high integral heat for the bigger time period of the re-entry. To verify the solution a whole testing plan is envisaged, which as part of it includes thermal shock test by infra-red heating (heating flux up to 1 MW/m2) and vibration test under launcher conditions (Volna and Ariane 5). Sub-scale tile samples (100×100 mm2) representative of the whole system (dual ablator/ceramic layers, insulation, stand-offs) are specifically designed, assembled and tested (including the integration of thermocouples). Both the thermal and the vibration test are analysed numerically by simulation tools using Finite Element Models. The experimental results are in good agreement with the expected calculated parameters and moreover the solution is qualified according to the specified requirements.

Intermediate Experimental Vehicle (IXV): Avionics and Software of the ESA Reentry Demonstrator

NASA Astrophysics Data System (ADS)

Malucchi, Giovanni; Dussy, Stephane; Camuffo, Fabrizio

2012-08-01

The IXV project is conceived as a technology platform that would perform the step forward with respect to the Atmospheric Reentry Demonstrator (ARD), by increasing the system maneuverability and verifying the critical technology performances against a wider re- entry corridor.The main objective is to design, develop and to perform an in-flight verification of an autonomous lifting and aerodynamically controlled (by a combined use of thrusters and aerodynamic surfaces) reentry system.The project also includes the verification and experimentation of a set of critical reentry technologies and disciplines:Thermal Protection System (TPS), for verification and characterization of thermal protection technologies in representative operational environment;Aerodynamics - Aerthermodynamics (AED-A TD), for understanding and validation of aerodynamics and aerothermodyamics phenomena with improvement of design tools;Guidance, Navigation and Control (GNC), for verification of guidance, navigation and control techniques in representative operational environment (i.e. reentry from Low Earth Orbit);Flight dynamics, to update and validate the vehicle model during actual flight, focused on stability and control derivatives.The above activities are being performed through the implementation of a strict system design-to-cost approach with a proto-flight model development philosophy.In 2008 and 2009, the IXV project activities reached the successful completion of the project Phase-B, including the System PDR, and early project Phase-C.In 2010, following a re-organization of the industrial consortium, the IXV project successfully completed a design consolidation leading to an optimization of the technical baseline including the GNC, avionics (i.e. power, data handling, radio frequency and telemetry), measurement sensors, hot and cold composite structures, thermal protections and control, with significant improvements of the main system budgets.The project has successfully closed the System CDR during 2011 and it is currently running the Phase-D with the target to be launched with Vega from Kourou in 2014The paper will provide an overview of the IXV design and mission objectives in the frame of the atmospheric reentry overall activities, focusing on the avionics and software architecture and design.

Analysis of Electromagnetic Wave Propagation in a Magnetized Re-Entry Plasma Sheath Via the Kinetic Equation

NASA Technical Reports Server (NTRS)

Manning, Robert M.

2009-01-01

Based on a theoretical model of the propagation of electromagnetic waves through a hypersonically induced plasma, it has been demonstrated that the classical radiofrequency communications blackout that is experienced during atmospheric reentry can be mitigated through the appropriate control of an external magnetic field of nominal magnitude. The model is based on the kinetic equation treatment of Vlasov and involves an analytical solution for the electric and magnetic fields within the plasma allowing for a description of the attendant transmission, reflection and absorption coefficients. The ability to transmit through the magnetized plasma is due to the magnetic windows that are created within the plasma via the well-known whistler modes of propagation. The case of 2 GHz transmission through a re-entry plasma is considered. The coefficients are found to be highly sensitive to the prevailing electron density and will thus require a dynamic control mechanism to vary the magnetic field as the plasma evolves through the re-entry phase.

Analysis of the Accuracy of Ballistic Descent from a Circular Circumterrestrial Orbit

NASA Astrophysics Data System (ADS)

Sikharulidze, Yu. G.; Korchagin, A. N.

2002-01-01

The problem of the transportation of the results of experiments and observations to Earth every so often appears in space research. Its simplest and low-cost solution is the employment of a small ballistic reentry spacecraft. Such a spacecraft has no system of control of the descent trajectory in the atmosphere. This can result in a large spread of landing points, which make it difficult to search for the spacecraft and very often a safe landing. In this work, a choice of a compromise scheme of the flight is considered, which includes the optimum braking maneuver, adequate conditions of the entry into the atmosphere with limited heating and overload, and also the possibility of landing within the limits of a circle with a radius of 12.5 km. The following disturbing factors were taken into account in the analysis of the accuracy of landing: the errors of the braking impulse execution, the variations of the atmosphere density and the wind, the error of the specification of the ballistic coefficient of the reentry spacecraft, and a displacement of its center of mass from the symmetry axis. It is demonstrated that the optimum maneuver assures the maximum absolute value of the reentry angle and the insensitivity of the trajectory of descent with respect to small errors of orientation of the braking engine in the plane of the orbit. It is also demonstrated that the possible error of the landing point due to the error of specification of the ballistic coefficient does not depend (in the linear approximation) upon its value and depends only upon the reentry angle and the accuracy of specification of this coefficient. A guided parachute with an aerodynamic efficiency of about two should be used at the last leg of the reentry trajectory. This will allow one to land in a prescribed range and to produce adequate conditions for the interception of the reentry spacecraft by a helicopter in order to prevent a rough landing.

Base Flow Investigation of the Apollo AS-202 Command Module. Chapter 6

NASA Technical Reports Server (NTRS)

Walpot, Louis M. G.; Wright, Michael J.; Noeding, Peter; Schrijer, Ferry

2011-01-01

In recent years, both Europe and the US are developing hypersonic research and operational vehicles. These include (re)entry capsules (both ballistic and lifting) and lifting bodies such as ExoMars, EXPERT, ARV, CEV and IXV. The research programs are meant to enable technology and engineering capabilities to support during the next decade the development of affordable (possibly reusable) space transportation systems as well as hypersonic weapons systems for time critical targets. These programs have a broad range of goals, ranging from the qualification of thermal protection systems, the assessment of RCS performances, the development of GNC algorithms, to the full demonstration of the performance and operability of the integrated vehicles. Since the aerothermodynamic characteristics influence nearly all elements of the vehicle design, the accurate prediction of the aerothermal environment is a prerequisite for the design of efficient hypersonic systems. Significant uncertainties in the prediction of the hypersonic aerodynamic and the aerothermal loads can lead to conservative margins in the design of the vehicle including its Outer Mould Line (OML), thermal protection system, structure, and required control system robustness. The current level of aerothermal prediction uncertainties results therefore in reduced vehicle performances (e.g., sub-optimal payload to mass ratio, increased operational constraints). On the other hand, present computational capabilities enable the simulation of three dimensional flow fields with complex thermo-chemical models over complete trajectories and ease the validation of these tools by, e.g., reconstruction of detailed wind tunnel tests performed under identified and controlled conditions (flow properties and vehicle attitude in particular). These controlled conditions are typically difficult to achieve when performing in flight measurements which in turn results in large associated measurement uncertainties. Similar problems arise when attempting to rebuild measurements performed in "hot" ground facilities, where the difficulty level is increased by the addition of the free-flow characterization itself. The implementation of ever more sophisticated thermochemical models is no obvious cure to the aforementioned problems since their effect is often overwhelmed by the large measurement uncertainties incurred in both flight and ground high enthalpy facilities. Concurrent to the previous considerations, a major contributor to the overall vehicle mass of re-entry vehicles is the afterbody thermal protection system. This is due to the large acreage (equal or bigger than that of the forebody) to be protected. The present predictive capabilities for base flows are comparatively lower than those for windward flowfields and offer therefore a substantial potential for improving the design of future re-entry vehicles. To that end, it is essential to address the accuracy of high fidelity CFD tools exercised in the US and EU, which motivates a thorough investigation of the present status of hypersonic flight afterbody heating. This paper addresses the predictive capabilities of after body flow fields of re-entry vehicles investigated in the frame of the NATO/RTO - RTG-043 Task Group and is structured as follows: First, the verification of base flow topologies on the basis of available wind-tunnel results performed under controlled supersonic conditions (i.e., cold flows devoid of reactive effects) is performed. Such tests address the detailed characterization of the base flow with particular emphasis on separation/reattachment and their relation to Mach number effects. The tests have been performed on an Apollo-like re-entry capsule configuration. Second, the tools validated in the frame of the previous effort are exercised and appraised against flight-test data collected during the Apollo AS-202 re-entry.

Exploration Flight Test 1 Afterbody Aerothermal Environment Reconstruction

NASA Technical Reports Server (NTRS)

Hyatt, Andrew J.; Oliver, Brandon; Amar, Adam; Lessard, Victor

2016-01-01

The Exploration Flight Test 1 vehicle included roughly 100 near surface thermocouples on the after body of the vehicle. The temperature traces at each of these instruments have been used to perform inverse environment reconstruction to determine the aerothermal environment experienced during re-entry of the vehicle. This paper provides an overview of the reconstructed environments and identifies critical aspects of the environment. These critical aspects include transition and reaction control system jet influence. A blind test of the process and reconstruction tool was also performed to build confidence in the reconstructed environments. Finally, an uncertainty quantification analysis was also performed to identify the impact of each of the uncertainties on the reconstructed environments.

Reentry Women: A Literature Review with Recommendations for Counseling and Research.

ERIC Educational Resources Information Center

Padula, Marjorie A.

1994-01-01

Provides a comprehensive literature review of research--from 1980 to 1990--regarding reentry women. Discusses reentry trends; general characteristics; reasons for reentry; personality; role, values, and family; satisfaction in the student role; career choice; reentry women after graduation; research limitations; and research recommendations.…

14 CFR 431.57 - Information requirements for payload reentry review.

Code of Federal Regulations, 2010 CFR

2010-01-01

... reentry review. 431.57 Section 431.57 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL... VEHICLE (RLV) Payload Reentry Review and Determination § 431.57 Information requirements for payload reentry review. A person requesting reentry review of a particular payload or payload class must identify...

Recovery, Transportation and Acceptance to the Curation Facility of the Hayabusa Re-Entry Capsule

NASA Technical Reports Server (NTRS)

Abe, M.; Fujimura, A.; Yano, H.; Okamoto, C.; Okada, T.; Yada, T.; Ishibashi, Y.; Shirai, K.; Nakamura, T.; Noguchi, T.;

Effect of Counterflow Jet on a Supersonic Reentry Capsule

NASA Technical Reports Server (NTRS)

Chang, Chau-Lyan; Venkatachari, Balaji Shankar; Cheng, Gary C.

2006-01-01

Recent NASA initiatives for space exploration have reinvigorated research on Apollo-like capsule vehicles. Aerothermodynamic characteristics of these capsule configurations during reentry play a crucial role in the performance and safety of the planetary entry probes and the crew exploration vehicles. At issue are the forebody thermal shield protection and afterbody aeroheating predictions. Due to the lack of flight or wind tunnel measurements at hypersonic speed, design decisions on such vehicles would rely heavily on computational results. Validation of current computational tools against experimental measurement thus becomes one of the most important tasks for general hypersonic research. This paper is focused on time-accurate numerical computations of hypersonic flows over a set of capsule configurations, which employ a counterflow jet to offset the detached bow shock. The accompanying increased shock stand-off distance and modified heat transfer characteristics associated with the counterflow jet may provide guidance for future design of hypersonic reentry capsules. The newly emerged space-time conservation element solution element (CESE) method is used to perform time-accurate, unstructured mesh Navier-Stokes computations for all cases investigated. The results show good agreement between experimental and numerical Schlieren pictures. Surface heat flux and aerodynamic force predictions of the capsule configurations are discussed in detail.

A Program for Computing Steady Inviscid Three-Dimensional Supersonic Flow on Reentry Vehicles. Volume I: Analysis and Programming

DTIC Science & Technology

1977-02-11

Continue an reverse aide If necessaty and Identify by block number) A comprehensive computational procedure is presented for predicting the...Aeroballistic Reentry Technology ( ART ) program with some of the fundamental analytical and numerical work supported by NSWC Independent Research Funds. Most of...the Aerospace Corporation. The authors gratefully acknowledge the efforts of Mr. R. Feldhuhn, NSWC coordinator for the ART program, who was responsible

Analysis of SRB reentry acoustic environments. [aeroacoustic spectra determined from wind tunnel tests

NASA Technical Reports Server (NTRS)

Coffin, T.; Dandridge, R. E.; Haddock, U. W.

1979-01-01

Space shuttle solid rocket booster reentry aeroacoustic environments were estimated. Particular emphasis was given to the aft skirt/exit plane region for the Mach number regime 0.6 = or greater than M infinity = or less than 3.5. The analysis is based on the evaluation of wind tunnel model results in conjunction with Monte Carlo simulation of trajectory parameters. The experimental approach is described as well as the evaluation process utilized. Predicted environments are presented in terms of one-third octave band spectra representing space averaged values for critical regions on the solid rocket booster.

Review of ESOC re-entry prediction results of Salyut-7/Kosmos-1686

NASA Technical Reports Server (NTRS)

Klinkrad, H.

1991-01-01

An overview of activities at ESA/ESOC during the followup of the Salyut-7/Kosmos-1686 decay, and of related cooperations with space agencies, research institutes, and national bodies within the ESA Member States, within the U.S. and within the USSR, is presented. A postflight analysis indicated areas for improvement in the forecast procedures, especially during the last day of the orbital lifetime. Corresponding revised decay predictions are presented for Salyut-7/Kosmos-1686, and the improved procedures are verified by an analysis of the reentries of Kosmos-1402A and Kosmos-1402C.

Examining the Effects of Intensive Supervision and Aftercare Programs for At-Risk Youth: A Systematic Review and Meta-Analysis.

PubMed

Bouchard, Jessica; Wong, Jennifer S

2018-05-01

Community correctional sentences are administered to more juvenile offenders in North America than any other judicial sentence. Particularly prominent in juvenile corrections is intensive supervision probation and aftercare/reentry, yet the effects of these supervision-oriented interventions on recidivism are mixed. The purpose of this meta-analysis is to determine the effects of intensive supervision probation and aftercare/reentry on juvenile recidivism. An extensive search of the literature and application of strict inclusion criteria resulted in the selection of 27 studies that contributed 55 individual effect sizes. Studies were pooled based on intervention type (intensive supervision probation or aftercare/reentry) and outcome measure (alleged or convicted offenses). The pooled analyses yielded contradictory results with respect to outcome measure; in both cases, supervision had a beneficial effect on alleged offenses and negatively affected convicted offenses. These patterns across intervention type and outcome measure, as well as recommendations for future research, are discussed.

FLPP IXV Re-Entry Vehicle, Supersonic Charectisation Based on DNW SST Wind Tunnel Tests and CFD

NASA Astrophysics Data System (ADS)

Kapteijn, C.; Maseland, H.; Chiarelli, C.; Mareschi, V.; Tribot, J.-P.; Binetti, P.; Walloscheck, T.

2009-01-01

The European Space Agency ESA, has engaged in 2004, the IXV project (Intermediate eXperimental Vehicle) which is part of the FLPP (Future Launcher Preparatory Programme) aiming at answering to critical technological issues for controlled re-entry, while supporting the future generation launchers and to improve in general European capabilities in the strategic field of atmospheric re-entry for future space transportation, exploration and scientific applications. The IXV key mission and system objectives are the design, development, manufacturing, assembling and on- ground to in-flight verification of an autonomous European lifting and aerodynamically controlled re- entry system, integrating the critical re- entry technologies at the system level. In particular, the IXV shall demonstrate system integrated key technologies such as lifting flight control by means of aerodynamic surfaces that are one of the main primary objectives of the experimental investigation. Lifting and aerodynamic controlled re-entry represents a significant capability advancement with respect to the ballistic re-entry of capsules like the ARD. Since hypersonic aerodynamics is essentially different from supersonic aerodynamics, the current mission is to perform an atmospheric re-entry in combination with a safe recovery the in supersonic flight regime. However, mission extension to trimmed transonic flight is under consideration based on a preliminary analysis of the aerodynamic characteristics of the IXV configuration. Since the beginning of the IXV project, an aerodynamic data base (AEDB) has been built up and continuously updated integrating the additional information mainly provided by means of CFD (ie: Euler and Navier-Stokes) and lately also by means of WTTs. This AEDB serves for flying qualities analysis and for re-entry simulations. During the development phase B2/C1, the effectiveness of the control surfaces and their impact on te vehicle's aerodynamic forces in the supersonic regime is measured for a number of discrete deflection settings in the Super-Sonic wind Tunnel (SST) of DNW. Enabling an improved understanding of the measured aerodynamic characteristics, complementary computations were performed by Thales Alenia Space. The complete set of data was analyzed and compared enabling a consolidation of the nominal aerodynamic and aerodynamic uncertainties as well. The paper presents the main objectives of the supersonic characterisation of IXV including WTTs, and the main outcomes of the current data comparisons.

High-fidelity modeling and impact footprint prediction for vehicle breakup analysis

NASA Astrophysics Data System (ADS)

Ling, Lisa

For decades, vehicle breakup analysis had been performed for space missions that used nuclear heater or power units in order to assess aerospace nuclear safety for potential launch failures leading to inadvertent atmospheric reentry. Such pre-launch risk analysis is imperative to assess possible environmental impacts, obtain launch approval, and for launch contingency planning. In order to accurately perform a vehicle breakup analysis, the analysis tool should include a trajectory propagation algorithm coupled with thermal and structural analyses and influences. Since such a software tool was not available commercially or in the public domain, a basic analysis tool was developed by Dr. Angus McRonald prior to this study. This legacy software consisted of low-fidelity modeling and had the capability to predict vehicle breakup, but did not predict the surface impact point of the nuclear component. Thus the main thrust of this study was to develop and verify the additional dynamics modeling and capabilities for the analysis tool with the objectives to (1) have the capability to predict impact point and footprint, (2) increase the fidelity in the prediction of vehicle breakup, and (3) reduce the effort and time required to complete an analysis. The new functions developed for predicting the impact point and footprint included 3-degrees-of-freedom trajectory propagation, the generation of non-arbitrary entry conditions, sensitivity analysis, and the calculation of impact footprint. The functions to increase the fidelity in the prediction of vehicle breakup included a panel code to calculate the hypersonic aerodynamic coefficients for an arbitrary-shaped body and the modeling of local winds. The function to reduce the effort and time required to complete an analysis included the calculation of node failure criteria. The derivation and development of these new functions are presented in this dissertation, and examples are given to demonstrate the new capabilities and the improvements made, with comparisons between the results obtained from the upgraded analysis tool and the legacy software wherever applicable.

Cell cycle re-entry sensitizes podocytes to injury induced death.

PubMed

Hagen, Manuel; Pfister, Eva; Kosel, Andrea; Shankland, Stuart; Pippin, Jeffrey; Amann, Kerstin; Daniel, Christoph

2016-07-17

Podocytes are terminally differentiated renal cells, lacking the ability to regenerate by proliferation. However, during renal injury, podocytes re-enter into the cell cycle but fail to divide. Earlier studies suggested that re-entry into cell cycle results in loss of podocytes, but a direct evidence for this is lacking. Therefore, we established an in vitro model to test the consequences of re-entry into the cell cycle on podocyte survival. A mouse immortalized podocyte cell line was differentiated to non-permissive podocytes and stimulated with e.g. growth factors. Stimulated cells were analyzed for mRNA-expression or stained for cell cycle analysis using flow cytometry and immunocytofluorescence microscopy. After stimulation to re-entry into cell cycle, podocytes were stressed with puromycin aminonucleoside (PAN) and analyzed for survival. During permissive stage more than 40% of immortalized podocytes were in the S-phase. In contrast, S-phase in non-permissive differentiated podocytes was reduced to 5%. Treatment with b-FGF dose dependently induced re-entry into cell cycle increasing the number of podocytes in the S-phase to 10.7% at an optimal bFGF dosage of 10 ng/ml. Forty eight hours after stimulation with bFGF the number of bi-nucleated podocytes significantly increased. A secondary injury stimulus significantly reduced podocyte survival preferentially in bi-nucleated podocytes In conclusion, stimulation of podocytes using bFGF was able to induce re-entry of podocytes into the cell cycle and to sensitize the cells for cell death by secondary injuries. Therefore, this model is appropriate for testing new podocyte protective substances that can be used for therapy.

Thermal response of Space Shuttle wing during reentry heating

NASA Technical Reports Server (NTRS)

Gong, L.; Ko, W. L.; Quinn, R. D.

1984-01-01

A structural performance and resizing (SPAR) finite element thermal analysis computer program was used in the heat transfer analysis of the space shuttle orbiter that was subjected to reentry aerodynamic heatings. One wing segment of the right wing (WS 240) and the whole left wing were selected for the thermal analysis. Results showed that the predicted thermal protection system (TPS) temperatures were in good agreement with the space transportation system, trajectory 5 (STS-5) flight-measured temperatures. In addition, calculated aluminum structural temperatures were in fairly good agreement with the flight data up to the point of touchdown. Results also showed that the internal free convection had a considerable effect on the change of structural temperatures after touchdown.

The Potential of Computational Fluid Dynamics Simulation on Serial Monitoring of Hemodynamic Change in Type B Aortic Dissection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Simon C. H., E-mail: simonyu@cuhk.edu.hk; Liu, Wen; Wong, Randolph H. L.

PurposeWe aimed to assess the potential of computational fluid dynamics simulation (CFD) in detecting changes in pressure and flow velocity in response to morphological changes in type B aortic dissection.Materials and MethodsPressure and velocity in four morphological models of type B aortic dissection before and after closure of the entry tear were calculated with CFD and analyzed for changes among the different scenarios. The control model (Model 1) was patient specific and built from the DICOM data of CTA, which bore one entry tear and three re-entry tears. Models 2–4 were modifications of Model 1, with two re-entry tears lessmore » in Model 2, one re-entry tear more in Model 3, and a larger entry tear in Model 4.ResultsThe pressure and velocity pertaining to each of the morphological models were unique. Changes in pressure and velocity findings were accountable by the changes in morphological features of the different models. There was no blood flow in the false lumen across the entry tear after its closure, the blood flow direction across the re-entry tears was reversed after closure of the entry tear.ConclusionCFD simulation is probably useful to detect hemodynamic changes in the true and false lumens of type B aortic dissection in response to morphological changes, it may potentially be developed into a non-invasive and patient-specific tool for serial monitoring of hemodynamic changes of type B aortic dissection before and after treatment.« less

An Overview of the Role of Systems Analysis in NASA's Hypersonics Project

NASA Technical Reports Server (NTRS)

Robinson, Jeffrey S.; Martin John G.; Bowles, Jeffrey V> ; Mehta, Unmeel B.; Snyder, CHristopher A.

2006-01-01

NASA's Aeronautics Research Mission Directorate recently restructured its Vehicle Systems Program, refocusing it towards understanding the fundamental physics that govern flight in all speed regimes. Now called the Fundamental Aeronautics Program, it is comprised of four new projects, Subsonic Fixed Wing, Subsonic Rotary Wing, Supersonics, and Hypersonics. The Aeronautics Research Mission Directorate has charged the Hypersonics Project with having a basic understanding of all systems that travel at hypersonic speeds within the Earth's and other planets atmospheres. This includes both powered and unpowered systems, such as re-entry vehicles and vehicles powered by rocket or airbreathing propulsion that cruise in and accelerate through the atmosphere. The primary objective of the Hypersonics Project is to develop physics-based predictive tools that enable the design, analysis and optimization of such systems. The Hypersonics Project charges the systems analysis discipline team with providing it the decision-making information it needs to properly guide research and technology development. Credible, rapid, and robust multi-disciplinary system analysis processes and design tools are required in order to generate this information. To this end, the principal challenges for the systems analysis team are the introduction of high fidelity physics into the analysis process and integration into a design environment, quantification of design uncertainty through the use of probabilistic methods, reduction in design cycle time, and the development and implementation of robust processes and tools enabling a wide design space and associated technology assessment capability. This paper will discuss the roles and responsibilities of the systems analysis discipline team within the Hypersonics Project as well as the tools, methods, processes, and approach that the team will undertake in order to perform its project designated functions.

Maneuver Analysis and Targeting Strategy for the Stardust Re-Entry Capsule

NASA Technical Reports Server (NTRS)

Helfrich, Cliff; Bhat, Ramachand S.; Kangas, Julie A.; Wilson, Roby S.; Wong, Mau C.; Potts, Christopher L.; Williams, Kenneth E.

2006-01-01

The Stardust Sample Return Capsule (SRC) returned to Earth on January 15, 2006 after seven years of collecting interstellar and comet particles over three heliocentric revolutions, as shown in Figure 1. The SRC was carried on board the Stardust spacecraft, as shown in Figure 2. Because the spacecraft was built with unbalanced thrusters, turns and attitude control maintenance resulted in undesirable delta-v being imparted to the trajectory. As a result, a carefully planned maneuver strategy was devised to accurately target the Stardust capsule to the Utah Test and Training Range (UTTR). This paper provides an overview of the Stardust spacecraft and mission and describes the maneuver strategy that was employed to achieve the stringent targeting requirements for landing in Utah. In addition, an overview of Stardust maneuver analysis tools and techniques will also be presented.

Modified fused silicide coatings for tantalum (Ta-10W) reentry heat shields

NASA Technical Reports Server (NTRS)

Packer, C. M.; Perkins, R. A.

1973-01-01

Results are presented of a program of research to develop a reliable, high performance, fused slurry silicide coating for the Ta-10W alloy. The effort was directed toward developing new and improved formulations for use at 2600 to 2800 F (1700 to 1811 K) in an atmospheric reentry thermal protection system with a 100-mission capability. Based on a thorough characterization of isothermal and cyclic oxidation behavior, bend transition temperatures, room- and elevated-temperature tensile properties, and creep behavior, a 2.5 Mn-33Ti-64.5Si coating (designated MTS) provides excellent protection for the Ta-10W alloy in simulated reentry environments. An extensive analysis of the oxidation behavior and characteristics of the MTS coating in terms of fundamental mechanisms also is presented.

Using Pressure- and Temperature-Sensitive Paint for Global Surface Pressure and Temperature Measurements on the Aft-Body of a Capsule Reentry Vehicle

NASA Technical Reports Server (NTRS)

Watkins, A. Neal; Buck, Gregory M.; Leighty, Bradley D.; Lipford, William E.; Oglesby, Donald M.

2008-01-01

Pressure Sensitive Paint (PSP) and Temperature Sensitive Paint (TSP) were used to visualize and quantify the surface interactions of reaction control system (RCS) jets on the aft body of capsule reentry vehicle shapes. The first model tested was an Apollo-like configuration and was used to focus primarily on the effects of the forward facing roll and yaw jets. The second model tested was an early Orion Crew Module configuration blowing only out of its forward-most yaw jet, which was expected to have the most intense aerodynamic heating augmentation on the model surface. This paper will present the results from the experiments, which show that with proper system design, both PSP and TSP are effective tools for studying these types of interaction in hypersonic testing environments.

The effects of bed rest on crew performance during simulated shuttle reentry. Volume 1: Study overview and physiological results

NASA Technical Reports Server (NTRS)

Chambers, A.; Vykukal, H. C.

1974-01-01

A centrifuge study was carried out to measure physiological stress and control task performance during simulated space shuttle orbiter reentry. Jet pilots were tested with, and without, anti-g-suit protection. The pilots were exposed to simulated space shuttle reentry acceleration profiles before, and after, ten days of complete bed rest, which produced physiological deconditioning similar to that resulting from prolonged exposure to orbital zero g. Pilot performance in selected control tasks was determined during simulated reentry, and before and after each simulation. Physiological stress during reentry was determined by monitoring heart rate, blood pressure, and respiration rate. Study results indicate: (1) heart rate increased during the simulated reentry when no g protection was given, and remained at or below pre-bed rest values when g-suits were used; (2) pilots preferred the use of g-suits to muscular contraction for control of vision tunneling and grayout during reentry; (3) prolonged bed rest did not alter blood pressure or respiration rate during reentry, but the peak reentry acceleration level did; and (4) pilot performance was not affected by prolonged bed rest or simulated reentry.

The Reentry of Navy Science Assistance Program Personnel: Analysis and Recommendations for Improving the Process

DTIC Science & Technology

1986-12-01

Purpose The purposes of this project were to (1) identify organizational and personnel management practices that foster or hinder the reentry of FTMs...transition of NSAP FTMs. Latack (1984) found that individuals experiencing major career transitions experience more personal life transitions. Research...lent credibility to the claim that changes initiated in the workplace may "trigger" changes in one’s personal liife. Latack found that an individual’s

A study of RSI under combined stresses

NASA Technical Reports Server (NTRS)

Kibler, J. J.; Rosen, B. W.

1974-01-01

The behavior of typical rigidized surface insulation material (RSI) under combined loading states was investigated. In particular, the thermal stress states induced during reentry of the space shuttle were of prime concern. A typical RSI tile was analyzed for reentry thermal stresses under computed thermal gradients for a model of the RSI material. The results of the thermal stress analyses were then used to aid in defining typical combined stress states for the failure analysis of RSI.

Aerothermodynamic Analysis of a Reentry Brazilian Satellite

NASA Astrophysics Data System (ADS)

Santos, Wilson F. N.

2012-12-01

This work deals with a computational investigation on the small ballistic reentry Brazilian vehicle SAtélite de Reentrada Atmosférica (SARA). Hypersonic flows over the vehicle SARA at zero-degree angle of attack in chemical equilibrium and thermal nonequilibrium are modeled by the direct simulation Monte Carlo method, which has become the main technique for studying complex multidimensional rarefied flows, and which properly accounts for the nonequilibrium aspects of the flows. The emphasis of this paper is to examine the behavior of the primary properties during the high-altitude portion of SARA reentry. In this way, velocity, density, pressure, and temperature field are investigated for altitudes of 100, 95, 90, 85, and 80 km. In addition, comparisons based on geometry are made between axisymmetric and planar two-dimensional configurations. Some significant differences between these configurations were noted on the flowfield structure in the reentry trajectory. The analysis showed that the flow disturbances have different influence on velocity, density, pressure, and temperature along the stagnation streamline ahead of the capsule nose. It was found that the stagnation region is a thermally stressed zone. It was also found that the stagnation region is a zone of strong compression, high wall pressure. Wall pressure distributions are compared with those of available experimental data, and good agreement is found along the spherical nose for the altitude range investigated.

Procedural and Early Outcomes of Two Re-entry Devices for Subintimal Recanalization of Aortoiliac and Femoropopliteal Chronic Total Occlusions.

PubMed

Vuruskan, Ertan; Saracoglu, Erhan

2017-01-01

Subintimal angioplasty is a common treatment choice for chronic total occlusions (CTO) in the iliac and femoropopliteal arteries. This article describes the technical aspects and early outcomes of two different re-entry devices and comparison with manual re-entry technique. A retrospective review of 61 patients (re-entry group) treated with Outback or Pioneer Plus catheters was carried out. A matched cohort of patients (n=62) who underwent lower extremity interventions without the use of re-entry devices (manual re-entry group) were also analyzed (overall 123 patients were analyzed). Procedural success, procedural durations, patency estimates, ankle-brachial indices, and complications were analyzed. Sixty-one patients underwent Outback or Pioneer Plus guided subintimal recanalization. After the procedure, ankle-brachial indices significantly increased in all patients during follow-up. Primary patency for the entire cohort was 83% in the first month. When the re-entry device group was compared with manual re-entry group, no difference was found with respect to success, complication, and patencies between the two groups during follow-up. However, procedure duration and the amount of contrast agent used was significantly decreased in re-entry groups (p<0.001). Also, re-entry time was significantly decreased in Pioneer plus group according to Outback group (p<0.001). Recanalization of CTO using re-entry devices for aortoiliac or femoropopliteal arteries is safe and effective. These devices shorten the procedure time, the re-entry time, reduce radiation risk, and reduce the amount of contrast agent employed.

GOCE SSTI GNSS Receiver Re-Entry Phase Analysis

NASA Astrophysics Data System (ADS)

Zin, A.; Zago, S.; Scaciga, L.; Marradi, L.; Floberghagen, R.; Fehringer, M.; Bigazzi, A.; Piccolo, A.; Luini, L.

2015-03-01

Gravity field and Ocean Circulation Explorer (GOCE) was an ESA Earth Explorer mission dedicated to the measure of the Earth Gravity field. The Spacecraft has been launched in 2009 and the re-entry in atmosphere happened at the end of 2013 [1]. The mean orbit altitude was set to 260 km to maximize the ultra-sensitive accelerometers on board. GOCE was equipped with two main payloads: the Electrostatic Gravity Gradiometer (EGG), a set of six 3-axis accelerometers able to measure the gravity field with unrivalled precision and then to produce the most accurate shape of the ‘geoid’ and two GPS receivers (nominal and redundant), used as a Satellite-to-Satellite Tracking Instrument (SSTI) to geolocate the gradiometer measurements and to measure the long wavelength components of the gravity field with an accuracy never reached before. Previous analyses have shown that the Precise Orbit Determination (POD) of the GOCE satellite, derived by processing the dual-frequency SSTI data (carrier phases and pseudoranges) are at the “state-of-art” of the GPS based POD: kinematic Orbits Average of daily 3D-RMS is 2,06 cm [2]. In most cases the overall accuracy is better than 2 cm 3D RMS. Moreover, the “almost continuous” [2] 1 Hz data availability from the SSTI receiver is unique and allows for a time series of kinematic positions with only 0.5% of missing epochs [2]. In October 2013 GOCE mission was concluded and in November the GOCE spacecraft re-entered in the atmosphere. During the re-entry phase the two SSTI receivers have been switched on simultaneously in order to maximize the data availability. In summer 2013, the SSTI firmware was tailored in order to sustain additional dynamic error (tracking loops robustness), expected during the re-entry phase. The SW was uploaded on SSTI-B (and purposely not on SSTI-A). Therefore this was an unique opportunity to compare a “standard” receiver behaviour (SSTI-A) with an improved one (SSTI-B) in the challenging reentry phase. This paper focuses on the analysis of the data from summer 2013 up to the re-entry phase in November 2013.

Verification of the Icarus Material Response Tool

NASA Technical Reports Server (NTRS)

Schroeder, Olivia; Palmer, Grant; Stern, Eric; Schulz, Joseph; Muppidi, Suman; Martin, Alexandre

2017-01-01

Due to the complex physics encountered during reentry, material response solvers are used for two main purposes: improve the understanding of the physical phenomena; and design and size thermal protection systems (TPS). Icarus, is a three dimensional, unstructured material response tool that is intended to be used for design while maintaining the flexibility to easily implement physical models as needed. Because TPS selection and sizing is critical, it is of the utmost importance that the design tools be extensively verified and validated before their use. Verification tests aim at insuring that the numerical schemes and equations are implemented correctly by comparison to analytical solutions and grid convergence tests.

Simulation for Prediction of Entry Article Demise (SPEAD): an Analysis Tool for Spacecraft Safety Analysis and Ascent/Reentry Risk Assessment

NASA Technical Reports Server (NTRS)

Ling, Lisa

2014-01-01

For the purpose of performing safety analysis and risk assessment for a probable offnominal suborbital/orbital atmospheric reentry resulting in vehicle breakup, a synthesis of trajectory propagation coupled with thermal analysis and the evaluation of node failure is required to predict the sequence of events, the timeline, and the progressive demise of spacecraft components. To provide this capability, the Simulation for Prediction of Entry Article Demise (SPEAD) analysis tool was developed. This report discusses the capabilities, modeling, and validation of the SPEAD analysis tool. SPEAD is applicable for Earth or Mars, with the option for 3 or 6 degrees-of-freedom (DOF) trajectory propagation. The atmosphere and aerodynamics data are supplied in tables, for linear interpolation of up to 4 independent variables. The gravitation model can include up to 20 zonal harmonic coefficients. The modeling of a single motor is available and can be adapted to multiple motors. For thermal analysis, the aerodynamic radiative and free-molecular/continuum convective heating, black-body radiative cooling, conductive heat transfer between adjacent nodes, and node ablation are modeled. In a 6- DOF simulation, the local convective heating on a node is a function of Mach, angle-ofattack, and sideslip angle, and is dependent on 1) the location of the node in the spacecraft and its orientation to the flow modeled by an exposure factor, and 2) the geometries of the spacecraft and the node modeled by a heating factor and convective area. Node failure is evaluated using criteria based on melting temperature, reference heat load, g-load, or a combination of the above. The failure of a liquid propellant tank is evaluated based on burnout flux from nucleate boiling or excess internal pressure. Following a component failure, updates are made as needed to the spacecraft mass and aerodynamic properties, nodal exposure and heating factors, and nodal convective and conductive areas. This allows the trajectory to be propagated seamlessly in a single run, inclusive of the trajectories of components that have separated from the spacecraft. The node ablation simulates the decreasing mass and convective/reference areas, and variable heating factor. A built-in database provides the thermo-mechanical properties of For the purpose of performing safety analysis and risk assessment for a probable offnominal suborbital/orbital atmospheric reentry resulting in vehicle breakup, a synthesis of trajectory propagation coupled with thermal analysis and the evaluation of node failure is required to predict the sequence of events, the timeline, and the progressive demise of spacecraft components. To provide this capability, the Simulation for Prediction of Entry Article Demise (SPEAD) analysis tool was developed. This report discusses the capabilities, modeling, and validation of the SPEAD analysis tool. SPEAD is applicable for Earth or Mars, with the option for 3 or 6 degrees-of-freedom (DOF) trajectory propagation. The atmosphere and aerodynamics data are supplied in tables, for linear interpolation of up to 4 independent variables. The gravitation model can include up to 20 zonal harmonic coefficients. The modeling of a single motor is available and can be adapted to multiple motors. For thermal analysis, the aerodynamic radiative and free-molecular/continuum convective heating, black-body radiative cooling, conductive heat transfer between adjacent nodes, and node ablation are modeled. In a 6- DOF simulation, the local convective heating on a node is a function of Mach, angle-ofattack, and sideslip angle, and is dependent on 1) the location of the node in the spacecraft and its orientation to the flow modeled by an exposure factor, and 2) the geometries of the spacecraft and the node modeled by a heating factor and convective area. Node failure is evaluated using criteria based on melting temperature, reference heat load, g-load, or a combination of the above. The failure of a liquid propellant tank is evaluated based on burnout flux from nucleate boiling or excess internal pressure. Following a component failure, updates are made as needed to the spacecraft mass and aerodynamic properties, nodal exposure and heating factors, and nodal convective and conductive areas. This allows the trajectory to be propagated seamlessly in a single run, inclusive of the trajectories of components that have separated from the spacecraft. The node ablation simulates the decreasing mass and convective/reference areas, and variable heating factor. A built-in database provides the thermo-mechanical properties of

Cell cycle re-entry sensitizes podocytes to injury induced death

PubMed Central

Hagen, Manuel; Pfister, Eva; Kosel, Andrea; Shankland, Stuart; Pippin, Jeffrey; Amann, Kerstin; Daniel, Christoph

2016-01-01

ABSTRACT Podocytes are terminally differentiated renal cells, lacking the ability to regenerate by proliferation. However, during renal injury, podocytes re-enter into the cell cycle but fail to divide. Earlier studies suggested that re-entry into cell cycle results in loss of podocytes, but a direct evidence for this is lacking. Therefore, we established an in vitro model to test the consequences of re-entry into the cell cycle on podocyte survival. A mouse immortalized podocyte cell line was differentiated to non-permissive podocytes and stimulated with e.g. growth factors. Stimulated cells were analyzed for mRNA-expression or stained for cell cycle analysis using flow cytometry and immunocytofluorescence microscopy. After stimulation to re-entry into cell cycle, podocytes were stressed with puromycin aminonucleoside (PAN) and analyzed for survival. During permissive stage more than 40% of immortalized podocytes were in the S-phase. In contrast, S-phase in non-permissive differentiated podocytes was reduced to 5%. Treatment with b-FGF dose dependently induced re-entry into cell cycle increasing the number of podocytes in the S-phase to 10.7% at an optimal bFGF dosage of 10 ng/ml. Forty eight hours after stimulation with bFGF the number of bi-nucleated podocytes significantly increased. A secondary injury stimulus significantly reduced podocyte survival preferentially in bi-nucleated podocytes In conclusion, stimulation of podocytes using bFGF was able to induce re-entry of podocytes into the cell cycle and to sensitize the cells for cell death by secondary injuries. Therefore, this model is appropriate for testing new podocyte protective substances that can be used for therapy. PMID:27232327

An Analysis of Soviet Military Writing on United States Reentry Vehicle Technology, 1965-1983

DTIC Science & Technology

1986-05-01

accomplish its maneuvering "with the help of Jet fins [struynyy rul’].൞ In fact, the B(MV, as tested in 1967, contained a propulsion system for...ICBMs.6" An active coating was, however, flight tested on a U.S. RV in * late 1974-approximately six months after this author’s book was signed to...U.S. MIRV deployments had begun the previous year (1970); maneuvering re-entry vehicles--while undergoing flight testing during this period--were still

The pioneering work of George Mines on cardiac arrhythmias: groundbreaking ideas that remain influential in contemporary cardiac electrophysiology

PubMed Central

Aguilar, Martin

2016-01-01

Abstract George Mines was a pioneering physiologist who, despite an extremely short period of professional activity and only primitive experimental methodology, succeeded in formulating concepts that continue to be of great influence today. Here, we review some of his most important discoveries and their impact on contemporary concepts and clinical practice. Mines’ greatest contribution was his conceptualization and characterization of circus movement reentry. His observations and ideas about the basis for cardiac reentrant activity underlie how we understand and manage a wide range of important clinical rhythm disturbances today. The notions he introduced regarding the influence of premature extrastimuli on reentry (termination, resetting and entrainment) are central to contemporary assessment of arrhythmia mechanisms in clinical electrophysiology laboratories and modern device therapy of cardiac tachyarrhythmias. Refinements of his model of reentry have led to sophisticated biophysical theories of the mechanisms underlying cardiac fibrillation. His seminal observations on the influence of electrolyte derangements and autonomic tone on the heart are relevant to our understanding of the physiology and pharmacology of arrhythmias caused by cardiac pathology. In this era of advanced technology, it is important to appreciate that ideas of lasting impact come from great minds and do not necessarily require great tools. PMID:26607760

Analysis of generic reentry vehicle flight dynamics

NASA Astrophysics Data System (ADS)

Metsker, Yu.; Weinand, K.; Geulen, G.; Haidn, O. J.

2018-06-01

The knowledge of reentry vehicles (RV) flight characteristics regarding geometrical shape, dimensions, and mechanical properties is essential for precise prediction of their flight trajectory, impact point, and possible deviations according to simulation uncertainties. The flight characteristic estimations of existing RV require both body dimensions and mechanical properties of the objects. Due to comparatively simple and reliable methods of specifying the vehicle outer dimensions, e. g., photos and videomaterials, the estimation of mechanical properties is a subject of higher uncertainties. Within this study, a generic medium range ballistic missile (MRBM) RV was examined for several modifications such as center of gravity (CoG) position, weight moment of inertia, and initial reentry flight states. Combinations of these variables with constant aerodynamic properties for maximal lateral accelerations will be determined. Basing on these, potential evasion maneuver capabilities of the RV will be described.

Assessment Of The Aerodynamic And Aerothermodynamic Performance Of The USV-3 High-Lift Re-Entry Vehicle

NASA Astrophysics Data System (ADS)

Pezzella, Giuseppe; Richiello, Camillo; Russo, Gennaro

2011-05-01

This paper deals with the aerodynamic and aerothermodynamic trade-off analysis carried out with the aim to design a hypersonic flying test bed (FTB), namely USV3. Such vehicle will have to be launched with a small expendable launcher and shall re-enter the Earth atmosphere allowing to perform several experiments on critical re-entry phenomena. The demonstrator under study is a re-entry space glider characterized by a relatively simple vehicle architecture able to validate hypersonic aerothermodynamic design database and passenger experiments, including thermal shield and hot structures. Then, a summary review of the aerodynamic characteristics of two FTB concepts, compliant with a phase-A design level, has been provided hereinafter. Indeed, several design results, based both on engineering approach and computational fluid dynamics, are reported and discussed in the paper.

SHEFEX - the vehicle and sub-systems for a hypersonic re-entry flight experiment

NASA Astrophysics Data System (ADS)

Turner, John; Hörschgen, Marcus; Turner, Peter; Ettl, Josef; Jung, Wolfgang; Stamminger, Andreas

2005-08-01

The purpose of the Sharp Edge Flight Experiment (SHEFEX) is to investigate the aerodynamic behaviour and thermal problems of an unconventional shape for re-entry vehicles, comprising multi-facetted surfaces with sharp edges. The main object of this experiment is the correlation of numerical analysis with real flight data in terms of the aerodynamic effects and structural concept for the thermal protection system (TPS). The Mobile Rocket Base of the German Aerospace Center (DLR) is responsible for the test flight of SHEFEX on a two stage unguided solid propellant sounding rocket which is required to provide a velocity of the order of March 7 for more than 30 seconds during atmospheric re-entry. This paper discusses the problems associated with the mission requirements and the solutions developed for the vehicle and sub-systems.

Pathological implications of cell cycle re-entry in Alzheimer disease.

PubMed

Bonda, David J; Lee, Hyun-pil; Kudo, Wataru; Zhu, Xiongwei; Smith, Mark A; Lee, Hyoung-gon

2010-06-29

The complex neurodegeneration underlying Alzheimer disease (AD), although incompletely understood, is characterised by an aberrant re-entry into the cell cycle in neurons. Pathological evidence, in the form of cell cycle markers and regulatory proteins, suggests that cell cycle re-entry is an early event in AD, which precedes the formation of amyloid-beta plaques and neurofibrillary tangles (NFTs). Although the exact mechanisms that induce and mediate these cell cycle events in AD are not clear, significant advances have been made in further understanding the pathological role of cell cycle re-entry in AD. Importantly, recent studies indicate that cell cycle re-entry is not a consequence, but rather a cause, of neurodegeneration, suggesting that targeting of cell cycle re-entry may provide an opportunity for therapeutic intervention. Moreover, multiple inducers of cell cycle re-entry and their interactions in AD have been proposed. Here, we review the most recent advances in understanding the pathological implications of cell cycle re-entry in AD.

Incidence and outcome of re-entry injury in redo cardiac surgery: benefits of preoperative planning.

PubMed

Imran Hamid, Umar; Digney, Ruairi; Soo, Lorraine; Leung, Samantha; Graham, Alastair N J

2015-05-01

Repeat sternotomy for redo cardiac surgery may be associated with catastrophic injuries to mediastinal structures. The purpose of this study was to determine the frequency of these injuries, associated outcome and if a preoperative computerized tomography (CT) scan reduces the risk of re-entry injury. Five hundred and forty-four patients who underwent redo cardiac surgery between 2001 and 2011 were identified by review of our unit's prospectively maintained cardiac surgery database. Demographic details, surgical strategy, re-entry injuries, hospital stay, in-hospital mortality and long-term survival were analysed. The mean age was 61 years; 326 were male, 218 were female. Four hundred and eighty six patients underwent first time redo surgery, while 58 patients had multiple previous operations. The median logistic EuroSCORE was 11, in-hospital mortality rate was 9.5% and observed to expected mortality rate was 0.8. Re-entry complications occurred in 15 cases (2.7%). These included injuries to the aorta (n = 2), right atrium (n = 1), innominate vein (n = 2), internal mammary artery (n = 2), pulmonary artery (n = 2), lung parenchyma (n = 1), saphenous vein graft (n = 2), right ventricle (n = 2) and ventricular fibrillation (n = 1). The mortality rate in patients with re-entry injury was 26% (n = 4) compared with 9% (n = 48) in those without re-entry complications. Preoperative planning by CT scan was performed in 162 cases and adherence of vital structures to the sternum was found in 60 cases; the right ventricle, innominate vein and bypass grafts in 41, 11 and 8, respectively. The incidence rate of re-entry injury was 0.6% in these patients vs 3.6% in those who did not have a preoperative CT scan (P = 0.046). Peripheral arterial cannulation was carried out in 35 patients (6.4%) to establish cardiopulmonary bypass (CPB) prior to sternotomy, and there were no mediastinal injuries observed in these cases. Multivariate logistic regression analysis revealed re-entry injury as one of the independent predictors of in-hospital mortality (P = 0.039). The incidence of re-entry injury during repeat sternotomy is low; however, it is associated with a significant increase in the risk of in-hospital mortality. Preoperative planning using CT scan reduces the risk by identifying adherent structures, and, in selected patients, establishing CPB prior to sternotomy is a safe strategy in redo cardiac surgery. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Fast optimization of glide vehicle reentry trajectory based on genetic algorithm

NASA Astrophysics Data System (ADS)

Jia, Jun; Dong, Ruixing; Yuan, Xuejun; Wang, Chuangwei

2018-02-01

An optimization method of reentry trajectory based on genetic algorithm is presented to meet the need of reentry trajectory optimization for glide vehicle. The dynamic model for the glide vehicle during reentry period is established. Considering the constraints of heat flux, dynamic pressure, overload etc., the optimization of reentry trajectory is investigated by utilizing genetic algorithm. The simulation shows that the method presented by this paper is effective for the optimization of reentry trajectory of glide vehicle. The efficiency and speed of this method is comparative with the references. Optimization results meet all constraints, and the on-line fast optimization is potential by pre-processing the offline samples.

Characterisation of re-entrant circuit (or rotational activity) in vitro using the HL1-6 myocyte cell line.

PubMed

Houston, Charles; Tzortzis, Konstantinos N; Roney, Caroline; Saglietto, Andrea; Pitcher, David S; Cantwell, Chris D; Chowdhury, Rasheda A; Ng, Fu Siong; Peters, Nicholas S; Dupont, Emmanuel

2018-06-01

Fibrillation is the most common arrhythmia observed in clinical practice. Understanding of the mechanisms underlying its initiation and maintenance remains incomplete. Functional re-entries are potential drivers of the arrhythmia. Two main concepts are still debated, the "leading circle" and the "spiral wave or rotor" theories. The homogeneous subclone of the HL1 atrial-derived cardiomyocyte cell line, HL1-6, spontaneously exhibits re-entry on a microscopic scale due to its slow conduction velocity and the presence of triggers, making it possible to examine re-entry at the cellular level. We therefore investigated the re-entry cores in cell monolayers through the use of fluorescence optical mapping at high spatiotemporal resolution in order to obtain insights into the mechanisms of re-entry. Re-entries in HL1-6 myocytes required at least two triggers and a minimum colony area to initiate (3.5 to 6.4 mm 2 ). After electrical activity was completely stopped and re-started by varying the extracellular K + concentration, re-entries never returned to the same location while 35% of triggers re-appeared at the same position. A conduction delay algorithm also allows visualisation of the core of the re-entries. This work has revealed that the core of re-entries is conduction blocks constituted by lines and/or groups of cells rather than the round area assumed by the other concepts of functional re-entry. This highlights the importance of experimentation at the microscopic level in the study of re-entry mechanisms. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

On-ground casualty risk reduction by structural design for demise

NASA Astrophysics Data System (ADS)

Lemmens, Stijn; Funke, Quirin; Krag, Holger

2015-06-01

In recent years, awareness concerning the on-ground risk posed by un-controlled re-entering space systems has increased. On average over the past decade, an object with mass above 800 kg re-enters every week from which only a few, e.g. ESA's GOCE in 2013 and NASA's UARS in 2011, appeared prominent in international media. Space agencies and nations have discussed requirements to limit the on-ground risk for future missions. To meet the requirements, the amount of debris falling back on Earth has to be limited in number, mass and size. Design for demise (D4D) refers to all measures taken in the design of a space object to increase the potential for demise of the object and its components during re-entry. SCARAB (Spacecraft Atmospheric Re-entry and Break-Up) is ESA's high-fidelity tool which analyses the thermal and structural effects of atmospheric re-entry on spacecraft with a finite-element approach. For this study, a model of a representative satellite is developed in SCARAB to serve as test-bed for D4D analyses on a structural level. The model is used as starting point for different D4D approaches based on increasing the exposure of the satellite components to the aero-thermal environment, as a way to speed up the demise. Statistical bootstrapping is applied to the resulting on-ground fragment lists in order to compare the different re-entry scenarios and to determine the uncertainties of the results. Moreover, the bootstrap results can be used to analyse the casualty risk estimator from a theoretical point of view. The risk reductions for the analysed D4D techniques are presented with respect to the reference scenario for the modelled representative satellite.

75 FR 75621 - Office of Commercial Space Transportation; Waiver of Autonomous Reentry Restriction for a Reentry...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-06

... Space Transportation; Waiver of Autonomous Reentry Restriction for a Reentry Vehicle AGENCY: Federal... concerns two petitions for waiver submitted to the Federal Aviation Administration (FAA) by Space Exploration Technologies Corp. (SpaceX): A petition to waive the requirement that a waiver petition be...

78 FR 50421 - Guidance for Industry: Recommendations for Donor Questioning, Deferral, Reentry, and Product...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-19

..., Reentry, and Product Management To Reduce the Risk of Transfusion-Transmitted Malaria; Availability AGENCY... Questioning, Deferral, Reentry and Product Management to Reduce the Risk of Transfusion-Transmitted Malaria... their reentry, and product management to reduce the risk of transfusion-transmitted malaria. This...

Correctional Practitioners on Reentry: A Missed Perspective

ERIC Educational Resources Information Center

Gunnison, Elaine; Helfgott, Jacqueline B.; Wilhelm, Cecilie

2015-01-01

Much of the literature on reentry of formerly incarcerated individuals revolves around discussions of failures they incur during reintegration or the identification of needs and challenges that they have during reentry from the perspective of community corrections officers. The present research fills a gap in the reentry literature by examining…

ABLATIVE COMPOSITES FOR LIFTING REENTRY THERMAL PROTECTION.

DTIC Science & Technology

MECHANICAL PROPERTIES, THERMAL CONDUCTIVITY, ABLATION, DENSITY, TABLES(DATA), SPECIFIC HEAT, THERMOGRAVIMETRIC ANALYSIS, CORROSION RESISTANCE, COLORIMETRY , HEAT RESISTANT MATERIALS, ATMOSPHERE ENTRY.

Ares I-X Separation and Reentry Trajectory Analyses

NASA Technical Reports Server (NTRS)

Tartabini, Paul V.; Starr, Brett R.

2011-01-01

The Ares I-X Flight Test Vehicle was launched on October 28, 2009 and was the first and only test flight of NASA s two-stage Ares I launch vehicle design. The launch was successful and the flight test met all of its primary and secondary objectives. This paper discusses the stage separation and reentry trajectory analysis that was performed in support of the Ares I-X test flight. Pre-flight analyses were conducted to assess the risk of stage recontact during separation, to evaluate the first stage flight dynamics during reentry, and to define the range safety impact ellipses of both stages. The results of these pre-flight analyses were compared with available flight data. On-board video taken during flight showed that the flight test vehicle successfully separated without any recontact. Reconstructed trajectory data also showed that first stage flight dynamics were well characterized by pre-flight Monte Carlo results. In addition, comparisons with flight data indicated that the complex interference aerodynamic models employed in the reentry simulation were effective in capturing the flight dynamics during separation. Finally, the splash-down locations of both stages were well within predicted impact ellipses.

Aero-thermo-dynamic analysis of a low ballistic coefficient deployable capsule in Earth re-entry

NASA Astrophysics Data System (ADS)

Zuppardi, G.; Savino, R.; Mongelluzzo, G.

2016-10-01

The paper deals with a microsatellite and the related deployable recovery capsule. The aero-brake is folded at launch and deployed in space and is able to perform a de-orbiting controlled re-entry. This kind of capsule, with a flexible, high temperature resistant fabric, thanks to its lightness and modulating capability, can be an alternative to the current ;conventional; recovery capsules. The present authors already analyzed the trajectory and the aerodynamic behavior of low ballistic coefficient capsules during Earth re-entry and Mars entry. In previous studies, aerodynamic longitudinal stability analysis and evaluation of thermal and aerodynamic loads for a possible suborbital re-entry demonstrator were carried out in both continuum and rarefied regimes. The present study is aimed at providing preliminary information about thermal and aerodynamic loads and longitudinal stability for a similar deployable capsule, as well as information about the electronic composition of the plasma sheet and its possible influence on radio communications at the altitudes where GPS black-out could occur. Since the computer tests were carried out at high altitudes, therefore in rarefied flow fields, use of Direct Simulation Monte Carlo codes was mandatory. The computations involved both global aerodynamic quantities (drag and longitudinal moment coefficients) and local aerodynamic quantities (heat flux and pressure distributions along the capsule surface). The results verified that the capsule at high altitude (150 km) is self-stabilizing; it is stable around the nominal attitude or at zero angle of attack and unstable around the reverse attitude or at 180° angle of attack. The analysis also pointed out the presence of extra statically stable equilibrium trim points.

Reentry Thermal Analysis of a Generic Crew Exploration Vehicle Structure

NASA Technical Reports Server (NTRS)

Ko, William L.; Gong, Leslie; Quinn, Robert D.

2007-01-01

Comparative studies were performed on the heat-shielding characteristics of honeycomb-core sandwich panels fabricated with different materials for possible use as wall panels for the proposed crew exploration vehicle. Graphite/epoxy sandwich panel was found to outperform aluminum sandwich panel under the same geometry due to superior heat-shielding qualities and lower material density. Also, representative reentry heat-transfer analysis was performed on the windward wall structures of a generic crew exploration vehicle. The Apollo low Earth orbit reentry trajectory was used to calculate the reentry heating rates. The generic crew exploration vehicle has a graphite/epoxy composite honeycomb sandwich exterior wall and an aluminum honeycomb sandwich interior wall, and is protected with the Apollo thermal protection system ablative material. In the thermal analysis computer program used, the TPS ablation effect was not yet included; however, the results from the nonablation heat-transfer analyses were used to develop a "virtual ablation" method to estimate the ablation heat loads and the thermal protection system recession thicknesses. Depending on the severity of the heating-rate time history, the virtual ablation period was found to last for 87 to 107 seconds and the ablation heat load was estimated to be in the range of 86 to 88 percent of the total heat load for the ablation time period. The thermal protection system recession thickness was estimated to be in the range of 0.08 to 0.11 inches. For the crew exploration vehicle zero-tilt and 18-degree-tilt stagnation points, thermal protection system thicknesses of h = {0.717, 0.733} inches were found to be adequate to keep the substructural composite sandwich temperature below the limit of 300 F.

Preventing re-entry to foster care.

PubMed

Carnochan, Sarah; Rizik-Baer, Daniel; Austin, Michael J

2013-01-01

Re-entry to foster care generally refers to circumstances in which children who have been discharged from foster care to be reunified with their family of origin, adopted, or provided kinship guardianship are returned to foster care. In the context of the federal performance measurement system, re-entry refers specifically to a return to foster care following an unsuccessful reunification. The federal Children and Family Services Review measures re-entry to foster care with a single indicator, called the permanency of reunification indicator, one of four indicators comprising the reunification composite measure. This review focuses on research related to the re-entry indicator, including the characteristics of children, caregivers and families, as well as case and child welfare services that are associated with a higher or lower risk of re-entry to foster care. Promising post-reunification services designed to prevent re-entry to foster care are described.

An Empirical Study of Reentry Women.

ERIC Educational Resources Information Center

Pickering, Glenn S.; Galvin-Schaefers, Kate

1988-01-01

Compared 76 reentry working women with 78 career women. Found reentry women held lower-level jobs and scored lower on measures of assertiveness and autonomy than did career women. Reentry women did not score lower on self-esteem measures or dominance measures, and did not score higher than career women on either conflict or need for achievement…

Thermal Analysis and Design of Multi-layer Insulation for Re-entry Aerodynamic Heating

NASA Technical Reports Server (NTRS)

Daryabeigi, Kamran

2001-01-01

The combined radiation/conduction heat transfer in high-temperature multi-layer insulations was modeled using a finite volume numerical model. The numerical model was validated by comparison with steady-state effective thermal conductivity measurements, and by transient thermal tests simulating re-entry aerodynamic heating conditions. A design of experiments technique was used to investigate optimum design of multi-layer insulations for re-entry aerodynamic heating. It was found that use of 2 mm foil spacing and locating the foils near the hot boundary with the top foil 2 mm away from the hot boundary resulted in the most effective insulation design. A 76.2 mm thick multi-layer insulation using 1, 4, or 16 foils resulted in 2.9, 7.2, or 22.2 percent mass per unit area savings compared to a fibrous insulation sample at the same thickness, respectively.

8 CFR 211.3 - Expiration of immigrant visas, reentry permits, refugee travel documents, and Form I-551.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Expiration of immigrant visas, reentry... Expiration of immigrant visas, reentry permits, refugee travel documents, and Form I-551. An immigrant visa... holder embarked or enplaned before the expiration of his or her immigrant visa, reentry permit, or...

The efficacy of family reunification practices: reentry rates and correlates of reentry for abused and neglected children reunited with their families.

PubMed

Terling, T

1999-12-01

Since the 1980s Child Protective Services has increasingly relied on family reunification for abused/neglected children rather than long term foster care or adoption. While family reunification practices are controversial, little research is available to inform the debate. This research explores the efficacy of these practices. This study utilizes two CPS data sources and both quantitative and qualitative methodologies to identify reentry rates and correlates of reentry for abused and neglected children returned to their families by CPS. System reentry due to additional maltreatment is considerable. Thirty-seven percent of the children reunited with their families reenter the system within 3 1/2 years. Correlates of reentry are identified as; abuse type, CPS history, parental competency, race, criminal history, substance abuse, and social support. Notably, assessments of risk made by caseworkers are found to be unrelated to reentry. The high reentry rate and the limitations of current risk assessment procedures suggest that CPS family reunification practices have not been entirely successful. The identification of specific risks of reentry, such as those revealed in this study, will be helpful in assessing risk on cases. In addition, future studies should explore the systemic deficiencies that contribute to the additional maltreatment that occurs for a sizable proportion of the children served by the system.

From the Classroom to the Community: Exploring the Role of Education during Incarceration and Reentry

ERIC Educational Resources Information Center

Brazzell, Diana; Crayton, Anna; Mukamal, Debbie A.; Solomon, Amy L.; Lindahl, Nicole

2009-01-01

Recognizing the pressing need to explore the issues surrounding education, incarceration, and reentry, the Prisoner Reentry Institute at John Jay College of Criminal Justice and the Urban Institute hosted the Reentry Roundtable on Education on March 31 and April 1, 2008, at John Jay College of Criminal Justice in New York City. The two-day…

Cross-cultural re-entry for missionaries: a new application for the Dual Process Model.

PubMed

Selby, Susan; Clark, Sheila; Braunack-Mayer, Annette; Jones, Alison; Moulding, Nicole; Beilby, Justin

Nearly half a million foreign aid workers currently work worldwide, including over 140,000 missionaries. During re-entry these workers may experience significant psychological distress. This article positions previous research about psychological distress during re-entry, emphasizing loss and grief. At present there is no identifiable theoretical framework to provide a basis for assessment, management, and prevention of re-entry distress in the clinical setting. The development of theoretical concepts and frameworks surrounding loss and grief including the Dual Process Model (DPM) are discussed. All the parameters of the DPM have been shown to be appropriate for the proposed re-entry model, the Dual Process Model applied to Re-entry (DPMR). It is proposed that the DPMR is an appropriate framework to address the processes and strategies of managing re-entry loss and grief. Possible future clinical applications and limitations of the proposed model are discussed. The DPMR is offered for further validation and use in clinical practice.

"The stress will kill you": prisoner reentry as experienced by family members and the urgent need for support services.

PubMed

Grieb, Suzanne M; Crawford, Amelia; Fields, Julie; Smith, Horace; Harris, Richard; Matson, Pamela

2014-08-01

The role of incarceration and community reentry after incarceration has been studied extensively for individual and community health; however, little attention has been given to the experiences of individuals who provide support to those in reentry. Through a community-academic partnership, seven focus groups were conducted with 39 individuals supporting a family member in reentry in the summer of 2012. The primary objectives of the focus groups were to explore community experiences and perspectives regarding providing support during a family member's reentry from a period of incarceration and any desired support for themselves during this time. Five themes emerged under a metatheme of stress, indicating that family members experience acute stress as a result of family reentry that adds to the chronic stress they already endure. Programs that acknowledge the difficult role of family members as supporters during an individual's reentry and provide support to them are desperately needed.

Re-Entry of Women to the Labour Market After an Interruption in Employment.

ERIC Educational Resources Information Center

Seear, B. N.

The problems involved in the re-entry of women into employment were studied, and the extent to which there exists a demand for employment for re-entry women was examined. A growing number of women are seeking re-entry in a wide range of income levels. The demand for part-time work appears to exceed supply. Official machinery for assisting re-entry…

Optogenetic manipulation of anatomical re-entry by light-guided generation of a reversible local conduction block.

PubMed

Watanabe, Masaya; Feola, Iolanda; Majumder, Rupamanjari; Jangsangthong, Wanchana; Teplenin, Alexander S; Ypey, Dirk L; Schalij, Martin J; Zeppenfeld, Katja; de Vries, Antoine A F; Pijnappels, Daniël A

2017-03-01

Anatomical re-entry is an important mechanism of ventricular tachycardia, characterized by circular electrical propagation in a fixed pathway. It's current investigative and therapeutic approaches are non-biological, rather unspecific (drugs), traumatizing (electrical shocks), or irreversible (ablation). Optogenetics is a new biological technique that allows reversible modulation of electrical function with unmatched spatiotemporal precision using light-gated ion channels. We therefore investigated optogenetic manipulation of anatomical re-entry in ventricular cardiac tissue. Transverse, 150-μm-thick ventricular slices, obtained from neonatal rat hearts, were genetically modified with lentiviral vectors encoding Ca2+-translocating channelrhodopsin (CatCh), a light-gated depolarizing ion channel, or enhanced yellow fluorescent protein (eYFP) as control. Stable anatomical re-entry was induced in both experimental groups. Activation of CatCh was precisely controlled by 470-nm patterned illumination, while the effects on anatomical re-entry were studied by optical voltage mapping. Regional illumination in the pathway of anatomical re-entry resulted in termination of arrhythmic activity only in CatCh-expressing slices by establishing a local and reversible, depolarization-induced conduction block in the illuminated area. Systematic adjustment of the size of the light-exposed area in the re-entrant pathway revealed that re-entry could be terminated by either wave collision or extinction, depending on the depth (transmurality) of illumination. In silico studies implicated source-sink mismatches at the site of subtransmural conduction block as an important factor in re-entry termination. Anatomical re-entry in ventricular tissue can be manipulated by optogenetic induction of a local and reversible conduction block in the re-entrant pathway, allowing effective re-entry termination. These results provide distinctively new mechanistic insight into re-entry termination and a novel perspective for cardiac arrhythmia management. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

Targeted True Lumen Re-Entry With the Outback Catheter: Accuracy, Success, and Complications in 100 Peripheral Chronic Total Occlusions and Systematic Review of the Literature.

PubMed

Kitrou, Panagiotis; Parthipun, Aneeta; Diamantopoulos, Athanasios; Paraskevopoulos, Ioannis; Karunanithy, Narayan; Katsanos, Konstantinos

2015-08-01

To report a single-center experience with the Outback re-entry device for targeted distal true lumen re-entry during subintimal recanalization of chronic total occlusions (CTOs) and compare the results with a systematic review of the literature. Between February 2011 and July 2013, 104 Outback devices were employed in 91 patients (mean age 64±9 years; 57 men) for subintimal recanalization of 100 vessels with CTOs after initial failure of spontaneous reentry. Fifty-two cases involved a retrograde approach to aortoiliac occlusions and 48 were re-entry attempts in infrainguinal CTOs. Outcome measures included complications and technical success, defined as successful targeted re-entry at the preplanned site of the distal true lumen. To evaluate device accuracy, the re-entry distance (between the point of true vessel reconstitution and the eventual re-entry point) was measured. Outback success was 93% (93/100); only 7 cases failed owing to heavy calcification (5/52 aortoiliac vs 2/48 infrainguinal, p=0.44). Re-entry was highly accurate, with a re-entry distance of ~1 cm in both subgroups (1.2±0.1 cm in aortoiliac vs 1.3±0.1 cm in infrainguinal, p=0.40). There were no major and 17 minor complications (9/52 aortoiliac vs 8/48 infrainguinal, p=0.93). Results are in line with the systematic review that identified 11 studies (only 1 randomized trial) involving mostly the femoropopliteal segment (119 aortoiliac and 464 infrainguinal segments). The pooled Outback success rate was 90% (95% confidence interval 85% to 94%) and the pooled complication rate was 4.3% (95% confidence interval 1.6% to 8.3%). The Outback device is safe and has a very high rate of achieving targeted true lumen re-entry, which minimizes the sacrifice of healthy vessel in the aortoiliac and infrainguinal arteries. © The Author(s) 2015.

A theoretical study of the initiation, maintenance and termination of gastric slow wave re-entry.

PubMed

Du, Peng; Paskaranandavadivel, Niranchan; O'Grady, Greg; Tang, Shou-Jiang; Cheng, Leo K

2015-12-01

Gastric slow wave dysrhythmias are associated with motility disorders. Periods of tachygastria associated with slow wave re-entry were recently recognized as one important dysrhythmia mechanism, but factors promoting and sustaining gastric re-entry are currently unknown. This study reports two experimental forms of gastric re-entry and presents a series of multi-scale models that define criteria for slow wave re-entry initiation, maintenance and termination. High-resolution electrical mapping was conducted in porcine and canine models and two spatiotemporal patterns of re-entrant activities were captured: single-loop rotor and double-loop figure-of-eight. Two separate multi-scale mathematical models were developed to reproduce the velocity and entrainment frequency of these experimental recordings. A single-pulse stimulus was used to invoke a rotor re-entry in the porcine model and a figure-of-eight re-entry in the canine model. In both cases, the simulated re-entrant activities were found to be perpetuated by tachygastria that was accompanied by a reduction in the propagation velocity in the re-entrant pathways. The simulated re-entrant activities were terminated by a single-pulse stimulus targeted at the tip of re-entrant wave, after which normal antegrade propagation was restored by the underlying intrinsic frequency gradient. (i) the stability of re-entry is regulated by stimulus timing, intrinsic frequency gradient and conductivity; (ii) tachygastria due to re-entry increases the frequency gradient while showing decreased propagation velocity; (iii) re-entry may be effectively terminated by a targeted stimulus at the core, allowing the intrinsic slow wave conduction system to re-establish itself. © The authors 2014. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

A theoretical study of the initiation, maintenance and termination of gastric slow wave re-entry

PubMed Central

Du, Peng; Paskaranandavadivel, Niranchan; O’Grady, Greg; Tang, Shou-Jiang; Cheng, Leo K.

2015-01-01

Gastric slow wave dysrhythmias are associated with motility disorders. Periods of tachygastria associated with slow wave re-entry were recently recognized as one important dysrhythmia mechanism, but factors promoting and sustaining gastric re-entry are currently unknown. This study reports two experimental forms of gastric re-entry and presents a series of multi-scale models that define criteria for slow wave re-entry initiation, maintenance and termination. High-resolution electrical mapping was conducted in porcine and canine models and two spatiotemporal patterns of re-entrant activities were captured: single-loop rotor and double-loop figure-of-eight. Two separate multi-scale mathematical models were developed to reproduce the velocity and entrainment frequency of these experimental recordings. A single-pulse stimulus was used to invoke a rotor re-entry in the porcine model and a figure-of-eight re-entry in the canine model. In both cases, the simulated re-entrant activities were found to be perpetuated by tachygastria that was accompanied by a reduction in the propagation velocity in the re-entrant pathways. The simulated re-entrant activities were terminated by a single-pulse stimulus targeted at the tip of re-entrant wave, after which normal antegrade propagation was restored by the underlying intrinsic frequency gradient. Main findings: (i) the stability of re-entry is regulated by stimulus timing, intrinsic frequency gradient and conductivity; (ii) tachygastria due to re-entry increases the frequency gradient while showing decreased propagation velocity; (iii) re-entry may be effectively terminated by a targeted stimulus at the core, allowing the intrinsic slow wave conduction system to re-establish itself. PMID:25552487

Comparison of cryoablation with 3D mapping versus conventional mapping for the treatment of atrioventricular re-entrant tachycardia and right-sided paraseptal accessory pathways.

PubMed

Russo, Mario S; Drago, Fabrizio; Silvetti, Massimo S; Righi, Daniela; Di Mambro, Corrado; Placidi, Silvia; Prosperi, Monica; Ciani, Michele; Naso Onofrio, Maria T; Cannatà, Vittorio

2016-06-01

Aim Transcatheter cryoablation is a well-established technique for the treatment of atrioventricular nodal re-entry tachycardia and atrioventricular re-entry tachycardia in children. Fluoroscopy or three-dimensional mapping systems can be used to perform the ablation procedure. The aim of this study was to compare the success rate of cryoablation procedures for the treatment of right septal accessory pathways and atrioventricular nodal re-entry circuits in children using conventional or three-dimensional mapping and to evaluate whether three-dimensional mapping was associated with reduced patient radiation dose compared with traditional mapping. In 2013, 81 children underwent transcatheter cryoablation at our institution, using conventional mapping in 41 children - 32 atrioventricular nodal re-entry tachycardia and nine atrioventricular re-entry tachycardia - and three-dimensional mapping in 40 children - 24 atrioventricular nodal re-entry tachycardia and 16 atrioventricular re-entry tachycardia. Using conventional mapping, the overall success rate was 78.1 and 66.7% in patients with atrioventricular nodal re-entry tachycardia or atrioventricular re-entry tachycardia, respectively. Using three-dimensional mapping, the overall success rate was 91.6 and 75%, respectively (p=ns). The use of three-dimensional mapping was associated with a reduction in cumulative air kerma and cumulative air kerma-area product of 76.4 and 67.3%, respectively (p<0.05). The use of three-dimensional mapping compared with the conventional fluoroscopy-guided method for cryoablation of right septal accessory pathways and atrioventricular nodal re-entry circuits in children was associated with a significant reduction in patient radiation dose without an increase in success rate.

Relative potency estimates of acceptable residues and reentry intervals after nerve agent release

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watson, A.P.; Jones, T.D.; Adams, J.D.

1992-06-01

In the event of an unplanned release of a chemical warfare agent during any stage of the Chemical Stockpile Disposal Program, the potential exists for off-post contamination of drinking water, forage crops, grains, garden produce, and livestock. The more persistent agents, such as the organophosphate nerve agent VX, pose the greatest human health concern for reentry. A relative potency approach comparing the toxicity of VX to organophosphate insecticide analogues is developed and used to estimate allowable residues for VX in agricultural products and reentry intervals for public access to contaminated areas. Analysis of mammalian LD50 data by all exposure routesmore » indicates that VX is 10(3) to 10(4) times more toxic than most commercially available organophosphate insecticides. Thus, allowable residues of VX could be considered at concentration levels 10(3) to 10(4) lower than those established for certain insecticides by the U.S. EPA. Evaluation of reentry intervals developed for these organophosphate analogues indicate that, if environmental monitoring cannot reliably demonstrate acceptable levels of VX, restricted access to suspect or contaminated areas may be on the order of weeks to months following agent release. Planning for relocation, mass care centers, and quarantine should take this time period into account.« less

Orion Exploration Flight Test Post-Flight Inspection and Analysis

NASA Technical Reports Server (NTRS)

Miller, J. E.; Berger, E. L.; Bohl, W. E.; Christiansen, E. L.; Davis, B. A.; Deighton, K. D.; Enriquez, P. A.; Garcia, M. A.; Hyde, J. L.; Oliveras, O. M.

2017-01-01

The multipurpose crew vehicle, Orion, is being designed and built for NASA to handle the rigors of crew launch, sustainment and return from scientific missions beyond Earth orbit. In this role, the Orion vehicle is meant to operate in the space environments like the naturally occurring meteoroid and the artificial orbital debris environments (MMOD) with successful atmospheric reentry at the conclusion of the flight. As a result, Orion's reentry module uses durable porous, ceramic tiles on almost thirty square meters of exposed surfaces to accomplish both of these functions. These durable, non-ablative surfaces maintain their surface profile through atmospheric reentry; thus, they preserve any surface imperfections that occur prior to atmospheric reentry. Furthermore, Orion's launch abort system includes a shroud that protects the thermal protection system while awaiting launch and during ascent. The combination of these design features and a careful pre-flight inspection to identify any manufacturing imperfections results in a high confidence that damage to the thermal protection system identified post-flight is due to the in-flight solid particle environments. These favorable design features of Orion along with the unique flight profile of the first exploration flight test of Orion (EFT-1) have yielded solid particle environment measurements that have never been obtained before this flight.

Displacements of Metallic Thermal Protection System Panels During Reentry

NASA Technical Reports Server (NTRS)

Daryabeigi, Kamran; Blosser, Max L.; Wurster, Kathryn E.

2006-01-01

Bowing of metallic thermal protection systems for reentry of a previously proposed single-stage-to-orbit reusable launch vehicle was studied. The outer layer of current metallic thermal protection system concepts typically consists of a honeycomb panel made of a high temperature nickel alloy. During portions of reentry when the thermal protection system is exposed to rapidly varying heating rates, a significant temperature gradient develops across the honeycomb panel thickness, resulting in bowing of the honeycomb panel. The deformations of the honeycomb panel increase the roughness of the outer mold line of the vehicle, which could possibly result in premature boundary layer transition, resulting in significantly higher downstream heating rates. The aerothermal loads and parameters for three locations on the centerline of the windward side of this vehicle were calculated using an engineering code. The transient temperature distributions through a metallic thermal protection system were obtained using 1-D finite volume thermal analysis, and the resulting displacements of the thermal protection system were calculated. The maximum deflection of the thermal protection system throughout the reentry trajectory was 6.4 mm. The maximum ratio of deflection to boundary layer thickness was 0.032. Based on previously developed distributed roughness correlations, it was concluded that these defections will not result in tripping the hypersonic boundary layer.

Sonic boom measurement test plan for Space Shuttle STS-3 reentry

NASA Technical Reports Server (NTRS)

Henderson, H. R.

1982-01-01

The lateral area from the reentry ground track affected by sonic boom overpressure levels is determined. Four data acquisition stations are deployed laterally to the STS-3 reentry flight track. These stations provide six intermediate band FM channels of sonic boom data, universal time synchronization, and voice annotation. All measurements are correlated with the vehicle reentry flight track information along with atmospheric and vehicle operation conditions.

Teaching Composition to Re-Entry Students

ERIC Educational Resources Information Center

Foulkes, Natalie; Taines, Beatrice

1978-01-01

Describes the Women's Re-Entry Program at Diablo Valley College which uses structured teaching methods to alleviate the two principal weaknesses found in English compositions written by re-entry women, vagueness and lack of organization. (TP)

Dynamics of tether-assisted reentry vehicle systems

NASA Astrophysics Data System (ADS)

Zhu, Renzhang; Misra, A. K.; Lin, Huabao

The dynamics of tether-assisted reentry of a capsule is considered in this paper. A major advantage in tethered-assisted reentry is the ability to replace a retro-rocket by a tether. In this reentry procedure, a capsule is deployed down to a design altitude near the local vertical, and at an appropriate time the capsule is disconnected from the tether and enters into a reentry trajectory. In addition to static release, swing release is also considered in this paper. Three deployment schemes appropriate for swing release are considered. A two-stage accelerated-exponential/decelerated-exponential deployment appears to be the best of the three. In comparison with static release, for the same duration of return, this swing release can lead to about 22 percent reduction in tether length at the cost of an increase in tension in the tether by only 8 to 12 percent, and thus, it could decrease the tether mass launched into space. The paper analyzes the detailed dynamics of the tethered system before release as well as the reentry dynamics of the capsule after release along with the heat generated during reentry.

Techniques and Tools of NASA's Space Shuttle Columbia Accident Investigation

NASA Technical Reports Server (NTRS)

McDanels, Steve J.

2005-01-01

The Space Shuttle Columbia accident investigation was a fusion of many disciplines into a single effort. From the recovery and reconstruction of the debris, Figure 1, to the analysis, both destructive and nondestructive, of chemical and metallurgical samples, Figure 2, a multitude of analytical techniques and tools were employed. Destructive and non-destructive testing were utilized in tandem to determine if a breach in the left wing of the Orbiter had occurred, and if so, the path of the resultant high temperature plasma flow. Nondestructive analysis included topometric scanning, laser mapping, and real-time radiography. These techniques were useful in constructing a three dimensional virtual representation of the reconstruction project, specifically the left wing leading edge reinforced carbon/carbon heat protectant panels. Similarly, they were beneficial in determining where sampling should be performed on the debris. Analytic testing included such techniques as Energy Dispersive Electron Microprobe Analysis (EMPA), Electron Spectroscopy Chemical Analysis (ESCA), and X-Ray dot mapping; these techniques related the characteristics of intermetallics deposited on the leading edge of the left wing adjacent to the location of a suspected plasma breach during reentry. The methods and results of the various analyses, along with their implications into the accident, are discussed, along with the findings and recommendations of the Columbia Accident Investigation Board. Likewise, NASA's Return To Flight efforts are highlighted.

An Analysis of the Selected Materials Used in Step Measurements During Pre-Fits of Thermal Protection System Tiles and the Accuracy of Measurements Made Using These Selected Materials

NASA Technical Reports Server (NTRS)

Kranz, David William

2010-01-01

The goal of this research project was be to compare and contrast the selected materials used in step measurements during pre-fits of thermal protection system tiles and to compare and contrast the accuracy of measurements made using these selected materials. The reasoning for conducting this test was to obtain a clearer understanding to which of these materials may yield the highest accuracy rate of exacting measurements in comparison to the completed tile bond. These results in turn will be presented to United Space Alliance and Boeing North America for their own analysis and determination. Aerospace structures operate under extreme thermal environments. Hot external aerothermal environments in high Mach number flights lead to high structural temperatures. The differences between tile heights from one to another are very critical during these high Mach reentries. The Space Shuttle Thermal Protection System is a very delicate and highly calculated system. The thermal tiles on the ship are measured to within an accuracy of .001 of an inch. The accuracy of these tile measurements is critical to a successful reentry of an orbiter. This is why it is necessary to find the most accurate method for measuring the height of each tile in comparison to each of the other tiles. The test results indicated that there were indeed differences in the selected materials used in step measurements during prefits of Thermal Protection System Tiles and that Bees' Wax yielded a higher rate of accuracy when compared to the baseline test. In addition, testing for experience level in accuracy yielded no evidence of difference to be found. Lastly the use of the Trammel tool over the Shim Pack yielded variable difference for those tests.

The reentry catheter: a second chance for endoluminal reentry at difficult lower extremity subintimal arterial recanalizations.

PubMed

Etezadi, Vahid; Benenati, James F; Patel, Parag J; Patel, Rahul S; Powell, Alex; Katzen, Barry T

2010-05-01

From January 2005 to July 2008, a retrospective study was conducted at a single institution to investigate technical success of the use of a reentry device (Outback LTD reentry catheter) in aortoiliac and femoropopliteal artery recanalization in 34 patients (18 men; mean age +/- SD, 72 years +/- 11) in whom the conventional guide wires and catheters failed to reenter the true lumen. True lumen reentry was achieved in 87% (n = 23) and 91% (n = 11) of patients with femoropopliteal and aortoiliac occlusions, respectively. The overall technical success rate with the device was 88% (n = 34). The device success rate in Transatlantic Inter-Society Consensus II class D lesions was significantly lower than in lower lesion classes (71.4% vs 100%; P < .05). No procedure-related complications were encountered. In conclusion, the use of the reentry catheter enhances the likelihood of successful subintimal recanalization of chronic occlusions in femoropopliteal and aortoiliac arteries.

Gender Differences in the Perceived Needs and Barriers of Youth Offenders Preparing for Community Reentry

PubMed Central

Abrams, Laura S.

2010-01-01

This study explored how gender differences may influence the community reentry experiences of incarcerated youth. Structured surveys assessing risk factors for re-offending, perceived reentry needs, and anticipated barriers to meeting these needs were administered to a convenience sample of males (n = 36) and females (n = 35) who were within 60 days of release from two probation camps in Southern California. Bivariate analyses found significant gender differences in prior risk factors, educational aspirations, expressed mental health needs, anticipated use of services, and reentry concerns. Minimal gender differences were detected in perceived employment needs and barriers and self-efficacy to avoid recidivism. The findings support the need for gender-specific reentry programming in some key areas and also draw attention to the importance of removing barriers to successful reentry for all incarcerated youth. PMID:20730108

KSC-04PD-1234

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. United Space Alliance workers begin packing pieces of Columbia debris for shipment to The Aerospace Corporation in El Segundo, Calif. The pieces have been released for loan to the non-governmental agency for testing and research. The Aerospace Corporation requested and will receive graphite/epoxy honeycomb skins from an Orbital Maneuvering System pod, Main Propulsion System Helium tanks, a Reaction Control System Helium tank and a Power Reactant Storage Distribution system tank. The company will use the parts to study re-entry effects on composite materials. NASA notified the Columbia crews families about the loan before releasing the items for study. Researchers believe the testing will show how materials are expected to respond to various heating and loads' environments. The findings will help calibrate tools and models used to predict hazards to people and property from reentering hardware. The Aerospace Corporation will have the debris for one year to perform analyses to estimate maximum temperatures during reentry based upon the geometry and mass of the recovered composite. Columbias debris is stored in the VAB.

A two-state comparative implementation of peer-support intervention to link veterans to health-related services after incarceration: a study protocol.

PubMed

Simmons, Molly M; Fincke, Benjamin G; Drainoni, Mari-Lynn; Kim, Bo; Byrne, Tom; Smelson, David; Casey, Kevin; Ellison, Marsha L; Visher, Christy; Blue-Howells, Jessica; McInnes, D Keith

2017-09-12

Approximately 600,000 persons are released from prison annually in the United States. Relatively few receive sufficient re-entry services and are at risk for unemployment, homelessness, poverty, substance abuse relapse and recidivism. Persons leaving prison who have a mental illness and/or a substance use disorder are particularly challenged. This project aims to create a peer mentor program to extend the reach and effectiveness of reentry services provided by the Department of Veterans' Affairs (VA). We will implement a peer support for reentry veterans sequentially in two states. Our outcome measures are 1) fidelity of the intervention, 2) linkage to VA health care and, 3) continued engagement in health care. The aims for this project are as follows: (1) Conduct contextual analysis to identify VA and community reentry resources, and describe how reentry veterans use them. (2) Implement peer-support, in one state, to link reentry veterans to Veterans' Health Administration (VHA) primary care, mental health, and SUD services. (3) Port the peer-support intervention to another, geographically, and contextually different state. This intervention involves a 2-state sequential implementation study (Massachusetts, followed by Pennsylvania) using a Facilitation Implementation strategy. We will conduct formative and summative analyses, including assessment of fidelity, and a matched comparison group to evaluate the intervention's outcomes of veteran linkage and engagement in VHA health care (using health care utilization measures). The study proceeds in 3 phases. We anticipate that a peer support program will be effective at improving the reentry process for veterans, particularly in linking them to health, mental health, and SUD services and helping them to stay engaged in those services. It will fill a gap by providing veterans with access to a trusted individual, who understands their experience as a veteran and who has experienced justice involvement. The outputs from this project, including training materials, peer guidebooks, and implementation strategies can be adapted by other states and regions that wish to enhance services for veterans (or other populations) leaving incarceration. A larger cluster-randomized implementation-effectiveness study is planned. This protocol is registered with clinicaltrials.gov on November 4, 2016 and was assigned the number NCT02964897 .

Flight Performance of the Inflatable Reentry Vehicle Experiment 3

NASA Technical Reports Server (NTRS)

Dillman, Robert; DiNonno, John; Bodkin, Richard; Gsell, Valerie; Miller, Nathanael; Olds, Aaron; Bruce, Walter

2013-01-01

The Inflatable Reentry Vehicle Experiment 3 (IRVE-3) launched July 23, 2012, from NASA Wallops Flight Facility (WFF) on a Black Brant XI suborbital sounding rocket and successfully performed its mission, demonstrating the survivability of a hypersonic inflatable aerodynamic decelerator (HIAD) in the reentry heating environment and also illustrating the effect of an offset center of gravity on the HIAD's lift-to-drag ratio. IRVE-3 was a follow-on to 2009's IRVE-II mission, which demonstrated exo-atmospheric inflation, reentry survivability - without significant heating - and the aerodynamic stability of a HIAD down to subsonic flight conditions. NASA Langley Research Center is leading the development of HIAD technology for use on future interplanetary and Earth reentry missions.

Academic Continuity and School Reentry Support as a Standard of Care in Pediatric Oncology.

PubMed

Thompson, Amanda L; Christiansen, Heather L; Elam, Megan; Hoag, Jennifer; Irwin, Mary Kay; Pao, Maryland; Voll, Megan; Noll, Robert B; Kelly, Katherine Patterson

2015-12-01

Clinicians agree that return to school after diagnosis promotes the positive adjustment of children and adolescents with cancer; however, the school reentry process can present challenges. The aim of this review was to critically evaluate the literature on school reentry support for youth with cancer. Seventeen publications were identified. School reentry services were well-received by families and educators; increased teacher and peer knowledge about childhood cancer; influenced peer and educator attitudes toward the patient; and improved communication and collaboration between patients/families, school, and the healthcare team. Evidence supports a strong recommendation for school reentry support for youth with cancer. © 2015 Wiley Periodicals, Inc.

Re-entry and reintegration: returning home after combat.

PubMed

Doyle, Michael E; Peterson, Kris A

2005-01-01

Soldier life exists on a continuum of readiness for deployment. Re-entry and reintegration-the return home and reunion with family and community-key the success of the deployment cycle. In current and projected future operations, the Army and society will both bear the burden of this re-entry and re-integration. Programs and procedures in place work towards improving communication, mitigating distress and resolving crises during reentry and reintegration. Key elements include: inclusion of families and communities early into the planning for reentry and reintegration; normalization (non-medicalization of distress); easy access to behavioral health professionals; and education of families on resources and benefits. Through broad collaboration, maximal benefit to the Soldier, family members and society be realized.

A Concept of a Manned Satellite Reentry Which is Completed with a Glide Landing

NASA Technical Reports Server (NTRS)

Cheatham, Donald C. (Compiler)

1959-01-01

A concept for a manned satellite reentry from a near space orbit and a glide landing on a normal size airfield is presented. The reentry vehicle configuration suitable for this concept would employ a variable geometry feature in order that the reentry could be made at 90 deg. angle of attack and the landing could be made with a conventional glide approach. Calculated results for reentry at a flight-path angle of -1 deg. show that with an accuracy of 1 percent in the impulse of a retrorocket, the desired flight-path angle at reentry can be controlled within 0.02 deg. and the distance traveled to the reentry point, within 100 miles. The reentry point is arbitrarily defined as the point at which the satellite passes through an altitude of about 70 miles. Misalignment of the retrorocket by 10 deg. increased these errors by as much as 0.02 deg. and 500 miles. Intra-atmospheric trajectory calculations show that pure drag reentries starting with flight-path angles of -1 deg. or less produce a peak deceleration of 8g. Lift created by varying the angle of attack between 90 and 60 deg. is effective in decreasing the maximum deceleration and allows the range to the "recovery" point (where transition is made from reentry to gliding flight) to be increased by as much as 2,300 miles. A sideslip angle of 30 deg. allows lateral displacement of the flight path by as much as 60 deg. miles. Reaction controls would provide control-attitude alignment during the orbit phase. For the reentry phase this configuration should have low static longitudinal and roll stability in the 90 deg. angle-of-attack attitude. Control could be effected by leading-edge and trailing-edge flaps. Transition into the landing phase would be accomplished at an altitude of about 100,000 feet by unfolding the outer wing panels and pitching over to low angles of attack. Calculations indicate that glides can be made from the recovery point to airfields at ranges of from 150 to 200 miles, depending upon the orientation with respect to the original course.

EXPERT: An atmospheric re-entry test-bed

NASA Astrophysics Data System (ADS)

Massobrio, F.; Viotto, R.; Serpico, M.; Sansone, A.; Caporicci, M.; Muylaert, J.-M.

2007-06-01

In recognition of the importance of an independent European access to the International Space Station (ISS) and in preparation for the future needs of exploration missions, ESA is conducting parallel activities to generate flight data using atmospheric re-entry test-beds and to identify vehicle design solutions for human and cargo transportation vehicles serving the ISS and beyond. The EXPERT (European eXPErimental Re-entry Test-bed) vehicle represents the major on-going development in the first class of activities. Its results may also benefit in due time scientific missions to planets with an atmosphere and future reusable launcher programmes. The objective of EXPERT is to provide a test-bed for the validation of aerothermodynamics models, codes and ground test facilities in a representative flight environment, to improve the understanding of issues related to analysis, testing and extrapolation to flight. The vehicle will be launched on a sub-orbital trajectory using a Volna missile. The EXPERT concept is based on a symmetrical re-entry capsule whose shape is composed of simple geometrical elements. The suborbital trajectory will reach 120 km altitude and a re-entry velocity of 5 6km/s. The dimensions of the capsule are 1.6 m high and 1.3 m diameter; the overall mass is in the range of 250 350kg, depending upon the mission parameters and the payload/instrumentation complement. A consistent number of scientific experiments are foreseen on-board, from innovative air data system to shock wave/boundary layer interaction, from sharp hot structures characterisation to natural and induced regime transition. Currently the project is approaching completion of the phase B, with Alenia Spazio leading the industrial team and CIRA coordinating the scientific payload development under ESA contract.

Singular perturbation analysis of AOTV-related trajectory optimization problems

NASA Technical Reports Server (NTRS)

Calise, Anthony J.; Bae, Gyoung H.

1990-01-01

The problem of real time guidance and optimal control of Aeroassisted Orbit Transfer Vehicles (AOTV's) was addressed using singular perturbation theory as an underlying method of analysis. Trajectories were optimized with the objective of minimum energy expenditure in the atmospheric phase of the maneuver. Two major problem areas were addressed: optimal reentry, and synergetic plane change with aeroglide. For the reentry problem, several reduced order models were analyzed with the objective of optimal changes in heading with minimum energy loss. It was demonstrated that a further model order reduction to a single state model is possible through the application of singular perturbation theory. The optimal solution for the reduced problem defines an optimal altitude profile dependent on the current energy level of the vehicle. A separate boundary layer analysis is used to account for altitude and flight path angle dynamics, and to obtain lift and bank angle control solutions. By considering alternative approximations to solve the boundary layer problem, three guidance laws were derived, each having an analytic feedback form. The guidance laws were evaluated using a Maneuvering Reentry Research Vehicle model and all three laws were found to be near optimal. For the problem of synergetic plane change with aeroglide, a difficult terminal boundary layer control problem arises which to date is found to be analytically intractable. Thus a predictive/corrective solution was developed to satisfy the terminal constraints on altitude and flight path angle. A composite guidance solution was obtained by combining the optimal reentry solution with the predictive/corrective guidance method. Numerical comparisons with the corresponding optimal trajectory solutions show that the resulting performance is very close to optimal. An attempt was made to obtain numerically optimized trajectories for the case where heating rate is constrained. A first order state variable inequality constraint was imposed on the full order AOTV point mass equations of motion, using a simple aerodynamic heating rate model.

Flutter Analysis of the Shuttle Tile Overlay Repair Concept

NASA Technical Reports Server (NTRS)

Bey, Kim S.; Scott, Robert C.; Bartels, Robert E.; Waters, William A.; Chen, Roger

2007-01-01

The Space Shuttle tile overlay repair concept, developed at the NASA Johnson Space Center, is designed for on-orbit installation over an area of damaged tile to permit safe re-entry. The thin flexible plate is placed over the damaged area and secured to tile at discreet points around its perimeter. A series of flutter analyses were performed to determine if the onset of flutter met the required safety margins. Normal vibration modes of the panel, obtained from a simplified structural analysis of the installed concept, were combined with a series of aerodynamic analyses of increasing levels of fidelity in terms of modeling the flow physics to determine the onset of flutter. Results from these analyses indicate that it is unlikely that the overlay installed at body point 1800 will flutter during re-entry.

Targeting of cytosolic phospholipase A2α impedes cell cycle re-entry of quiescent prostate cancer cells.

PubMed

Yao, Mu; Xie, Chanlu; Kiang, Mei-Yee; Teng, Ying; Harman, David; Tiffen, Jessamy; Wang, Qian; Sved, Paul; Bao, Shisan; Witting, Paul; Holst, Jeff; Dong, Qihan

2015-10-27

Cell cycle re-entry of quiescent cancer cells has been proposed to be involved in cancer progression and recurrence. Cytosolic phospholipase A2α (cPLA2α) is an enzyme that hydrolyzes membrane glycerophospholipids to release arachidonic acid and lysophospholipids that are implicated in cancer cell proliferation. The aim of this study was to determine the role of cPLA2α in cell cycle re-entry of quiescent prostate cancer cells. When PC-3 and LNCaP cells were rendered to a quiescent state, the active form of cPLA2α with a phosphorylation at Ser505 was lower compared to their proliferating state. Conversely, the phospho-cPLA2α levels were resurgent during the induction of cell cycle re-entry. Pharmacological inhibition of cPLA2α with Efipladib upon induction of cell cycle re-entry inhibited the re-entry process, as manifested by refrained DNA synthesis, persistent high proportion of cells in G0/G1 and low percentage of cells in S and G2/M phases, together with a stagnant recovery of Ki-67 expression. Simultaneously, Efipladib prohibited the emergence of Skp2 while maintained p27 at a high level in the nuclear compartment during cell cycle re-entry. Inhibition of cPLA2α also prevented an accumulation of cyclin D1/CDK4, cyclin E/CDK2, phospho-pRb, pre-replicative complex proteins CDC6, MCM7, ORC6 and DNA synthesis-related protein PCNA during induction of cell cycle re-entry. Moreover, a pre-treatment of the prostate cancer cells with Efipladib during induction of cell cycle re-entry subsequently compromised their tumorigenic capacity in vivo. Hence, cPLA2α plays an important role in cell cycle re-entry by quiescent prostate cancer cells.

Canal switch and re-entry phenomenon in benign paroxysmal positional vertigo: difference between immediate and delayed occurrence.

PubMed

Dispenza, F; DE Stefano, A; Costantino, C; Rando, D; Giglione, M; Stagno, R; Bennici, E

2015-04-01

This prospective study was designed to evaluate the differences between immediate and delayed canal re-entry of otoliths after therapeutic manoeuvres in patients with benign paroxysmal positional vertigo (BPPV). A total of 196 patients with BPPV were visited and 127 matched our inclusion criteria. The mean age was 54.74 years. The horizontal semicircular canal (HSC) was involved in 30 cases and the posterior semicircular canal (PSC) in 97 patients. Patients with hearing loss in the ear affected by BPPV have a more recurrent form, compared to those with normal hearing. An immediate canal re-entry was recorded in 3 patients with HSC BPPV, all with geotropic nystagmus. In 7 patients with PSC BPPV, the immediate canal re-entry was detected and the delayed form was noted in 5 patients. The patients with the delayed canal re-entry underwent more than 2 previous manoeuvres. The canal re-entry was not related to the manoeuvre performed. The timing of the Dix-Hallpike test to verify the resolution of the BPPV had a significant role in immediate canal re-entry. A recurrence in the follow-up at least one month after treatment was recorded in 20 patients and was more frequent in patients that had canal re-entry. The canal re-entry or canal switch is a clinical entity that should be kept in mind of the neurotologist when approaching BPPV patients. It is important to distinguish it from recurrence when delayed and from manoeuvre failure when immediate. The timing of manoeuvre performing, in particular the final verification test after therapeutic sessions, is important to prevent the immediate reflux of particles into canals.

Multiple Re-entry Closures After TEVAR for Ruptured Chronic Post-dissection Thoraco-abdominal Aortic Aneurysm.

PubMed

Kinoshita, R; Ganaha, F; Ito, J; Ohyama, N; Abe, N; Yamazato, T; Munakata, H; Mabuni, K; Kugai, T

2018-01-01

Although thoracic endovascular aortic repair (TEVAR) has become a promising treatment for complicated acute type B dissection, its role in treating chronic post-dissection thoraco-abdominal aortic aneurysm (TAA) is still limited owing to persistent retrograde flow into the false lumen (FL) through abdominal or iliac re-entry tears. A case of chronic post-dissection TAA treatment, in which a dilated descending FL ruptured into the left thorax, is described. The primary entry tear was closed by emergency TEVAR and multiple abdominal re-entries were closed by EVAR. In addition, major re-entries at the detached right renal artery and iliac bifurcation were closed using covered stents. To close re-entries as far as possible, EVAR was carried out using the chimney technique, and additional aortic extenders were placed above the coeliac artery. A few re-entries remained, but complete FL thrombosis of the rupture site was achieved. Follow-up computed tomography showed significant shrinkage of the FL. In treating post-dissection TAA, entry closure by TEVAR is sometimes insufficient, owing to persistent retrograde flow into the FL from abdominal or iliac re-entries. Adjunctive techniques are needed to close these distal re-entries to obtain complete FL exclusion, especially in rupture cases. Recently, encouraging results of complete coverage of the thoraco-abdominal aorta with fenestrated or branched endografts have been reported; however, the widespread employment of such techniques appears to be limited owing to technical difficulties. The present method with multiple re-entry closures using off the shelf and immediately available devices is an alternative for the endovascular treatment of post-dissection TAA, especially in the emergency setting.

Factors associated with a second deferral among donors eligible for re-entry after a false-positive screening test for syphilis, HCV, HBV and HIV.

PubMed

Grégoire, Y; Germain, M; Delage, G

2018-05-01

Since 25 May 2010, all donors at our blood centre who tested false-positive for HIV, HBV, HCV or syphilis are eligible for re-entry after further testing. Donors who have a second false-positive screening test, either during qualification for or after re-entry, are deferred for life. This study reports on factors associated with the occurrence of such deferrals. Rates of second false-positive results were compared by year of deferral, transmissible disease marker, gender, age, donor status (new or repeat) and testing platform (same or different) both at qualification for re-entry and afterwards. Chi-square tests were used to compare proportions. Cox regression was used for multivariate analyses. Participation rates in the re-entry programme were 42·1%: 25·6% failed to qualify for re-entry [different platform: 2·7%; same platform: 42·9% (P < 0·0001)]. After re-entry, rates of deferral for second false-positive results were 8·4% after 3 years [different platform: 1·8%; same platform: 21·4% (P < 0·0001)]. Deferral rates were higher for HIV and HCV than for HBV at qualification when tested on the same platform. The risk, when analysed by multivariate analyses, of a second deferral for a false-positive result, both at qualification and 3 years after re-entry, was lower for donors deferred on a different platform; this risk was higher for HIV, HCV and syphilis than for HBV and for new donors if tested on the same platform. Re-entry is more often successful when donors are tested on a testing platform different from the one on which they obtained their first false-positive result. © 2018 International Society of Blood Transfusion.

Cardiac re-entry dynamics and self-termination in DT-MRI based model of Human Foetal Heart

NASA Astrophysics Data System (ADS)

Biktasheva, Irina V.; Anderson, Richard A.; Holden, Arun V.; Pervolaraki, Eleftheria; Wen, Fen Cai

2018-02-01

The effect of human foetal heart geometry and anisotropy on anatomy induced drift and self-termination of cardiac re-entry is studied here in MRI based 2D slice and 3D whole heart computer simulations. Isotropic and anisotropic models of 20 weeks of gestational age human foetal heart obtained from 100μm voxel diffusion tensor MRI data sets were used in the computer simulations. The fiber orientation angles of the heart were obtained from the orientation of the DT-MRI primary eigenvectors. In a spatially homogeneous electrophysiological monodomain model with the DT-MRI based heart geometries, cardiac re-entry was initiated at a prescribed location in a 2D slice, and in the 3D whole heart anatomy models. Excitation was described by simplified FitzHugh-Nagumo kinetics. In a slice of the heart, with propagation velocity twice as fast along the fibres than across the fibers, DT-MRI based fiber anisotropy changes the re-entry dynamics from pinned to an anatomical re-entry. In the 3D whole heart models, the fiber anisotropy changes cardiac re-entry dynamics from a persistent re-entry to the re-entry self-termination. The self-termination time depends on the re-entry’s initial position. In all the simulations with the DT-MRI based cardiac geometry, the anisotropy of the myocardial tissue shortens the time to re-entry self-termination several folds. The numerical simulations depend on the validity of the DT-MRI data set used. The ventricular wall showed the characteristic transmural rotation of the helix angle of the developed mammalian heart, while the fiber orientation in the atria was irregular.

Reentry Hazard Analysis Handbook

DOT National Transportation Integrated Search

2005-01-28

The Aerospace Corporation was tasked by the Volpe National Transportation Systems Center provide technical support to the Federal Aviation Administration, Office of Commercial Space Transportation (FAA/AST), in developing acceptable methods of evalua...

ATV reentry

NASA Image and Video Library

2012-10-03

ISS033-E-009232 (3 Oct. 2012) --- This still photo taken by the Expedition 33 crew members aboard the International Space Station shows evidence of the fiery plunge through Earth?s atmosphere and the destructive re-entry of the European Automated Transfer Vehicle-3 (ATV-3) spacecraft, also known as ?Edoardo Amaldi.? The end of the ATV took place over a remote swath of the Pacific Ocean where any surviving debris safely splashed down a short time later, at around 1:30 a.m. (GMT) on Oct. 3, thus concluding the highly successful ATV-3 mission. Aboard the craft during re-entry was the Re Entry Breakup Recorder (REBR), a spacecraft ?black box? designed to gather data on vehicle disintegration during re-entry in order to improve future spacecraft re-entry models.

Study and Development of a Sub-Orbital Re-Entry Demonstrator

NASA Astrophysics Data System (ADS)

Savino, R.

The Italian and European Space Agencies are supporting a research programme, developed in Campania region by a cluster of industries, research institutes and universities, on a low-cost re-entry capsule, able to return payloads from the ISS to Earth and/or to perform short-duration scientific missions in Low Earth Orbit (LEO). The ballistic capsule is characterized by a deployable, disposable "umbrella-like" heat shield that allows relatively small dimensions at launch and a sufficient exposed surface area in re-entry conditions, reducing the ballistic coefficient and leading to acceptable heat fluxes, mechanical loads and final descent velocity. ESA is supporting a preliminary study to develop a flight demonstrator of the capsule to be embarked as a secondary payload onboard a sub-orbital sounding rocket. The deployable thermal protection system concept may be applied to future science and robotic exploration mission requiring planetary entry and, possibly also to missions in the framework of Human Space flight, requiring planetary entry or re-entry. The technology offers also an interesting potential for aerobraking, aerocapture and for de-orbiting. This paper summarizes the results of these activities, which are being more and more refined as the work proceeds, including the definition and analysis of the mission scenario, the aerodynamic, aerothermodynamic, mechanical and structural analyses and the technical definition of avionics, instrumentation and main subsystems.

Systematic review of qualitative evaluations of reentry programs addressing problematic drug use and mental health disorders amongst people transitioning from prison to communities.

PubMed

Kendall, Sacha; Redshaw, Sarah; Ward, Stephen; Wayland, Sarah; Sullivan, Elizabeth

2018-03-02

The paper presents a systematic review and metasynthesis of findings from qualitative evaluations of community reentry programs. The programs sought to engage recently released adult prison inmates with either problematic drug use or a mental health disorder. Seven biomedical and social science databases, Cinahl, Pubmed, Scopus, Proquest, Medline, Sociological abstracts and Web of Science and publisher database Taylor and Francis were searched in 2016 resulting in 2373 potential papers. Abstract reviews left 140 papers of which 8 were included after detailed review. Major themes and subthemes were identified through grounded theory inductive analysis of results from the eight papers. Of the final eight papers the majority (6) were from the United States. In total, the papers covered 405 interviews and included 121 (30%) females and 284 (70%) males. Findings suggest that the interpersonal skills of case workers; access to social support and housing; and continuity of case worker relationships throughout the pre-release and post-release period are key social and structural factors in program success. Evaluation of community reentry programs requires qualitative data to contextualize statistical findings and identify social and structural factors that impact on reducing incarceration and improving participant health. These aspects of program efficacy have implications for reentry program development and staff training and broader social and health policy and services.

Trajectory Design and Control for the Compton Gamma Ray Observatory Re-Entry

NASA Technical Reports Server (NTRS)

Hoge, Susan; Vaughn, Frank; Bauer, Frank H. (Technical Monitor)

2000-01-01

The Compton Gamma Ray Observatory (CGRO) controlled re-entry operation was successfully conducted in June of 2000. The surviving parts of the spacecraft landed in the Pacific Ocean within the predicted footprint. The design of the maneuvers to control the trajectory to accomplish this re-entry presented several challenges. These challenges included timing and duration of the maneuvers, fuel management, post maneuver position knowledge, collision avoidance with other spacecraft, accounting for the break-up of the spacecraft into several pieces with a wide range of ballistic coefficients, and ensuring that the impact footprint would remain within the desired landing area in the event of contingencies. This paper presents the initial re-entry trajectory design and the evolution of the design into the maneuver sequence used for the re-entry. The paper discusses the constraints on the trajectory design, the modifications made to the initial design and the reasons behind these modifications. Data from the re-entry operation are presented.

Trajectory Design and Control for the Compton Gamma Ray Observatory Re-Entry

NASA Technical Reports Server (NTRS)

Hoge, Susan; Vaughn, Frank J., Jr.

2001-01-01

The Compton Gamma Ray Observatory (CGRO) controlled re-entry operation was successfully conducted in June of 2000. The surviving parts of the spacecraft landed in the Pacific Ocean within the nominal impact target zone. The design of the maneuvers to control the trajectory to accomplish this re-entry presented several challenges. These challenges included the timing and duration of the maneuvers, propellant management, post-maneuver state determination, collision avoidance with other spacecraft, accounting for the break-up of the spacecraft into several pieces with a wide range of ballistic coefficients, and ensuring that the impact footprint would remain within the desired impact target zone in the event of contingencies. This paper presents the initial re-entry trajectory design and traces the evolution of that design into the maneuver sequence used for the re-entry. The paper also discusses the spacecraft systems and operational constraints imposed on the trajectory design and the required modifications to the initial design based on those constraints. Data from the reentry operation are also presented.

Wetlab-2 - Quantitative PCR Tools for Spaceflight Studies of Gene Expression Aboard the International Space Station

NASA Technical Reports Server (NTRS)

Schonfeld, Julie E.

2015-01-01

Wetlab-2 is a research platform for conducting real-time quantitative gene expression analysis aboard the International Space Station. The system enables spaceflight genomic studies involving a wide variety of biospecimen types in the unique microgravity environment of space. Currently, gene expression analyses of space flown biospecimens must be conducted post flight after living cultures or frozen or chemically fixed samples are returned to Earth from the space station. Post-flight analysis is limited for several reasons. First, changes in gene expression can be transient, changing over a timescale of minutes. The delay between sampling on Earth can range from days to months, and RNA may degrade during this period of time, even in fixed or frozen samples. Second, living organisms that return to Earth may quickly re-adapt to terrestrial conditions. Third, forces exerted on samples during reentry and return to Earth may affect results. Lastly, follow up experiments designed in response to post-flight results must wait for a new flight opportunity to be tested.

Foster care re-entry: Exploring the role of foster care characteristics, in-home child welfare services and cross-sector services.

PubMed

Lee, Sangmoo; Jonson-Reid, Melissa; Drake, Brett

2012-09-01

This study seeks to advance our understanding of how modifiable and non-modifiable factors may impact the likelihood of re-entry into foster care. Children who entered foster care for the first time following at least one report of maltreatment and were then reunified were followed from exit to re-entry, age 18 or the end of the study period using longitudinal administrative data. Risk of re-entry was explored according to a range of modifiable and non-modifiable case and service characteristics. Children removed from homes with parents who had multiple risk factors (e.g., no high school diploma, mental health diagnosis, criminal record, or teen parents) or were receiving AFDC prior to entry were more likely to re-enter. The receipt of in-home child welfare services during or after foster care was associated with reduced risk of re-entry. Having the longest placement with a relative was associated with decreased risk of re-entry. In conclusion, both modifiable and non-modifiable factors are associated with re-entry into foster care. Among modifiable factors, services appear to have a particularly strong relationship to re-entry. Our data also suggest that in-home child welfare services provided during and after foster care may be associated with improved long-term permanency after return home. Given the continued import of caregiver risk factors even among reunified families, services provided to support reunification should include attention to caregiver needs outside parenting.

Evaluation and Influence of Brachiocephalic Branch Re-entry in Patients With Type A Acute Aortic Dissection.

PubMed

Yasuda, Shota; Imoto, Kiyotaka; Uchida, Keiji; Karube, Norihisa; Minami, Tomoyuki; Goda, Motohiko; Suzuki, Shinichi; Masuda, Munetaka

2016-12-22

Stanford type A acute aortic dissection (A-AAD) extends to the brachiocephalic branches in some patients. After ascending aortic replacement, a remaining re-entry tear in the distal brachiocephalic branches may act as an entry and result in a patent false lumen in the aortic arch. However, the effect of brachiocephalic branch re-entry concomitant with A-AAD remains unknown.Methods and Results:Eighty-five patients with A-AAD who underwent ascending aortic replacement in which both preoperative and postoperative multiple-detector computed tomography (MDCT) scans could be evaluated were retrospectively studied. The presence of a patent false lumen in at least one of the brachiocephalic branches on preoperative MDCT was defined as brachiocephalic branch re-entry, and 41 patients (48%) had this. Postoperatively, 47 of 85 (55%) patients had a patent false lumen in the aortic arch. False lumen remained patent after operation in 34 out of the 41 (83%) patients with brachiocephalic branch re-entry, as compared to that in 13 of the 44 (30%) patients without such re-entry (P<0.001). Brachiocephalic branch re-entry was a significant risk factor for a late increase in the aortic arch diameter greater than 10 mm (P=0.047). Brachiocephalic branch re-entry in patients with A-AAD is related to a patent false lumen in the aortic arch early after ascending aortic replacement and is a risk factor for late aortic arch enlargement.

Predictors of re-entry into the child protection system in Singapore: a cumulative ecological-transactional risk model.

PubMed

Li, Dongdong; Chu, Chi Meng; Ng, Wei Chern; Leong, Wai

2014-11-01

This study examines the risk factors of re-entry for 1,750 child protection cases in Singapore using a cumulative ecological-transactional risk model. Using administrative data, the present study found that the overall percentage of Child Protection Service (CPS) re-entry in Singapore is 10.5% based on 1,750 cases, with a range from 3.9% (within 1 year) to 16.5% (within 8 years after case closure). One quarter of the re-entry cases were observed to occur within 9 months from case closure. Seventeen risk factors, as identified from the extant literature, were tested for their utility to predict CPS re-entry in this study using a series of Cox regression analyses. A final list of seven risk factors (i.e., children's age at entry, case type, case closure result, duration of case, household income, family size, and mother's employment status) was used to create a cumulative risk score. The results supported the cumulative risk model in that higher risk score is related to higher risk of CPS re-entry. Understanding the prevalence of CPS re-entry and the risk factors associated with re-entry is the key to informing practice and policy in a culturally relevant way. The results from this study could then be used to facilitate critical case management decisions in order to enhance positive outcomes of families and children in Singapore's care system. Copyright © 2014 Elsevier Ltd. All rights reserved.

Foster care re-entry: Exploring the role of foster care characteristics, in-home child welfare services and cross-sector services☆

PubMed Central

Lee, Sangmoo; Jonson-Reid, Melissa; Drake, Brett

2013-01-01

This study seeks to advance our understanding of how modifiable and non-modifiable factors may impact the likelihood of re-entry into foster care. Children who entered foster care for the first time following at least one report of maltreatment and were then reunified were followed from exit to re-entry, age 18 or the end of the study period using longitudinal administrative data. Risk of re-entry was explored according to a range of modifiable and non-modifiable case and service characteristics. Children removed from homes with parents who had multiple risk factors (e.g., no high school diploma, mental health diagnosis, criminal record, or teen parents) or were receiving AFDC prior to entry were more likely to re-enter. The receipt of in-home child welfare services during or after foster care was associated with reduced risk of re-entry. Having the longest placement with a relative was associated with decreased risk of re-entry. In conclusion, both modifiable and non-modifiable factors are associated with re-entry into foster care. Among modifiable factors, services appear to have a particularly strong relationship to re-entry. Our data also suggest that in-home child welfare services provided during and after foster care may be associated with improved long-term permanency after return home. Given the continued import of caregiver risk factors even among reunified families, services provided to support reunification should include attention to caregiver needs outside parenting. PMID:23729947

14 CFR 435.7 - Payload reentry determination.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Payload reentry determination. 435.7 Section 435.7 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION... transport a payload to Earth on a reentry vehicle unless the proposed payload is exempt from payload review...

14 CFR 431.57 - Information requirements for payload reentry review.

Code of Federal Regulations, 2011 CFR

2011-01-01

... AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH... payload reentry review; (d) Type, amount, and container of hazardous materials, as defined in § 401.5 of this chapter, and radioactive materials in the payload; (e) Explosive potential of payload materials...

14 CFR 431.57 - Information requirements for payload reentry review.

Code of Federal Regulations, 2014 CFR

2014-01-01

... AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH... payload reentry review; (d) Type, amount, and container of hazardous materials, as defined in § 401.5 of this chapter, and radioactive materials in the payload; (e) Explosive potential of payload materials...

14 CFR 431.57 - Information requirements for payload reentry review.

Code of Federal Regulations, 2013 CFR

2013-01-01

... AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH... payload reentry review; (d) Type, amount, and container of hazardous materials, as defined in § 401.5 of this chapter, and radioactive materials in the payload; (e) Explosive potential of payload materials...

14 CFR 431.57 - Information requirements for payload reentry review.

Code of Federal Regulations, 2012 CFR

2012-01-01

... AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH... payload reentry review; (d) Type, amount, and container of hazardous materials, as defined in § 401.5 of this chapter, and radioactive materials in the payload; (e) Explosive potential of payload materials...

Limitations of the Outback LTD re-entry device in femoropopliteal chronic total occlusions.

PubMed

Shin, Susanna H; Baril, Donald; Chaer, Rabih; Rhee, Robert; Makaroun, Michel; Marone, Luke

2011-05-01

Subintimal recanalization for the treatment of femoropopliteal chronic total occlusions (CTO) occasionally requires re-entry devices to access the true lumen distally, but limited information is available on factors predicting the success or failure of these devices. We evaluated the Outback LTD re-entry device (LuMend, Redwood City, Calif; acquired by Cordis Corp, Miami Lakes, Fla). A retrospective review of patients with femoropopliteal CTO from August 2006 to August 2009 was performed. Age, gender, occlusion length, site of re-entry, and the angle of the aortic bifurcation were recorded. Procedural angiograms were used to assign a calcification score (none, mild, moderate, severe) at the re-entry site. Univariate and multivariate logistic regression analyses were used to identify factors predicting failure of re-entry into the true lumen. Of 249 CTOs treated, the re-entry device was used 52 times (20.9%): 47 superficial femoral artery (SFA) occlusions and 5 combined SFA and popliteal artery occlusions (33 TransAtlantic InterSociety Consensus II type C and 18 type D lesions). Of 48 procedures with available angiograms for review, the target re-entry site was at the adductor canal in 30 (62.5%), the above-knee popliteal artery in 13 (27.1%), behind the knee joint in 4 (8.3%), and the mid-SFA in 2 (4.2%). Patients (54% men) were a mean age of 73.1 years. Re-entry was successful in 34 attempts (64.5%). Causes of failure included inability to re-enter the true lumen in 11 (61.1%), difficulty tracking the device over a wire in 3 (16.7%), acute angle of aortic bifurcation in 2 (11.1%), mechanical failure of the device in 1 (5.6%), and difficulty tracking the device through the lesion in 1 (5.6%). Moderate or severe calcification at the site of re-entry was the only significant predictor of failure (odds ratio, 6.3; 95% confidence interval, 1.45-24.48; P = .01). An aortic bifurcation angle ≥40° did trend toward predicting success (odds ratio, 0.23; 95% confidence interval, 0.05-1.02; P = .054). Although the Outback re-entry device can be successful in extending the applicability of endovascular management to difficult femoropopliteal occlusions, it is not uniformly successful in current clinical practice. Significant calcification at the proposed re-entry site is a strong predictor of failure. Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Investigation of plasma-surface interaction effects on pulsed electrostatic manipulation for reentry blackout alleviation

NASA Astrophysics Data System (ADS)

Krishnamoorthy, S.; Close, S.

2017-03-01

The reentry blackout phenomenon affects most spacecraft entering a dense planetary atmosphere from space, due to the presence of a plasma layer that surrounds the spacecraft. This plasma layer is created by ionization of ambient air due to shock and frictional heating, and in some cases is further enhanced due to contamination by ablation products. This layer causes a strong attenuation of incoming and outgoing electromagnetic waves including those used for command and control, communication and telemetry over a period referred to as the ‘blackout period’. The blackout period may last up to several minutes and is a major contributor to the landing error ellipse at best, and a serious safety hazard in the worst case, especially in the context of human spaceflight. In this work, we present a possible method for alleviation of reentry blackout using electronegative DC pulses applied from insulated electrodes on the reentry vehicle’s surface. We study the reentry plasma’s interaction with a DC pulse using a particle-in-cell (PIC) model. Detailed models of plasma-insulator interaction are included in our simulations. The absorption and scattering of ions and electrons at the plasma-dielectric interface are taken into account. Secondary emission from the insulating surface is also considered, and its implications on various design issues is studied. Furthermore, we explore the effect of changing the applied voltage and the impact of surface physics on the creation and stabilization of communication windows. The primary aim of this analysis is to examine the possibility of restoring L- and S-band communication from the spacecraft to a ground station. Our results provide insight into the effect of key design variables on the response of the plasma to the applied voltage pulse. Simulations show the creation of pockets where electron density in the plasma layer is reduced three orders of magnitude or more in the vicinity of the electrodes. These pockets extend to distances up to three times the electrode length normal to the vehicle surface. Based on our results, we postulate that pulsed electrostatic manipulation (PEM) may be a viable candidate for reentry blackout alleviation in the future.

Computational Aspects of Heat Transfer in Structures

NASA Technical Reports Server (NTRS)

Adelman, H. M. (Compiler)

1982-01-01

Techniques for the computation of heat transfer and associated phenomena in complex structures are examined with an emphasis on reentry flight vehicle structures. Analysis methods, computer programs, thermal analysis of large space structures and high speed vehicles, and the impact of computer systems are addressed.

SHEFEX II Flight Instrumentation And Preparation Of Post Flight Analysis

NASA Astrophysics Data System (ADS)

Thiele, Thomas; Siebe, Frank; Gulhan, Ali

2011-05-01

A main disadvantage of modern TPS systems for re- entry vehicles is the expensive manufacturing and maintenance process due to the complex geometry of these blunt nose configurations. To reduce the costs and to improve the aerodynamic performance the German Aerospace Center (DLR) is following a different approach using TPS structures consisting of flat ceramic tiles. To test these new sharp edged TPS structures the SHEFEX I flight experiment was designed and successfully performed by DLR in 2005. To further improve the reliability of the sharp edged TPS design at even higher Mach numbers, a second flight experiment SHEFEX II will be performed in September 2011. In comparison to SHEFEX I the second flight experiment has a fully symmetrical shape and will reach a maximum Mach number of about 11. Furthermore the vehicle has an active steering system using four canards to control the flight attitude during re-entry, e.g. roll angle, angle of attack and sideslip. After a successful flight the evaluation of the flight data will be performed using a combination of numerical and experimental tools. The data will be used for the improvement of the present numerical analysis tools and to get a better understanding of the aerothermal behaviour of sharp TPS structures. This paper presents the flight instrumentation of the SHEFEX II TPS. In addition the concept of the post flight analysis is presented.

Reentry Works: The Implementation and Effectiveness of a Serious and Violent Offender Reentry Initiative

ERIC Educational Resources Information Center

Bouffard, Jeffrey A.; Bergeron, Lindsey E.

2006-01-01

Spurred by large increases in prison populations and other recent sentencing and correctional trends, the federal government has supported the development and implementation of Serious and Violent Offender Reentry Initiatives (SVORI) nationwide. While existing research demonstrates the effectiveness of the separate components of these programs…

Reentry Planning for Mentally Disordered Inmates: A Social Investment Perspective

ERIC Educational Resources Information Center

Wolff, Nancy; Bjerklie, J. R.; Maschi, Tina

2005-01-01

Correctional facilities are under increasing pressure to respond to the treatment needs of mentally disordered offenders during their incarceration and to arrange for treatment post release through reentry planning. This paper constructs cost estimates for three different reentry investments using data on the population (n = 2715) of male mentally…

Heat source reentry vehicle design study

NASA Technical Reports Server (NTRS)

Ryan, R. L.

1971-01-01

The design details are presented of a flight-type heat source reentry vehicle and heat exchanger compatible with the isotope Brayton power conversion system. The reference reentry vehicle and heat exchanger were modified, orbital and superorbital capability was assessed, and a complete set of detail design layout drawings were provided.

School Reentry for the Child with Chronic Illness.

ERIC Educational Resources Information Center

Sexson, Sandra B.; Madan-Swain, Avi

1993-01-01

This article focuses on the issues of reintegrating the chronically ill child into the school setting, the types of school problems encountered, the process of school reentry, (including a successful school reentry plan), and the implications for the school and the family of returning the chronically ill child to school. (DB)

Re-Entry: Managing Cross-Cultural Transitions.

ERIC Educational Resources Information Center

Adler, Nancy J.

1981-01-01

Studied the re-entry process of corporate and governmental employees (N=200) returning to Canada after working overseas. Research found re-entry into the original culture was a more difficult transition than moving to the foreign culture. Home-country managers tended to exhibit xenophobia in assessing the potential and actual effectiveness of…

Preparing International Students for the Re-Entry Transition.

ERIC Educational Resources Information Center

Arthur, Nancy

2003-01-01

Counselors play an integral role in assisting international students to manage cross-cultural transitions. Re-entry counseling can support international students to examine their transition experiences, provide education about re-entry, and help to develop anticipatory coping strategies. An example of a workshop is described as a method of…

Locking Nut with Stress-Distributing Insert

NASA Technical Reports Server (NTRS)

Daniels, Christopher C.

2010-01-01

Reusable holders have been devised for evaluating high-temperature, plasma-resistant re-entry materials, especially fabrics. Typical material samples tested support thermal-protection-system damage repair requiring evaluation prior to re-entry into terrestrial atmosphere. These tests allow evaluation of each material to withstand the most severe predicted re-entry conditions.

14 CFR 431.7 - Payload and payload reentry determinations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Payload and payload reentry determinations. 431.7 Section 431.7 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION... payload reentry determination is required to reenter a payload to Earth on an RLV unless the proposed...

76 FR 72236 - Agency Information Collection Activities: Requests for Comments; Clearance of Renewed Approval of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-22

..., FAA invites public comments about our intention to request the Office of Management and Budget (OMB... reentry vehicle, its operational capabilities, and its designated reentry site. DATES: Written comments... vehicle, its operational capabilities, and its designated reentry site. Respondents: Approximately 1...

Guiding Principles for Physician Reentry Programs

ERIC Educational Resources Information Center

Kenagy, Gretchen P.; Schneidman, Barbara S.; Barzansky, Barbara; Dalton, Claudette; Sirio, Carl A.; Skochelak, Susan E.

2011-01-01

Physician reentry is defined by the American Medical Association (AMA) as: "A return to clinical practice in the discipline in which one has been trained or certified following an extended period of clinical inactivity not resulting from discipline or impairment." Physician reentry programs are creating an avenue for physicians who have left…

Reentry Motion and Aerodynamics of the MUSES-C Sample Return Capsule

NASA Astrophysics Data System (ADS)

Ishii, Nobuaki; Yamada, Tetsuya; Hiraki, Koju; Inatani, Yoshifumi

The Hayabusa spacecraft (MUSES-C) carries a small capsule for bringing asteroid samples back to the earth. The initial spin rate of the reentry capsule together with the flight path angle of the reentry trajectory is a key parameter for the aerodynamic motion during the reentry flight. The initial spin rate is given by the spin-release mechanism attached between the capsule and the mother spacecraft, and the flight path angle can be modified by adjusting the earth approach orbit. To determine the desired values of both parameters, the attitude motion during atmospheric flight must be clarified, and angles of attack at the maximum dynamic pressure and the parachute deployment must be assessed. In previous studies, to characterize the aerodynamic effects of the reentry capsule, several wind-tunnel tests were conducted using the ISAS high-speed flow test facilities. In addition to the ground test data, the aerodynamic properties in hypersonic flows were analyzed numerically. Moreover, these data were made more accurate using the results of balloon drop tests. This paper summarized the aerodynamic properties of the reentry capsule and simulates the attitude motion of the full-configuration capsule during atmospheric flight in three dimensions with six degrees of freedom. The results show the best conditions for the initial spin rates and flight path angles of the reentry trajectory.

A Method for Semi-quantitative Assessment of Exposure to Pesticides of Applicators and Re-entry Workers: An Application in Three Farming Systems in Ethiopia.

PubMed

Negatu, Beyene; Vermeulen, Roel; Mekonnen, Yalemtshay; Kromhout, Hans

2016-07-01

To develop an inexpensive and easily adaptable semi-quantitative exposure assessment method to characterize exposure to pesticide in applicators and re-entry farmers and farm workers in Ethiopia. Two specific semi-quantitative exposure algorithms for pesticides applicators and re-entry workers were developed and applied to 601 farm workers employed in 3 distinctly different farming systems [small-scale irrigated, large-scale greenhouses (LSGH), and large-scale open (LSO)] in Ethiopia. The algorithm for applicators was based on exposure-modifying factors including application methods, farm layout (open or closed), pesticide mixing conditions, cleaning of spraying equipment, intensity of pesticide application per day, utilization of personal protective equipment (PPE), personal hygienic behavior, annual frequency of application, and duration of employment at the farm. The algorithm for re-entry work was based on an expert-based re-entry exposure intensity score, utilization of PPE, personal hygienic behavior, annual frequency of re-entry work, and duration of employment at the farm. The algorithms allowed estimation of daily, annual and cumulative lifetime exposure for applicators, and re-entry workers by farming system, by gender, and by age group. For all metrics, highest exposures occurred in LSGH for both applicators and female re-entry workers. For male re-entry workers, highest cumulative exposure occurred in LSO farms. Female re-entry workers appeared to be higher exposed on a daily or annual basis than male re-entry workers, but their cumulative exposures were similar due to the fact that on average males had longer tenure. Factors related to intensity of exposure (like application method and farm layout) were indicated as the main driving factors for estimated potential exposure. Use of personal protection, hygienic behavior, and duration of employment in surveyed farm workers contributed less to the contrast in exposure estimates. This study indicated that farmers' and farm workers' exposure to pesticides can be inexpensively characterized, ranked, and classified. Our method could be extended to assess exposure to specific active ingredients provided that detailed information on pesticides used is available. The resulting exposure estimates will consequently be used in occupational epidemiology studies in Ethiopia and other similar countries with few resources. © The Author 2016. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Structural Analysis and Testing of the Inflatable Re-entry Vehicle Experiment (IRVE)

NASA Technical Reports Server (NTRS)

Lindell, Michael C.; Hughes, Stephen J.; Dixon, Megan; Wiley, Cliff E.

2006-01-01

The Inflatable Re-entry Vehicle Experiment (IRVE) is a 3.0 meter, 60 degree half-angle sphere cone, inflatable aeroshell experiment designed to demonstrate various aspects of inflatable technology during Earth re-entry. IRVE will be launched on a Terrier-Improved Orion sounding rocket from NASA s Wallops Flight Facility in the fall of 2006 to an altitude of approximately 164 kilometers and re-enter the Earth s atmosphere. The experiment will demonstrate exo-atmospheric inflation, inflatable structure leak performance throughout the flight regime, structural integrity under aerodynamic pressure and associated deceleration loads, thermal protection system performance, and aerodynamic stability. Structural integrity and dynamic response of the inflatable will be monitored with photogrammetric measurements of the leeward side of the aeroshell during flight. Aerodynamic stability and drag performance will be verified with on-board inertial measurements and radar tracking from multiple ground radar stations. In addition to demonstrating inflatable technology, IRVE will help validate structural, aerothermal, and trajectory modeling and analysis techniques for the inflatable aeroshell system. This paper discusses the structural analysis and testing of the IRVE inflatable structure. Equations are presented for calculating fabric loads in sphere cone aeroshells, and finite element results are presented which validate the equations. Fabric material properties and testing are discussed along with aeroshell fabrication techniques. Stiffness and dynamics tests conducted on a small-scale development unit and a full-scale prototype unit are presented along with correlated finite element models to predict the in-flight fundamental mod

Hazard Analysis of Commercial Space Transportation: Volume 1: Operations. Volume 2: Hazards. Volume 3: Risk Analysis

DOT National Transportation Integrated Search

1988-05-01

The report is devoted to the review and discussion of generic hazards associated with the ground, launch, orbital and re-entry phases of space operations. Since the DOT Office of Commercial Space Transportation (OCST) has been charged with protecting...

It's Deja Vu All over Again: Using Multiple-Spell Discrete-Time Survival Analysis.

ERIC Educational Resources Information Center

Willett, John B.; Singer, Judith D.

1995-01-01

The multiple-spell discrete-time survival analysis method is introduced and illustrated using longitudinal data on exit from and reentry into the teaching profession. The method is applicable to many educational problems involving the sequential occurrence of disparate events or episodes. (SLD)

Vulnerability to re-entry in simulated two-dimensional cardiac tissue: effects of electrical restitution and stimulation sequence.

PubMed

Tran, Diana X; Yang, Ming-Jim; Weiss, James N; Garfinkel, Alan; Qu, Zhilin

2007-12-01

Ventricular fibrillation is a lethal arrhythmia characterized by multiple wavelets usually starting from a single or figure-of-eight re-entrant circuit. Understanding the factors regulating vulnerability to the re-entry is essential for developing effective therapeutic strategies to prevent ventricular fibrillation. In this study, we investigated how pre-existing tissue heterogeneities and electrical restitution properties affect the initiation of re-entry by premature extrastimuli in two-dimensional cardiac tissue models. We studied two pacing protocols for inducing re-entry following the "sinus" rhythm (S1) beat: (1) a single premature (S2) extrastimulus in heterogeneous tissue; (2) two premature extrastimuli (S2 and S3) in homogeneous tissue. In the first case, the vulnerable window of re-entry is determined by the spatial dimension and extent of the heterogeneity, and is also affected by electrical restitution properties and the location of the premature stimulus. The vulnerable window first increases as the action potential duration (APD) difference between the inside and outside of the heterogeneous region increases, but then decreases as this difference increases further. Steeper APD restitution reduces the vulnerable window of re-entry. In the second case, electrical restitution plays an essential role. When APD restitution is flat, no re-entry can be induced. When APD restitution is steep, re-entry can be induced by an S3 over a range of S1S2 intervals, which is also affected by conduction velocity restitution. When APD restitution is even steeper, the vulnerable window is reduced due to collision of the spiral tips.

Simulation of launch and re-entry acceleration profiles for testing of shuttle and unmanned microgravity research payloads

NASA Astrophysics Data System (ADS)

Cassanto, J. M.; Ziserman, H. I.; Chapman, D. K.; Korszun, Z. R.; Todd, P.

Microgravity experiments designed for execution in Get-Away Special canisters, Hitchhiker modules, and Reusable Re-entry Satellites will be subjected to launch and re-entry accelerations. Crew-dependent provisions for preventing acceleration damage to equipment or products will not be available for these payloads during flight; therefore, the effects of launch and re-entry accelerations on all aspects of such payloads must be evaluated prior to flight. A procedure was developed for conveniently simulating the launch and re-entry acceleration profiles of the Space Shuttle (3.3 and 1.7 × g maximum, respectively) and of two versions of NASA's proposed materials research Re-usable Re-entry Satellite (8 × g maximum in one case and 4 × g in the other). By using the 7 m centrifuge of the Gravitational Plant Physiology Laboratory in Philadelphia it was found possible to simulate the time dependence of these 5 different acceleration episodes for payload masses up to 59 kg. A commercial low-cost payload device, the “Materials Dispersion Apparatus” of Instrumentation Technology Associates was tested for (1) integrity of mechanical function, (2) retention of fluid in its compartments, and (3) integrity of products under simulated re-entry g-loads. In particular, the sharp rise from 1 g to maximum g-loading that occurs during re-entry in various unmanned vehicles was successfully simulated, conditions were established for reliable functioning of the MDA, and crystals of 5 proteins suspended in compartments filled with mother liquor were subjected to this acceleration load.

14 CFR 440.12 - Duration of coverage for licensed reentry; modifications.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Duration of coverage for licensed reentry; modifications. 440.12 Section 440.12 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION..., shall attach upon commencement of licensed reentry, and remain in full force and effect as follows: (1...

14 CFR 440.12 - Duration of coverage for licensed reentry; modifications.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Duration of coverage for licensed reentry; modifications. 440.12 Section 440.12 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION..., shall attach upon commencement of licensed reentry, and remain in full force and effect as follows: (1...

14 CFR 440.12 - Duration of coverage for licensed reentry; modifications.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Duration of coverage for licensed reentry; modifications. 440.12 Section 440.12 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION..., shall attach upon commencement of licensed reentry, and remain in full force and effect as follows: (1...

14 CFR 440.12 - Duration of coverage for licensed reentry; modifications.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Duration of coverage for licensed reentry; modifications. 440.12 Section 440.12 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION..., shall attach upon commencement of licensed reentry, and remain in full force and effect as follows: (1...

14 CFR 440.12 - Duration of coverage for licensed reentry; modifications.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Duration of coverage for licensed reentry; modifications. 440.12 Section 440.12 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION..., shall attach upon commencement of licensed reentry, and remain in full force and effect as follows: (1...

Recidivism among Participants of a Reentry Program for Prisoners Released without Supervision

ERIC Educational Resources Information Center

Wikoff, Nora; Linhorst, Donald M.; Morani, Nicole

2012-01-01

As higher numbers of individuals are released from prison and rejoin society, reentry programs can help former offenders reintegrate into society without continuing to engage in crime. This quasi-experimental study examined whether participation in reentry programming was associated with reduced recidivism among offenders who were no longer under…

Role Management, Educational Satisfaction, and Role Dynamics in Post-Secondary, Re-entry Women.

ERIC Educational Resources Information Center

Edmondon, Mary Ellen; And Others

1986-01-01

A sample of 42 post-secondary, educational re-entry women completed questionnaires focusing on background status, role dynamics, and satisfaction with their re-entry experience. Results showed no differences between students in a vocational program and those in a traditional, academic program. Role-dynamic variables--but not background-status…

Gender Differences and Offender Reentry: A Review of the Literature

ERIC Educational Resources Information Center

Spjeldnes, Solveig; Goodkind, Sara

2009-01-01

Historically, men have been incarcerated at rates far greater than women. As a result, reentry and reintegration programs have focused mainly on men's needs. The Second Chance Act of 2007 authorized funding for offender reentry programs and research on special populations--including about women and parents acknowledging the importance of…

Adaptable Holders for Arc-Jet Screening Candidate Thermal Protection System Repair Materials

NASA Technical Reports Server (NTRS)

Riccio, Joe; Milhoan, Jim D.

2010-01-01

Reusable holders have been devised for evaluating high-temperature, plasma-resistant re-entry materials, especially fabrics. Typical material samples tested support thermal-protection-system damage repair requiring evaluation prior to re-entry into terrestrial atmosphere. These tests allow evaluation of each material to withstand the most severe predicted re-entry conditions.

Reentry and Renegotiating Motherhood: Maternal Identity and Success on Parole

ERIC Educational Resources Information Center

Brown, Marilyn; Bloom, Barbara

2009-01-01

Parenting women emerging from prison on parole face numerous challenges to their successful reentry into the community. Along with finding housing, employment, and satisfying the conditions of their supervision, parenting women must also reassume their roles as mothers. This article adds to the literature on reentry by placing women's maternal…

8 CFR 211.3 - Expiration of immigrant visas, reentry permits, refugee travel documents, and Form I-551.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Expiration of immigrant visas, reentry... OF HOMELAND SECURITY IMMIGRATION REGULATIONS DOCUMENTARY REQUIREMENTS: IMMIGRANTS; WAIVERS § 211.3 Expiration of immigrant visas, reentry permits, refugee travel documents, and Form I-551. An immigrant visa...

Reintegration Success and Failure: Factors Impacting Reintegration among Incarcerated and Formerly Incarcerated Women

ERIC Educational Resources Information Center

Cobbina, Jennifer E.

2010-01-01

Criminologists have explored the reentry experience of formerly incarcerated adults, documented the pressing challenges of reentry, the correlates of recidivism, and the causes of desistance. Given scholars' focus on reentry to explain what factors impact criminal outcome, this raises the interesting question of whether and how such factors shape…

Fear of Success and Achievement Anxiety in Reentry Versus Non-Reentry Women.

ERIC Educational Resources Information Center

Sherman, Pamela; And Others

Women who reenter college after years of work or family responsibilities were compared to women with similar backgrounds who do not reenter school on measures of fear of success and achievement anxiety. A questionnaire designed to determine reentry status, age, socioeconomic standing, facilitating and debilitating anxiety, and fear of success was…

Educational Experiences and Transitions of Reentry College Women: Special Considerations for African American Female Students.

ERIC Educational Resources Information Center

Thomas, Veronica G.

2001-01-01

Examined motivators, obstacles, and support systems of reentry college women, particularly African American women. Student surveys indicated that respondents were motivated and excited about college reentry, generally reporting increased self-confidence since returning to school but identifying role overload and role conflict as major obstacles.…

Re-Entry, Recruitment, and Retention: A Community Relations Model for Sacramento City College.

ERIC Educational Resources Information Center

White, Maureen E.

Enrollment statistics and projections confirm the importance of focusing community college student recruitment and retention efforts on re-entry students. Re-entry students are a distinct and growing population whose educational requirements often differ from those of younger, traditional students. The literature on adult learners indicates that:…

Use of a Re-entry Device in Left Subclavian Occlusion: Case Series.

PubMed

Thomas, Wiliam Rhodri; Chick, Christopher; Goyal, Nimit

2018-01-01

To describe the use of a re-entry catheter in the endovascular treatment of left subclavian stenosis. We present three patients where initial attempts at re-vascularisation using standard techniques were unsuccessful. An OUTBACK catheter was employed to facilitate re-entry in these patients. True lumen re-entry was achieved in all patients, leading to successful treatment of all stenoses. There was a lack of filling of the left vertebral artery post-angioplasty in one patient; this was not clinically significant. The case series presented is encouraging for the use of a re-entry catheter in the treatment of subclavian occlusion. In our limited experience this has proved to be a safe technique for use in patients who fail re-vascularisation by standard methods; a larger study is required to confirm this.

Simulated Reentry Heating by Torching

NASA Technical Reports Server (NTRS)

Harvey, Gale A.

2008-01-01

The two first order reentry heating parameters are peak heating flux (W/cm2) and peak heat load (kJ/cm2). Peak heating flux (and deceleration, gs) is higher for a ballistic reentry and peak heat load is higher for a lifting reentry. Manned vehicle reentries are generally lifting reentries at nominal 1-5 gs so that personnel will not be crushed by high deceleration force. A few off-nominal manned reentries have experienced 8 or more gs with corresponding high heating flux (but below nominal heat load). The Shuttle Orbiter reentries provide about an order of magnitude difference in peak heating flux at mid-bottom (TPS tiles, approximately 6 W/cm2 or 5 BTU/ft2- sec) and leading edge (RCC, approximately 60 W/cm2 or 50 BTU/ft2- sec). Orion lunar return and Mars sample lander are of the same order of magnitude as orbiter leading edge peak heat loads. Flight temperature measurements are available for some orbiter TPS tile and RCC locations. Return-to-Flight on-orbit tile-repair-candidate-material-heating performance was evaluated by matching propane torch heating of candidate-materials temperatures at several depths to orbiter TPS tile flight-temperatures. Char and ash characteristics, heat expansion, and temperature histories at several depths of the cure-in-place ablator were some of the TPS repair material performance characteristics measured. The final char surface was above the initial surface for the primary candidate (silicone based) material, in contrast to a receded surface for the Apollo-type ablative heat shield material. Candidate TPS materials for Orion CEV (LEO and lunar return), and for Mars sample lander are now being evaluated. Torching of a candidate ablator material, PICA, was performed to match the ablation experienced by the STARDUST PICA heat shield. Torching showed that the carbon fiberform skeleton in a sample of PICA was inhomogeneous in that sample, and allowed measurements (of the clumps and voids) of the inhomogeneity. Additional reentry heating-performance characterizations of high temperature insulation materials were performed.

Trajectory optimization study of a lifting body re-entry vehicle for medium to intermediate range applications

NASA Astrophysics Data System (ADS)

Rizvi, S. Tauqeer ul Islam; Linshu, He; ur Rehman, Tawfiq; Rafique, Amer Farhan

2012-11-01

A numerical optimization study of lifting body re-entry vehicles is presented for nominal as well as shallow entry conditions for Medium and Intermediate Range applications. Due to the stringent requirement of a high degree of accuracy for conventional vehicles, lifting re-entry can be used to attain the impact at the desired terminal flight path angle and speed and thus can potentially improve accuracy of the re-entry vehicle. The re-entry of a medium range and intermediate range vehicles is characterized by very high negative flight path angle and low re-entry speed as compared to a maneuverable re-entry vehicle or a common aero vehicle intended for an intercontinental range. Highly negative flight path angles at the re-entry impose high dynamic pressure as well as heat loads on the vehicle. The trajectory studies are carried out to maximize the cross range of the re-entry vehicle while imposing a maximum dynamic pressure constraint of 350 KPa with a 3 MW/m2 heat rate limit. The maximum normal acceleration and the total heat load experienced by the vehicle at the stagnation point during the maneuver have been computed for the vehicle for possible future conceptual design studies. It has been found that cross range capability of up to 35 km can be achieved with a lifting-body design within the heat rate and the dynamic pressure boundary at normal entry conditions. For shallow entry angle of -20 degree and intermediate ranges a cross range capability of up to 250 km can be attained for a lifting body design with less than 10 percent loss in overall range. The normal acceleration also remains within limits. The lifting-body results have also been compared with wing-body results at shallow entry condition. An hp-adaptive pseudo-spectral method has been used for constrained trajectory optimization.

Design Criteria for Low Risk Re-Entry Vehicles

NASA Astrophysics Data System (ADS)

Monti, R.; Pezzella, G.

2005-02-01

The paper shows how a sharp vehicle with low wing loading, is able to follow re-entry trajectories with low thermal risks by using Ultra High Temperature Ceramics (UHTC) to thermally protect the vehicle front edges. These reusable materials can withstand the global radiative equilibrium temperatures that are experienced during reentry characterized by a longer and a more gradual conversion of the kinetic and potential energy of the vehicle into thermal energy. A number of aerothermodynamic problems are addressed to assess the feasibility of the vehicle design and of the thermal protection of the payload. In particular, the boundary layer thermal protection concept is illustrated to show how a UHTC massive tip edges (fuselage and wings) are able to protect also the remaining vehicle structure made of conventional material, promoting a revolutionary approach to the Thermal Protection System (TPS) configuration for hypersonic vehicle flying at small angle of attack. CFD results and engineering formulations are adopted for the computation of the aerodynamic coefficients and heat fluxes. The analysis identifies the design criteria for a conventional looking vehicle for a crew return from LEO (e.g. from the International Space Station).

Incarcerated women's relationship-based strategies to avoid drug use after community re-entry.

PubMed

Snell-Rood, Claire; Staton-Tindall, Michele; Victor, Grant

2016-10-01

While recent research has stressed the supportive role that family and friends play for incarcerated persons as they re-enter the community, drug-using incarcerated women re-entering the community often have to rely on family, community, and intimate relationships that have played a role in their substance abuse and criminalization. In this study the authors conducted qualitative analysis of clinical sessions with rural, drug-using women (N = 20) in a larger prison-based HIV risk reduction intervention in Kentucky during 2012-2014 to examine incarcerated women's perceptions of the role of their family, community, and intimate relationships in their plans to decrease their substance abuse upon community re-entry. Women stressed the obstacles to receiving support in many of their family and drug-using relationships after community re-entry. Nonetheless, they asserted that changes in their relationships could support their desires to end their substance abuse by setting limits on and using their positive relationships, particularly with their children, to motivate them to change. Interventions to promote incarcerated women's health behavior changes-including substance abuse-must acknowledge the complex social environments in which they live.

Evaluation of the Positive Re-Entry in Corrections Program: A Positive Psychology Intervention With Prison Inmates.

PubMed

Huynh, Kim H; Hall, Brittany; Hurst, Mark A; Bikos, Lynette H

2015-08-01

Two groups of male inmates (n = 31, n = 31) participated in the Positive Re-Entry in Corrections Program (PRCP). This positive psychology intervention focused on teaching offenders skills that facilitate re-entry into the community. Offenders participated in weekly lectures, discussions, and homework assignments focused on positive psychology principles. The two groups differed in duration of treatment (8 weeks and 12 weeks). Participants completed pre- and post-intervention measures of gratitude, hope, and life satisfaction. Using a 2 × 2 mixed design ANOVA, we hypothesized that the intervention (with two between-subjects levels of 8 and 12 weeks) and duration (with two repeated measures levels of pre and post) of treatment would moderate pre- to post-intervention change. Results indicated significant differences on pre- and post-intervention scores for both groups of offenders on all measures. The analysis did not yield statistically significant differences between groups, demonstrating no additive benefits from the inclusion of four additional sessions, thus saving time and money for correctional programming and funding. This research supports the use of positive psychology in prison interventions. © The Author(s) 2014.

Back home: a qualitative study exploring re-entering cross-cultural missionary aid workers' loss and grief.

PubMed

Selby, Susan; Moulding, Nicole; Clark, Sheila; Jones, Alison; Braunack-Mayer, Annette; Beilby, Justin

2009-01-01

Over 200 Australian, American, and British Non-Government Organizations send aid workers overseas including missionaries. On re-entry, they may suffer psychological distress; however, there is little research about their psychosocial issues and management in the family practice setting. Research suggests loss and grief as a suitable paradigm for family practitioners dealing with psychosocial issues. The aim of this study was to explore loss and grief issues for adult Australian missionary cross-cultural aid workers during their re-entry adjustment. Mixed methods were used and this study reports the qualitative method: semi-structured interviews conducted with 15 participants. Results were analyzed using framework analysis. Themes of re-entry loss and grief were identified with sub-themes of multiple varied losses, mechanisms of loss, loss of control, common grief phenomena, disenfranchised grief, and reactivation of past grief. Theoretical and clinical implications are discussed. Findings of this study suggest that loss and grief is an appropriate paradigm for the management of these workers in the family practice setting. Further research is needed to enable appropriate care.

Dynamical and thermal qualification of the C-SiC nose for the IXV

NASA Astrophysics Data System (ADS)

Buffenoir, François; Escafre, David; Brault, Tiana; Rival, Loic; Girard, Florent

2016-07-01

The Intermediate experimental Vehicle (IXV) atmospheric re-entry demonstrator, developed within the FLPP (Future Launcher Preparatory Program) and funded by ESA, was aimed at developing a demonstration vehicle that gave Europe a unique opportunity to increase its knowledge in the field of advanced atmospheric re-entry technologies. Within this program, HERAKLES, Safran Group, was in charge of the TPS of the windward and nose assemblies of the vehicle, and has developed and manufactured SepcarbInox® Ceramic Matrix Composite (CMC) protection systems that provided a high temperature resistant nonablative outer mold line (OML) for enhanced aerodynamic control. A key component of this TPS is the nose assembly, which is one the most loaded part during re-entry. The paper describes the analysis activities that led to the qualification of the nose assembly, through two activities: Dynamical behavior of the nose. Thermal behavior of the nose For both cases, the paper shows how FE models, compared with tests results, led to the understanding and simulation of the nose assembly behavior, allowing HERAKLES to confirm the design margins before flight.

Female Ex-Offender Perspectives on Drug Initiation, Relapse, and Desire to Remain Drug Free

PubMed Central

Nyamathi, Adeline M.; Srivastava, Neha; Salem, Benissa E.; Wall, Sarah; Kwon, Jordan; Ekstrand, Maria; Hall, Elizabeth; Turner, Susan F.; Faucette, Mark

2016-01-01

Recently-released homeless women residing in temporary residential drug treatment programs are at a critical juncture in the process of recovery, transition and reentry. The purpose of this study was to explore factors influencing initial use of drugs and relapse triggers among a sample of incarcerated women exiting jails and prisons, and who are residing in a residential drug treatment (RDT) program and preparing for reentry into their communities. Among this population, relapse to drug use and recidivism are common. A qualitative study was conducted utilizing focus groups to understand the perspectives of formerly incarcerated, currently homeless women residing in a RDT program. Content analysis generated the development of three broad categories: a) factors associated with first drug use; b) factors involved in relapse; c) factors influencing desire to remain drug free. A discussion follows highlighting the importance of targeted interventions at RDT sites that integrate physical, psychological and social needs to optimize reentry into communities. This would include a focus on building self-esteem, life skills, and providing access to resources such as housing, employment, and healthcare. PMID:27195929

Diagnostic Tools for Plasma Wind Tunnels and Reentry Vehicles at the IRS

DTIC Science & Technology

2000-04-01

activ n e pronte . pwindkanal", Dissertation, Universittit Stuttgart, 1998. A mass spectrometer probe can be used with low [A.9] Auweter-Kurtz, M., Laure...obtained ffrom experiments at a plasma state with a mass flowFig. B2.28: RtooOISobandfrom dintensities in a 3D -view rate of 2 g/s air and an ambient...spectrometer work is based on the estimations either in solid food stuffs or organic chopped-light (AC) principle which is illustrated in materials ( e.g

Application of the FADS system on the Re-entry Module

NASA Astrophysics Data System (ADS)

Zhen, Huang

2016-07-01

The aerodynamic model for Flush Air Data Sensing System (FADS) is built based on the surface pressure distribution obtained through the pressure orifices laid on specific positions of the surface,and the flight parameters,such as angle of attack,angle of side-slip,Mach number,free-stream static pressure and dynamic pressure are inferred from the aerodynamic model.The flush air data sensing system (FADS) has been used on several flight tests of aircraft and re-entry vehicle,such as,X-15,space shuttle,F-14,X-33,X-43A and so on. This paper discusses the application of the FADS on the re-entry module with blunt body to obtain high-precision aerodynamic parameters.First of all,a basic theory and operating principle of the FADS is shown.Then,the applications of the FADS on typical aircrafts and re-entry vehicles are described.Thirdly,the application mode on the re-entry module with blunt body is discussed in detail,including aerodynamic simulation,pressure distribution,trajectory reconstruction and the hardware shoule be used,such as flush air data sensing system(FADS),inertial navigation system (INS),data acquisition system,data storage system.Finally,ablunt module re-entry flight test from low earth orbit (LEO) is planned to obtain aerodynamic parameters and amend the aerodynamic model with this FADS system data.The results show that FADS system can be applied widely in re-entry module with blunt bodies.

Application of the V-Gamma map to vehicle breakup analysis

NASA Technical Reports Server (NTRS)

Salama, Ahmed; McRonald, Angus; Ahmadi, Reza; LIng, Lisa; Accad, Elie; Kim, Alex

2003-01-01

The V-Gamma map consists of all possible pairs of speed and flight path angle at atmospheric entry interface for accidental Earth reentries resulting from steady misaligned burns, incomplete burns, or no burn.

Utilization of sounding rockets and balloons in the German Space Programme

NASA Astrophysics Data System (ADS)

Preu, Peter; Friker, Achim; Frings, Wolfgang; Püttmann, Norbert

2005-08-01

Sounding rockets and balloons are important tools of Germany's Space Programme. DLR manages these activities and promotes scientific experiments and validation programmes within (1) Space Science, (2) Earth Observation, (3) Microgravity Research and (4) Re-entry Technologies (SHEFEX). In Space Science the present focus is at atmospheric research. Concerning Earth Observation balloon-borne measurements play a key role in the validation of atmospheric satellite sounders (ENVISAT). TEXUS and MAXUS sounding rockets are successfully used for short duration microgravity experiments. The Sharp Edge Flight Experiment SHEFEX will deliver data from a hypersonic flight for the validation of a new Thermal Protection System (TPS), wind tunnel testing and numerical analysis of aerothermodynamics. Signing the Revised Esrange and Andøya Special Project (EASP) Agreement 2006-2010 in June 2004 Germany has made an essential contribution to the long-term availability of the Scandinavian ranges for the European science community.

DEBRISK, a Tool for Re-Entry Risk Analysis

NASA Astrophysics Data System (ADS)

Omaly, P.; Spel, M.

2012-01-01

An act of French parliament, adopted in 2008, imposes satellite constructors to evaluate the end-of-life operations in order to assure the risk mitigation of their satellites. One important element in this evaluation is the estimation of the mass and impact energy of the satellite debris after atmospheric re-entry. For this purpose, CNES has developed the tool DEBRISK which allows the operator to simulate the re-entry phase and to study the demise altitudes or impact energy of the individual fragments of the original satellite. DEBRISK is based on the so called object based approach. Using this approach, a breakup altitude is assumed where the satellite disintegrates due to the pressure loads. This altitude is typically around 78 km. After breakup, the satellite structure is modelled by a parent-child approach, where each child has its birth criterion. In the simplest approach the child is born after demise of the parent object. This could be the case of an object A containing an object B which is in the interior of object A and thus not exposed to the atmosphere. Each object is defined by: - its shape, attitude and dimensions, - the material along with their physical properties - the state and velocity vectors. The shape, attitude and dimensions define the aerodynamic drag of the object which is input to the 3DOF trajectory modelling. The aerodynamic mass used in the equation of motion is defined as the sum of the object's own mass and the mass of the object's offspring. A new born object inherits the state vector of the parent object. The shape, attitude and dimensions also define the heating rates experienced by the object. The heating rate is integrated in time up to the point where the melting temperature is reached. The mass of melted material is computed from the excess heat and the material properties. After each step the amount of ablated material is determined using the lumped mass approach and is peeled off from the object, updating mass and shape of the ablated object. The mass in the lumped mass equation is termed 'thermal mass' and consists of the part of the object that is exposed to the flow (so excluding the mass of the contained children). A fair amount of predefined materials is implemented, along with their thermal properties. In order to allow the users to modify the properties or to add new materials, user defined materials can be used. In that case the properties such as specific heat, emissivity and conductivity can either be entered as a constant or as being temperature dependent by entering a table. Materials can be derived from existing objects, which is useful in case only one or few of the material properties change. The code has been developed in the Java language, benefitting from the object oriented approach. Most methods that are used in DEBRISK to compute drag coefficients and heating rates are based on engineering methods developed in the 1950 to 1960's, which are used as well in similar tools (ORSAT, SESAME, ORSAT-J, ...). The paper presents a set of comparisons with literature cases of similar tools in order to verify the implementation of those methods in the developed software.

Reentry Orientation and Alumni Networking in U.S. Colleges and Universities with Agriculture and Natural Resources Programs. Survey Report.

ERIC Educational Resources Information Center

Huntsberger, Paul E.

This report presents results of a survey of U.S. postsecondary institutions with agriculture and natural resources programs, concerning institutional support for reentry orientation and alumni networking programs. Reentry orientation" involves programs that help international students become aware of the adjustment aspects of returning home,…

Exploring Career Decision-Making Experiences of Mexican American Re-Entry Community College Women

ERIC Educational Resources Information Center

Dominguez, Cecilia Sophia

2010-01-01

The purpose of this phenomenological investigation was to increase understanding of the career perspectives of 12 Mexican American, re-entry women who were attending a community college. The questions guiding this investigation were: (a) How do Mexican American re-entry college women describe their career decision-making experiences, (b) What do…

A Randomized Trial of a Multimodal Community-Based Prisoner Reentry Program Emphasizing Substance Abuse Treatment

ERIC Educational Resources Information Center

Grommon, Eric; Davidson, William S., II; Bynum, Timothy S.

2013-01-01

Prisoner reentry programs continue to be developed and implemented to ease the process of transition into the community and to curtail fiscal pressures. This study describes and provides relapse and recidivism outcome findings related to a randomized trial evaluating a multimodal, community-based reentry program that prioritized substance abuse…

Gender Differences in the Perceived Needs and Barriers of Youth Offenders Preparing for Community Reentry

ERIC Educational Resources Information Center

Fields, Diane; Abrams, Laura S.

2010-01-01

This study explored how gender differences may influence the community reentry experiences of incarcerated youth. Structured surveys assessing risk factors for re-offending, perceived reentry needs, and anticipated barriers to meeting these needs were administered to a convenience sample of males (n = 36) and females (n = 35) who were within 60…

78 FR 29428 - Office of Commercial Space Transportation; Notice of Availability of a Record of Decision (ROD...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-20

... Martin Corporation for the Reentry of the Orion Multi-Purpose Crew Vehicle (MPCV) From Earth Orbit to a... reentry license to Lockheed Martin Corporation for the reentry of the Orion MPCV from Earth orbit to a.... SUPPLEMENTARY INFORMATION: The potential environmental consequences of the Orion MPCV reentering the Earth's...

Re-Thinking Re-Entry: New Approaches to Supporting Students after Study Abroad

ERIC Educational Resources Information Center

Brubaker, Cate

2017-01-01

While participation in study abroad continues to increase, and both pre-departure and in-country support and interventions have become more robust, the re-entry experience after a program ends still typically takes a back seat to other priorities. Consequently, most students are left to navigate the re-entry transition on their own. This article…

Re-entry experiences of Black men living with HIV/AIDS after release from prison: Intersectionality and implications for care.

PubMed

Sun, Shufang; Crooks, Natasha; Kemnitz, Rebecca; Westergaard, Ryan P

2018-06-12

Both the HIV epidemic and incarceration disproportionately affect Black men in the United States. A critical period for incarcerated Black men living with HIV/AIDS is re-entry into the community, which is often associated with adverse health outcomes. Additionally, Black men living with HIV/AIDS involved in the criminal justice system are burdened by multiple, intersecting disadvantaged identities and social positions. This study aimed to examine community re-entry experiences among Black men living with HIV/AIDS from an intersectional perspective. In-depth, semi-structured interviews were conducted with 16 incarcerated Black men in Wisconsin, at pre-release from prison and six months after re-entry. Thematic analysis guided by intersectionality theory was used to analyze interview transcripts. Seven emerged themes included Intersectional Identities and Social Positions, Family Support, Neighborhood Violence, Relationship with Law Enforcement, Employment, Mental Health Concerns, and Medical Care and Medication Management. Intersecting identities and social positions interact with factors at multiple levels to inform health and HIV care. A conceptual framework was developed to illustrate relationships among themes. Findings demonstrate the relevance of intersectionality theory in HIV care with Black men involved in criminal justice system. Incorporating a social-ecological perspective into intersectionality framework could be useful in theoretical and empirical research. Disenfranchised communities may particularly benefit from interventions that address community- and systemic-level issues. Copyright © 2018 Elsevier Ltd. All rights reserved.

A Software Upgrade of the NASA Aeroheating Code "MINIVER"

NASA Technical Reports Server (NTRS)

Louderback, Pierce Mathew

2013-01-01

Computational Fluid Dynamics (CFD) is a powerful and versatile tool simulating fluid and thermal environments of launch and re-entry vehicles alike. Where it excels in power and accuracy, however, it lacks in speed. An alternative tool for this purpose is known as MINIVER, an aeroheating code widely used by NASA and within the aerospace industry. Capable of providing swift, reasonably accurate approximations of the fluid and thermal environment of launch vehicles, MINIVER is used where time is of the essence and accuracy need not be exact. However, MINIVER is an old, aging tool: running on a user-unfriendly, legacy command-line interface, it is difficult for it to keep pace with more modem software tools. Florida Institute of Technology was tasked with the construction of a new Graphical User Interface (GUI) that implemented the legacy version's capabilities and enhanced them with new tools and utilities. This thesis provides background to the legacy version of the program, the progression and final version of a modem user interface, and benchmarks to demonstrate its usefulness.

Thermodynamic energy balance equations for Space Shuttle Orbiter gas compartment during ascent and re-entry

NASA Technical Reports Server (NTRS)

Ting, P. C.

1982-01-01

Thermodynamic energy balance equations are derived and applied to midsection Orbiter-payload atmospheric thermal math models (TMMs) to predict Orbiter component, element, compartment, internal insolation and structure temperatures in support of NASA/JSC mission planning, postflight thermal analysis and payload thermal integration planning. The equations are extended and applied to the forward section, midsection, and aft section of the TMMs for five Orbiter mission phases: prelaunch on pad with purge, lift-off to ascent, re-entry to touchdown, post landing without purge, and post-landing with purge. Predicted results from the 390 node/DFI atmospheric TMM are in good agreement with STS-1 flight measurement data.

School re-entry of the pediatric heart transplant recipient.

PubMed

Weil, Constance M; Rodgers, S; Rubovits, S

2006-12-01

Pediatric cardiac transplant has become increasingly frequent in the last decade and survival rates have improved remarkably. Outcome research on this population suggests that the majority of children have the capacity for healthy adaptation although 25-40% have been shown to have some type of psychiatric difficulties. As school plays a major role in these children's lives, early intervention and close liaison with schools is indicated to reduce psychological morbidity, enhance adaptation within the school environment and enhance overall adjustment. This paper proposes a model for a school re-entry program for this population. The school re-entry program is aimed at children who are undergoing cardiac transplant and will be entering or re-entering the school system. They may range in academic age from preschool to college level and have been attending private or public schools with placements in regular education programs, regular education programs with resource support, special education programs, and alternative school programs. Others may not have been attending school because of the severity of their medical condition and have been receiving in-home tutoring. Each child is offered school re-entry assistance by a multi-disciplinary team composed of members from the Cardiology Transplant Service. The re-entry program includes cognitive and psychosocial assessment, liaison with the child's school pre- and post-transplant, academic planning and provision of academic, emotional, and behavioral support before, during, and immediately after transplant, a school re-entry visit, and an ongoing school consultation. The goal is to address issues necessary for a successful school re-entry including appropriate academic placement and support, psychosocial adjustment, education of school personnel and ongoing health needs of the student. The next step is to formally evaluate the efficacy of this program in successful school re-entry.

Early afterdepolarizations promote transmural reentry in ischemic human ventricles with reduced repolarization reserve

PubMed Central

Dutta, Sara; Mincholé, Ana; Zacur, Ernesto; Quinn, T. Alexander; Taggart, Peter; Rodriguez, Blanca

2016-01-01

Aims Acute ischemia is a major cause of sudden arrhythmic death, further promoted by potassium current blockers. Macro-reentry around the ischemic region and early afterdepolarizations (EADs) caused by electrotonic current have been suggested as potential mechanisms in animal and isolated cell studies. However, ventricular and human-specific arrhythmia mechanisms and their modulation by repolarization reserve remain unclear. The goal of this paper is to unravel multiscale mechanisms underlying the modulation of arrhythmic risk by potassium current (IKr) block in human ventricles with acute regional ischemia. Methods and results A human ventricular biophysically-detailed model, with acute regional ischemia is constructed by integrating experimental knowledge on the electrophysiological ionic alterations caused by coronary occlusion. Arrhythmic risk is evaluated by determining the vulnerable window (VW) for reentry following ectopy at the ischemic border zone. Macro-reentry around the ischemic region is the main reentrant mechanism in the ischemic human ventricle with increased repolarization reserve due to the ATP-sensitive potassium current (IK(ATP)) activation. Prolongation of refractoriness by 4% caused by 30% IKr reduction counteracts the establishment of macro-reentry and reduces the VW for reentry (by 23.5%). However, a further decrease in repolarization reserve (50% IKr reduction) is less anti-arrhythmic despite further prolongation of refractoriness. This is due to the establishment of transmural reentry enabled by electrotonically-triggered EADs in the ischemic border zone. EADs are produced by L-type calcium current (ICaL) reactivation due to prolonged low amplitude electrotonic current injected during the repolarization phase. Conclusions Electrotonically-triggered EADs are identified as a potential mechanism facilitating intramural reentry in a regionally-ischemic human ventricles model with reduced repolarization reserve. PMID:26850675

Intermediate experimental vehicle, ESA program aerodynamics-aerothermodynamics key technologies for spacecraft design and successful flight

NASA Astrophysics Data System (ADS)

Dutheil, Sylvain; Pibarot, Julien; Tran, Dac; Vallee, Jean-Jacques; Tribot, Jean-Pierre

2016-07-01

With the aim of placing Europe among the world's space players in the strategic area of atmospheric re-entry, several studies on experimental vehicle concepts and improvements of critical re-entry technologies have paved the way for the flight of an experimental space craft. The successful flight of the Intermediate eXperimental Vehicle (IXV), under ESA's Future Launchers Preparatory Programme (FLPP), is definitively a significant step forward from the Atmospheric Reentry Demonstrator flight (1998), establishing Europe as a key player in this field. The IXV project objectives were the design, development, manufacture and ground and flight verification of an autonomous European lifting and aerodynamically controlled reentry system, which is highly flexible and maneuverable. The paper presents, the role of aerodynamics aerothermodynamics as part of the key technologies for designing an atmospheric re-entry spacecraft and securing a successful flight.

Diversion at re-entry using criminogenic CBT: Review and prototypical program development.

PubMed

Heilbrun, Kirk; Pietruszka, Victoria; Thornewill, Alice; Phillips, Sarah; Schiedel, Rebecca

2017-09-01

Society and the criminal justice system prioritize the reduction of reoffending risk as part of any criminal justice intervention. The Sequential Intercept Model identifies five points of interception at which justice-involved individuals can be diverted into a more rehabilitative alternative: (1) law enforcement/emergency services; (2) booking/initial court hearings; (3) jails/courts; (4) re-entry; and (5) community corrections/community support. The present article focuses on diversion as part of Intercept 5 - re-entry planning and specialized services in the community. We describe the challenges associated with diversion at this stage, and review the relevant research. Next, we describe a "criminogenic cognitive behavioral therapy" project that has been developed and implemented as part of a federal re-entry court. Finally, we discuss the implications of the challenges of intervention at this stage, and the recently developed "Re-entry Project," for research, policy, and practice. Copyright © 2017 John Wiley & Sons, Ltd.

Automatic rapid attachable warhead section

DOEpatents

Trennel, A.J.

1994-05-10

Disclosed are a method and apparatus for automatically selecting warheads or reentry vehicles from a storage area containing a plurality of types of warheads or reentry vehicles, automatically selecting weapon carriers from a storage area containing at least one type of weapon carrier, manipulating and aligning the selected warheads or reentry vehicles and weapon carriers, and automatically coupling the warheads or reentry vehicles with the weapon carriers such that coupling of improperly selected warheads or reentry vehicles with weapon carriers is inhibited. Such inhibition enhances safety of operations and is achieved by a number of means including computer control of the process of selection and coupling and use of connectorless interfaces capable of assuring that improperly selected items will be rejected or rendered inoperable prior to coupling. Also disclosed are a method and apparatus wherein the stated principles pertaining to selection, coupling and inhibition are extended to apply to any item-to-be-carried and any carrying assembly. 10 figures.

Re-entry Adjustment and Job Embeddedness: The Mediating Role of Professional Identity in Indonesian Returnees.

PubMed

Andrianto, Sonny; Jianhong, Ma; Hommey, Confidence; Damayanti, Devi; Wahyuni, Honey

2018-01-01

The present study examined the relationship between difficulty in re-entry adjustment and job embeddedness, considering the mediating role of sense of professional identity. The online data on demographic characteristics, difficulty on re-entry adjustment, sense of professional identity, and job embeddedness were collected from 178 Indonesian returnees from multiple organizations. The results showed that difficulty in re-entry adjustment was a significant predictor of a sense of professional identity; a sense of professional identity was a significant predictor of job embeddedness. Furthermore, sense of professional identity is an effective mediating variable, bridging the relationship between post-return conditions to the home country and work atmosphere. Finally, the key finding of this study was that sense of professional identity mediated the effect of difficulty in re-entry adjustment on job embeddedness. The theoretical and practical implications, study limitations, and future research needs of our findings are noted.

Public Risk Criteria and Rationale for Commercial Launch and Reentry

NASA Astrophysics Data System (ADS)

Wilde, P. D.

2012-01-01

This paper summarizes the rationale for risk criteria intended to protect the public during commercial spaceflight, including launch, reentry, and suborbital missions. The recommended approach includes: (1) safety goals to guide periodic updates of the quantitative collective risk limits if warranted based on the quantity of launch and reentry missions; the demonstrated safety record and benefits provided; technological capabilities and maturity of the industry; and contemporary attitudes about the risks from commercial space transportation; (2) separate limits on the risks from each type of mission with explicit definitions of the extent of launch and reentry missions; and (3) quantitative risk limits consistent with the safety goals. For current conditions, the author's recommends (a) maximum of 1E-6 probability of casualty per-mission (b) a maximum of 100E-6 expected casualties per-mission, and (c) equal per-mission risk limits for orbital and suborbital launches, as well as controlled and uncontrolled reentries.

Automatic rapid attachable warhead section

DOEpatents

Trennel, Anthony J.

1994-05-10

Disclosed are a method and apparatus for (1) automatically selecting warheads or reentry vehicles from a storage area containing a plurality of types of warheads or reentry vehicles, (2) automatically selecting weapon carriers from a storage area containing at least one type of weapon carrier, (3) manipulating and aligning the selected warheads or reentry vehicles and weapon carriers, and (4) automatically coupling the warheads or reentry vehicles with the weapon carriers such that coupling of improperly selected warheads or reentry vehicles with weapon carriers is inhibited. Such inhibition enhances safety of operations and is achieved by a number of means including computer control of the process of selection and coupling and use of connectorless interfaces capable of assuring that improperly selected items will be rejected or rendered inoperable prior to coupling. Also disclosed are a method and apparatus wherein the stated principles pertaining to selection, coupling and inhibition are extended to apply to any item-to-be-carried and any carrying assembly.

Aerobrake plasmadynamics - Macroscopic effects

NASA Technical Reports Server (NTRS)

Shebalin, John V.

1990-01-01

The flow around an aerobraking spacecraft (such as the Aeroassist Flight Experiment reentry vehicle) will contain a region of partially ionized gas, that is, a plasma. It is shown here by numerical simulation that macroscopic plasmadynamic effects (which are not included in standard aerothermodynamic simulations) will have a noticeable effect on the reentry flow field. In particular, there are thermoelectric phenomena which can have a major influence in flow dynamics at the front of an ionizing bowshock. These thermoelectric phenomena arise because of the presence of large density and temperature gradients at the front of a reentry bowshock, and they include strong local magnetic fields, electric currents, and ohmic heating. One important result is the dramatic increase in temperature (over the case where plasma effects are neglected) at a reentry shock front; the implication is that macroscopic plasmadynamic effects can no longer be neglected in simulations of hypersonic reentry flow fields.

Space Shuttle Debris Impact Tool Assessment Using the Modern Design of Experiments

NASA Technical Reports Server (NTRS)

DeLoach, Richard; Rayos, Elonsio M.; Campbell, Charles H.; Rickman, Steven L.; Larsen, Curtis E.

2007-01-01

Complex computer codes are used to estimate thermal and structural reentry loads on the Shuttle Orbiter induced by ice and foam debris impact during ascent. Such debris can create cavities in the Shuttle Thermal Protection System. The sizes and shapes of these cavities are approximated to accommodate a code limitation that requires simple "shoebox" geometries to describe the cavities -- rectangular areas and planar walls that are at constant angles with respect to vertical. These approximations induce uncertainty in the code results. The Modern Design of Experiments (MDOE) has recently been applied to develop a series of resource-minimal computational experiments designed to generate low-order polynomial graduating functions to approximate the more complex underlying codes. These polynomial functions were then used to propagate cavity geometry errors to estimate the uncertainty they induce in the reentry load calculations performed by the underlying code. This paper describes a methodological study focused on evaluating the application of MDOE to future operational codes in a rapid and low-cost way to assess the effects of cavity geometry uncertainty.

KSC-04pd1231

NASA Image and Video Library

2004-05-25

KENNEDY SPACE CENTER, FLA. - United Space Alliance technician J.C. Harrison steers while NASA’s Scott Thurston guides a piece of Columbia debris through a gate in the Vehicle Assembly Building, where the debris is stored. This piece is one of eight being released to The Aerospace Corporation in El Segundo, Calif., for testing and research. Thurston is the Columbia debris coordinator. The Aerospace Corporation requested and will receive graphite/epoxy honeycomb skins from an Orbital Maneuvering System pod, Main Propulsion System Helium tanks, a Reaction Control System Helium tank and a Power Reactant Storage Distribution system tank. The company will use the parts to study re-entry effects on composite materials. NASA notified the Columbia crew’s families about the loan before releasing the items for study. Researchers believe the testing will show how materials are expected to respond to various heating and loads' environments. The findings will help calibrate tools and models used to predict hazards to people and property from reentering hardware. The Aerospace Corporation will have the debris for one year to perform analyses to estimate maximum temperatures during reentry based upon the geometry and mass of the recovered composite.

KSC-04pd1233

NASA Image and Video Library

2004-05-25

KENNEDY SPACE CENTER, FLA. - United Space Alliance workers J.C. Harrison (left) and Amy Mangiacapra (right) pack up pieces of Columbia debris for shipment to The Aerospace Corporation in El Segundo, Calif. The pieces have been released for loan to the non-governmental agency for testing and research. The Aerospace Corporation requested and will receive graphite/epoxy honeycomb skins from an Orbital Maneuvering System pod, Main Propulsion System Helium tanks, a Reaction Control System Helium tank and a Power Reactant Storage Distribution system tank. The company will use the parts to study re-entry effects on composite materials. NASA notified the Columbia crew’s families about the loan before releasing the items for study. Researchers believe the testing will show how materials are expected to respond to various heating and loads' environments. The findings will help calibrate tools and models used to predict hazards to people and property from reentering hardware. The Aerospace Corporation will have the debris for one year to perform analyses to estimate maximum temperatures during reentry based upon the geometry and mass of the recovered composite. Columbia’s debris is stored in the VAB.

KSC-04pd1234

NASA Image and Video Library

2004-05-25

KENNEDY SPACE CENTER, FLA. - United Space Alliance workers begin packing pieces of Columbia debris for shipment to The Aerospace Corporation in El Segundo, Calif. The pieces have been released for loan to the non-governmental agency for testing and research. The Aerospace Corporation requested and will receive graphite/epoxy honeycomb skins from an Orbital Maneuvering System pod, Main Propulsion System Helium tanks, a Reaction Control System Helium tank and a Power Reactant Storage Distribution system tank. The company will use the parts to study re-entry effects on composite materials. NASA notified the Columbia crew’s families about the loan before releasing the items for study. Researchers believe the testing will show how materials are expected to respond to various heating and loads' environments. The findings will help calibrate tools and models used to predict hazards to people and property from reentering hardware. The Aerospace Corporation will have the debris for one year to perform analyses to estimate maximum temperatures during reentry based upon the geometry and mass of the recovered composite. Columbia’s debris is stored in the VAB.

KSC-04pd1235

NASA Image and Video Library

2004-05-25

KENNEDY SPACE CENTER, FLA. - United Space Alliance workers J.C. Harrison (left) and Amy Mangiacapra pack pieces of Columbia debris for transfer to the shipping facility for travel to The Aerospace Corporation in El Segundo, Calif. The pieces have been released for loan to the non-governmental agency for testing and research. The Aerospace Corporation requested and will receive graphite/epoxy honeycomb skins from an Orbital Maneuvering System pod, Main Propulsion System Helium tanks, a Reaction Control System Helium tank and a Power Reactant Storage Distribution system tank. The company will use the parts to study re-entry effects on composite materials. NASA notified the Columbia crew’s families about the loan before releasing the items for study. Researchers believe the testing will show how materials are expected to respond to various heating and loads' environments. The findings will help calibrate tools and models used to predict hazards to people and property from reentering hardware. The Aerospace Corporation will have the debris for one year to perform analyses to estimate maximum temperatures during reentry based upon the geometry and mass of the recovered composite. Columbia’s debris is stored in the VAB.

KSC-04pd1236

NASA Image and Video Library

2004-05-25

KENNEDY SPACE CENTER, FLA. - After being wrapped and secured on pallets, pieces of Columbia debris are loaded onto a truck to transport them to the shipping facility for travel to The Aerospace Corporation in El Segundo, Calif. The pieces have been released for loan to the non-governmental agency for testing and research. The Aerospace Corporation requested and will receive graphite/epoxy honeycomb skins from an Orbital Maneuvering System pod, Main Propulsion System Helium tanks, a Reaction Control System Helium tank and a Power Reactant Storage Distribution system tank. The company will use the parts to study re-entry effects on composite materials. NASA notified the Columbia crew’s families about the loan before releasing the items for study. Researchers believe the testing will show how materials are expected to respond to various heating and loads' environments. The findings will help calibrate tools and models used to predict hazards to people and property from reentering hardware. The Aerospace Corporation will have the debris for one year to perform analyses to estimate maximum temperatures during reentry based upon the geometry and mass of the recovered composite. Columbia’s debris is stored in the VAB.

KSC-04PD-1233

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. United Space Alliance workers J.C. Harrison (left) and Amy Mangiacapra (right) pack up pieces of Columbia debris for shipment to The Aerospace Corporation in El Segundo, Calif. The pieces have been released for loan to the non-governmental agency for testing and research. The Aerospace Corporation requested and will receive graphite/epoxy honeycomb skins from an Orbital Maneuvering System pod, Main Propulsion System Helium tanks, a Reaction Control System Helium tank and a Power Reactant Storage Distribution system tank. The company will use the parts to study re-entry effects on composite materials. NASA notified the Columbia crews families about the loan before releasing the items for study. Researchers believe the testing will show how materials are expected to respond to various heating and loads' environments. The findings will help calibrate tools and models used to predict hazards to people and property from reentering hardware. The Aerospace Corporation will have the debris for one year to perform analyses to estimate maximum temperatures during reentry based upon the geometry and mass of the recovered composite. Columbias debris is stored in the VAB.

KSC-04PD-1232

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. United Space Alliance workers J.C. Harrison (far left) and Amy Mangiacapra guide a wrapped piece of Columbia debris through the Vehicle Assembly Building, where it is stored. Alongside is NASAs Scott Thurston, who is the Columbia debris coordinator. This piece is one of eight being released to The Aerospace Corporation in El Segundo, Calif., for testing and research. The Aerospace Corporation requested and will receive graphite/epoxy honeycomb skins from an Orbital Maneuvering System pod, Main Propulsion System Helium tanks, a Reaction Control System Helium tank and a Power Reactant Storage Distribution system tank. The company will use the parts to study re-entry effects on composite materials. NASA notified the Columbia crews families about the loan before releasing the items for study. Researchers believe the testing will show how materials are expected to respond to various heating and loads' environments. The findings will help calibrate tools and models used to predict hazards to people and property from reentering hardware. The Aerospace Corporation will have the debris for one year to perform analyses to estimate maximum temperatures during reentry based upon the geometry and mass of the recovered composite.

KSC-04PD-1235

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. United Space Alliance workers J.C. Harrison (left) and Amy Mangiacapra pack pieces of Columbia debris for transfer to the shipping facility for travel to The Aerospace Corporation in El Segundo, Calif. The pieces have been released for loan to the non-governmental agency for testing and research. The Aerospace Corporation requested and will receive graphite/epoxy honeycomb skins from an Orbital Maneuvering System pod, Main Propulsion System Helium tanks, a Reaction Control System Helium tank and a Power Reactant Storage Distribution system tank. The company will use the parts to study re-entry effects on composite materials. NASA notified the Columbia crews families about the loan before releasing the items for study. Researchers believe the testing will show how materials are expected to respond to various heating and loads' environments. The findings will help calibrate tools and models used to predict hazards to people and property from reentering hardware. The Aerospace Corporation will have the debris for one year to perform analyses to estimate maximum temperatures during reentry based upon the geometry and mass of the recovered composite. Columbias debris is stored in the VAB.

KSC-04PD-1231

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. United Space Alliance technician J.C. Harrison steers while NASAs Scott Thurston guides a piece of Columbia debris through a gate in the Vehicle Assembly Building, where the debris is stored. This piece is one of eight being released to The Aerospace Corporation in El Segundo, Calif., for testing and research. Thurston is the Columbia debris coordinator. The Aerospace Corporation requested and will receive graphite/epoxy honeycomb skins from an Orbital Maneuvering System pod, Main Propulsion System Helium tanks, a Reaction Control System Helium tank and a Power Reactant Storage Distribution system tank. The company will use the parts to study re-entry effects on composite materials. NASA notified the Columbia crews families about the loan before releasing the items for study. Researchers believe the testing will show how materials are expected to respond to various heating and loads' environments. The findings will help calibrate tools and models used to predict hazards to people and property from reentering hardware. The Aerospace Corporation will have the debris for one year to perform analyses to estimate maximum temperatures during reentry based upon the geometry and mass of the recovered composite.

Orbiter Return-To-Flight Entry Aeroheating

NASA Technical Reports Server (NTRS)

Campbell, Charles H.; Anderson, Brian; Bourland, Gary; Bouslog, Stan; Cassady, Amy; Horvath, Tom; Berry, Scott A.; Gnoffo, Peter; Wood, Bill; Reuther, James;

Numerical-experimental analysis of a carbon-phenolic composite via plasma jet ablation test

NASA Astrophysics Data System (ADS)

Guilherme Silva Pesci, Pedro; Araújo Machado, Humberto; Silva, Homero de Paula e.; Cley Paterniani Rita, Cristian; Petraconi Filho, Gilberto; Cocchieri Botelho, Edson

2018-06-01

Materials used in space vehicles components are subjected to thermally aggressive environments when exposed to atmospheric reentry. In order to protect the payload and the vehicle itself, ablative composites are employed as TPS (Thermal Protection System). The development of TPS materials generally go through phases of obtaining, atmospheric reentry tests and comparison with a mathematical model. The state of the art presents some reentry tests in a subsonic or supersonic arc-jet facility, and a complex type of mathematical model, which normally requires large computational cost. This work presents a reliable method for estimate the performance of ablative composites, combining empirical and experimental data. Tests of composite materials used in thermal protection systems through exposure to a plasma jet are performed, where the heat fluxes emulate those present in atmospheric reentry of space vehicles components. The carbon/phenolic material samples have been performed in the hypersonic plasma tunnel of Plasma and Process Laboratory, available in Aeronautics Institute of Technology (ITA), by a plasma torch with a 50 kW DC power source. The plasma tunnel parameters were optimized to reproduce the conditions close to the critical re-entry point of the space vehicles payloads developed by the Aeronautics and Space Institute (IAE). The specimens in study were developed and manufactured in Brazil. Mass loss and specific mass loss rates of the samples and the back surface temperatures, as a function of the exposure time to the thermal flow, were determined. A computational simulation based in a two-front ablation model was performed, in order to compare the tests and the simulation results. The results allowed to estimate the ablative behavior of the tested material and to validate the theoretical model used in the computational simulation for its use in geometries close to the thermal protection systems used in the Brazilian space and suborbital vehicles.

Post-Flight Analysis of GPSR Performance During Orion Exploration Flight Test 1

NASA Technical Reports Server (NTRS)

Barker, Lee; Mamich, Harvey; McGregor, John

2016-01-01

On 5 December 2014, the first test flight of the Orion Multi-Purpose Crew Vehicle executed a unique and challenging flight profile including an elevated re-entry velocity and steeper flight path angle to envelope lunar re-entry conditions. A new navigation system including a single frequency (L1) GPS receiver was evaluated for use as part of the redundant navigation system required for human space flight. The single frequency receiver was challenged by a highly dynamic flight environment including flight above low Earth orbit, as well as single frequency operation with ionospheric delay present. This paper presents a brief description of the GPS navigation system, an independent analysis of flight telemetry data, and evaluation of the GPSR performance, including evaluation of the ionospheric model employed to supplement the single frequency receiver. Lessons learned and potential improvements will be discussed.

Parametric Study of Cantilever Plates Exposed to Supersonic and Hypersonic Flows

NASA Astrophysics Data System (ADS)

Sri Harsha, A.; Rizwan, M.; Kuldeep, S.; Giridhara Prasad, A.; Akhil, J.; Nagaraja, S. R.

2017-08-01

Analysis of hypersonic flows associated with re-entry vehicles has gained a lot of significance due to the advancements in Aerospace Engineering. An area that is studied extensively by researchers is the simultaneous reduction aerodynamic drag and aero heating in re-entry vehicles. Out of the many strategies being studied, the use of aerospikes at the stagnation point of the vehicle is found to give favourable results. The structural stability of the aerospike becomes important as it is exposed to very high pressures and temperatures. Keeping this in view, the deflection and vibration of an inclined cantilever plate in hypersonic flow is carried out using ANSYS. Steady state pressure distribution obtained from Fluent is applied as load to the transient structural module for analysis. After due validation of the methods, the effects of parameters like flow Mach number, plate inclination and plate thickness on the deflection and vibration are studied.

Ares I-X First Stage Internal Aft Skirt Re-Entry Heating Data and Modeling

NASA Technical Reports Server (NTRS)

Schmitz, Craig P.; Tashakkor, Scott B.

2011-01-01

The CLVSTATE engineering code is being used to predict Ares-I launch vehicle first stage reentry aerodynamic heating. An engineering analysis is developed which yields reasonable predictions for the timing of the first stage aft skirt thermal curtain failure and the resulting internal gas temperatures. The analysis is based on correlations of the Ares I-X internal aft skirt gas temperatures and has been implemented into CLVSTATE. Validation of the thermal curtain opening models has been accomplished using additional Ares I-X thermocouple, calorimeter and pressure flight data. In addition, a technique which accounts for radiation losses at high altitudes has been developed which improves the gas temperature measurements obtained by the gas temperature probes (GTP). Updates to the CLVSTATE models are shown to improve the accuracy of the internal aft skirt heating predictions which will result in increased confidence in future vehicle designs

Reentry and the (Unmet) Needs of Women

ERIC Educational Resources Information Center

Scroggins, Jennifer R.; Malley, Sara

2010-01-01

The number of women under community-based criminal justice supervision in the U.S. has reached an all-time high. Because of this, there is an increased need for programs meant to address the unique needs of reentry women. In this article we examine a sample of 155 such programs to determine whether currently available reentry programs in the 10…

Community-Based Juvenile Reentry Services: The Effects of Service Dosage on Juvenile and Adult Recidivism

ERIC Educational Resources Information Center

Abrams, Laura S.; Terry, Diane; Franke, Todd M.

2011-01-01

In this study the authors examined the influence of length of participation in a community-based reentry program on the odds of reconviction in the juvenile and adult criminal justice systems. A structured telephone survey of reentry program alumni was conducted with 75 transition-age (18-25 year-old) young men. Binary logistic regression analysis…

State Policies Affecting the "Adult Re-Entry Pipeline" in Postsecondary Education: Results of a Fifty-State Inventory

ERIC Educational Resources Information Center

Boeke, Marianne; Zis, Stacey; Ewell, Peter

2011-01-01

With support from the Bill and Melinda Gates Foundation, the National Center for Higher Education Management Systems (NCHEMS) is engaged in a two year project centered on state policies that foster student progression and success in the "adult re-entry pipeline." The adult re-entry pipeline consists of the many alternative pathways to…

Research on Aeroheating of Hypersonic Reentry Vehicle Base Flow Fields

NASA Astrophysics Data System (ADS)

Xuguo, Qin; Yongtao, Shui; Yonghai, Wang; Gang, Chen; Qiang, Li

2017-09-01

The structure of the base flow of a hypersonic reentry vehicle and the resulting base pressure and heat transfer have been studied by numerical study. The compressible Navier-Stokes equations are solved by the finite-volume method. SST k-ω turbulence model is used, and comparisons are made with flight test. Attention was focused on assessing the effects of angle of attack and Mach number. It was found that angle of attack can significantly alter the wake flow structure and reentry vehicle base pressure and heating distributions. The results of the simulation may provide a theoretical basis for the design of the thermal protection system of hypersonic reentry vehicles.

An adaptive reentry guidance method considering the influence of blackout zone

NASA Astrophysics Data System (ADS)

Wu, Yu; Yao, Jianyao; Qu, Xiangju

2018-01-01

Reentry guidance has been researched as a popular topic because it is critical for a successful flight. In view that the existing guidance methods do not take into account the accumulated navigation error of Inertial Navigation System (INS) in the blackout zone, in this paper, an adaptive reentry guidance method is proposed to obtain the optimal reentry trajectory quickly with the target of minimum aerodynamic heating rate. The terminal error in position and attitude can be also reduced with the proposed method. In this method, the whole reentry guidance task is divided into two phases, i.e., the trajectory updating phase and the trajectory planning phase. In the first phase, the idea of model predictive control (MPC) is used, and the receding optimization procedure ensures the optimal trajectory in the next few seconds. In the trajectory planning phase, after the vehicle has flown out of the blackout zone, the optimal reentry trajectory is obtained by online planning to adapt to the navigation information. An effective swarm intelligence algorithm, i.e. pigeon inspired optimization (PIO) algorithm, is applied to obtain the optimal reentry trajectory in both of the two phases. Compared to the trajectory updating method, the proposed method can reduce the terminal error by about 30% considering both the position and attitude, especially, the terminal error of height has almost been eliminated. Besides, the PIO algorithm performs better than the particle swarm optimization (PSO) algorithm both in the trajectory updating phase and the trajectory planning phases.

Rescue Shuttle Flight Re-Entry: Controlling Astronaut Thermal Exposure

NASA Technical Reports Server (NTRS)

Gillis, David B.; Hamilton, Douglas; Ilcus, Stana; Stepaniak, Phil; Polk, J. D.; Son, Chang; Bue, Grant

2008-01-01

A rescue mission for the STS-125 Hubble Telescope Repair Mission requires reentry from space with 11 crew members aboard, exceeding past cabin thermal load experience and risking crew thermal stress potentially causing cognitive performance and physiological decrements. The space shuttle crew cabin air revitalization system (ARS) was designed to support a nominal crew complement of 4 to 7 crew and 10 persons in emergencies, all in a shirt-sleeve environment. Subsequent to the addition of full pressure suits with individual cooling units, the ARS cannot maintain a stable temperature in the crew cabin during reentry thermal loads. Bulk cabin thermal models, used for rescue mission planning and analysis of crew cabin air, were unable to accurately represent crew workstation values of air flow, carbon dioxide, and heat content for the middeck. Crew temperature models suggested significantly elevated core temperatures. Planning for an STS-400 potential rescue of seven stranded crew utilized computational fluid dynamics (CFD) models to demonstrate inhomogeneous cabin thermal properties and improve analysis compared to bulk models. In the absence of monitoring of crew temperature, heart rate, metabolic rate and incomplete engineering data on the performance of the integrated cooling garment/cooling unit (ICG/CU) at cabin temperatures above 75 degrees F, related systems & models were reevaluated and tests conducted with humans in the loop. Changes to the cabin ventilation, ICU placement, crew reentry suit-donning procedures, Orbiter Program wave-off policy and post-landing power down and crew extraction were adopted. A second CFD and core temperature model incorporated the proposed changes and confirmed satisfactory cabin temperature, improved air distribution, and estimated core temperatures within safe limits. CONCLUSIONS: These changes in equipment, in-flight and post-landing procedures, and policy were implemented for the STS-400 rescue shuttle & will be implemented in any future rescue flights from the International Space Station of stranded shuttle crews.

Preliminary Subsystem Designs for the Assured Crew Return Vehicle (ACRV), volumes 1-3

NASA Technical Reports Server (NTRS)

1990-01-01

A long term manned facility in space must include provisions for the safety of the crew. The resolution of this need was the design of an Assured Crew Return Vehicle (ACRV). The main focus is on the braking and landing system of the ACRV. This subsystem of the ACRV was divided into three phases. The Phase 1 analysis showed that the use of a tether to aid in the reentry of the ACRV was infeasible due to cost and efficiency. Therefore, a standard rocket would be used for reentry. It was also found that the continental United States was an achievable landing site for the ACRV. The Phase 2 analysis determined the L/D of the vehicle to be 1.8, thus requiring the use of a lifting body for reentry. It was also determined that shuttle tiles would be used for the thermal protection system. In addition, a parachute sequence for further deceleration was included, namely a ringslot drogue chute, a pilot chute, and finally a ringsail main parachute. This sequence was found to be capable of slowing the vehicle to a descent velocity of 9 to 10 m/s, which is the required velocity for aerial recovery. The Phase 3 analysis proved that a Sikorsky CH-53E helicopter is capable of retrieving the ACRV at 5.5 km altitude with minimal g-forces induced on the ACRV and minimal induced moments on the helicopter upon hookup. The helicopter would be modified such that it could stabilize the ACRV close to the bottom of helicopter and carry it to the nearest designated trauma center.

Post-Flight Analysis of the Guidance, Navigation, and Control Performance During Orion Exploration Flight Test 1

NASA Technical Reports Server (NTRS)

Barth, Andrew; Mamich, Harvey; Hoelscher, Brian

2015-01-01

The first test flight of the Orion Multi-Purpose Crew Vehicle presented additional challenges for guidance, navigation and control as compared to a typical re-entry from the International Space Station or other Low Earth Orbit. An elevated re-entry velocity and steeper flight path angle were chosen to achieve aero-thermal flight test objectives. New IMU's, a GPS receiver, and baro altimeters were flight qualified to provide the redundant navigation needed for human space flight. The guidance and control systems must manage the vehicle lift vector in order to deliver the vehicle to a precision, coastal, water landing, while operating within aerodynamic load, reaction control system, and propellant constraints. Extensive pre-flight six degree-of-freedom analysis was performed that showed mission success for the nominal mission as well as in the presence of sensor and effector failures. Post-flight reconstruction analysis of the test flight is presented in this paper to show whether that all performance metrics were met and establish how well the pre-flight analysis predicted the in-flight performance.

A Youth Reentry Specialist Program for Released Incarcerated Youth with Handicapping Conditions. First Annual Report, September 1, 1985-August 31, 1986. Final Report.

ERIC Educational Resources Information Center

Wisconsin Univ. - Stout, Menomonie. Center for the Study of Correctional Education.

The Youth Reentry Specialist (YRS) project was designed to coordinate the reentry of handicapped youth from a juvenile corrections facility into special education programs and the world of work. The project's goal was to increase the probability of special education and vocational program participation of handicapped parolees. The project resulted…

The Rewarding Challenge: Welcoming Re-Entry Women Students to the Small College.

ERIC Educational Resources Information Center

Midland Lutheran Coll., Fremont, NE.

This handbook was designed to offer a low-cost, local, and practical approach to working with re-entry women college students. It is intended for use by staff in small colleges (under 1,000 students) where women's centers and on-campus child care are rare and where the needs of re-entry students have not been adequately addressed. The information…

Substance Abuse and Prison Recidivism: Themes from Qualitative Interviews

ERIC Educational Resources Information Center

Phillips, Lindsay A.

2010-01-01

This qualitative analysis explores the role of substance abuse in reentry from prison to society. Participants who recidivated (N = 20) in an urban prison system identified substance abuse as their primary reason for recidivism. Treatment implications are discussed.

The X-38 V-201 Flap Actuator Mechanism

NASA Technical Reports Server (NTRS)

Hagen, Jeff; Moore, Landon; Estes, Jay; Layer, Chris

2004-01-01

The X-38 Crew Rescue Vehicle V-201 space flight test article was designed to achieve an aerodynamically controlled re-entry from orbit in part through the use of two body mounted flaps on the lower rear side. These flaps are actuated by an electromechanical system that is partially exposed to the re-entry environment. These actuators are of a novel configuration and are unique in their requirement to function while exposed to re-entry conditions. The authors are not aware of any other vehicle in which a major actuator system was required to function throughout the complete re-entry profile while parts of the actuator were directly exposed to the ambient environment.

STRUCTURAL INEQUALITY AND SOCIAL SUPPORT FOR WOMEN PRISONERS RELEASED TO RURAL COMMUNITIES

PubMed Central

Nicdao, Ethel G.; Trott, Elise M.; Kellett, Nicole C.

2016-01-01

Incarceration and community reentry for rural women reflect gendered processes. We draw upon in-depth semi-structured interviews and focus groups to examine the return of women prisoners to underserved rural communities, while attending to the perspectives of their closest social supporters. Our findings underscore the complexity of the reentry process for rural women and its particular impact on their families. We challenge dominant discourses of personal responsibility that detract from the structura violence and injustice shaping reentry experiences for women and their social supporters. We also consider the policy implications of discharge and reentry planning for rural women and their families, as well as strategies to reduce recidivism. PMID:27274615

Orbiter Gap Filler Bending Model for Re-entry

NASA Technical Reports Server (NTRS)

Campbell, Charles H.

2007-01-01

Pressure loads on a protruding gap filler during an Orbiter reentry are investigated to evaluate the likelihood of extraction due to pressure loads, and to ascertain how much bending will be induced by re-entry pressure loads. Oblique shock wave theory is utilized to develop a representation of the pressure loads induced on a gap filler for the ISSHVFW trajectory, representative of a heavy weight ISS return. A free body diagram is utilized to react the forces induced by the pressure forces. Preliminary results developed using these methods demonstrate that pressure loads, alone, are not likely causes of gap filler extraction during reentry. Assessment of the amount a gap filler will bend over is presented. Implications of gap filler bending during re-entry include possible mitigation of early boundary layer transition concerns, uncertainty in ground based measurement of protruding gap fillers from historical Orbiter flight history, and uncertainty in the use of Orbiter gap fillers for boundary layer prediction calibration. Authors will be added to the author list as appropriate.

Empirical Accuracies of U.S. Space Surveillance Network Reentry Predictions

NASA Technical Reports Server (NTRS)

Johnson, Nicholas L.

2008-01-01

The U.S. Space Surveillance Network (SSN) issues formal satellite reentry predictions for objects which have the potential for generating debris which could pose a hazard to people or property on Earth. These prognostications, known as Tracking and Impact Prediction (TIP) messages, are nominally distributed at daily intervals beginning four days prior to the anticipated reentry and several times during the final 24 hours in orbit. The accuracy of these messages depends on the nature of the satellite s orbit, the characteristics of the space vehicle, solar activity, and many other factors. Despite the many influences on the time and the location of reentry, a useful assessment of the accuracies of TIP messages can be derived and compared with the official accuracies included with each TIP message. This paper summarizes the results of a study of numerous uncontrolled reentries of spacecraft and rocket bodies from nearly circular orbits over a span of several years. Insights are provided into the empirical accuracies and utility of SSN TIP messages.

A Novel 'Cheese Wire' Technique for Stent Positioning Following Difficult Iliac Artery Subintimal Dissection and Aortic Re-Entry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watkinson, A. F., E-mail: anthony.watkinson@rdeft.nhs.u

2009-07-15

Subintimal wire dissection is a well-established method for traversing difficult vascular occlusions. This technique relies on re-entry of the true lumen distal to the occlusion, which may be difficult in diseased vessels with significant calcification. This case report describes a novel 'cheese wire' technique to allow stent positioning without the use of proprietary re-entry devices.

Visible Signatures of Hypersonic Reentry

DTIC Science & Technology

2013-02-01

cases, these viewing zones extend a significant distance from the impact location and/or include the impact location for a potentially significant...period of time before impact . Nomenclature V = reentry body velocity [m/s] ρ = ambient air density [kg/m3] ρ0 = sea-level air density [kg/m3] φ...time from first noticeability to impact . IV. Conclusion For a given reentry body, methods in this paper allow calculation of noticeability and

Demonstrator of atmospheric reentry system with hyperbolic velocity—DASH

NASA Astrophysics Data System (ADS)

Morita, Yasuhiro; Kawaguchi, Jun'ichiro; Inatani, Yoshifumi; Abe, Takashi

2003-01-01

Among a wide variety of challenging projects planned for the coming decade is the MUSES-C mission designed by the ISAS of Japan. Despite huge amount of data collected by the previous interplanetary spacecraft and probes, the origin and evolution of the solar system still remains unveiled due to their limited information. Thus, our concern has been directed toward a sample return to carry sample from an asteroid back to the earth, which will contribute to better understanding of the system. One of the keys to success is considered the reentry technology with hyperbolic velocity, which has not been demonstrated yet. With this as background, the demonstrator of atmospheric reentry system with hyperbolic velocity, DASH, has been given a commitment to demonstrate the high-speed reentry technology, which will be launched in summer of next year by Japan's H-IIA rocket in a piggyback configuration. The spaceship, composed of a reentry capsule and its carrier, will be injected into a geostationary transfer orbit (GTO) and after several revolutions it will deorbit by burn of a solid propellant deorbit motor. The capsule, identical to that of the sample return mission, can experience the targeted level of thermal environment even from the GTO by tracing a specially designed reentry trajectory.

Potential application of X-ray communication through a plasma sheath encountered during spacecraft reentry into earth's atmosphere

NASA Astrophysics Data System (ADS)

Li, Huan; Tang, Xiaobin; Hang, Shuang; Liu, Yunpeng; Chen, Da

2017-03-01

Rapid progress in exploiting X-ray science has fueled its potential application in communication networks as a carrier wave for transmitting information through a plasma sheath during spacecraft reentry into earth's atmosphere. In this study, we addressed the physical transmission process of X-rays in the reentry plasma sheath and near-earth space theoretically. The interactions between the X-rays and reentry plasma sheath were investigated through the theoretical Wentzel-Kramers-Brillouin method, and the Monte Carlo simulation was employed to explore the transmission properties of X-rays in the near-earth space. The simulation results indicated that X-ray transmission was not influenced by the reentry plasma sheath compared with regular RF signals, and adopting various X-ray energies according to different spacecraft reentry altitudes is imperative when using X-ray uplink communication especially in the near-earth space. Additionally, the performance of the X-ray communication system was evaluated by applying the additive white Gaussian noise, Rayleigh fading channel, and plasma sheath channel. The Doppler shift, as a result of spacecraft velocity changes, was also calculated through the Matlab Simulink simulation, and various plasma sheath environments have no significant influence on X-ray communication owing to its exceedingly high carrier frequency.

Analysis Of The ATV1 Re-Entry Using Near-UV Spectroscopic Data From The ESA/NASA Multi-Instrument Aircraft Observation Campaign

NASA Astrophysics Data System (ADS)

Lohle, Stefan; Marynowski, Thomas; Knapp, Andreas; Wernitz, Ricarda; Lips, Tobias

2011-05-01

The first Automated Transfer Vehicle (ATV1) named Jules Verne was launched in March 2009 to carry over seven tons of experiments, fuel, water, food and other supplies to the International Space Station (ISS) orbiting at about 350 km. Attached to the ISS, it served as an extension to the space station, giving extra space for the six astronauts and cosmonauts who will ultimately form the permanent ISS Crew. On September 29, 2009, a controlled de-orbit maneuver lead the spacecraft to enter the Earth's atmosphere over the south pacific ocean. The following destructive re-entry was observed by two aircraft equipped with a wide variety of imaging and spectroscopic instruments. In this paper, we present quantitative results from the near-UV spectroscopic measurements acquired aboard an experimental DC-8 aircraft operated by NASA. The wavelength range of observation allows a determination of temperatures from radiation and the investigation of atomic radiation with respect to the identification of the destructive process. Furthermore, the excitation temperatures of chromium give an insight into the explosive events occurring during re-entry. Analysing the continuum of the measured spectra, the Planck radiation temperature is fitted to the data. These temperatures indicate that most of the radiating parts are titanium alloys, i.e. the outer structure of ATV1. All results within this paper are compared to a simulated break-up scenario and related to basic results from other experimenters which allows drawing an overall scenario for this destructive re-entry.

Ukrainian prisoners and community reentry challenges: implications for transitional care

PubMed Central

Morozova, Olga; Azbel, Lyuba; Grishaev, Yevgeny; Dvoryak, Sergii; Wickersham, Jeffrey A.; Altice, Frederick L.

2013-01-01

Purpose The study aims to assess reentry challenges faced by Ukrainian prisoners and to determine the factors associated with having a greater number of challenges in order to suggest pre- and post-release interventions with the aim of facilitating community reintegration. Design/methodology/approach A representative national cross-sectional study with a sample size of 402 prisoners was conducted among imprisoned adults within six months of release. The study consisted of interviews and biological testing for infectious diseases. Anticipated reentry challenges were assessed using a structured questionnaire. Findings The most difficult and relatively important challenges identified were finding a job or a stable source of income and staying out of prison following release. Risk-specific challenges pertinent to drug users and HIV-infected individuals were assessed as difficult, but generally less important. Similarly, challenges associated with reducing drug relapse were ranked as less important, with only 0.6 percent identifying opioid substitution therapy as a helpful measure. In the multivariate analysis, having a greater number of challenges is associated with previous incarcerations, drug use immediately before incarceration and lower levels of social support. Practical implications To facilitate community re-integration, it is vital to design interventions aimed at reducing recidivism and improvement of social support through comprehensive case management as well as to improve understanding about and address drug dependence issues among inmates by implementing evidence-based treatment both within prisons and after release. Originality/value This is the first comprehensive assessment of community reentry challenges by prisoners in the former Soviet Union. PMID:25152767

Factors associated with re-entry to out-of-home care among children in England.

PubMed

Mc Grath-Lone, Louise; Dearden, Lorraine; Harron, Katie; Nasim, Bilal; Gilbert, Ruth

2017-01-01

Exiting and re-entering out-of-home care (OHC) is considered a disruption to permanence which may have long-lasting, negative consequences for children due to a lack of stability and continuity. Each year approximately one-third of children in OHC in England exit, but information is lacking on rates of re-entries and associated factors. Using national administrative data, we calculated rates of re-entry among children exiting OHC from 2007 to 2012, identified key child and care factors associated with re-entry using Cox proportional hazards modelling, and developed a simple probability calculator to estimate which groups of children are most likely to re-enter OHC within three months. Between 2007 and 2012 re-entries to OHC in England decreased (from 23.3% to 14.4% within one year of exit, p<0.001), possibly due to concurrent changes in the way children exited OHC. Overall, more than one-third of children exiting OHC in 2008 re-entered within five years (35.3%, N=4076), but rates of re-entry varied by child and care characteristics including age, ethnicity, mode of exit, and placement stability. Based on these associated factors, we developed a calculator that can estimate the likelihood of rapid re-entry to OHC for a group of children and could be used by social care practitioners or service planners. Our findings provide insight into which groups of children are most likely to re-enter OHC, who may benefit from additional support or ongoing monitoring. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Epicardial mapping of ventricular fibrillation over the posterior descending artery and left posterior papillary muscle of the swine heart.

PubMed

Nielsen, Thomas D; Huang, Jian; Rogers, Jack M; Killingsworth, Cheryl R; Ideker, Raymond E

2009-01-01

Recent studies suggest that during ventricular fibrillation (VF) epicardial vessels may be a site of conduction block and the posterior papillary muscle (PPM) in the left ventricle (LV) may be the location of a "mother rotor." The goal of this study was to obtain evidence to support or refute these possibilities. Epicardial activation over the posterior LV and right ventricle (RV) was mapped during the first 20 s of electrically induced VF in six open-chest pigs with a 504 electrode plaque covering a 20 cm(2) area centered over the posterior descending artery (PDA). The locations of epicardial breakthrough as well as reentry clustered in time and space during VF. Spatially, reentry occurred significantly more frequently over the LV than the RV in all 48 episodes, and breakthrough clustered near the PPM (p < 0.001). Significant temporal clustering occurred in 79% of breakthrough episodes and 100% of reentry episodes. These temporal clusters occurred at different times so that there was significantly less breakthrough when reentry was present (p < 0.0001). Conduction block occurred significantly more frequently near the PDA than elsewhere. The PDA is a site of epicardial block which may contribute to VF maintenance. Epicardial breakthrough clusters near the PPM. Reentry also clusters in space but at a separate site. The fact that breakthrough and reentry cluster at different locations and at different times supports the possibility of a drifting filament at the PPM so that at times reentry is present on the surface but at other times the reentrant wavefront breaks through to the epicardium.

How do children with a chronic or long-term illness perceive their school re-entry after a period of homebound instruction?

PubMed

Boonen, H; Petry, K

2012-07-01

A considerable number of children are confronted with a chronic or long-term illness in their lives. For these children, absenteeism is problematic, because education plays a major role in stimulating their cognitive development and in promoting a sense of normalcy and psychosocial well-being. In the literature, a great deal of attention has been paid to school reintegration programmes, which try to counter the barriers that these children may face when they return to school. Another way of surmounting these barriers is through the use of homebound instruction, in which the educational process for the child is continued during the period of absence. Despite the growing awareness of the necessity of education for these children, there is still little empirical research available addressing programmes that facilitate school re-entry. The major goal of this study is to investigate how parents and their children with a chronic or long-term illness perceive school re-entry after a period of homebound instruction, by using a descriptive-explorative, multi-informant research design. Participants were 60 children and their parents who filled in a self-constructed questionnaire. Both parents and children perceived the period of homebound instruction, as well as their school re-entry, predominantly positively. Most of the children stated that they had been able to keep up with their subjects, and that they had good contact with their peers when they returned to school. According to parents, homebound instruction made a positive contribution to the school re-entry of their child. The current study is one of the first to explore the school re-entry of children with a chronic or long-term illness. According to both parents and children, the school re-entry process passed off positively. However, more research is needed with regard to the quality of education and the programmes aimed at facilitating school re-entry. © 2011 Blackwell Publishing Ltd.

Optimal Earth's reentry disposal of the Galileo constellation

NASA Astrophysics Data System (ADS)

Armellin, Roberto; San-Juan, Juan F.

2018-02-01

Nowadays there is international consensus that space activities must be managed to minimize debris generation and risk. The paper presents a method for the end-of-life (EoL) disposal of spacecraft in Medium Earth Orbit (MEO). The problem is formulated as a multiobjective optimisation one, which is solved with an evolutionary algorithm. An impulsive manoeuvre is optimised to reenter the spacecraft in Earth's atmosphere within 100 years. Pareto optimal solutions are obtained using the manoeuvre Δv and the time-to-reentry as objective functions to be minimised. To explore at the best the search space a semi-analytical orbit propagator, which can propagate an orbit for 100 years in few seconds, is adopted. An in-depth analysis of the results is carried out to understand the conditions leading to a fast reentry with minimum propellant. For this aim a new way of representing the disposal solutions is introduced. With a single 2D plot we are able to fully describe the time evolution of all the relevant orbital parameters as well as identify the conditions that enables the eccentricity build-up. The EoL disposal of the Galileo constellation is used as test case.

Incarcerated Women's Relationship-based Strategies to Avoid Drug Use After Community Re-Entry

PubMed Central

Snell-Rood, Claire; Staton-Tindall, Michele; Victor, Grant

2016-01-01

While recent research has stressed the supportive role that family and friends play for incarcerated persons as they reenter the community, drug-using incarcerated women reentering the community often have to rely on family, community, and intimate relationships that have played a role in their substance abuse and criminalization. In this study the authors conducted qualitative analysis of clinical sessions with rural, drug-using women (N = 20) in a larger prison-based HIV risk reduction intervention in Kentucky during 2012–2014 to examine incarcerated women's perceptions of the role of their family, community, and intimate relationships in their plans to decrease their substance abuse upon community re-entry. Women stressed the obstacles to receiving support in many of their family and drug-using relationships after community re-entry. Nonetheless, they asserted that changes in their relationships could support their desires to end their substance abuse by setting limits on and using their positive relationships, particularly with their children, to motivate them to change. Interventions to promote incarcerated women's health behavior changes—including substance abuse—must acknowledge the complex social environments in which they live. PMID:26643029

Development of thermal protection system of the MUSES-C/DASH reentry capsule

NASA Astrophysics Data System (ADS)

Yamada, Tetsuya; Inatani, Yoshifumi; Honda, Masahisa; Hirai, Ken'ich

2002-07-01

In the final phase of the MUSES-C mission, a small capsule with asteroid sample conducts reentry flight directly from the interplanetary transfer orbit at the velocity over 12 km/s. The severe heat flux, the complicated functional requirements, and small weight budget impose several engineering challenges on the designing of the thermal protection system of the capsule. The heat shield is required to function not only as ablator but also as a structural component. The cloth-layered carbon-phenolic ablator, which has higher allowable stress, is developed in newly-devised fabric method for avoiding delamination due to the high aerodynamic heating. The ablation analysis code, which takes into account of the effect of pyrolysis gas on the surface recession rate, has been developed and verified in the arc-heating tests in the facility environment of broad range of enthalpy level. The capsule was designed to be ventilated during the reentry flight up to about atmospheric pressure by the time of parachute deployment by being sealed with porous flow-restrict material. The designing of the thermal protection system, the hardware specifications, and the ground-based test programs of both MUSES-C and DASH capsule are summarized and discussed here in this paper.

STS-69 Flight Day 10 Highlights

NASA Technical Reports Server (NTRS)

1995-01-01

In honor of the Extravehicular Activity (EVA) spacewalk today, the tenth day of the STS-69 mission, the astronauts, Cmdr. Dave Walker, Pilot Ken Cockrell, and Mission Specialists Jim Voss, Jim Newman, and Mike Gernhardt, were awakened to the Frankie Valle and the Four Seasons tune, 'Walk Like A Man.' Voss and Gernhardt tested the new thermal spacesuits and some new tools in the shuttle's cargo bay for six hours. The EVA was successful. The rest of the astronauts monitored the EVA and packed up the equipment and experiments in preparation for their reentry flight tomorrow.

Ready4Work "In Brief": Update on Outcomes; Reentry May Be Critical for States, Cities. P/PV In Brief. Issue 6

ERIC Educational Resources Information Center

Farley, Chelsea; McClanahan, Wendy S.

2007-01-01

This issue of "P/PV In Brief" provides updated data from the Ready4Work prisoner reentry initiative, with a focus on the prison crisis occurring in many cities and states. While much more research is needed to understand the true, long-term impact of prisoner reentry initiatives, outcomes from Ready4Work were extremely promising in terms of…

Charts Depicting Kinematic and Heating Parameters for a Ballistic Reentry at Speeds of 26,000 to 45,000 Feet Per Second

NASA Technical Reports Server (NTRS)

Lovelace, Uriel M.

1961-01-01

Reentry trajectories, including computations of convective and radiative stagnation-point heat transfer, have been calculated by using equations for a point-mass reentry vehicle entering the atmosphere of a rotating, oblate earth. Velocity was varied from 26,000 to 45,000 feet per second; reentry angle, from the skip limit to -20 deg; ballistic drag parameter, from 50 to 200. Initial altitude was 400,000 feet. Explicit results are presented in charts which were computed for an initial latitude of 38 deg N and an azimuth of 90 deg from north. A method is presented whereby these results may be made valid for a range of initial latitude and azimuth angles.

Behavioral health problems, ex-offender reentry policies, and the "Second Chance Act".

PubMed

Pogorzelski, Wendy; Wolff, Nancy; Pan, Ko-Yu; Blitz, Cynthia L

2005-10-01

The federal "Second Chance Act of 2005" calls for expanding reentry services for people leaving prison, yet existing policies restrict access to needed services for those with criminal records. We examined the interaction between individual-level characteristics and policy-level restrictions related to criminal conviction, and the likely effects on access to resources upon reentry, using a sample of prisoners with Axis I mental disorders (n=3073). We identified multiple challenges related to convictions, including restricted access to housing, public assistance, and other resources. Invisible punishments embedded within existing policies were inconsistent with the call for second chances. Without modification of federal and state policies, the ability of reentry services to foster behavioral health and community reintegration is limited.

Atmospheric reentry flight test of winged space vehicle

NASA Astrophysics Data System (ADS)

Inatani, Yoshifumi; Akiba, Ryojiro; Hinada, Motoki; Nagatomo, Makoto

A summary of the atmospheric reentry flight experiment of winged space vehicle is presented. The test was conducted and carried out by the Institute of Space and Astronautical Science (ISAS) in Feb. 1992 in Kagoshima Space Center. It is the first Japanese atmospheric reentry flight of the controlled lifting vehicle. A prime objective of the flight is to demonstrate a high speed atmospheric entry flight capability and high-angle-of-attack flight capability in terms of aerodynamics, flight dynamics and flight control of these kind of vehicles. The launch of the winged vehicle was made by balloon and solid propellant rocket booster which was also the first trial in Japan. The vehicle accomplishes the lfight from space-equivalent condition to the atmospheric flight condition where reaction control system (RCS) attitude stabilization and aerodynamic control was used, respectively. In the flight, the vehicle's attitude was measured by both an inertial measurement unit (IMU) and an air data sensor (ADS) which were employed into an auto-pilot flight control loop. After completion of the entry transient flight, the vehicle experienced unexpected instability during the atmospheric decelerating flight; however, it recovered the attitude orientation and completed the transonic flight after that. The latest analysis shows that it is due to the ADS measurement error and the flight control gain scheduling; what happened was all understood. Some details of the test and the brief summary of the current status of the post flight analysis are presented.

Experimental Space Shuttle Orbiter Studies to Acquire Data for Code and Flight Heating Model Validation

NASA Technical Reports Server (NTRS)

Wadhams, T. P.; Holden, M. S.; MacLean, M. G.; Campbell, Charles

2010-01-01

In an experimental study to obtain detailed heating data over the Space Shuttle Orbiter, CUBRC has completed an extensive matrix of experiments using three distinct models and two unique hypervelocity wind tunnel facilities. This detailed data will be employed to assess heating augmentation due to boundary layer transition on the Orbiter wing leading edge and wind side acreage with comparisons to computational methods and flight data obtained during the Orbiter Entry Boundary Layer Flight Experiment and HYTHIRM during STS-119 reentry. These comparisons will facilitate critical updates to be made to the engineering tools employed to make assessments about natural and tripped boundary layer transition during Orbiter reentry. To achieve the goals of this study data was obtained over a range of Mach numbers from 10 to 18, with flight scaled Reynolds numbers and model attitudes representing key points on the Orbiter reentry trajectory. The first of these studies were performed as an integral part of Return to Flight activities following the accident that occurred during the reentry of the Space Shuttle Columbia (STS-107) in February of 2003. This accident was caused by debris, which originated from the foam covering the external tank bipod fitting ramps, striking and damaging critical wing leading edge heating tiles that reside in the Orbiter bow shock/wing interaction region. During investigation of the accident aeroheating team members discovered that only a limited amount of experimental wing leading edge data existed in this critical peak heating area and a need arose to acquire a detailed dataset of heating in this region. This new dataset was acquired in three phases consisting of a risk mitigation phase employing a 1.8% scale Orbiter model with special temperature sensitive paint covering the wing leading edge, a 0.9% scale Orbiter model with high resolution thin-film instrumentation in the span direction, and the primary 1.8% scale Orbiter model with detailed thin-film resolution in both the span and chord direction in the area of peak heating. Additional objectives of this first study included: obtaining natural or tripped turbulent wing leading edge heating levels, assessing the effectiveness of protuberances and cavities placed at specified locations on the orbiter over a range of Mach numbers and Reynolds numbers to evaluate and compare to existing engineering and computational tools, obtaining cavity floor heating to aid in the verification of cavity heating correlations, acquiring control surface deflection heating data on both the main body flap and elevons, and obtain high speed schlieren videos of the interaction of the orbiter nose bow shock with the wing leading edge. To support these objectives, the stainless steel 1.8% scale orbiter model in addition to the sensors on the wing leading edge was instrumented down the windward centerline, over the wing acreage on the port side, and painted with temperature sensitive paint on the starboard side wing acreage. In all, the stainless steel 1.8% scale Orbiter model was instrumented with over three-hundred highly sensitive thin-film heating sensors, two-hundred of which were located in the wing leading edge shock interaction region. Further experimental studies will also be performed following the successful acquisition of flight data during the Orbiter Entry Boundary Layer Flight Experiment and HYTHIRM on STS-119 at specific data points simulating flight conditions and geometries. Additional instrumentation and a protuberance matching the layout present during the STS-119 boundary layer transition flight experiment were added with testing performed at Mach number and Reynolds number conditions simulating conditions experienced in flight. In addition to the experimental studies, CUBRC also performed a large amount of CFD analysis to confirm and validate not only the tunnel freestream conditions, but also 3D flows over the orbiter acreage, wing leading edge, and controlurfaces to assess data quality, shock interaction locations, and control surface separation regions. This analysis is a standard part of any experimental program at CUBRC, and this information was of key importance for post-test data quality analysis and understanding particular phenomena seen in the data. All work during this effort was sponsored and paid for by the NASA Space Shuttle Program Office at the Johnson Space Center in Houston, Texas.

Short-Lasting Episodes of Torsade de Pointes in the Chronic Atrioventricular Block Dog Model Have a Focal Mechanism, While Longer-Lasting Episodes Are Maintained by Re-Entry.

PubMed

Vandersickel, Nele; Bossu, Alexandre; De Neve, Jan; Dunnink, Albert; Meijborg, Veronique M F; van der Heyden, Marcel A G; Beekman, Jet D M; De Bakker, Jacques M T; Vos, Marc A; Panfilov, Alexander V

2017-12-26

This study investigated the arrhythmogenic mechanisms responsible for torsade de pointes (TdP) in the chronic atrioventricular block dog model, known for its high susceptibility for TdP. The mechanism of TdP arrhythmias has been under debate for many years. Focal activity as well as re-entry have both been mentioned in the initiation and the perpetuation of TdP. In 5 TdP-sensitive chronic atrioventricular block dogs, 56 needle electrodes were evenly distributed transmurally to record 240 unipolar local electrograms simultaneously. Nonterminating (NT) episodes were defibrillated after 10 s. Software was developed to automatically detect activation times and to create 3-dimensional visualizations of the arrhythmia. For each episode of ectopic activity (ranging from 2 beats to NT episodes), a novel methodology was created to construct directed graphs of the wave propagation and detect re-entry loops by using an iterative depth-first-search algorithm. Depending on the TdP definition (number of consecutive ectopic beats), we analyzed 29 to 54 TdP: 29 were longer than 5 beats. In the total group, 9 were NT and 45 were self-terminating. Initiation and termination were always based on focal activity. Re-entry becomes more important in the longer-lasting episodes (>14 beats), whereas in all NT TdP, re-entry was the last active mechanism. During re-entry, excitation fronts were constantly present in the heart, while during focal TdP, there was always a silent interval between 2 consecutive waves (142 ms) during which excitation fronts were absent. Interbeat intervals were significantly smaller for re-entry episodes-220 versus 310 ms in focal. Electrograms recorded in particular areas during NT TdP episodes had significantly smaller amplitude (0.38) than during focal episodes (0.59). TdP can be driven by focal activity as well as by re-entry depending on the duration of the episode. NT episodes are always maintained by re-entry, which can be identified in local unipolar electrograms by shorter interbeat intervals and smaller deflection amplitude. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Levels and determinants of pesticide exposure in re-entry workers in vineyards: results of the PESTEXPO study.

PubMed

Baldi, Isabelle; Lebailly, P; Bouvier, G; Rondeau, V; Kientz-Bouchart, V; Canal-Raffin, M; Garrigou, A

2014-07-01

Physical contact with branches, leaves, fruit or vegetables in previously treated crops is responsible for the transfer of pesticides to the worker's skin in agricultural tasks such as harvesting, pruning, thinning, cutting or sorting. Few studies have documented workers' exposure during re-entry in vineyards. In the PESTEXPO study, we described levels of exposure and analyzed their determinants during re-entry and harvesting in vineyards in the Bordeaux area, France. Between 2002 and 2007, volunteers performing re-entry tasks (N=46 days) or harvesting (N=48 days) after dithiocarbamate or folpet treatment were observed. Detailed information on the tasks was collected and dermal contamination was assessed using patches placed on the skin and hand-washing at the end of each working phase. Daily median contamination was 1 967.7 μl of mixture during re-entry (90(e) percentile: 5 045.3 μl) and 18.7 μl during harvesting (90(e) percentile: 911.4 μl). The type of task was the parameter found to be the most strongly associated with contamination. For re-entry, the highest contaminations were observed during raising of wires and cutting of branches. During the harvest, the contamination was maximal for grape-picking. The delay since the last treatment and the rate of active ingredient per hectare played a role, together with other factors such as meteorological factors, crop and farm characteristics, gloves and clothes. Our results underline the necessity to take into account exposures during re-entry and harvest when considering pesticide exposure, both for epidemiological research and preventive action. Copyright © 2014 Elsevier Inc. All rights reserved.

Epicardial mapping of ventricular fibrillation over the posterior descending artery and left posterior papillary muscle of the swine heart

PubMed Central

Nielsen, Thomas D.; Huang, Jian; Rogers, Jack M.; Killingsworth, Cheryl R.

2008-01-01

Background Recent studies suggest that during ventricular fibrillation (VF) epicardial vessels may be a site of conduction block and the posterior papillary muscle (PPM) in the left ventricle (LV) may be the location of a “mother rotor.” The goal of this study was to obtain evidence to support or refute these possibilities. Methods Epicardial activation over the posterior LV and right ventricle (RV) was mapped during the first 20 s of electrically induced VF in six open-chest pigs with a 504 electrode plaque covering a 20 cm2 area centered over the posterior descending artery (PDA). Results The locations of epicardial breakthrough as well as reentry clustered in time and space during VF. Spatially, reentry occurred significantly more frequently over the LV than the RV in all 48 episodes, and breakthrough clustered near the PPM (p<0.001). Significant temporal clustering occurred in 79% of breakthrough episodes and 100% of reentry episodes. These temporal clusters occurred at different times so that there was significantly less breakthrough when reentry was present (p<0.0001). Conduction block occurred significantly more frequently near the PDA than elsewhere. Conclusions The PDA is a site of epicardial block which may contribute to VF maintenance. Epicardial breakthrough clusters near the PPM. Reentry also clusters in space but at a separate site. The fact that breakthrough and reentry cluster at different locations and at different times supports the possibility of a drifting filament at the PPM so that at times reentry is present on the surface but at other times the reentrant wavefront breaks through to the epicardium. PMID:18839296

Formation of virtual isthmus: A new scenario of spiral wave death after a decrease in excitability

NASA Astrophysics Data System (ADS)

Erofeev, I. S.; Agladze, K. I.

2015-11-01

Termination of rotating (spiral) waves or reentry is crucial when fighting with the most dangerous cardiac tachyarrhythmia. To increase the efficiency of the antiarrhythmic drugs as well as finding new prospective ones it is decisive to know the mechanisms how they act and influence the reentry dynamics. The most popular view on the mode of action of the contemporary antiarrhythmic drugs is that they increase the core of the rotating wave (reentry) to that extent that it is not enough space in the real heart for the reentry to exist. Since the excitation in cardiac cells is essentially change of the membrane potential, it relies on the functioning of the membrane ion channels. Thus, membrane ion channels serve as primary targets for the substances, which may serve as antiarrhythmics. At least, the entire group of antiarrhythmics class I (modulating activity of sodium channels) and partially class IV (modulating activity of calcium channels) are believed to destabilize and terminate reentry by decreasing the excitability of cardiac tissue. We developed an experimental model employing cardiac tissue culture and photosensitizer (AzoTAB) to study the process of the rotating wave termination while decreasing the excitability of the tissue. A new scenario of spiral wave cessation was observed: an asymmetric growth of the rotating wave core and subsequent formation of a virtual isthmus, which eventually caused a conduction block and the termination of the reentry.

Ongoing Capabilities and Developments of Re-Entry Plasma Ground Tests at EADS-ASTRIUM

NASA Technical Reports Server (NTRS)

Jullien, Pierre

2008-01-01

During re-entry, spacecrafts are subjected to extreme thermal loads. On mars, they may go through dust storms. These external heat loads are leading the design of re-entry vehicles or are affecting it for spacecraft facing solid propellant jet stream. Sizing the Thermal Protection System require a good knowledge of such solicitations and means to model and reproduce them on earth. Through its work on European projects, ASTRIUM has developed the full range of competences to deal with such issues. For instance, we have designed and tested the heat-shield of the Huygens probe which landed on Titan. In particular, our plasma generators aim to reproduce a wide variety of re-entry conditions. Heat loads are generated by the huge speed of the probes. Such conditions cannot be fully reproduced. Ground tests focus on reproducing local aerothermal loads by using slower but hotter flows. Our inductive plasma torch enables to test little samples at low TRL. Amongst the arc-jets, one was design to test architecture design of ISS crew return system and others fit more severe re-entry such as sample returns or Venus re-entry. The last developments aimed in testing samples in seeded flows. First step was to design and test the seeding device. Special diagnostics characterizing the resulting flow enabled us to fit it to the requirements.

ENTRYSAT: A 3U Cubesat to Study the Re-Entry Atmospheric Environment

NASA Astrophysics Data System (ADS)

Garcia, R. F.; Chaix, J.; Mimoun, D.; EntrySat student Team

2014-04-01

The EntrySat is a 3U CubeSat designed to study the uncontrolled atmospheric re-entry. The project, developed by ISAE in collaboration with ONERA, is funded by CNES and is intended to be launched in January 2016, in the context of the QB50 network. The scientific goal is to relate the kinematics of the satellite with the aerothermodynamic environment during re-entry. In particular, data will be compared with the computations of MUSIC/FAST, a new 6-degree of freedom code developed by ONERA to predict the trajectory of space debris. According to these requirements, the satellite will measure the temperature, pressure, heat flux, and drag force during re-entry, as well as the trajectory and attitude of the satellite. One of the major technological challenges is the retrieval of data during the re-entry phase, which will be based on the Iridium satellite network. The system design is based on the use of commercial COTS components, and is mostly developed by students from ISAE. As such, the EntrySat has an important educational value in the formation of young engineers.

The IXV experience, from the mission conception to the flight results

NASA Astrophysics Data System (ADS)

Tumino, G.; Mancuso, S.; Gallego, J.-M.; Dussy, S.; Preaud, J.-P.; Di Vita, G.; Brunner, P.

2016-07-01

The atmospheric re-entry domain is a cornerstone of a wide range of space applications, ranging from reusable launcher stages developments, robotic planetary exploration, human space flight, to innovative applications such as reusable research platforms for in orbit validation of multiple space applications technologies. The Intermediate experimental Vehicle (IXV) is an advanced demonstrator which has performed in-flight experimentation of atmospheric re-entry enabling systems and technologies aspects, with significant advancements on Europe's previous flight experiences, consolidating Europe's autonomous position in the strategic field of atmospheric re-entry. The IXV mission objectives were the design, development, manufacturing, assembling and on-ground to in-flight verification of an autonomous European lifting and aerodynamically controlled reentry system, integrating critical re-entry technologies at system level. Among such critical technologies of interest, special attention was paid to aerodynamic and aerothermodynamics experimentation, including advanced instrumentation for aerothermodynamics phenomena investigations, thermal protections and hot-structures, guidance, navigation and flight control through combined jets and aerodynamic surfaces (i.e. flaps), in particular focusing on the technologies integration at system level for flight, successfully performed on February 11th, 2015.

KSC-04pd1232

NASA Image and Video Library

2004-05-25

KENNEDY SPACE CENTER, FLA. - United Space Alliance workers J.C. Harrison (far left) and Amy Mangiacapra guide a wrapped piece of Columbia debris through the Vehicle Assembly Building, where it is stored. Alongside is NASA’s Scott Thurston, who is the Columbia debris coordinator. This piece is one of eight being released to The Aerospace Corporation in El Segundo, Calif., for testing and research. The Aerospace Corporation requested and will receive graphite/epoxy honeycomb skins from an Orbital Maneuvering System pod, Main Propulsion System Helium tanks, a Reaction Control System Helium tank and a Power Reactant Storage Distribution system tank. The company will use the parts to study re-entry effects on composite materials. NASA notified the Columbia crew’s families about the loan before releasing the items for study. Researchers believe the testing will show how materials are expected to respond to various heating and loads' environments. The findings will help calibrate tools and models used to predict hazards to people and property from reentering hardware. The Aerospace Corporation will have the debris for one year to perform analyses to estimate maximum temperatures during reentry based upon the geometry and mass of the recovered composite.

KSC-04pd1228

NASA Image and Video Library

2004-05-25

KENNEDY SPACE CENTER, FLA. - In the Vehicle Assembly Building (VAB), Scott Thurston looks at pieces of Columbia debris being prepared for transfer to the shipping facility before their delivery to The Aerospace Corporation in El Segundo, Calif. Thurston is the Columbia debris coordinator. The pieces have been released for loan to the non-governmental agency for testing and research. The Aerospace Corporation requested and will receive graphite/epoxy honeycomb skins from an Orbital Maneuvering System pod, Main Propulsion System Helium tanks, a Reaction Control System Helium tank and a Power Reactant Storage Distribution system tank. The company will use the parts to study re-entry effects on composite materials. NASA notified the Columbia crew’s families about the loan before releasing the items for study. Researchers believe the testing will show how materials are expected to respond to various heating and loads' environments. The findings will help calibrate tools and models used to predict hazards to people and property from reentering hardware. The Aerospace Corporation will have the debris for one year to perform analyses to estimate maximum temperatures during reentry based upon the geometry and mass of the recovered composite. Columbia’s debris is stored in the VAB.

KSC-04pd1230

NASA Image and Video Library

2004-05-25

KENNEDY SPACE CENTER, FLA. - With NASA’s Scott Thurston (left) alongside, United Space Alliance workers J.C. Harrison (in cap) and Amy Mangiacapra (right) begin moving a piece of Columbia debris being shipped to The Aerospace Corporation in El Segundo, Calif. Thurston is the Columbia debris coordinator. The pieces have been released for loan to the non-governmental agency for testing and research. The Aerospace Corporation requested and will receive graphite/epoxy honeycomb skins from an Orbital Maneuvering System pod, Main Propulsion System Helium tanks, a Reaction Control System Helium tank and a Power Reactant Storage Distribution system tank. The company will use the parts to study re-entry effects on composite materials. NASA notified the Columbia crew’s families about the loan before releasing the items for study. Researchers believe the testing will show how materials are expected to respond to various heating and loads' environments. The findings will help calibrate tools and models used to predict hazards to people and property from reentering hardware. The Aerospace Corporation will have the debris for one year to perform analyses to estimate maximum temperatures during reentry based upon the geometry and mass of the recovered composite. Columbia’s debris is stored in the VAB.

KSC-04PD-1228

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. In the Vehicle Assembly Building (VAB), Scott Thurston looks at pieces of Columbia debris being prepared for transfer to the shipping facility before their delivery to The Aerospace Corporation in El Segundo, Calif. Thurston is the Columbia debris coordinator. The pieces have been released for loan to the non-governmental agency for testing and research. The Aerospace Corporation requested and will receive graphite/epoxy honeycomb skins from an Orbital Maneuvering System pod, Main Propulsion System Helium tanks, a Reaction Control System Helium tank and a Power Reactant Storage Distribution system tank. The company will use the parts to study re-entry effects on composite materials. NASA notified the Columbia crews families about the loan before releasing the items for study. Researchers believe the testing will show how materials are expected to respond to various heating and loads' environments. The findings will help calibrate tools and models used to predict hazards to people and property from reentering hardware. The Aerospace Corporation will have the debris for one year to perform analyses to estimate maximum temperatures during reentry based upon the geometry and mass of the recovered composite. Columbias debris is stored in the VAB.

KSC-04PD-1230

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. With NASAs Scott Thurston (left) alongside, United Space Alliance workers J.C. Harrison (in cap) and Amy Mangiacapra (right) begin moving a piece of Columbia debris being shipped to The Aerospace Corporation in El Segundo, Calif. Thurston is the Columbia debris coordinator. The pieces have been released for loan to the non-governmental agency for testing and research. The Aerospace Corporation requested and will receive graphite/epoxy honeycomb skins from an Orbital Maneuvering System pod, Main Propulsion System Helium tanks, a Reaction Control System Helium tank and a Power Reactant Storage Distribution system tank. The company will use the parts to study re-entry effects on composite materials. NASA notified the Columbia crews families about the loan before releasing the items for study. Researchers believe the testing will show how materials are expected to respond to various heating and loads' environments. The findings will help calibrate tools and models used to predict hazards to people and property from reentering hardware. The Aerospace Corporation will have the debris for one year to perform analyses to estimate maximum temperatures during reentry based upon the geometry and mass of the recovered composite. Columbias debris is stored in the VAB.

Structural Integrity Of Low-Velocity Impacted C/SIC Ceramic Matrix Composites

NASA Astrophysics Data System (ADS)

Knoche, R.; Drose, A.

2012-07-01

Carbon fibre reinforced silicon carbide (C/SiC) ceramic matrix composites (CMC) are most favourable for thermal protection systems & hot structures in re-entry vehicles since they offer superior heat resistance, high specific strength as well as a low coefficient of temperature expansion (CTE). To ensure the structural integrity of these C/SiC structures and thus mission safety all potential degradation effects during manufacturing and lifetime have to be considered. One of the most probable defects which may harm the structural integrity significantly can be caused by low-velocity impacts (LVI) which may occur during transportation and integration by e.g. dropping of tools. Thus the present study focuses on the residual mechanical and thermo-mechanical performance of C/SiC composites after being exposed to a low-velocity impact in terms of initial and residual mechanical performance, changes in microstructure, as well as thermo-mechanical performance through exposing specimens to multiple experimentally simulated re-entries. The results reveal the impact characteristics and damage mechanisms of C/SiC CMC exposed to a low-velocity impact and evidence the functional reliability as well as the damage tolerance of the C/SiC material investigated.

Gravity wave and tidal structures between 60 and 140 km inferred from space shuttle reentry data

NASA Technical Reports Server (NTRS)

Fritts, David C.; Wang, Ding-Yi; Blanchard, Robert C.

1993-01-01

This study presents an analysis of density measurements made using high-resolution accelerometers aboard several space shuttles at altitudes from 60 to 140 km during reentry into the earth's atmosphere. The observed density fluctuations are interpreted in terms of gravity waves and tides and provide evidence of the importance of such motions well into the thermosphere. Height profiles of fractional density variance reveal that wave amplitudes increase at a rate consistent with observations at lower levels up to about 90 km. The rate of amplitude growth decreases at greater heights, however, and appears to cease above about 110 km. Wave amplitudes are nevertheless large at these heights and suggest that gravity waves may play an important role in forcing of the lower thermosphere.

KSC-98pc1639

NASA Image and Video Library

1998-11-12

The Stardust spacecraft sits in the Payload Hazardous Service Facility waiting to undergo installation and testing of the solar arrays, plus final installation and testing of spacecraft instruments followed by an overall spacecraft functional test. At the top is the re-entry capsule. Built by Lockheed Martin Astronautics near Denver, Colo., for the Jet Propulsion Laboratory (JPL) and NASA, the spacecraft Stardust will use a unique medium called aerogel to capture comet particles flying off the nucleus of comet Wild 2 in January 2004, plus collect interstellar dust for later analysis. Stardust will be launched aboard a Boeing Delta 7426 rocket from Complex 17, Cape Canaveral Air Station, targeted for Feb. 6, 1999. The collected samples will return to Earth in the re-entry capsule to be jettisoned from Stardust as it swings by Earth in January 2006

KSC-98pc1640

NASA Image and Video Library

1998-11-12

The Stardust spacecraft sits in the Payload Hazardous Service Facility waiting to undergo installation and testing of the solar arrays, plus final installation and testing of spacecraft instruments followed by an overall spacecraft functional test. At the top is the re-entry capsule. Built by Lockheed Martin Astronautics near Denver, Colo., for the Jet Propulsion Laboratory (JPL) and NASA, the spacecraft Stardust will use a unique medium called aerogel to capture comet particles flying off the nucleus of comet Wild 2 in January 2004, plus collect interstellar dust for later analysis. Stardust will be launched aboard a Boeing Delta 7426 rocket from Complex 17, Cape Canaveral Air Station, targeted for Feb. 6, 1999. The collected samples will return to Earth in the re-entry capsule to be jettisoned from Stardust as it swings by Earth in January 2006

Radiative properties of advanced spacecraft heat shield materials

NASA Technical Reports Server (NTRS)

Cunnington, G. R.; Funai, A. I.; Mcnab, T. K.

1983-01-01

Experimental results are presented to show the effects of simulated reentry exposure by convective heating and by radiant heating on spectral and total emittance of statically oxidized Inconel 617 and Haynes HS188 superalloys to 1260 K and a silicide coatea (R512E) columbium 752 alloy to 1590 K. Convective heating exposures were conducted in a supersonic arc plasma wind tunnel using a wedge-shaped specimen configuration. Radiant tests were conducted at a pressure of .003 atmospheres of dry air at a flow velocity of several meters per second. Convective heating specimens were subjected to 8, 20, and 38 15-min heating cycles, and radiant heating specimens were tested for 10, 20, 50, and 100 30-min heating cycles. Changes in radiative properties are explained in terms of changes in composition resulting from simulated reentry tests. The methods used to evaluate morphological, compositional and crystallographic changes include: Auger electron spectroscopy; scanning electron microscopy; X-ray diffraction analysis; and electron microprobe analysis.

Aerothermal Performance Constraint Analysis of Sharp Nosecaps and Leading Edges

NASA Technical Reports Server (NTRS)

Rizk, Yehia; Gee, Ken

2004-01-01

The main objective of this work is to predict the Aerothermal Performance Constraint (APC) for a class of Crew Transfer Vehicles (CTV) with shap noses and wing leading edges made out of UHTC which is a family of Ultra High Temperature Ceramics materials developed at NASA Ames. The APC is based on the theoretical temperature limit of the material which is usually encountered at the CTV nose or wing leading edge. The APC places a lower limit on the trajectory of the CTV in the altitude velocity space. The APC is used as one of the constraints in developing reentry and abort trajectories for the CTV. The trajectories are then used to generate transient thermal response of the nosecaps and wing leading edges which are represented as either a one piece of UHTC or two piece (UHTC + RCC) with perfect axial contact. The final paper will include more details about the analysis procedure and will also include results for reentry and abort design trajectories.

Flight and ground tests of a very low density elastomeric ablative material

NASA Technical Reports Server (NTRS)

Olsen, G. C.; Chapman, A. J., III

1972-01-01

A very low density ablative material, a silicone-phenolic composite, was flight tested on a recoverable spacecraft launched by a Pacemaker vehicle system; and, in addition, it was tested in an arc heated wind tunnel at three conditions which encompassed most of the reentry heating conditions of the flight tests. The material was composed, by weight, of 71 percent phenolic spheres, 22.8 percent silicone resin, 2.2 percent catalyst, and 4 percent silica fibers. The tests were conducted to evaluate the ablator performance in both arc tunnel and flight tests and to determine the predictability of the albator performance by using computed results from an existing one-dimensional numerical analysis. The flight tested ablator experienced only moderate surface recession and retained a smooth surface except for isolated areas where the char was completely removed, probably following reentry and prior to or during recovery. Analytical results show good agreement between arc tunnel and flight test results. The thermophysical properties used in the analysis are tabulated.

An Automated Method to Compute Orbital Re-entry Trajectories with Heating Constraints

NASA Technical Reports Server (NTRS)

Zimmerman, Curtis; Dukeman, Greg; Hanson, John; Fogle, Frank R. (Technical Monitor)

2002-01-01

Determining how to properly manipulate the controls of a re-entering re-usable launch vehicle (RLV) so that it is able to safely return to Earth and land involves the solution of a two-point boundary value problem (TPBVP). This problem, which can be quite difficult, is traditionally solved on the ground prior to flight. If necessary, a nearly unlimited amount of time is available to find the 'best' solution using a variety of trajectory design and optimization tools. The role of entry guidance during flight is to follow the pre- determined reference solution while correcting for any errors encountered along the way. This guidance method is both highly reliable and very efficient in terms of onboard computer resources. There is a growing interest in a style of entry guidance that places the responsibility of solving the TPBVP in the actual entry guidance flight software. Here there is very limited computer time. The powerful, but finicky, mathematical tools used by trajectory designers on the ground cannot in general be converted to do the job. Non-convergence or slow convergence can result in disaster. The challenges of designing such an algorithm are numerous and difficult. Yet the payoff (in the form of decreased operational costs and increased safety) can be substantiaL This paper presents an algorithm that incorporates features of both types of guidance strategies. It takes an initial RLV orbital re-entry state and finds a trajectory that will safely transport the vehicle to Earth. During actual flight, the computed trajectory is used as the reference to be flown by a more traditional guidance method.

Re-Entry Point Targeting for LEO Spacecraft using Aerodynamic Drag

NASA Technical Reports Server (NTRS)

Omar, Sanny; Bevilacqua, Riccardo; Fineberg, Laurence; Treptow, Justin; Johnson, Yusef; Clark, Scott

2016-01-01

Most Low Earth Orbit (LEO) spacecraft do not have thrusters and re-enter atmosphere in random locations at uncertain times. Objects pose a risk to persons, property, or other satellites. Has become a larger concern with the recent increase in small satellites. Working on a NASA funded project to design a retractable drag device to expedite de-orbit and target a re-entry location through modulation of the drag area. Will be discussing the re-entry point targeting algorithm here.

Utilizing Weather RADAR for Rapid Location of Meteorite Falls and Space Debris Re-Entry

NASA Technical Reports Server (NTRS)

Fries, Marc D.

2016-01-01

This activity utilizes existing NOAA weather RADAR imagery to locate meteorite falls and space debris falls. The near-real-time availability and spatial accuracy of these data allow rapid recovery of material from both meteorite falls and space debris re-entry events. To date, at least 22 meteorite fall recoveries have benefitted from RADAR detection and fall modeling, and multiple debris re-entry events over the United States have been observed in unprecedented detail.

Long-term outcomes after re-entry device use for recanalization of common iliac artery chronic total occlusions.

PubMed

Kokkinidis, Damianos G; Alvandi, Bejan; Cotter, Ryan; Hossain, Prio; Foley, T Raymond; Singh, Gagan D; Waldo, Stephen W; Laird, John R; Armstrong, Ehrin J

2018-03-09

To examine the impact of re-entry device (RED) use on 1- and 5-year outcomes after endovascular treatment of common iliac artery (CIA) chronic total Occlusions (CTOs). There are not enough data regarding the long-term safety and efficacy of RED. We performed a two-center retrospective study of 115 patients (140 lesions) undergoing CIA CTO endovascular intervention between 2006 and 2016. Baseline characteristics and long-term outcomes were described. A Cox proportional hazard model was developed to determine if REDs were associated with target lesion revascularization (TLR) or major adverse limb events (MALE) after 1 and 5 years. Among 140 lesions, 43 (31%) required use of a RED. The mean age was 63.9 years and the majority (n = 80) of patients were male. An antegrade crossing approach and treatment of restenotic lesions were less common in the RED group (10% vs. 29%, P < .05 and 0% vs. 21%, P < .05, respectively). There were no significant differences in Rutherford class, pre-procedure ABI, or patient presentation. The procedural complication rates were similar between the two groups. The 1- and 5-year TLR rates for lesions treated with re-entry device vs. standard approaches were 11% vs. 9%; P = 0.8 and 29% vs. 29%; P = 0.9 respectively. The 1 and 5-year MALE rates for lesions treated with re-entry device were 5% vs. 6%; P = 0.8 and 11% vs. 11%; P = 0.9 respectively. This retrospective analysis found that recanalization of CIA occlusions using a RED is safe and is associated with long-term clinical outcomes similar to that of standard crossing techniques. © 2018 Wiley Periodicals, Inc.

The interaction of oblique shocks in a shock layer in hypersonic flow

NASA Astrophysics Data System (ADS)

Baird, John P.; Thomas, J.; Joe, W. S.

1990-07-01

A new generation of spacecraft is currently being designed. Some of the proposed concepts involve the use of air breathing engines during part of the earth to orbit flight phase. In the case of the HOTOL concept studies, the engine intakes will be covered for the re-entry phase, and will protrude through the windward surface shock layer during re-entry. An understanding of the complex flow which will occur over the closed intakes during the hypersonic re-entry is important for at least two reasons. Firstly, the heat transfer on the surfaces has to be estimated to allow for suitable intake cover design. Secondly, the wake of the intakes interacts with the underside of the wings and control surfaces, and could possibly cause handling anomalies. The present paper describes a study in which a simplified model involving a double wedge mounted on a flat plate at incidence (Fig. 1) was tested in the Free Piston Shock Tunnel T3 at the Australian National University. Heat transfer measurements and shock luminosity photographs were recorded at two operating conditions, one with a stagnation enthalpy of 22 MJ/kg and the other with 2.8 MJ/kg. A flow analysis which identified a number of significantly different flow regimes was also performed. Heat transfer measurements indicate that heating rates well in excess of those expected at the stagnation point on the nose of the spacecraft can be expected. The results also highlighted a compromise which is a necessary feature of this type of design. The compromise involves a trade off between intake efficiency during the air breathing phase of operation and the reduction of heat transfer during the re-entry phase.

14 CFR 440.3 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... for the launch or reentry of a reusable suborbital rocket. Permitted activity means the launch or reentry of a reusable suborbital rocket conducted under a permit issued by the FAA. Property damage means...

14 CFR 440.3 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... for the launch or reentry of a reusable suborbital rocket. Permitted activity means the launch or reentry of a reusable suborbital rocket conducted under a permit issued by the FAA. Property damage means...

14 CFR 440.3 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... for the launch or reentry of a reusable suborbital rocket. Permitted activity means the launch or reentry of a reusable suborbital rocket conducted under a permit issued by the FAA. Property damage means...

Guttiferone K impedes cell cycle re-entry of quiescent prostate cancer cells via stabilization of FBXW7 and subsequent c-MYC degradation.

PubMed

Xi, Z; Yao, M; Li, Y; Xie, C; Holst, J; Liu, T; Cai, S; Lao, Y; Tan, H; Xu, H-X; Dong, Q

2016-06-02

Cell cycle re-entry by quiescent cancer cells is an important mechanism for cancer progression. While high levels of c-MYC expression are sufficient for cell cycle re-entry, the modality to block c-MYC expression, and subsequent cell cycle re-entry, is limited. Using reversible quiescence rendered by serum withdrawal or contact inhibition in PTEN(null)/p53(WT) (LNCaP) or PTEN(null)/p53(mut) (PC-3) prostate cancer cells, we have identified a compound that is able to impede cell cycle re-entry through c-MYC. Guttiferone K (GUTK) blocked resumption of DNA synthesis and preserved the cell cycle phase characteristics of quiescent cells after release from the quiescence. In vehicle-treated cells, there was a rapid increase in c-MYC protein levels upon release from the quiescence. However, this increase was inhibited in the presence of GUTK with an associated acceleration in c-MYC protein degradation. The inhibitory effect of GUTK on cell cycle re-entry was significantly reduced in cells overexpressing c-MYC. The protein level of FBXW7, a subunit of E3 ubiquitin ligase responsible for degradation of c-MYC, was reduced upon the release from the quiescence. In contrast, GUTK stabilized FBXW7 protein levels during release from the quiescence. The critical role of FBXW7 was confirmed using siRNA knockdown, which impaired the inhibitory effect of GUTK on c-MYC protein levels and cell cycle re-entry. Administration of GUTK, either in vitro prior to transplantation or in vivo, suppressed the growth of quiescent prostate cancer cell xenografts. Furthermore, elevation of FBXW7 protein levels and reduction of c-MYC protein levels were found in the xenografts of GUTK-treated compared with vehicle-treated mice. Hence, we have identified a compound that is capable of impeding cell cycle re-entry by quiescent PTEN(null)/p53(WT) and PTEN(null)/p53(mut) prostate cancer cells likely by promoting c-MYC protein degradation through stabilization of FBXW7. Its usage as a clinical modality to prevent prostate cancer progression should be further evaluated.

Prediction methodologies for target scene generation in the aerothermal targets analysis program (ATAP)

NASA Astrophysics Data System (ADS)

Hudson, Douglas J.; Torres, Manuel; Dougherty, Catherine; Rajendran, Natesan; Thompson, Rhoe A.

2003-09-01

The Air Force Research Laboratory (AFRL) Aerothermal Targets Analysis Program (ATAP) is a user-friendly, engineering-level computational tool that features integrated aerodynamics, six-degree-of-freedom (6-DoF) trajectory/motion, convective and radiative heat transfer, and thermal/material response to provide an optimal blend of accuracy and speed for design and analysis applications. ATAP is sponsored by the Kinetic Kill Vehicle Hardware-in-the-Loop Simulator (KHILS) facility at Eglin AFB, where it is used with the CHAMP (Composite Hardbody and Missile Plume) technique for rapid infrared (IR) signature and imagery predictions. ATAP capabilities include an integrated 1-D conduction model for up to 5 in-depth material layers (with options for gaps/voids with radiative heat transfer), fin modeling, several surface ablation modeling options, a materials library with over 250 materials, options for user-defined materials, selectable/definable atmosphere and earth models, multiple trajectory options, and an array of aerodynamic prediction methods. All major code modeling features have been validated with ground-test data from wind tunnels, shock tubes, and ballistics ranges, and flight-test data for both U.S. and foreign strategic and theater systems. Numerous applications include the design and analysis of interceptors, booster and shroud configurations, window environments, tactical missiles, and reentry vehicles.

Resubmission of Gap Analysis Workshop for Training for Reintegration of Surgical Skills

DTIC Science & Technology

2011-10-01

the ABS, many other organizations do not have current reentry requirements but work with physicians on a case-by-case basis. Global competency...facs.org/education/ • Animal Labs • American Urological Association (AUA) Core Curriculum - http://www.auanet.org/eforms/ elearning /core

Reentry Women and Feminist Therapy: A Career Counseling Model.

ERIC Educational Resources Information Center

Christian, Connie; Wilson, Jean

1985-01-01

Using the tenets of feminist therapy, presents a career counseling model for reentry women. Describes goals, intervention strategies, and feminist tenets for each of three stages: stabilization; personal growth; and action. (MCF)

Ceramic Foams for TPS Applications

NASA Technical Reports Server (NTRS)

Stockpoole, Mairead

2003-01-01

Ceramic foams have potential in many areas of Thermal Protection Systems (TPS) including acreage and tile leading edges as well as being suitable as a repair approach for re-entry vehicles. NASA Ames is conducting ongoing research in developing lower-density foams from pre-ceramic polymer routes. One of the key factors to investigate, when developing new materials for re-entry applications, is their oxidation behavior in the appropriate re-entry environment which can be simulated using ground based arc jet (plasma jet) testing. Arc jet testing is required to provide the appropriate conditions (stagnation pressures, heat fluxes, enthalpies, heat loads and atmospheres) encountered during flight. This work looks at the response of ceramic foams (Si systems) exposed to simulated reentry environments and investigates the influence of microstructure and composition on the material? response. Other foam properties (mechanical and thermal) will also be presented.

Scratch2 prevents cell cycle re-entry by repressing miR-25 in postmitotic primary neurons.

PubMed

Rodríguez-Aznar, Eva; Barrallo-Gimeno, Alejandro; Nieto, M Angela

2013-03-20

During the development of the nervous system the regulation of cell cycle, differentiation, and survival is tightly interlinked. Newly generated neurons must keep cell cycle components under strict control, as cell cycle re-entry leads to neuronal degeneration and death. However, despite their relevance, the mechanisms controlling this process remain largely unexplored. Here we show that Scratch2 is involved in the control of the cell cycle in neurons in the developing spinal cord of the zebrafish embryo. scratch2 knockdown induces postmitotic neurons to re-enter mitosis. Scratch2 prevents cell cycle re-entry by maintaining high levels of the cycle inhibitor p57 through the downregulation of miR-25. Thus, Scratch2 appears to safeguard the homeostasis of postmitotic primary neurons by preventing cell cycle re-entry.

Reentry Tachycardia in Children: Adenosine Can Make It Worse.

PubMed

Hien, Maximilian D; Benito Castro, Fernando; Fournier, Philippe; Filleron, Anne; Tran, Tu-Anh

2016-10-08

We report on a rare but severe complication of adenosine use in a child with reentry tachycardia. Treatment with adenosine, which is the standard medical therapy of atrioventricular reentry tachycardia, led to the development of an irregular wide complex tachycardia, caused by rapid ventricular response to atrial fibrillation. The girl was finally stabilized with electrical cardioversion. We analyze the pathomechanism and discuss possible treatment options. Atrial fibrillation, as well as its conduction to the ventricles, can be caused by adenosine. Rapid ventricular response in children with Wolff-Parkinson-White syndrome is more frequent than previously believed. A patient history of atrial fibrillation is a contraindication for cardioversion with adenosine and needs to be assessed in children with reentry tachycardia. High-risk patients may potentially profit from prophylactic comedication with antiarrhythmic agents, such as flecainide, ibutilide, or vernakalant, before adenosine administration.

Thermal-Structural Evaluation of TD Ni-20Cr Thermal Protection System Panels

NASA Technical Reports Server (NTRS)

Eidinoff, H. L.; Rose, L.

1974-01-01

The results of a thermal-structural test program to verify the performance of a metallic/radiative Thermal Protection System (TPS) under reentry conditions are presented. This TPS panel is suitable for multiple reentry, high L/D space vehicles, such as the NASA space shuttle, having surface temperatures up to 1200 C (2200 F). The TPS panel tested consists of a corrugation-stiffened, beaded-skin TD Ni-20Cr metallic heat shield backed by a flexible fibrous quartz and radiative shield insulative system. Test conditions simulated the critical heating and aerodynamic pressure environments expected during 100 repeated missions of a reentry vehicle. Temperatures were measured during each reentry cycle; heat-shield flatness surveys to measure permanent set of the metallic components were made every 10 cycles. The TPS panel, in spite of localized surface failures, performed its designated function.

Advanced Technology and Mitigation (ATDM) SPARC Re-Entry Code Fiscal Year 2017 Progress and Accomplishments for ECP.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crozier, Paul; Howard, Micah; Rider, William J.

The SPARC (Sandia Parallel Aerodynamics and Reentry Code) will provide nuclear weapon qualification evidence for the random vibration and thermal environments created by re-entry of a warhead into the earth’s atmosphere. SPARC incorporates the innovative approaches of ATDM projects on several fronts including: effective harnessing of heterogeneous compute nodes using Kokkos, exascale-ready parallel scalability through asynchronous multi-tasking, uncertainty quantification through Sacado integration, implementation of state-of-the-art reentry physics and multiscale models, use of advanced verification and validation methods, and enabling of improved workflows for users. SPARC is being developed primarily for the Department of Energy nuclear weapon program, with additional developmentmore » and use of the code is being supported by the Department of Defense for conventional weapons programs.« less

Acute amiodarone promotes drift and early termination of spiral wave re-entry.

PubMed

Nakagawa, Harumichi; Honjo, Haruo; Ishiguro, Yuko S; Yamazaki, Masatoshi; Okuno, Yusuke; Harada, Masahide; Takanari, Hiroki; Sakuma, Ichiro; Kamiya, Kaichiro; Kodama, Itsuo

2010-07-01

Intravenous application of amiodarone is commonly used in the treatment of life-threatening arrhythmias, but the underlying mechanism is not fully understood. The purpose of the present study is to investigate the acute effects of amiodarone on spiral wave (SW) re-entry, the primary organization machinery of ventricular tachycardia/fibrillation (VT/VF), in comparison with lidocaine. A two-dimensional ventricular myocardial layer was obtained from 24 Langendorff-perfused rabbit hearts, and epicardial excitations were analyzed by high-resolution optical mapping. During basic stimulation, amiodarone (5 microM) caused prolongation of action potential duration (APD) by 5.6%-9.1%, whereas lidocaine (15 microM) caused APD shortening by 5.0%-6.4%. Amiodarone and lidocaine reduced conduction velocity similarly. Ventricular tachycardias induced by DC stimulation in the presence of amiodarone were of shorter duration (sustained-VTs >30 s/total VTs: 2/58, amiodarone vs 13/52, control), whereas those with lidocaine were of longer duration (22/73, lidocaine vs 14/58, control). Amiodarone caused prolongation of VT cycle length and destabilization of SW re-entry, which is characterized by marked prolongation of functional block lines, frequent wavefront-tail interactions near the rotation center, and considerable drift, leading to its early annihilation via collision with anatomical boundaries. Spiral wave re-entry in the presence of lidocaine was more stabilized than in control. In the anisotropic ventricular myocardium, amiodarone destabilizes SW re-entry facilitating its early termination. Lidocaine, in contrast, stabilizes SW re-entry resulting in its persistence.

Aerothermodynamics and planetary entry; Aerospace Sciences Meeting, 18th, Pasadena, CA, January 14-16, 1980 and Thermophysics Conference, 15th, Snowmass, CO, July 14-16, 1980, Technical Papers

NASA Astrophysics Data System (ADS)

Crosbie, A. L.

Aspects of aerothermodynamics are considered, taking into account aerodynamic heating for gaps in laminar and transitional boundary layers, the correlation of convection heat transfer for open cavities in supersonic flow, the heat transfer and pressure on a flat plate downstream of heated square jet in a Mach 0.4 to 0.8 crossflow, the effect of surface roughness character on turbulent reentry heating, three-dimensional protuberance interference heating in high-speed flow, and hypersonic flow over small span flaps in a thick turbulent boundary layer. Questions of thermal protection are investigated, giving attention to thermochemical ablation of tantalum carbide loaded carbon-carbons, the catalytic recombination of nitrogen and oxygen on high-temperature reusable surface insulation, particle acceleration using a helium arc heater, a temperature and ablation optical sensor, a wind-tunnel study of ascent heating of multiple reentry vehicle configurations, and reentry vehicle soft-recovery techniques. Subjects examined in connection with a discussion of planetary entry are related to a thermal protection system for the Galileo mission atmospheric entry probe, the viscosity of multicomponent partially ionized gas mixtures associated with Jovian entry, coupled laminar and turbulent flow solutions for Jovian entry, and a preliminary aerothermal analysis for Saturn entry.

Prevalence and correlates of community re-entry challenges faced by HIV-infected male prisoners in Malaysia

PubMed Central

Choi, P; Kavasery, R; Desai, M M; Govindasamy, S; Kamarulzaman, A; Altice, F L

2010-01-01

Summary HIV-infected prisoners face an inordinate number of community re-entry challenges. In 2007, 102 HIV-infected prisoners in Malaysia were surveyed anonymously within six months prior to release to assess the prevalence and correlates of community re-entry challenges. Staying out of prison (60.8%), remaining off drugs (39.2%), finding employment (35.3%) and obtaining HIV care (32.4%) were the re-entry challenges reported most frequently. Global stigma, negative self-image and public attitudes-related stigma were independently associated with challenges to obtaining HIV care. In multivariate analyses, those with previous incarcerations (adjusted odds ratio [AOR], 3.2; 95% confidence interval [CI], 1.4–7.6), higher HIV-related symptoms (AOR, 2.0; 95% CI, 1.0–4.1) and higher public attitudes-related stigma (AOR, 2.5; 95% CI, 1.2–5.1) had a significantly higher likelihood of identifying more re-entry challenges. Targeted interventions, such as effective drug treatment, HIV care and public awareness campaigns, are crucial for stemming the HIV epidemic and improving health outcomes among HIV-infected prisoners in Malaysia. PMID:20606222

Financial Responsibility for Reentry Vehicle Operations

DOT National Transportation Integrated Search

1995-05-01

The Department of Transportation's Office of Commercial Space Transportation is : in the process of assessing the safety of a reentry vehicle and its operation : and is developing an associated regulatory framework for ensuring public safety : while ...

ANNOTATED BIBLIOGRAPHY OF ASTRODYNAMICS AND RE-ENTRY MECHANICS,

DTIC Science & Technology

A selected list of references in the fields of astronautics and re-entry mechanics is classified and discussed, and a comprehensive subject and author index is included for ease in locating the references. (Author)

Methods to Determine the Deformation of the IRVE Hypersonic Inflatable Aerodynamic Decelerator

NASA Technical Reports Server (NTRS)

Young, William R.

2011-01-01

Small resonant targets used in conjunction with a microwave reflectometer to determine the deformation of the Hypersonic Inflatable Aerodynamic Decelerator (HIAD) during reentry are investigated. The reflectometer measures the distance to the targets and from this the HIAD deformation is determined. The HIAD is used by the Inflatable Reentry Vehicle Experiment (IRVE) which investigates the use of inflatable heat shields for atmospheric reentry. After several different microwave reflectometer systems were analyzed and compared it was determined that the most desirable for this application is the Frequency Doubling Target method.

Missile Aerodynamics for Ascent and Re-entry

NASA Technical Reports Server (NTRS)

Watts, Gaines L.; McCarter, James W.

2012-01-01

Aerodynamic force and moment equations are developed for 6-DOF missile simulations of both the ascent phase of flight and a tumbling re-entry. The missile coordinate frame (M frame) and a frame parallel to the M frame were used for formulating the aerodynamic equations. The missile configuration chosen as an example is a cylinder with fixed fins and a nose cone. The equations include both the static aerodynamic coefficients and the aerodynamic damping derivatives. The inclusion of aerodynamic damping is essential for simulating a tumbling re-entry. Appended information provides insight into aerodynamic damping.

Experiences of Asian Psychologists and Counselors Trained in the USA: An Exploratory Study

ERIC Educational Resources Information Center

Goh, Michael; Yon, Kyu Jin; Shimmi, Yukiko; Hirai, Tatsuya

2014-01-01

This study qualitatively explored the pre-departure to reentry experiences of Asian international psychologists and counselors trained in the USA. Semi-structured interviews were conducted with 10 participants from four different Asian countries. Inductive analysis with Consensual Qualitative Research methods was used to analyze the interview…

International Instrumentation Symposium, 39th, Albuquerque, NM, May 2-6, 1993, Proceedings

NASA Astrophysics Data System (ADS)

Various papers on instrumentation are presented. The general topics addressed include: data acquisition and processing, wind tunnels, pressure measurements, thermal measurements, force measurements, aerospace, metrology, flow measurements, real-time systems, measurement uncertainty, data analysis and calibration, computer applications, special tests, reentry vehicle systems, and human engineering.

IXV re-entry demonstrator: Mission overview, system challenges and flight reward

NASA Astrophysics Data System (ADS)

Angelini, Roberto; Denaro, Angelo

2016-07-01

The Intermediate eXperimental Vehicle (IXV) is an advanced re-entry demonstrator vehicle aimed to perform in-flight experimentation of atmospheric re-entry enabling systems and technologies. The IXV integrates key technologies at the system level, with significant advancements on Europe's previous flying test-beds. The project builds on previous achievements at system and technology levels, and provides a unique and concrete way of establishing and consolidating Europe's autonomous position in the strategic field of atmospheric re-entry. The IXV mission and system objectives are the design, development, manufacturing, assembling and on-ground to in-flight verification of an autonomous European lifting and aerodynamically controlled reentry system, integrating critical re-entry technologies at system level. Among such critical technologies of interest, special attention is paid to aerodynamic and aerothermodynamics experimentation, including advanced instrumentation for aerothermodynamics phenomena investigations, thermal protections and hot-structures, guidance, navigation and flight control through combined jets and aerodynamic surfaces (i.e. flaps), in particular focusing on the technologies integration at system level for flight. Following the extensive detailed design, manufacturing, qualification, integration and testing of the flight segment and ground segment elements, IXV has performed a full successful flight on February 11th 2015. After the launch with the VEGA launcher form the CSG spaceport in French Guyana, IXV has performed a full nominal mission ending with a successful splashdown in the Pacific Ocean. During Flight Phase, the IXV space and ground segments worked perfectly, implementing the whole flight program in line with the commanded maneuvers and trajectory prediction, performing an overall flight of 34.400 km including 7.600 km with hot atmospheric re-entry in automatic guidance, concluding with successful precision landing at a distance of ~1 km from the target, including the wind drift acting on the parachute from an altitude of 4.5 km.

KSC-98pc1638

NASA Image and Video Library

1998-11-12

In the Payload Hazardous Service Facility, a worker looks over the re-entry capsule on top of the Stardust spacecraft. The spacecraft will undergo installation and testing of the solar arrays, plus final installation and testing of spacecraft instruments followed by an overall spacecraft functional test. Built by Lockheed Martin Astronautics near Denver, Colo., for the Jet Propulsion Laboratory (JPL) and NASA, the spacecraft Stardust will use a unique medium called aerogel to capture comet particles flying off the nucleus of comet Wild 2 in January 2004, plus collect interstellar dust for later analysis. Stardust will be launched aboard a Boeing Delta 7426 rocket from Complex 17, Cape Canaveral Air Station, targeted for Feb. 6, 1999. The collected samples will return to Earth in the re-entry capsule to be jettisoned from Stardust as it swings by Earth in January 2006

Risk Assessment During the Final Phase of an Uncontrolled Re-Entry

NASA Astrophysics Data System (ADS)

Gaudel, A.; Hourtolle, C.; Goester, J. F.; Fuentes, N.

2013-09-01

As French National Space Agency, CNES is empowered to monitor compliance with technical regulations of the French Space Operation Act, FSOA, and to take all necessary measures to ensure the safety of people, property, public health and environment for all space operations involving French responsibility at international level.Therefore, CNES developed ELECTRA that calculates the risk for ground population involved in three types of events: rocket launching, controlled re-entry and uncontrolled re-entry. For the first two cases, ELECTRA takes into account degraded cases due to a premature stop of propulsion.Major evolutions were implemented recently on ELECTRA to meet new users' requirements, like the risk assessment during the final phase of uncontrolled re-entry, that can be combined with the computed risk for each country involved by impacts.The purpose of this paper is to provide an overview of the ELECTRA method and main functionalities, and then to highlight these recent improvements.

Pico Reentry Probes: Affordable Options for Reentry Measurements and Testing

NASA Technical Reports Server (NTRS)

Ailor, William H.; Kapoor, Vinod B.; Allen, Gay A., Jr.; Venkatapathy, Ethiraj; Arnold, James O.; Rasky, Daniel J.

2005-01-01

It is generally very costly to perform in-space and atmospheric entry experiments. This paper presents a new platform - the Pico Reentry Probe (PREP) - that we believe will make targeted flight-tests and planetary atmospheric probe science missions considerably more affordable. Small, lightweight, self-contained, it is designed as a "launch and forget" system, suitable for experiments that require no ongoing communication with the ground. It contains a data recorder, battery, transmitter, and user-customized instrumentation. Data recorded during reentry or space operations is returned at end-of-mission via transmission to Iridium satellites (in the case of earth-based operations) or a similar orbiting communication system for planetary missions. This paper discusses possible applications of this concept for Earth and Martian atmospheric entry science. Two well-known heritage aerodynamic shapes are considered as candidates for PREP: the shape developed for the Planetary Atmospheric Experiment Test (PAET) and that for the Deep Space II Mars Probe.

Distal re-entry closure with neobranching technique after thoracic endovascular aortic repair of Type B aortic dissection.

PubMed

Yamamoto, Masaki; Fukutomi, Takashi; Noguchi, Tatsuya; Orihashi, Kazumasa

2018-04-01

Retrograde false-lumen flow after thoracic endovascular aortic repair of Type B aortic dissection occurs occasionally and may have a negative impact on aortic remodelling and even prevent the decompression of the false lumen. A 67-year-old man with a Type B aortic dissection underwent thoracic endovascular aortic repair for severe compression of the true lumen and visceral malperfusion 7 weeks after the onset. Intraoperative angiography revealed proximal entry tear closure, but the false-lumen flow increased because of retrograde flow through the re-entry tear. Additional intervention including re-entry tear closure was performed with a neobranching technique with covered stent placement in the visceral artery from the aortic true lumen through the distal re-entry tear. We report a case of Type B aortic dissection and discuss the surgical techniques used.

Advances in Procedural Techniques - Antegrade

PubMed Central

Wilson, William; Spratt, James C.

2014-01-01

There have been many technological advances in antegrade CTO PCI, but perhaps most importantly has been the evolution of the “hybrid’ approach where ideally there exists a seamless interplay of antegrade wiring, antegrade dissection re-entry and retrograde approaches as dictated by procedural factors. Antegrade wire escalation with intimal tracking remains the preferred initial strategy in short CTOs without proximal cap ambiguity. More complex CTOs, however, usually require either a retrograde or an antegrade dissection re-entry approach, or both. Antegrade dissection re-entry is well suited to long occlusions where there is a healthy distal vessel and limited “interventional” collaterals. Early use of a dissection re-entry strategy will increase success rates, reduce complications, and minimise radiation exposure, contrast use as well as procedural times. Antegrade dissection can be achieved with a knuckle wire technique or the CrossBoss catheter whilst re-entry will be achieved in the most reproducible and reliable fashion by the Stingray balloon/wire. It should be avoided where there is potential for loss of large side branches. It remains to be seen whether use of newer dissection re-entry strategies will be associated with lower restenosis rates compared with the more uncontrolled subintimal tracking strategies such as STAR and whether stent insertion in the subintimal space is associated with higher rates of late stent malapposition and stent thrombosis. It is to be hoped that the algorithms, which have been developed to guide CTO operators, allow for a better transfer of knowledge and skills to increase uptake and acceptance of CTO PCI as a whole. PMID:24694104

Torque equilibrium attitude control for Skylab reentry

NASA Technical Reports Server (NTRS)

Glaese, J. R.; Kennel, H. F.

1979-01-01

All the available torque equilibrium attitudes (most were useless from the standpoint of lack of electrical power) and the equilibrium seeking method are presented, as well as the actual successful application during the 3 weeks prior to Skylab reentry.

34 CFR 668.4 - Payment period.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the State; or (iii) Ten percent of the clock hours in the payment period. (f) Re-entry within 180 days... provisions of § 668.22. (g) Re-entry after 180 days or transfer. (1) Except as provided in paragraph (g)(3...

34 CFR 668.4 - Payment period.

Code of Federal Regulations, 2012 CFR

2012-07-01

... the State; or (iii) Ten percent of the clock hours in the payment period. (f) Re-entry within 180 days... provisions of § 668.22. (g) Re-entry after 180 days or transfer. (1) Except as provided in paragraph (g)(3...

34 CFR 668.4 - Payment period.

Code of Federal Regulations, 2013 CFR

2013-07-01

... the State; or (iii) Ten percent of the clock hours in the payment period. (f) Re-entry within 180 days... provisions of § 668.22. (g) Re-entry after 180 days or transfer. (1) Except as provided in paragraph (g)(3...

34 CFR 668.4 - Payment period.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the State; or (iii) Ten percent of the clock hours in the payment period. (f) Re-entry within 180 days... provisions of § 668.22. (g) Re-entry after 180 days or transfer. (1) Except as provided in paragraph (g)(3...

34 CFR 668.4 - Payment period.

Code of Federal Regulations, 2014 CFR

2014-07-01

... the State; or (iii) Ten percent of the clock hours in the payment period. (f) Re-entry within 180 days... provisions of § 668.22. (g) Re-entry after 180 days or transfer. (1) Except as provided in paragraph (g)(3...

Causes and mitigation of radio frequency (RF) blackout during reentry of reusable launch vehicles

DOT National Transportation Integrated Search

2007-01-26

The Aerospace Corporation was tasked to assess radio frequency (RF) blackout phenomena caused by plasma generation around vehicles during reentry and presently known methodologies for mitigation of this condition inhibiting communications. The purpos...

Successful revascularization of chronic total occlusion of lower extremity arteries: a wire only and bail out use of re-entry device approach.

PubMed

Langhoff, R; Stumpe, S; Treitl, M; Schulte, K L

2013-10-01

The management of progressive peripheral artery disease experienced a vast change in paradigms over the last decades for the benefit of minimal invasive therapy as a first-line strategy. With the constant development of new devices, materials and dedicated access strategies, more complex lesions can be managed but the limitations to successfully treat chronic total occlusions are still the challenge to re-enter the true lumen. The aim of this retrospective study was to investigate, if a "wire only" strategy leads to an acceptable success rate in a mixed cohort of CTO lesions and to what extend re-entry devices are used. We retrospectively analyzed patients treated at the Vascular Center Berlin between 2011 and 2013 with chronic total occlusion out of a prospective conducted database (Endovascular MILestones - EMIL) for demographics, risk factors, co-morbidities, technical success rates, lesion characteristics and use of guidewires as well as re-entry systems. A total of 128 patients with 146 lesions, which represent a subgroup of all the cases performed in our center, following a predefined treatment algorithm for chronic total occlusions (CTOs), have been analyzed. We achieved a technical success in 133 (91.1%) of all cases following a "wire only" strategy. Out of 13 (8.9%) CTOs with technical failure in 7 (53.9%) CTOs a re-entry device (Off-Road®) with a 100% technical success has been used. In 91.1% of chronic total occlusion lesions the use of 2 wires only (88.7%) led to a successful recanalization. A "wire only" strategy followed by the use of a re-entry device as a bail out strategy, led to a total of 140 (96%) lesions to be successfully recanalized. In more than 90% of all cases with chronic total occlusion of peripheral lower extremity arteries, endovascular intervention has been successful following a "wire only" strategy. When deciding to use a re-entry device, in case of a failure of a proper wire re-entry at the reconstitution point, a technical success rate of 100% was achieved. Therefore following a strict wire algorithm and considering the use of a re-entry system as a bail out strategy will lead to a successful minimal invasive management of chronic total occlusion in nearly 100% of the cases with TASC II A - D lesions.

40 CFR 161.390 - Reentry protection data requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Reentry protection data requirements. 161.390 Section 161.390 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR REGISTRATION OF ANTIMICROBIAL PESTICIDES Data Requirement Tables...

Observation of Infrasonic/Acoustic/Seismic Waves Induced by Hypersonic Reentry of Hayabusa

NASA Astrophysics Data System (ADS)

Yamamoto, M.-Y.; Ishihara, Y.; Hiramatsu, Y.; Furumoto, M.; Fujita, K.

2012-05-01

Observation of infrasonic/acoustic/seismic waves induced by hypersonic reentry of HAYABUSA was carried out on June 13, 2010. Results by 3-sites arrayed observation will be shown in detail by comparison with multiple-sites optical observation.

A novel approach to spacecraft re-entry and recovery

NASA Astrophysics Data System (ADS)

Patten, Richard; Hedgecock, Judson C.

1990-01-01

A deployable radiative heat shield design for spacecraft reentry is discussed. The design would allow the spacecraft to be cylindrical instead of the the traditional conical shape, providing a greater internal volume and thus enhancing mission capabilities. The heat shield uses a flexible thermal blanket material which is deployed in a manner similar to an umbrella. Based on the radiative properties of this blanket material, heating constraints have been established which allow a descent trajectory to be designed. The heat shield and capsule configuration are analyzed for resistance to heat flux and aerodynamic stability based on reentry trajectory. Experimental tests are proposed.

Childhood cancer survivors' school (re)entry: Australian parents' perceptions.

PubMed

McLoone, J K; Wakefield, C E; Cohn, R J

2013-07-01

Starting or returning to school after intense medical treatment can be academically and socially challenging for childhood cancer survivors. This study aimed to evaluate the school (re)entry experience of children who had recently completed cancer treatment. Forty-two semi-structured telephone interviews were conducted to explore parents' perceptions of their child's (re)entry to school after completing treatment (23 mothers, 19 fathers, parent mean age 39.5 years; child mean age 7.76 years). Interviews were analysed using the framework of Miles and Huberman and emergent themes were organised using QSR NVivo8. Parents closely monitored their child's school (re)entry and fostered close relationships with their child's teacher to ensure swift communication of concerns should they arise. The most commonly reported difficulty related to aspects of peer socialisation; survivors either displayed a limited understanding of social rules such as turn taking, or related more to older children or teachers relative to their peers. Additionally, parents placed a strong emphasis on their child's overall personal development, above academic achievement alone. Improved parent, clinician and teacher awareness of the importance of continued peer socialisation during the treatment period is recommended in order to limit the ongoing ramifications this may have on school (re)entry post-treatment completion. © 2013 John Wiley & Sons Ltd.

Variations in the quality of inpatient rehabilitation care to facilitate school re-entry and cognitive and communication function for children with TBI.

PubMed

Ennis, Stephanie K; Rivara, Frederick P; Mangione-Smith, Rita; Konodi, Mark A; Mackenzie, Ellen J; Jaffe, Kenneth M

2013-01-01

To examine variations in processes of paediatric inpatient rehabilitation care related to school re-entry and management of cognitive and communication impairments after traumatic brain injury. Retrospective cohort study. Adherence to care processes recommended for children (aged 0-17) with moderate-to-severe traumatic brain injury and admitted for inpatient rehabilitation was assessed. Quality-of-care indicators for processes supporting school re-entry and cognitive and communication rehabilitation were applied to measure variations in care delivered to 174 children across nine facilities using medical record review. Adherence rates (the number of times recommended care was delivered or attempted divided by the number of times care was indicated) were calculated, revealing substantial variations in care within and between facilities. Overall, children received 51.3% (95% CI = 31.9-70.7) and 72.3% (95% CI = 61.1-83.5), of the care recommended for school re-entry and cognitive and communication rehabilitation, respectively. Substantial variations exist in the delivery of paediatric inpatient rehabilitation care processes for managing school re-entry and cognitive and communication impairments after traumatic brain injury. Measures of association of these care processes with patient outcomes are necessary. Reduction in this variation is essential to improving quality of care.

Late Functional Changes Post-Severe Traumatic Brain Injury Are Related to Community Reentry Support: Results From the PariS-TBI Cohort.

PubMed

Jourdan, Claire; Bayen, E; Vallat-Azouvi, C; Ghout, I; Darnoux, E; Azerad, S; Charanton, J; Aegerter, P; Pradat-Diehl, P; Ruet, A; Azouvi, P

To explore late functional changes after a traumatic brain injury and their relation to patients' characteristics and reentry support. Prospective follow-up of an inception cohort of adults with severe traumatic brain injury recruited in 2005-2007 in the Parisian area, France. One and 4-year assessments were performed by trained neuropsychologists. One-to-4-year change in the Glasgow Outcome Scale-Extended defined 3 groups: "improvement," "stability," and "worsening." Relationships between these groups and patients' characteristics were analyzed. Among 504 recruited patients and 245 four-year survivors, 93 participated in both evaluations. Overall Glasgow Outcome Scale-Extended improved by 0.4. Forty percent of the sample improved, 44% were stable, and 16% worsened. Being in a more unfavorable group was related to preinjury alcohol abuse and to higher anxiety and depression at 4 years. Attendance to a specialized community reentry unit was related to higher chances of being in the "improvement" group in univariate analyses and after adjustment for age, time to follow command, preinjury alcohol and occupation, and mood disorders (adjusted odds ratio [OR] = 4.6 [1.1-20]). Late functional changes were related to psychosocial variables and to reentry support. The effect of reentry support on late recovery needs to be confirmed by further investigations.

Transmission properties and physical mechanisms of X-ray communication for blackout mitigation during spacecraft reentry

NASA Astrophysics Data System (ADS)

Liu, Yunpeng; Li, Huan; Li, Yanlong; Hang, Shuang; Tang, Xiaobin

2017-11-01

Recent advances in X-ray science have witnessed the X-ray communication (XCOM), a new revolutionary technology first proposed by NASA since 2007. In combination with the advanced modulated X-ray source, XCOM shows a promising prospect for helping to alleviate the occurrence of inevitable blackout communication by using the regular radio frequency (RF) signal, paving the way towards realizing real-time communication during spacecraft reentry into atmosphere. Here, we acquired the detailed information of electron density distribution of plasma sheath encountered during vehicle reentry through Computational Fluid Dynamics simulation. Based on these derived parameters, Finite-difference Time-domain method was employed to investigate the transmission properties of X-rays through the plasma sheath, and the results indicated that X-ray transmission was not influenced by the reentry plasma sheath at different reentry altitudes and spacecraft surface positions compared with RF signal. In addition, 2D Particle-In-Cell simulation was also adopted to provide deeper insight into the transmission properties and physical mechanisms of X-ray carrier propagating through the plasma sheath, and results showed that the transmission coefficient was over 0.994 and the observation of plasma channel effect was also an important signature, which was of great importance to X-ray propagating through the plasma sheath.

Simultaneous Antegrade-Retrograde Subintimal Revascularization of a Femoropopliteal Chronic Total Occlusion by a Reentry Device-Facilitated Puncture of a Retrogradely Inserted Balloon.

PubMed

Goltz, Jan Peter; Anton, Susanne; Wiedner, Marcus; Barkhausen, Jörg; Stahlberg, Erik

2017-08-01

To report a rendezvous technique for subintimal revascularization of a chronic total occlusion (CTO) of the superficial femoral artery (SFA). This maneuver is appropriate after failure to cross a long SFA CTO via intra- and subintimal approaches from the ipsilateral femoral as well as retrograde posterior tibial artery (PTA) access sites. After predilation of the subintimal space from the femoral access, a reentry device was placed at the level of the first popliteal artery segment. A balloon was delivered via the retrograde PTA access and inflated at the corresponding level of the reentry device. The balloon was punctured with the needle of the reentry device under fluoroscopic control, and a 0.014-inch guidewire was placed within the punctured balloon. The balloon and the antegrade guidewire were retracted from the retrograde access while the guidewire was gently pushed from the femoral site. Conventional balloon angioplasty of the SFA occlusion was performed via the femoral access, followed by overlapping stent-graft implantation. Complete revascularization of the CTO was documented. In selected cases a transfemoral reentry device-assisted puncture of a retrogradely inserted balloon within the subintimal space may facilitate a rendezvous and revascularization if standard techniques to cross long CTOs have failed.

Reentry survivability modeling

NASA Astrophysics Data System (ADS)

Fudge, Michael L.; Maher, Robert L.

1997-10-01

Statistical methods for expressing the impact risk posed to space systems in general [and the International Space Station (ISS) in particular] by other resident space objects have been examined. One of the findings of this investigation is that there are legitimate physical modeling reasons for the common statistical expression of the collision risk. A combination of statistical methods and physical modeling is also used to express the impact risk posed by re-entering space systems to objects of interest (e.g., people and property) on Earth. One of the largest uncertainties in the expressing of this risk is the estimation of survivable material which survives reentry to impact Earth's surface. This point was recently demonstrated in dramatic fashion by the impact of an intact expendable launch vehicle (ELV) upper stage near a private residence in the continental United States. Since approximately half of the missions supporting ISS will utilize ELVs, it is appropriate to examine the methods used to estimate the amount and physical characteristics of ELV debris surviving reentry to impact Earth's surface. This paper examines reentry survivability estimation methodology, including the specific methodology used by Caiman Sciences' 'Survive' model. Comparison between empirical results (observations of objects which have been recovered on Earth after surviving reentry) and Survive estimates are presented for selected upper stage or spacecraft components and a Delta launch vehicle second stage.

Computational simulations of supersonic magnetohydrodynamic flow control, power and propulsion systems

NASA Astrophysics Data System (ADS)

Wan, Tian

This work is motivated by the lack of fully coupled computational tool that solves successfully the turbulent chemically reacting Navier-Stokes equation, the electron energy conservation equation and the electric current Poisson equation. In the present work, the abovementioned equations are solved in a fully coupled manner using fully implicit parallel GMRES methods. The system of Navier-Stokes equations are solved using a GMRES method with combined Schwarz and ILU(0) preconditioners. The electron energy equation and the electric current Poisson equation are solved using a GMRES method with combined SOR and Jacobi preconditioners. The fully coupled method has also been implemented successfully in an unstructured solver, US3D, and convergence test results were presented. This new method is shown two to five times faster than the original DPLR method. The Poisson solver is validated with analytic test problems. Then, four problems are selected; two of them are computed to explore the possibility of onboard MHD control and power generation, and the other two are simulation of experiments. First, the possibility of onboard reentry shock control by a magnetic field is explored. As part of a previous project, MHD power generation onboard a re-entry vehicle is also simulated. Then, the MHD acceleration experiments conducted at NASA Ames research center are simulated. Lastly, the MHD power generation experiments known as the HVEPS project are simulated. For code validation, the scramjet experiments at University of Queensland are simulated first. The generator section of the HVEPS test facility is computed then. The main conclusion is that the computational tool is accurate for different types of problems and flow conditions, and its accuracy and efficiency are necessary when the flow complexity increases.

An Automated Method to Compute Orbital Re-Entry Trajectories with Heating Constraints

NASA Technical Reports Server (NTRS)

Zimmerman, Curtis; Dukeman, Greg; Hanson, John; Fogle, Frank R. (Technical Monitor)

2002-01-01

Determining how to properly manipulate the controls of a re-entering re-usable launch vehicle (RLV) so that it is able to safely return to Earth and land involves the solution of a two-point boundary value problem (TPBVP). This problem, which can be quite difficult, is traditionally solved on the ground prior to flight. If necessary, a nearly unlimited amount of time is available to find the "best" solution using a variety of trajectory design and optimization tools. The role of entry guidance during flight is to follow the pre-determined reference solution while correcting for any errors encountered along the way. This guidance method is both highly reliable and very efficient in terms of onboard computer resources. There is a growing interest in a style of entry guidance that places the responsibility of solving the TPBVP in the actual entry guidance flight software. Here there is very limited computer time. The powerful, but finicky, mathematical tools used by trajectory designers on the ground cannot in general be made to do the job. Nonconvergence or slow convergence can result in disaster. The challenges of designing such an algorithm are numerous and difficult. Yet the payoff (in the form of decreased operational costs and increased safety) can be substantial. This paper presents an algorithm that incorporates features of both types of guidance strategies. It takes an initial RLV orbital re-entry state and finds a trajectory that will safely transport the vehicle to a Terminal Area Energy Management (TAEM) region. During actual flight, the computed trajectory is used as the reference to be flown by a more traditional guidance method.

Reentry heat transfer analysis of the space shuttle orbiter

NASA Technical Reports Server (NTRS)

Ko, W. L.; Quinn, R. D.; Gong, L.

1982-01-01

A structural performance and resizing finite element thermal analysis computer program was used in the reentry heat transfer analysis of the space shuttle. Two typical wing cross sections and a midfuselage cross section were selected for the analysis. The surface heat inputs to the thermal models were obtained from aerodynamic heating analyses, which assumed a purely turbulent boundary layer, a purely laminar boundary layer, separated flow, and transition from laminar to turbulent flow. The effect of internal radiation was found to be quite significant. With the effect of the internal radiation considered, the wing lower skin temperature became about 39 C (70 F) lower. The results were compared with fight data for space transportation system, trajectory 1. The calculated and measured temperatures compared well for the wing if laminar flow was assumed for the lower surface and bay one upper surface and if separated flow was assumed for the upper surfaces of bays other than bay one. For the fuselage, good agreement between the calculated and measured data was obtained if laminar flow was assumed for the bottom surface. The structural temperatures were found to reach their peak values shortly before touchdown. In addition, the finite element solutions were compared with those obtained from the conventional finite difference solutions.

Maneuver Analysis and Targeting Strategy for the Stardust Re-Entry Capsule

NASA Technical Reports Server (NTRS)

Helfrich, Clifford E.; Bhat, Ram; Kangas, Julie; Wilson, Roby; Wong, Mau; Potts, Chris; Williams, Ken

2006-01-01

Stardust employed biased maneuvers to limit turns and minimize execution errors. Biased maneuvers also addressed planetary protection and safety issues. Stardust utilized a fixed-direction burn for the final maneuver to match the prevailing attitude so no turns were needed. Performance of the final burn was calibrated in flight.

KSC-04pd1229

NASA Image and Video Library

2004-05-25

KENNEDY SPACE CENTER, FLA. - In the Vehicle Assembly Building (VAB), Scott Thurston (red shirt) stands by while a United Space Alliance worker (blue shirt) gets ready to start moving pieces of Columbia debris, such as the PRSD tank in front, for transfer to a shipping facility and delivery to The Aerospace Corporation in El Segundo, Calif. Thurston is the Columbia debris coordinator. The pieces have been released for loan to the non-governmental agency for testing and research. The Aerospace Corporation requested and will receive graphite/epoxy honeycomb skins from an Orbital Maneuvering System pod, Main Propulsion System Helium tanks, a Reaction Control System Helium tank and a Power Reactant Storage Distribution system tank. The company will use the parts to study re-entry effects on composite materials. NASA notified the Columbia crew’s families about the loan before releasing the items for study. Researchers believe the testing will show how materials are expected to respond to various heating and loads' environments. The findings will help calibrate tools and models used to predict hazards to people and property from reentering hardware. The Aerospace Corporation will have the debris for one year to perform analyses to estimate maximum temperatures during reentry based upon the geometry and mass of the recovered composite. Columbia’s debris is stored in the VAB.

KSC-04PD-1229

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. In the Vehicle Assembly Building (VAB), Scott Thurston (red shirt) stands by while a United Space Alliance worker (blue shirt) gets ready to start moving pieces of Columbia debris, such as the PRSD tank in front, for transfer to a shipping facility and delivery to The Aerospace Corporation in El Segundo, Calif. Thurston is the Columbia debris coordinator. The pieces have been released for loan to the non-governmental agency for testing and research. The Aerospace Corporation requested and will receive graphite/epoxy honeycomb skins from an Orbital Maneuvering System pod, Main Propulsion System Helium tanks, a Reaction Control System Helium tank and a Power Reactant Storage Distribution system tank. The company will use the parts to study re-entry effects on composite materials. NASA notified the Columbia crews families about the loan before releasing the items for study. Researchers believe the testing will show how materials are expected to respond to various heating and loads' environments. The findings will help calibrate tools and models used to predict hazards to people and property from reentering hardware. The Aerospace Corporation will have the debris for one year to perform analyses to estimate maximum temperatures during reentry based upon the geometry and mass of the recovered composite. Columbias debris is stored in the VAB.

Narrative change, narrative stability, and structural constraint: The case of prisoner reentry narratives

PubMed Central

Harding, David J.; Dobson, Cheyney C.; Wyse, Jessica J. B.; Morenoff, Jeffrey D.

2016-01-01

Cultural sociologists and other social scientists have increasingly used the concept of narrative as a theoretical tool to understand how individuals make sense of the links between their past, present, and future, how individuals construct social identities from cultural building blocks, and how culture shapes social action and individual behavior. Despite its richness, we contend that the narratives literature has yet to grapple with narrative change and stability when structural constraints or barriers challenge personal narratives and narrative identities. Particularly for marginalized groups, the potential incompatibility of personal narratives with daily experiences raises questions about the capacity of narratives to influence behavior and decision-making. In this study we draw on prospective longitudinal data on the reentry narratives and narrative identities of former prisoners to understand how narratives do and not change when confronted with contradictory experiences and structural constraints. We identify and describe the processes generating narrative change and stability among our subjects. These findings inform a framework for studying narrative change and stability based on four factors: the content of the narrative itself, the structural circumstances experienced by the individual, the institutional contexts in which the individual is embedded, and the social networks in which the individual is embedded. PMID:28316785

14 CFR 431.55 - Payload reentry review.

Code of Federal Regulations, 2012 CFR

2012-01-01

....55 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT... any issues that would adversely affect U.S. national security or foreign policy interests, would... reentry of a proposed payload presents any issues adversely affecting U.S. national security. (c) The FAA...

14 CFR 431.55 - Payload reentry review.

Code of Federal Regulations, 2013 CFR

2013-01-01

....55 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT... any issues that would adversely affect U.S. national security or foreign policy interests, would... reentry of a proposed payload presents any issues adversely affecting U.S. national security. (c) The FAA...

14 CFR 431.55 - Payload reentry review.

Code of Federal Regulations, 2010 CFR

2010-01-01

....55 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT... any issues that would adversely affect U.S. national security or foreign policy interests, would... reentry of a proposed payload presents any issues adversely affecting U.S. national security. (c) The FAA...

14 CFR 431.55 - Payload reentry review.

Code of Federal Regulations, 2011 CFR

2011-01-01

....55 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT... any issues that would adversely affect U.S. national security or foreign policy interests, would... reentry of a proposed payload presents any issues adversely affecting U.S. national security. (c) The FAA...

Hypersonic Cruise and Re-Entry Radio Frequency Blackout Mitigation: Alleviating the Communications Blackout Problem

NASA Technical Reports Server (NTRS)

Manning, Robert M.

2017-01-01

The work presented here will be a review of a NASA effort to provide a method to transmit and receive RF communications and telemetry through a re-entry plasma thus alleviating the classical RF blackout phenomenon.

Segment Specification for the Payload Segment of the Reusable Reentry Satellite: Rodent Module Version

NASA Technical Reports Server (NTRS)

1991-01-01

The Reusable Reentry Satellite (RRS) System is composed of the payload segment (PS), vehicle segment (VS), and mission support (MS) segments. This specification establishes the performance, design, development, and test requirements for the RRS Rodent Module (RM).

Entrainment and high-density three-dimensional mapping in right atrial macroreentry provide critical complementary information: Entrainment may unmask "visual reentry" as passive.

PubMed

Pathik, Bhupesh; Lee, Geoffrey; Nalliah, Chrishan; Joseph, Stephen; Morton, Joseph B; Sparks, Paul B; Sanders, Prashanthan; Kistler, Peter M; Kalman, Jonathan M

2017-10-01

With the recent advent of high-density (HD) 3-dimensional (3D) mapping, the utility of entrainment is uncertain. However, the limitations of visual representation and interpretation of these high-resolution 3D maps are unclear. The purpose of this study was to determine the strengths and limitations of both HD 3D mapping and entrainment mapping during mapping of right atrial macroreentry. Fifteen patients were studied. The number and type of circuits accounting for ≥90% of the tachycardia cycle length using HD 3D mapping were verified using systematic entrainment mapping. Entrainment sites with an unexpectedly long postpacing interval despite proximity to the active circuit were evaluated. Based on HD 3D mapping, 27 circuits were observed: 12 peritricuspid, 2 upper loop reentry, 10 lower loop reentry, and 3 lateral wall circuits. With entrainment, 17 of the 27 circuits were active: all 12 peritricuspid and 2 upper loop reentry. However, lower loop reentry was confirmed in only 3 of 10, and none of the 3 lateral wall circuits were present. Mean percentage of tachycardia cycle length covered by active circuits was 98% ± 1% vs 97% ± 2% for passive circuits (P = .09). None of the 345 entrainment runs terminated tachycardia or changed tachycardia mechanism. In 8 of 15 patients, 13 examples of unexpectedly long postpacing interval were observed at entrainment sites located distal to localized zones of slow conduction seen on HD 3D mapping. Using HD 3D mapping, "visual reentry" may be due to passive circuitous propagation rather than a critical reentrant circuit. HD 3D mapping provides new insights into regional conduction and helps explain unusual entrainment phenomena. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Dissection and re-entry techniques and longer-term outcomes following successful percutaneous coronary intervention of chronic total occlusion.

PubMed

Rinfret, Stéphane; Ribeiro, Henrique Barbosa; Nguyen, Can Manh; Nombela-Franco, Luis; Ureña, Marina; Rodés-Cabau, Josep

2014-11-01

New techniques involving dissection of the subintimal space and re-entry into the true lumen increase success rates in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). However, their long-term safety and efficacy were unknown. This study included a series of consecutive patients who underwent CTO PCI. All patients who did not present events were contacted 12 to 18 months after their PCI. The combined incidence of cardiac death, myocardial infarction, ischemia-driven target-vessel revascularization (TVR), or reocclusion was assessed as our primary outcome. From January 2010 to January 2013, of 212 CTOs treated in our CTO program, 192 (91%) were successfully opened (in 179 patients). Follow-up data were available for 187 CTOs (97.4%), with 82 (44%) that were opened with dissection re-entry and 105 (56%) with conventional wire escalation techniques. At a median follow-up of 398 days, the primary outcome occurred in 18 of 179 CTOs treated (10.7%), driven by TVR. No patient died from cardiac causes. Eleven CTOs (15.2%) treated with dissection re-entry versus 7 CTOs (7.3%) treated with wire escalation presented with the primary outcome (p = 0.17). With multivariate adjustment, dissection re-entry techniques had no significant impact on outcomes. However, treatment of an in-stent occlusion was independently associated with TVR (hazards ratio >6.0, p <0.001). In conclusion, dissection re-entry techniques have minimal impact on long-term outcomes after CTO PCI, which are favorable in most patients. However, treatment of an in-stent occlusion and use of sirolimus-eluting stent were predictors of subsequent adverse outcomes. Copyright © 2014 Elsevier Inc. All rights reserved.

Hydrodynamic boost: a novel re-entry technique in subintimal angioplasty of below-the-knee vessels.

PubMed

Ferraresi, Roberto; Hamade, Meneme; Gallicchio, Vito; Troisi, Nicola; Mauri, Giovanni

2016-08-01

To describe the hydrodynamic boost (HB) technique and report our preliminary results with this technique in the subintimal angioplasty of below-the-knee vessels. HB was used in 23 cases (14 males, mean age 73 ± 12 years) of critical limb ischemia, with long chronic total occlusion of tibial arteries extended to the ankle level. The operator performs a manual injection of diluted contrast dye through a 4 F catheter into the subintimal space, close to the patent true distal lumen, in order to achieve a tear in the intimal flap and a connection with the true lumen. In 19/23 (83 %) cases, the HB was effective in creating a connection between the subintimal space and the true distal lumen and it was possible to advance a wire and to conclude the procedure. In 4/23 (17 %) lesions, the HB failed and the procedure was successfully completed by retrograde approach. No major complications occurred. Mean length between catheter tip and re-entry point was 8 ± 5 mm. HB seems to be a feasible, safe and effective re-entry technique in distal below-the-knee vessels. This method represents an easy option for re-entry that extends the possibility of antegrade approach to obtain a successful revascularization. • In subintimal angioplasty of below-the-knee vessel re-entry can represent a challenge. • Inability to re-enter may determine the failure of the revascularization procedure. • HB is a novel re-entry technique feasible in distal below-the-knee vessels. • HB may increase the success rate of antegrade approach. • In case of failure, retrograde approach remains feasible.

In Depth Analysis of AVCOAT TPS Response to a Reentry Flow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Titov, E. V.; Kumar, Rakesh; Levin, D. A.

2011-05-20

Modeling of the high altitude portion of reentry vehicle trajectories with DSMC or statistical BGK solvers requires accurate evaluation of the boundary conditions at the ablating TPS surface. Presented in this article is a model which takes into account the complex ablation physics including the production of pyrolysis gases, and chemistry at the TPS surface. Since the ablation process is time dependent the modeling of the material response to the high energy reentry flow starts with the solution of the rarefied flow over the vehicle and then loosely couples with the material response. The objective of the present work ismore » to carry out conjugate thermal analysis by weakly coupling a flow solver to a material thermal response model. The latter model solves the one dimensional heat conduction equation accounting for the pyrolysis process that takes place in the reaction zone of an ablative thermal protection system (TPS) material. An estimate of the temperature range within which the pyrolysis reaction (decomposition and volatilization) takes place is obtained from Ref. [1]. The pyrolysis reaction results in the formation of char and the release of gases through the porous charred material. These gases remove additional amount of heat as they pass through the material, thus cooling the material (the process known as transpiration cooling). In the present work, we incorporate the transpiration cooling model in the material thermal response code in addition to the pyrolysis model. The flow in the boundary layer and in the vicinity of the TPS material is in the transitional flow regime. Therefore, we use a previously validated statistical BGK method to model the flow physics in the vicinity of the micro-cracks, since the BGK method allows simulations of flow at pressures higher than can be computed using DSMC.« less

Facilitation of school re-entry and peer acceptance of children with cancer: a review and meta-analysis of intervention studies.

PubMed

Helms, A S; Schmiegelow, K; Brok, J; Johansen, C; Thorsteinsson, T; Simovska, V; Larsen, H B

2016-01-01

Increased survival rates from childhood cancer call for efforts to reintegrate children with cancer back into their academic and social environments. The aims of this study were to: (1) review and analyse the existing literature on school re-entry interventions for children with cancer; and (2) discuss the importance of peer involvement in the treatment. Relevant databases were searched using equivalent search algorithms and six studies were selected that target children with cancer and/or their classmates. Two authors independently reviewed the literature for data extraction. The articles were reviewed using the PRISMA model for reporting reviews. Statistical calculations for the meta-analyses were done using Review Manager 5.2. The meta-analyses showed significant effects of school re-entry programmes in terms of enhancing academic achievement in children with cancer (P = 0.008) and lowering their levels of depression (P = 0.05). Increased knowledge among classmates was associated with less fear and a more positive attitude towards the child with cancer. Due to limited numbers of patients, lack of control groups, and the diversity of intervention strategies used in previous studies, there is a need for intervention programmes exploring the optimal path for the reintegration of children with cancer into the education system and into their peer groups. © 2014 John Wiley & Sons Ltd.

Fused slurry silicide coatings for columbium alloys reentry heat shields. Volume 1: Evaluation analysis

NASA Technical Reports Server (NTRS)

Fitzgerald, B.

1973-01-01

The R-512E (Si-20Cr-20Fe) fused slurry silicide coating process was optimized to coat full size (20in x 20in) single face rib and corrugation stiffened panels fabricated from FS-85 columbium alloy for 100 mission space shuttle heat shield applications. Structural life under simulated space shuttle lift-off stresses and reentry conditions demonstrated reuse capability well beyond 100 flights for R-512E coated FS-85 columbium heat shield panels. Demonstrated coating damage tolerance showed no immediate structural failure on exposure. The FS-85 columbium alloy was selected from five candidate alloys (Cb-752, C-129Y, WC-3015, B-66 and FS-85) based on the evaluation tests which have designed to determine: (1) change in material properties due to coating and reuse; (2) alloy tolerance to coating damage; (3) coating emittance characteristics under reuse conditions; and (4) new coating chemistries for improved coating life.

Development and flight qualification of the C-SiC thermal protection systems for the IXV

NASA Astrophysics Data System (ADS)

Buffenoir, François; Zeppa, Céline; Pichon, Thierry; Girard, Florent

2016-07-01

The Intermediate experimental Vehicle (IXV) atmospheric re-entry demonstrator, developed within the FLPP (Future Launcher Preparatory Programme) and funded by ESA, aimed at developing a demonstration vehicle that gave Europe a unique opportunity to increase its knowledge in the field of advanced atmospheric re-entry technologies. A key technology that has been demonstrated in real conditions through the flight of this ambitious vehicle is the thermal protection system (TPS) of the Vehicle. Within this programme, HERAKLES, Safran Group, has been in charge of the TPS of the windward and nose assemblies of the vehicle, and has developed and manufactured SepcarbInox® ceramic matrix composite (CMC) protection systems that provided a high temperature resistant non ablative outer mould line (OML) for enhanced aerodynamic control. The design and flight justification of these TPS has been achieved through extensive analysis and testing:

Thermal Testing of Ablators in the NASA Johnson Space Center Radiant Heat Test Facility

NASA Technical Reports Server (NTRS)

Del Papa, Steven; Milhoan, Jim; Remark, Brian; Suess, Leonard

2016-01-01

A spacecraft's thermal protection system (TPS) is required to survive the harsh environment experienced during reentry. Accurate thermal modeling of the TPS is required to since uncertainties in the thermal response result in higher design margins and an increase in mass. The Radiant Heat Test Facility (RHTF) located at the NASA Johnson Space Center (JSC) replicates the reentry temperatures and pressures on system level full scale TPS test models for the validation of thermal math models. Reusable TPS, i.e. tile or reinforced carbon-carbon (RCC), have been the primary materials tested in the past. However, current capsule designs for MPCV and commercial programs have required the use of an ablator TPS. The RHTF has successfully completed a pathfinder program on avcoat ablator material to demonstrate the feasibility of ablator testing. The test results and corresponding ablation analysis results are presented in this paper.

High-Energy Atmospheric Reentry Test Aerothermodynamic Analysis

NASA Technical Reports Server (NTRS)

Mazaheri, Alireza

2013-01-01

This paper presents an assessment of the aerothermodynamic environment around an 8.3 meter High Energy Atmospheric Reentry Test (HEART) vehicle. This study generated twelve nose shape configurations and compared their responses at the peak heating trajectory point against the baseline nose shape. The heat flux sensitivity to the angle of attack variations are also discussed. The possibility of a two-piece Thermal Protection System (TPS) design at the nose is also considered, as are the surface catalytic affects of the aeroheating environment of such configuration. Based on these analyses, an optimum nose shape is proposed to minimize the surface heating. A recommendation is also made for a two-piece TPS design, for which the surface catalytic uncertainty associated with the jump in heating at the nose-IAD juncture is reduced by a minimum of 93%. In this paper, the aeroshell is assumed to be rigid and the inflatable fluid interaction effect is left for future investigations

Long-term risk analysis associated with nuclear waste disposal in space

NASA Technical Reports Server (NTRS)

Friedlander, A. L.; Davis, D. R.

1979-01-01

An assessment and verification of previous analytic results on the long term risk of earth reentry for hazardous payloads is presented. The two areas were studied: (1) stability of nominal, near-circular storage orbits in the regions between Venus and earth and between earth and Mars, and (2) probability of earth reentry for off-nominal planet-crossing orbits resulting from deployment system failures. In the first area, numerical integrations of the equations of motion are compared with stability predications based on secular perturbation theory. The agreement is good in terms of the heliocentric distances covered and the general behavior of the orbital history, although certain near-resonance situations can lead to difficulty. In the second area, a Monte Carlo simulation of orbital evolution is used and the results compared with Opik's analytic theory of planetary encounters and collision statistics, with data verified to within a close order-of-magnitude.

Crystallographic Oxide Phase Identification of Char Deposits Obtained from Space Shuttle Columbia Window Debris

NASA Technical Reports Server (NTRS)

Olivas, J. D.; Wright, M. C.; Christoffersen, R.; Cone, D. M.; McDanels, S. J.

2009-01-01

Analyzing the remains of Space Shuttle Columbia has proven technically beneficial years after the vehicle breakup. This investigation focused on charred deposits on fragments of Columbia overhead windowpanes. Results were unexpected relative to the engineering understanding of material performance in a reentry environment. The TEM analysis demonstrated that the oxides of aluminum and titanium mixed with silicon oxides to preserve a history of thermal conditions to which portions of the vehicle were exposed. The presence of Ti during the beginning of the deposition process, along with the thermodynamic phase precipitation upon cool down, indicate that temperatures well above the Ti melt point were experienced. The stratified observations implied that additional exothermic reaction, expectedly metal combustion of a Ti structure, had to be present for oxide formation. Results are significant for aerospace vehicles where thermal protection system (TPS) breaches cause substructures to be in direct path with the reentry plasma. 1

Evaluation of a Prison Occupational Therapy Informal Education Program: A Pilot Study.

PubMed

Crabtree, Jeffrey L; Ohm, David; Wall, Jarrod M; Ray, Joseph

2016-12-01

This pilot study explored the strengths and weaknesses of an informal education program and identified elements of the program valued by participants. Participants were men living in a minimum security prison who had been incarcerated for ten or more years. The outside researcher was joined by three former program participants as co-researchers. Together, they interviewed 27 residents who completed the informal education program. Interviews were transcribed and de-identified. Researchers used the summative content analysis approach to analyze the data. Initial content analysis yielded five concepts: doing (engaging in purposeful activities); information (program handouts and discussions that included data and descriptions of all of the topics discussed); re-entry fears (socialization; making amends with victims and/or reuniting with family and friends); technology (includes, but not limited to, using smartphones, internet and other technology in all areas of occupation); and self-worth as a person. Further interpretation per the summative content analysis method yielded three themes: doing (engaged in purposeful activities), validation of self-worth (confirmation of being a valued human being in spite of having committed a serious crime) and concerns about the future (being able to successfully engage in virtually all occupations). Whilst informal education programs may help people who are incarcerated gain information, gain a sense of self-worth and allay some reentry fears, understanding the long-term affect such programs may have such as preparing them for successful re-entry to society or reducing recidivism rates, will require long-term follow-up. Regardless of the occupational therapy intervention, the practice of occupational therapy in the criminal justice system needs to be client-centred. Because of the small number of participants and limited access to participants, one should not generalize the findings of this study to other situations or populations. Further research to examine the effectiveness of an occupational therapy education program is warranted. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Assessing Intermediate Outcomes of a Faith-Based Residential Prisoner Reentry Program

ERIC Educational Resources Information Center

Roman, Caterina G.; Wolff, Ashley; Correa, Vanessa; Buck, Janeen

2007-01-01

Objective: This study examined intermediate outcomes of a faith-based prisoner reentry program by assessing how client spirituality related to client- and program-level characteristics, investigating differences between completers and terminators, and examining how religious preference, religiosity/spirituality, religious salience, and…

14 CFR 431.51 - General.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false General. 431.51 Section 431.51 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... approve reentry of the payload. (b) A payload reentry review may be conducted as part of an RLV mission...

14 CFR 431.51 - General.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false General. 431.51 Section 431.51 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... approve reentry of the payload. (b) A payload reentry review may be conducted as part of an RLV mission...

14 CFR 431.51 - General.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false General. 431.51 Section 431.51 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... approve reentry of the payload. (b) A payload reentry review may be conducted as part of an RLV mission...

14 CFR 431.51 - General.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false General. 431.51 Section 431.51 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... approve reentry of the payload. (b) A payload reentry review may be conducted as part of an RLV mission...

14 CFR 431.51 - General.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false General. 431.51 Section 431.51 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... approve reentry of the payload. (b) A payload reentry review may be conducted as part of an RLV mission...

14 CFR 433.9 - Environmental information.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Environmental information. 433.9 Section..., DEPARTMENT OF TRANSPORTATION LICENSING LICENSE TO OPERATE A REENTRY SITE § 433.9 Environmental information. An applicant shall submit environmental information concerning a proposed reentry site not covered by...

MS Garneau in his LES during re-entry preparations for STS-97

NASA Image and Video Library

2000-12-11

STS097-310-026 (11 December 2000) --- Astronaut Marc Garneau, mission specialist representing the Canadian Space Agency (CSA), is photographed in the launch and entry suit on the middeck of the Earth-orbiting Space Shuttle Endeavour prior to re-entry.

Predictions of cardiovascular responses during STS reentry using mathematical models

NASA Technical Reports Server (NTRS)

Leonard, J. I.; Srinivasan, R.

1985-01-01

The physiological adaptation to weightless exposure includes cardiovascular deconditioning arising in part from a loss of total circulating blood volume and resulting in a reduction of orthostatic tolerance. The crew of the Shuttle orbiter are less tolerant to acceleration forces in the head-to-foot direction during the reentry phase of the flight at a time they must function at a high level of performance. The factors that contribute to orthostatic intolerance during and following reentry and to predict the likelihood of impaired crew performance are evaluated. A computer simulation approach employing a mathematical model of the cardiovascular system is employed. It is shown that depending on the severity of blood volume loss, the reentry acceleration stress may be detrimental to physiologic function and may place the physiologic status of the crew near the borderline of some type of impairment. They are in agreement with conclusions from early ground-based experiments and from observations of early Shuttle flights.

Putting principals back into practice: an evaluation of a re-entry course for vocationally trained doctors.

PubMed Central

Baker, M; Williams, J; Petchey, R

1997-01-01

BACKGROUND: Current recruitment difficulties in general practice have sharpened the interest of the profession in non-principals. No re-entry course for general practice has previously been run in the UK. AIM: To design and evaluate a re-entry course for general practice. METHOD: A re-entry course was developed to help doctors return to general practice as principals. A telephone interview was carried out with each delegate prior to their attendance on the course and was repeated one month and six months after the course to measure any change in career intentions and the perceived benefit of attending the course. RESULTS: Six months after the course, 11 out of 14 delegates had taken positive steps to return to general practice or had increased their time commitment to medicine. This contrasts with only one of the control group having made any steps to change career. CONCLUSION: The course was evaluated and found to be beneficial, particularly in terms of increasing the confidence of the delegates. PMID:9463984

DOE Office of Scientific and Technical Information (OSTI.GOV)

Airoldi, Flavio, E-mail: flavio.airoldi@multimedica.it; Faglia, Ezio, E-mail: ezio.faglia@multimedica.it; Losa, Sergio, E-mail: sergio.losa@multimedica.it

Subintimal angioplasty (SAP) is frequently performed for the treatment of critical limb ischemia (CLI) and has been recognized as an effective technique for these patients. Nevertheless, this approach is limited by the lack of controlled re-entry into the true lumen of the target vessel. We describe a novel device for true lumen re-entry after subintimal recanalization of superficial femoral arteries (SFA). We report our experience with six patients treated between April 2009 and January 2010 with a novel system designed to facilitate true lumen re-entry. The device was advanced by ipsilateral antegrade approach through a 6-French sheath. Successful reaccess intomore » the true lumen was obtained in five of six patients without complications. The patient in whom the reaccess to the true lumen was not possible underwent successful bypass surgery. At 30 days follow-up, the SFA was patent in all patients according to echo-Doppler examination. Our preliminary experience indicates that this novel re-entry device increases the success rate of percutaneous revascularization of chronically occluded SFA.« less

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons checks the electroweld he performed on an insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-16

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons checks the electroweld he performed on an insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons continues electrowelding on an insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-16

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons continues electrowelding on an insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt attaches a Reinforced Carbon Carbon (RCC) panel onto the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-05

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt attaches a Reinforced Carbon Carbon (RCC) panel onto the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons electrowelds a crack formed in the insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-16

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons electrowelds a crack formed in the insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons prepares to electroweld a crack formed in the insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-16

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons prepares to electroweld a crack formed in the insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons prepares to electroweld a crack found on an insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-16

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons prepares to electroweld a crack found on an insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt (right) attaches a Reinforced Carbon Carbon (RCC) panel onto the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-05

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt (right) attaches a Reinforced Carbon Carbon (RCC) panel onto the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt (above) attaches a Reinforced Carbon Carbon (RCC) panel onto the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-05

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt (above) attaches a Reinforced Carbon Carbon (RCC) panel onto the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

Oxidation Behavior of HfB2-SiC Materials in Dissociated Environments

NASA Technical Reports Server (NTRS)

Ellerby, Don; Irby, Edward; Johnson, Sylvia M.; Beckman, Sarah; Gusman, Michael; Gasch, Matthew

2002-01-01

Hafnium diboride based materials have shown promise for use in extremely high temperature applications, such as sharp leading edges on future reentry vehicles. During reentry, the oxygen and nitrogen in the atmosphere are dissociated by the shock layer ahead of the sharp leading edge such that surface reactions are determined by reactions of monatomic oxygen and nitrogen rather than O2, and N2. Simulation of the reentry environment on the ground requires the use of arc jet (plasma jet) facilities that provide monatomic species and are the closest approximation to actual flight conditions. Simple static or flowing oxidation studies under ambient pressures and atmospheres are not adequate to develop an understanding of a materials behavior in flight. Arc jet testing is required to provide the appropriate stagnation pressures, heat fluxes, enthalpies, heat loads and atmospheres encountered during flight. This work looks at the response of HfB2/SiC materials exposed to various simulated reentry environments.

Thermal Vacuum Facility for Testing Thermal Protection Systems

NASA Technical Reports Server (NTRS)

Daryabeigi, Kamran; Knutson, Jeffrey R.; Sikora, Joseph G.

2002-01-01

A thermal vacuum facility for testing launch vehicle thermal protection systems by subjecting them to transient thermal conditions simulating re-entry aerodynamic heating is described. Re-entry heating is simulated by controlling the test specimen surface temperature and the environmental pressure in the chamber. Design requirements for simulating re-entry conditions are briefly described. A description of the thermal vacuum facility, the quartz lamp array and the control system is provided. The facility was evaluated by subjecting an 18 by 36 in. Inconel honeycomb panel to a typical re-entry pressure and surface temperature profile. For most of the test duration, the average difference between the measured and desired pressures was 1.6% of reading with a standard deviation of +/- 7.4%, while the average difference between measured and desired temperatures was 7.6% of reading with a standard deviation of +/- 6.5%. The temperature non-uniformity across the panel was 12% during the initial heating phase (t less than 500 sec.), and less than 2% during the remainder of the test.

Returning nurses to the workforce: developing a fast track back program.

PubMed

Burns, Helen K; Sakraida, Teresa J; Englert, Nadine C; Hoffmann, Rosemary L; Tuite, Patricia; Foley, Susan M

2006-01-01

Fast Track Back: Re-entry into Nursing Practice program. Describes the development, implementation, and evaluation of a state-of-the-art re-entry program facilitating the return of licensed nonpracticing RNs to the workforce through a quality education program that retools them for the workforce in the areas of pharmacology, skill development using the latest technology, practice standards, and nursing issues. The program consists of didactic content taught via classroom, Internet, skills laboratory, and high fidelity human simulated technology and a clinical component. The program is a mechanism that enables re-entry nurses to improve skills and competencies necessary to practice in today's healthcare environment.

Maternal Separations During the Reentry Years for 100 Infants Raised in a Prison Nursery

PubMed Central

Byrne, Mary W.; Goshin, Lorie; Blanchard-Lewis, Barbara

2011-01-01

Prison nurseries prevent maternal separations related to incarceration for the small subset of children whose pregnant mothers are incarcerated in states with such programs. For a cohort of 100 children accepted by corrections into one prison nursery, subsequent separation patterns are analyzed. The largest numbers are caused by corrections’ removal of infants from the nursery and infants reaching a one-year age limit. Criminal recidivism and substance abuse relapse threaten continued mothering during reentry. Focused and coordinated services are needed during prison stay and reentry years to sustain mothering for women and children accepted into prison nursery programs. PMID:22328865

Assessment of Aerothermodynamic Flight Prediction Tools through Ground and Flight Experimentation (Evaluation des outils aerothermodynamiques de prediction de vol par l’experimentation au sol et en vol)

DTIC Science & Technology

2011-11-01

6.5 Conclusions 6-30 6.6 Acknowledgments 6-31 6.7 References 6-31 Chapter 7 – Experimental Investigation of the Supersonic Wake of a Re-entry 7-1... Noise on the Axial Location of 4-4 Transition for the HIFiRE-1 Cone at Zero Angle of Attack and Mach 6 Figure 4-2 Correlations for Transition...Without Sting) Mach 2 AoA 19 Symmetry Plane Computed 6-14 with LORE: Effect of Sting/ Blade vs. No Sting/ Blade on 8M Cells Mesh Figure 6-12 Mach 2

School Reentry Following Traumatic Brain Injury

ERIC Educational Resources Information Center

Deidrick, Kathleen K. M.; Farmer, Janet E.

2005-01-01

Successful school reentry following traumatic brain injury (TBI) is critical to recovery. Physical, cognitive, behavioral, academic, and social problems can affect a child's school performance after a TBI. However, early intervention has the potential to improve child academic outcomes and promote effective coping with any persistent changes in…

14 CFR 435.21 - General.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false General. 435.21 Section 435.21 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and Approval for Reentry of a Reentry Vehicle § 435.21 General. The FAA issues a policy approval to a...

14 CFR 435.21 - General.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false General. 435.21 Section 435.21 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and Approval for Reentry of a Reentry Vehicle § 435.21 General. The FAA issues a policy approval to a...

14 CFR 435.21 - General.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false General. 435.21 Section 435.21 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and Approval for Reentry of a Reentry Vehicle § 435.21 General. The FAA issues a policy approval to a...

14 CFR 435.21 - General.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false General. 435.21 Section 435.21 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and Approval for Reentry of a Reentry Vehicle § 435.21 General. The FAA issues a policy approval to a...

14 CFR 435.21 - General.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false General. 435.21 Section 435.21 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... and Approval for Reentry of a Reentry Vehicle § 435.21 General. The FAA issues a policy approval to a...

School Reentry for Children with Acquired Central Nervous Systems Injuries

ERIC Educational Resources Information Center

Carney, Joan; Porter, Patricia

2009-01-01

Onset of acquired central nervous system (CNS) injury during the normal developmental process of childhood can have impact on cognitive, behavioral, and motor function. This alteration of function often necessitates special education programming, modifications, and accommodations in the education setting for successful school reentry. Special…

76 FR 58197 - Pre-Release Community Confinement

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-20

... for pre-release RRC [Residential Re- entry Centers] placement pursuant to 28 CFR 570.20-22 until such.... For clarity, we also add a parenthetical that explains that the Bureau includes residential re-entry... (including residential re-entry centers); and participation in gainful employment, employment search efforts...

78 FR 40531 - Self-Regulatory Organizations; BATS Exchange, Inc.; Notice of Filing of a Proposed Rule Change...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-05

... Exchange from allowing re-entry into the Program where the Exchange deems such re-entry as proper. CLP... its status as a CLP, such Member may re- apply for CLP status. Such application process shall occur at...

Comments on "Understanding Graduate Women's Reentry Experiences." Commentary.

ERIC Educational Resources Information Center

Lott, Bernice

1999-01-01

The case-study method used in "Understanding Graduate Women's Reentry Experiences" yielded personal information of considerable depth, but the conclusions drawn from the study are not all that different from those drawn from more quantitative investigations. Suggests that a multimethod approach is the best research strategy. (SLD)

Parasystole due to re-entry as the possible mechanism of ventricular parasystole with second-degree entrance block.

PubMed

Kinoshita, Shinji; Katoh, Takakazu; Yoshida, Hiroshi

2010-05-01

In 1974, Kinoshita reported a case of 'irregular parasystole' due to type I second-degree entrance block. Since then, many cases of such 'irregular' parasystole have been reported by us. To explain the mechanism of 'irregular' parasystole, two theories have been suggested, namely, 'electrotonic modulation' by Jalife and Moe, and 'type I second-degree entrance block' by us. On the contrary, in 1960, Kinoshita et al. reported a case of concealed bigeminy for the first time. The electrocardiographic findings in concealed bigeminy have suggested that there are dual re-entrant pathways with markedly long effective refractory periods in the re-entrant pathway. We have suggested that parasystole may be caused by re-entry in such re-entrant pathways. In this article, attempts are made to explain the mechanism of all the electrocardiographic findings in our cases of parasystole by 'parasystole due to re-entry'. Using 24 studies on parasystole and 21 studies on concealed extrasystoles that we have reported over 50 years, as well as three exemplary cases in this article, attempts are made to explain all electrocardiographic findings in parasystole by 'parasystole due to re-entry'. The electrocardiographic findings in our previous clinical cases of parasystole and concealed extrasystoles, as well as exemplary cases and diagrams in the present article, strongly suggest 'parasystole due to re-entry' as the mechanism of ventricular parasystole with second-degree entrance block.

Seismic Parameters of Mining-Induced Aftershock Sequences for Re-entry Protocol Development

NASA Astrophysics Data System (ADS)

Vallejos, Javier A.; Estay, Rodrigo A.

2018-03-01

A common characteristic of deep mines in hard rock is induced seismicity. This results from stress changes and rock failure around mining excavations. Following large seismic events, there is an increase in the levels of seismicity, which gradually decay with time. Restricting access to areas of a mine for enough time to allow this decay of seismic events is the main approach in re-entry strategies. The statistical properties of aftershock sequences can be studied with three scaling relations: (1) Gutenberg-Richter frequency magnitude, (2) the modified Omori's law (MOL) for the temporal decay, and (3) Båth's law for the magnitude of the largest aftershock. In this paper, these three scaling relations, in addition to the stochastic Reasenberg-Jones model are applied to study the characteristic parameters of 11 large magnitude mining-induced aftershock sequences in four mines in Ontario, Canada. To provide guidelines for re-entry protocol development, the dependence of the scaling relation parameters on the magnitude of the main event are studied. Some relations between the parameters and the magnitude of the main event are found. Using these relationships and the scaling relations, a space-time-magnitude re-entry protocol is developed. These findings provide a first approximation to concise and well-justified guidelines for re-entry protocol development applicable to the range of mining conditions found in Ontario, Canada.

Development of a Three-Dimensional, Unstructured Material Response Design Tool

NASA Technical Reports Server (NTRS)

Schulz, Joseph C.; Stern, Eric C.; Muppidi, Suman; Palmer, Grant E.; Schroeder, Olivia

2017-01-01

A preliminary verification and validation of a new material response model is presented. This model, Icarus, is intended to serve as a design tool for the thermal protection systems of re-entry vehicles. Currently, the capability of the model is limited to simulating the pyrolysis of a material as a result of the radiative and convective surface heating imposed on the material from the surrounding high enthalpy gas. Since the major focus behind the development of Icarus has been model extensibility, the hope is that additional physics can be quickly added. This extensibility is critical since thermal protection systems are becoming increasing complex, e.g. woven carbon polymers. Additionally, as a three-dimensional, unstructured, finite-volume model, Icarus is capable of modeling complex geometries. In this paper, the mathematical and numerical formulation is presented followed by a discussion of the software architecture and some preliminary verification and validation studies.

Differentiating the Interests of Mature Women: A Factor Analysis of the KOIS

ERIC Educational Resources Information Center

Tittle, Carol Kehr; And Others

1978-01-01

Scale scores of KOIS profiles of 202 reentry women were converted to within individual form by means of a z-score transformation. Seven factors emerged on the female-normed scales and 11 factors on the male-normed scales. Four factors were similar in both norm sets and two showed some overlap. (Author)

Computer simulation studies in fluid and calcium regulation and orthostatic intolerance

NASA Technical Reports Server (NTRS)

1985-01-01

The systems analysis approach to physiological research uses mathematical models and computer simulation. Major areas of concern during prolonged space flight discussed include fluid and blood volume regulation; cardiovascular response during shuttle reentry; countermeasures for orthostatic intolerance; and calcium regulation and bone atrophy. Potential contributions of physiologic math models to future flight experiments are examined.

Reentry of Emerging Adults: Adolescent Inmates' Transition Back into the Community

ERIC Educational Resources Information Center

Inderbitzin, Michelle

2009-01-01

This article is based on the sociological analysis of the experiences and perspectives of five young men making the transition out of one state's end-of-the-line maximum security juvenile correctional facility and attempting to reenter the community as emerging adults. As part of a larger ethnographic study of violent offenders in a cottage, these…

Estimates of nitric oxide production for lifting spacecraft reentry

NASA Technical Reports Server (NTRS)

Park, C.

1971-01-01

The amount of nitric oxide which may be produced by heating of air during an atmospheric reentry of a lifting spacecraft is estimated by three different methods. Two assume nitrogen fixation by the process of sudden freezing, and the third is a computer calculation using chemical rate equations.

14 CFR 431.33 - Safety organization.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Safety organization. 431.33 Section 431.33... TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE (RLV) Safety Review and Approval for Launch and Reentry of a Reusable Launch Vehicle § 431.33 Safety organization. (a) An applicant shall...

14 CFR 431.7 - Payload and payload reentry determinations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Payload and payload reentry determinations. 431.7 Section 431.7 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION... determination. Either an RLV mission license applicant or a payload owner or operator may request a review of...

14 CFR 431.7 - Payload and payload reentry determinations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Payload and payload reentry determinations. 431.7 Section 431.7 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION... determination. Either an RLV mission license applicant or a payload owner or operator may request a review of...

14 CFR 431.7 - Payload and payload reentry determinations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Payload and payload reentry determinations. 431.7 Section 431.7 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION... determination. Either an RLV mission license applicant or a payload owner or operator may request a review of...

14 CFR 431.7 - Payload and payload reentry determinations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Payload and payload reentry determinations. 431.7 Section 431.7 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION... determination. Either an RLV mission license applicant or a payload owner or operator may request a review of...

PIRATES: A Program for Offenders Transitioning into the World of Work

ERIC Educational Resources Information Center

Musgrove, Kate Racoff; Derzis, Nicholas C.; Shippen, Margaret E.; Brigman, Holly E.

2012-01-01

The study assessed the effectiveness of the Preparing Inmates for Re-Entry through Assistance, Training, and Employment Skills (PIRATES) group, which focused on improving dysfunctional career thoughts. Participants were male offenders (n = 14) enrolled in a re-entry training class. Results showed a statistically significant decrease in…

Effects of Angle of Attack on the Behaviour of Imperfections in Thermal Protection Systems of Re-entry Vehicles

NASA Astrophysics Data System (ADS)

Palharini, R. C.; Scanlon, T. J.; Reese, J. M.

The study of atmospheric re-entry under rarefied nonequilibrium flows is a challenging problem directly related to the development of new aerospace technologies, where the prediction of thermal loads acting over the spacecraft is critical during descent phase.

78 FR 72011 - Interpretation Concerning Involvement of NASA Astronauts During a Licensed Launch or Reentry

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-02

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 460 Interpretation Concerning Involvement of NASA Astronauts During a Licensed Launch or Reentry AGENCY: Federal Aviation...\\ Human Space Flight Requirements Final Rule, 71 FR at 75618. As can be seen, the FAA's concern with space...

Kuder Occupational Interest Survey Profiles of Reentry Women

ERIC Educational Resources Information Center

Tittle, Carol K.; Denker, Elenor R.

1977-01-01

The Kuder Occupational Interest Survey was administered to 202 women considering reentry into education. It was found that the KOIS does differentiate between women and individual interests are reflected for this sample of women. It was concluded that examination of male-normed scales is very useful in counseling. (Author)

A School Reentry Program for Chronically Ill Children.

ERIC Educational Resources Information Center

Worchel-Prevatt, Frances F.; Heffer, Robert W.; Prevatt, Bruce C.; Miner, Jennifer; Young-Saleme, Tammi; Horgan, Daniel; Lopez, Molly A.; Frankel, Lawrence; Rae, William A.

1998-01-01

Describes a school reintegration program aimed at overcoming the numerous psychological, physical, environmental, and family-based deterrents to school reentry for chronically ill children. The program uses a systems approach to children's mental health with an emphasis on multiple aspects of the child's environment (i.e., family, medical…

System specification for the reusable reentry satellite

NASA Technical Reports Server (NTRS)

1991-01-01

The RRS design shall provide a relatively inexpensive method of access to micro and fractional gravity space environments for an extended period of time, with eventual intact recovery on the surface of the Earth. This specification establishes the performance, design, development, and test requirements for the Reusable Reentry Satellite (RRS) system.

14 CFR 435.23 - Policy review requirements and procedures.

Code of Federal Regulations, 2010 CFR

2010-01-01

... VEHICLE (RLV) Policy Review and Approval for Reentry of a Reentry Vehicle § 435.23 Policy review... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Policy review requirements and procedures. 435.23 Section 435.23 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION...

Sacramento City College Re-Entry Services Comprehensive Plan.

ERIC Educational Resources Information Center

White, Maureen E.; Smith, William A.

Sacramento City College (SCC) established its Re-Entry Services program to provide information, referral and support services to students returning to the academic environment after an absence. Since the inception of the program in 1977, the college community has changed considerably. Among these changes are an aging student population, increased…

Astronauts McNair and Stewart prepare for reentry

NASA Technical Reports Server (NTRS)

1984-01-01

Astronauts Ronald E. McNair and Robert L. Stewart prepare for the re-entry phase of the shuttle Challenger near the end of the 41-B mission. The are stationed behind the crew commander and pilot. Stewart is already wearing his helmet. McNair is stowing some of his gear.

Theoretical analysis of the mechanisms of a gender differentiation in the propensity for orthostatic intolerance after spaceflight

PubMed Central

2010-01-01

Background A tendency to develop reentry orthostasis after a prolonged exposure to microgravity is a common problem among astronauts. The problem is 5 times more prevalent in female astronauts as compared to their male counterparts. The mechanisms responsible for this gender differentiation are poorly understood despite many detailed and complex investigations directed toward an analysis of the physiologic control systems involved. Methods In this study, a series of computer simulation studies using a mathematical model of cardiovascular functioning were performed to examine the proposed hypothesis that this phenomenon could be explained by basic physical forces acting through the simple common anatomic differences between men and women. In the computer simulations, the circulatory components and hydrostatic gradients of the model were allowed to adapt to the physical constraints of microgravity. After a simulated period of one month, the model was returned to the conditions of earth's gravity and the standard postflight tilt test protocol was performed while the model output depicting the typical vital signs was monitored. Conclusions The analysis demonstrated that a 15% lowering of the longitudinal center of gravity in the anatomic structure of the model was all that was necessary to prevent the physiologic compensatory mechanisms from overcoming the propensity for reentry orthostasis leading to syncope. PMID:20298577

Re-Entry Aeroheating Analysis of Tile-Repair Augers for the Shuttle Orbiter

NASA Technical Reports Server (NTRS)

Mazaheri, Ali R.; Wood, William A.

2007-01-01

Computational re-entry aerothermodynamic analysis of the Space Shuttle Orbiter s tile overlay repair (TOR) sub-assembly is presented. Entry aeroheating analyses are conducted to characterize the aerothermodynamic environment of the TOR and to provide necessary inputs for future TOR thermal and structural analyses. The TOR sub-assembly consists of a thin plate and several augers and spacers that serve as the TOR fasteners. For the computational analysis, the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) is used. A 5-species non-equilibrium chemistry model with a finite rate catalytic recombination model and a radiation equilibrium wall condition are used. It is assumed that wall properties are the same as reaction cured glass (RCG) properties with a surface emissivity of epsilon = 0.89. Surface heat transfer rates for the TOR and tile repair augers (TRA) are computed at a STS-107 trajectory point corresponding to Mach 18 free stream conditions. Computational results show that the average heating bump factor (BF), which is a ratio of local heat transfer rate to a design reference point located at the damage site, for the auger head alone is about 1.9. It is also shown that the average BF for the combined auger and washer heads is about 2.0.

Development of fused slurry silicide coatings for tantalum reentry heat shields

NASA Technical Reports Server (NTRS)

Warnock, R. V.; Stetson, A. R.

1972-01-01

A fused slurry silicide coating was developed to provide atmospheric reentry protection for the 90Ta-lOW alloy. Overlaying the silicide with a highly refractory glass greatly improved total lifetime and reliability of the coating system. Low pressure, slow cycle lifetimes in excess of 100 cycles were consistently recorded for 1700 K - 13 and 1300 N/sq m test conditions. A minimum of 25 cycles was obtained for 1810 K - 1300 N/sq m conditions. About 50 simulated reentry cycles (variable temperature, pressure, and stress) were endured by coated 1-inch miniature heat shield panels when exposed to a maximum of 1700 K and either internal or external pressure conditions.

HVI Ballistic Limit Characterization of Fused Silica Thermal Panes

NASA Technical Reports Server (NTRS)

Miller, J. E.; Bohl, W. D.; Christiansen, E. L.; Davis, B. A.; Deighton, K. D.

2015-01-01

Fused silica window systems are used heavily on crewed reentry vehicles, and they are currently being used on the next generation of US crewed spacecraft, Orion. These systems improve crew situational awareness and comfort, as well as, insulating the reentry critical components of a spacecraft against the intense thermal environments of atmospheric reentry. Additionally, these materials are highly exposed to space environment hazards like solid particle impacts. This paper discusses impact studies up to 10 km/s on a fused silica window system proposed for the Orion spacecraft. A ballistic limit equation that describes the threshold of perforation of a fuse silica pane over a broad range of impact velocities, obliquities and projectile materials is discussed here.

Prisoner reentry: a public health or public safety issue for social work practice?

PubMed

Patterson, George T

2013-01-01

A significant literature identifies the policy, economic, health, and social challenges that confront released prisoners. This literature also describes the public health and public safety risks associated with prisoner reentry, provides recommendations for improving the reentry process, and describes the effectiveness of prison-based programs on recidivism rates. Public health and public safety risks are particularly significant in communities where large numbers of prisoners are released and few evidence-based services exist. The purpose of this article is to describe the public health and public safety risks that released prisoners experience when they reenter communities, and to discuss the social justice issues relevant for social work practice.

DSMC Simulations of Apollo Capsule Aerodynamics for Hypersonic Rarefied Conditions

NASA Technical Reports Server (NTRS)

Moss, James N.; Glass, Christopher E.; Greene, Francis A.

2006-01-01

Direct simulation Monte Carlo DSMC simulations are performed for the Apollo capsule in the hypersonic low density transitional flow regime. The focus is on ow conditions similar to that experienced by the Apollo Command Module during the high altitude portion of its reentry Results for aerodynamic forces and moments are presented that demonstrate their sensitivity to rarefaction that is for free molecular to continuum conditions. Also aerodynamic data are presented that shows their sensitivity to a range of reentry velocity encompasing conditions that include reentry from low Earth orbit lunar return and Mars return velocities to km/s. The rarefied results are anchored in the continuum regime with data from Navier Stokes simulations

14 CFR 431.23 - Policy review.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Policy review. 431.23 Section 431.23... TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE (RLV) Policy Review and Approval for Launch and Reentry of a Reusable Launch Vehicle § 431.23 Policy review. (a) The FAA reviews an RLV...

Reentry Issues upon Returning from Study Abroad Programs

ERIC Educational Resources Information Center

Wielkiewicz, Richard M.; Turkowski, Laura W.

2010-01-01

The impact of returning from studying abroad was surveyed in 669 college students. Students who studied abroad scored significantly higher on a Reentry Shock scale, reflecting skepticism toward U.S. culture, than those who did not. They were also more likely to consume alcohol. Study abroad had no detectable influence on students' romantic…

14 CFR 431.61 - Incorporation of payload reentry determination in license application.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Incorporation of payload reentry determination in license application. 431.61 Section 431.61 Aeronautics and Space COMMERCIAL SPACE... payload or class of payload may be included by an RLV mission license applicant as part of its application...

14 CFR 431.61 - Incorporation of payload reentry determination in license application.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Incorporation of payload reentry determination in license application. 431.61 Section 431.61 Aeronautics and Space COMMERCIAL SPACE... payload or class of payload may be included by an RLV mission license applicant as part of its application...

14 CFR 431.61 - Incorporation of payload reentry determination in license application.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Incorporation of payload reentry determination in license application. 431.61 Section 431.61 Aeronautics and Space COMMERCIAL SPACE... payload or class of payload may be included by an RLV mission license applicant as part of its application...

14 CFR 431.61 - Incorporation of payload reentry determination in license application.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Incorporation of payload reentry determination in license application. 431.61 Section 431.61 Aeronautics and Space COMMERCIAL SPACE... payload or class of payload may be included by an RLV mission license applicant as part of its application...

14 CFR 431.61 - Incorporation of payload reentry determination in license application.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Incorporation of payload reentry determination in license application. 431.61 Section 431.61 Aeronautics and Space COMMERCIAL SPACE... payload or class of payload may be included by an RLV mission license applicant as part of its application...

Higher Education and Reentry: The Gifts They Bring. Reentry Research in the First Person

ERIC Educational Resources Information Center

Halkovic, Alexis; Fine, Michelle; Bae, John; Campbell, Leslie; Evans, Desheen; Gary, Chaka; Greene, Andrew; Ramirez, Marc; Riggs, Robert; Taylor, Michael; Tebout, Ray; Tejawi, Aenora

2013-01-01

Virtually every study of the impact of college on incarcerated and formerly incarcerated people demonstrates a positive effect on income, civic engagement, family, and personal health, as well as dramatically reduced recidivism rates. College in and after prison offers a singularly effective strategy for redeveloping individuals, families and…

Art Concept - Apollo VIII - Command Module (CM) - Re-Entry Orientation

NASA Image and Video Library

1968-01-01

S68-55292 (August 1968) --- A North American Rockwell Corporation artist's concept depicting the Apollo Command Module (CM), oriented in a blunt-end-forward attitude, re-entering Earth's atmosphere after returning from a lunar landing mission. Note the change in color caused by the extremely high temperatures encountered upon re-entry.

8 CFR 212.1 - Documentary requirements for nonimmigrants.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Cards and a valid Taiwan passport with a valid re-entry permit issued by the Taiwan Ministry of Foreign... valid re-entry permit issued by the Taiwan Ministry of Foreign Affairs. (2) Program Countries and... the United States from contiguous territory or adjacent islands at a land or sea port-of-entry. A...

Education for Perspective Transformation. Women's Re-entry Programs in Community Colleges.

ERIC Educational Resources Information Center

Mezirow, Jack; Marsick, Victoria

The national field study of women's re-entry programs in community colleges reported here was done to identify factors that impeded or facilitated the progress of these programs. After an introduction, the content is presented in three sections. The first section deals with perspective transformation, the adult development process occurring in the…

8 CFR 212.1 - Documentary requirements for nonimmigrants.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Cards and a valid Taiwan passport with a valid re-entry permit issued by the Taiwan Ministry of Foreign... Taiwan National Identity Card and a valid Taiwan passport with a valid re-entry permit issued by the... the United States from contiguous territory or adjacent islands at a land or sea port-of-entry. A...

8 CFR 212.1 - Documentary requirements for nonimmigrants.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Cards and a valid Taiwan passport with a valid re-entry permit issued by the Taiwan Ministry of Foreign... Taiwan National Identity Card and a valid Taiwan passport with a valid re-entry permit issued by the... the United States from contiguous territory or adjacent islands at a land or sea port-of-entry. A...

Jett, Tanner and Garneau during re-entry preparations for STS-97

NASA Image and Video Library

2000-12-11

STS097-310-032 (11 December 2000) --- Astronauts (left to right) Marc Garneau, Joseph R. Tanner, both mission specialists, and Brent W. Jett, mission commander, are photographed on the flight deck of the Space Shuttle Endeavour as they prepare for re-entry. Garneau represents the Canadian Space Agency (CSA).

Advanced Concept

NASA Image and Video Library

2008-02-15

THIS IS A MODEL TEST OF THE 1ST STAGE RE-ENTRY. HEAT TESTING OF A 3% MODEL TO SUPPORT THE ARES/CLV FIRST STAGE RE-ENTRY. THIS OCCURRED AT ARNOLD AIR FORCE BASE, TENNESSEE IN SUPPORT OF THE CONSTELLATION/ARES PROJECT. THIS IMAGE IS EXTRACTED FROM A HIGH DEFINITION VIDEO FILE AND IS THE HIGHEST RESOLUTION AVAILABLE.

8 CFR 212.1 - Documentary requirements for nonimmigrants.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Cards and a valid Taiwan passport with a valid re-entry permit issued by the Taiwan Ministry of Foreign... Taiwan National Identity Card and a valid Taiwan passport with a valid re-entry permit issued by the... the United States from contiguous territory or adjacent islands at a land or sea port-of-entry. A...

Career Reentry Strategies for Highly Educated, Stay-at-Home Mothers

ERIC Educational Resources Information Center

Guc, Cheryl M.

2017-01-01

Most stay-at-home mothers wish to return to the workplace; yet, the majority are not successful. There is a looming labor shortage and increasing organizational initiatives to increase female participation at most levels, providing opportunity for this talent pool. The purpose of this descriptive study was to examine the reentry strategies of…

From Corrections to Community: The Juvenile Reentry Experience as Characterized by Multiple Systems Involvement

ERIC Educational Resources Information Center

Cusick, Gretchen Ruth; Goerge, Robert M.; Bell, Katie Claussen

2009-01-01

This Chapin Hall report describes findings on the extent of system involvement among Illinois youth released from correctional facilities, tracking a population of youth under age 18 in Illinois following their release. Using administrative records, researchers develop profiles of reentry experiences across the many systems that serve youth and…

United States Department of Education Update, December 2004

ERIC Educational Resources Information Center

Linton, John

2004-01-01

In this update, Linton reports on Congressional filing of a number of bills that involve the topic of prisoner reentry. In addition, he presents a key section of Attorney General John Ashcroft's address (Cleveland, Ohio, September 2004) on prisoner reentry. In this speech, Ashcroft called for a concerted effort to managing a balanced approach:…

Runaways: Some Suggestions for Prevention, Coordinating Services, and Expediting the Reentry Process.

ERIC Educational Resources Information Center

Rohr, Michael E.; James, Richard

1994-01-01

Examines how school counselors can assist runaways. The authors focus on prevention, runaway programs, and how to expedite school reentry. Because school counselors invariably spend time with runaways, counselors can become more effective and efficient both in the short and long term in helping these troubled clients. (RJM)