Science.gov

Sample records for accurate unpowered reentry

  1. Unpowered wireless ultrasound tomography system

    NASA Astrophysics Data System (ADS)

    Zahedi, Farshad; Huang, Haiying

    2016-04-01

    In this paper, an unpowered wireless ultrasound tomography system is presented. The system consists of two subsystems; the wireless interrogation unit (WIU) and three wireless nodes installed on the structure. Each node is designed to work in generation and sensing modes, but operates at a specific microwave frequency. Wireless transmission of the ultrasound signals between the WIU and the wireless nodes is achieved by converting ultrasound signals to microwave signals and vice versa, using a microwave carrier signal. In the generation mode, both a carrier signal and an ultrasound modulated microwave signal are transmitted to the sensor nodes. Only the node whose operating frequency matches the carrier signal will receive these signals and demodulate them to recover the original ultrasound signal. In the sensing mode, a microwave carrier signal with two different frequency components matching the operating frequencies of the sensor nodes is broadcasted by the WIU. The sensor nodes, in turn, receive the corresponding carrier signals, modulate it with the ultrasound sensing signal, and wirelessly transmit the modulated signal back to the WIU. The demodulation of the sensing signals is performed in the WIU using a digital signal processing. Implementing a software receiver significantly reduces the complexity and the cost of the WIU. A wireless ultrasound tomography system is realized by interchanging the carrier frequencies so that the wireless transducers can take turn to serve as the actuator and sensors.

  2. Reentry analysis

    SciTech Connect

    Biehl, F.A.

    1984-05-01

    This paper presents the criteria, previous nuclear experience in space, analysis techniques, and possible breakup enhancement devices applicable to an acceptable SP-100 reentry from space. Reactor operation in nuclear-safe orbit will minimize the radiological risk; the remaining safeguards criteria need to be defined. A simple analytical point mass reentry technique and a more comprehensive analysis method that considers vehicle dynamics and orbit insertion malfunctions are presented. Vehicle trajectory, attitude, and possible breakup enhancement devices will be integrated in the simulation as required to ensure an adequate representation of the reentry process.

  3. 14 CFR 91.309 - Towing: Gliders and unpowered ultralight vehicles.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Towing: Gliders and unpowered ultralight vehicles. 91.309 Section 91.309 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF..., after release of a glider or unpowered ultralight vehicle, in a manner that endangers the life...

  4. 14 CFR 435.35 - Acceptable reentry risk for reentry of a reentry vehicle.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... reentry vehicle. 435.35 Section 435.35 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV) Safety Review and Approval for Reentry of a Reentry Vehicle §...

  5. 14 CFR 435.35 - Acceptable reentry risk for reentry of a reentry vehicle.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... reentry vehicle. 435.35 Section 435.35 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV) Safety Review and Approval for Reentry of a Reentry Vehicle §...

  6. 14 CFR 435.35 - Acceptable reentry risk for reentry of a reentry vehicle.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... reentry vehicle. 435.35 Section 435.35 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV) Safety Review and Approval for Reentry of a Reentry Vehicle §...

  7. 14 CFR 435.35 - Acceptable reentry risk for reentry of a reentry vehicle.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... reentry vehicle. 435.35 Section 435.35 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV) Safety Review and Approval for Reentry of a Reentry Vehicle §...

  8. Computational methods for reentry trajectories

    NASA Astrophysics Data System (ADS)

    Anselmo, L.; Pardini, C.

    The trajectory modeling of uncontrolled satellites close to reentry in the atmosphere is still a challenging activity. Tracking data may be sparse and not particularly accurate, the objects complicate shape and unknown attitude evolution may render quite tricky the aerodynamic computations and, last but not the least, the models used to predict the air density at the altitudes of interest, as a function of solar and geomagnetic activity, are affected by significant uncertainties. This paper presents the techniques developed and the experience matured in the field at ISTI (formerly CNUCE), specifically in support of the reentry predictions of risky space objects carried out for the Italian civil protection authorities. In these cases, an appropriate management of the intrinsic uncertainties of the problem is critical for the dissemination of the results, avoiding, as much as possible, misunderstandings and unjustified alarm.

  9. A new guidance strategy for unpowered Space Shuttle orbiter flight

    NASA Technical Reports Server (NTRS)

    Elias, A.

    1974-01-01

    A new guidance strategy for use during the TAEM (terminal area energy management) phase of the Shuttle reentry flight has been developed. This guidance system steers the vehicle from initial conditions at about 70,000 ft altitude and Mach 1.5 to the beginning of the final landing maneuver. Explicit control of the vehicle's total energy (potential plus kinetic) via the energy dissipation rate allows this system to effectively control the vehicle's energy in the presence of a head or tail wind without a-priori knowledge of the wind. Furthermore, this is accomplished while maintaining a wings-level attitude during most of the flight.

  10. 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.

  11. Small reentry vehicles

    NASA Astrophysics Data System (ADS)

    Sudmeijer, K. J.

    1987-12-01

    The design and potential applications of a small modular unguided reentry vehicle (SMURV) being developed for ESA are discussed. The first studies of the SMURV concept in the Spacemail program (for transporting small payloads from the Space Shuttle to earth) are recalled; the steps in a typical Spacemail operation are listed and briefly characterized; and the smaller version of SMURV (40 kg instead of 120 kg) developed for a Space Station Spacemail project (requiring 1000-1500 SMURVs) is described. This SMURV configuration comprises a detachable propulsion module and a reentry module (containing the parachute system and the recovery module). Consideration is given to a SMURV-type vehicle to return microgravity processing samples from the ESA Interim Flight Opportunity spacecraft, the technological challenges posed by SMURV design, and SMURV applications to the Comet Nucleus Sample Return and Cassini Titan Lander missions. Diagrams and drawings are provided.

  12. Dynamics of atmospheric re-entry

    NASA Astrophysics Data System (ADS)

    Regan, Frank J.; Anandakrishnan, Satya M.

    1993-03-01

    The present volume on dynamics of atmospheric reentry is an extention of the original book, Reentry Vehicle Dynamics. Topics addressed include atmospheric models, earth's form and gravitational field, axis transformations, force and moment equations, Keplerian motion, reentry vehicle particle mechanics, decoys and the identification of reentry vehicles, and particle motion in maneuvering reentry vehicles. Attention is also given to angular motion during the exoatmospheric (Keplerian) phase, a flowfield description, angular motion during reentry, error analysis, and inertial guidance.

  13. Reentry Experiment SAT-X

    NASA Astrophysics Data System (ADS)

    Woods, Maurice; Kuhns, Casey; Honda, Motoaki; Shiely, Robert; Adamson, Aaron; Aken, Jordan; Walch, Robert; Galovich, Cynthia; Semak, Matthew

    2011-10-01

    The challenge of reentering the Earth's atmosphere is not new. For years, NASA has successfully designed vessels that have endured the harsh process of reentry. However, in most cases, this is made possible only through the act of over-engineering; designing to withstand conditions far beyond what is expected to be encountered. Though this method has been effective, there would be benefit in knowing more precisely what to expect upon atmospheric reentry. The University of Northern Colorado Reentry Experiment SAT-X project, launched from Wallops Island, Virginia on July 21, 2011, was designed to shed light on the reentry process by collecting motion data for a capsule ejected from a rocket. Moreover, a secondary objective was to test the capability of the prototype capsule to serve as a platform for future reentry experiments. The mission and preliminary results from the launch will be described.

  14. Direct optimization method for reentry trajectory design

    NASA Astrophysics Data System (ADS)

    Jallade, S.; Huber, P.; Potti, J.; Dutruel-Lecohier, G.

    The software package called `Reentry and Atmospheric Transfer Trajectory' (RATT) was developed under ESA contract for the design of atmospheric trajectories. It includes four software TOP (Trajectory OPtimization) programs, which optimize reentry and aeroassisted transfer trajectories. 6FD and 3FD (6 and 3 degrees of freedom Flight Dynamic) are devoted to the simulation of the trajectory. SCA (Sensitivity and Covariance Analysis) performs covariance analysis on a given trajectory with respect to different uncertainties and error sources. TOP provides the optimum guidance law of a three degree of freedom reentry of aeroassisted transfer (AAOT) trajectories. Deorbit and reorbit impulses (if necessary) can be taken into account in the optimization. A wide choice of cost function is available to the user such as the integrated heat flux, or the sum of the velocity impulses, or a linear combination of both of them for trajectory and vehicle design. The crossrange and the downrange can be maximized during reentry trajectory. Path constraints are available on the load factor, the heat flux and the dynamic pressure. Results on these proposed options are presented. TOPPHY is the part of the TOP software corresponding to the definition and the computation of the optimization problemphysics. TOPPHY can interface with several optimizes with dynamic solvers: TOPOP and TROPIC using direct collocation methods and PROMIS using direct multiple shooting method. TOPOP was developed in the frame of this contract, it uses Hermite polynomials for the collocation method and the NPSOL optimizer from the NAG library. Both TROPIC and PROMIS were developed by the DLR (Deutsche Forschungsanstalt fuer Luft und Raumfahrt) and use the SLSQP optimizer. For the dynamic equation resolution, TROPIC uses a collocation method with Splines and PROMIS uses a multiple shooting method with finite differences. The three different optimizers including dynamics were tested on the reentry trajectory of the

  15. Re-entry Experiment Launch

    NASA Video Gallery

    On August 10, 2009, NASA successfully launched the Inflatable Re-entry Vehicle Experiment (IRVE) and proved that spacecraft can use inflatable heat shields to reduce speed and provide protection du...

  16. 49 CFR 238.307 - Periodic mechanical inspection of passenger cars and unpowered vehicles used in passenger trains.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Periodic mechanical inspection of passenger cars... Passenger Equipment § 238.307 Periodic mechanical inspection of passenger cars and unpowered vehicles used in passenger trains. (a) General. (1) Railroads shall conduct periodic mechanical inspections of...

  17. 49 CFR 238.307 - Periodic mechanical inspection of passenger cars and unpowered vehicles used in passenger trains.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Periodic mechanical inspection of passenger cars... Passenger Equipment § 238.307 Periodic mechanical inspection of passenger cars and unpowered vehicles used in passenger trains. (a) General. (1) Railroads shall conduct periodic mechanical inspections of...

  18. 49 CFR 238.307 - Periodic mechanical inspection of passenger cars and unpowered vehicles used in passenger trains.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Periodic mechanical inspection of passenger cars... Passenger Equipment § 238.307 Periodic mechanical inspection of passenger cars and unpowered vehicles used in passenger trains. (a) General. (1) Railroads shall conduct periodic mechanical inspections of...

  19. 49 CFR 238.307 - Periodic mechanical inspection of passenger cars and unpowered vehicles used in passenger trains.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Periodic mechanical inspection of passenger cars... Passenger Equipment § 238.307 Periodic mechanical inspection of passenger cars and unpowered vehicles used in passenger trains. (a) General. (1) Railroads shall conduct periodic mechanical inspections of...

  20. 49 CFR 238.307 - Periodic mechanical inspection of passenger cars and unpowered vehicles used in passenger trains.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Periodic mechanical inspection of passenger cars... Passenger Equipment § 238.307 Periodic mechanical inspection of passenger cars and unpowered vehicles used in passenger trains. (a) General. (1) Railroads shall conduct periodic mechanical inspections of...

  1. Unpowered Aerodynamic Characteristics of a 15-Percent Scale Model of a Twin-Engine Commuter Aircraft

    NASA Technical Reports Server (NTRS)

    Morgan, D. G.; Galloway, T. L.; Gambucci, B. J.

    1981-01-01

    An experimental investigation was conducted in the Ames 12-Foot Pressure Wind Tunnel to determine the unpowered aerodynamic characteristics of a 15-percent-scale model of a twin-engine commuter aircraft. Model longitudinal aerodynamic characteristics were examined at discrete flap deflections for various angle-of-attack and wind-tunnel-velocity ranges with the empennage on and off. Data are presented for the basic model configuration consisting of the fuselage, wing, basic wing leading edge, double slotted flaps, midengine nacelles, and empennage. Other configurations tested include a particle-span drooped leading edge (dropped outboard of the engine nacelles), a full-span drooped leading edge, low- and high-mounted engine nacelles, and a single-slotted flap. An evaluation was made of the model mounting system by comparing data obtained with the model mounted conventionally on the wind-tunnel model-support struts and the model inverted.

  2. Two-dimensional descent through a compressible atmosphere: Sequential deceleration of an unpowered load

    NASA Astrophysics Data System (ADS)

    Silverman, M. P.

    2010-02-01

    Equations, based on Rayleigh's drag law valid for high Reynolds number, are derived for two-dimensional motion through a compressible atmosphere in isentropic equilibrium, such as characterizes the Earth's troposphere. Solutions yield horizontal and vertical displacement, velocity, and acceleration as a function of altitude and ground-level temperature. An exact analytical solution to the equations linearized in the aero-thermodynamic parameter is given; in general the equations must be solved numerically. The theory, applied to the unpowered fall of a large aircraft stabilized to flat descent by symmetrical, sequential deployment of horizontal and vertical decelerators, shows that such an aircraft can be brought down with mean peak deployment and impact decelerations below 10g.

  3. 14 CFR 435.9 - Issuance of a reentry license.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV... reentry license authorizes a licensee to reenter a reentry vehicle and payload, if any, in accordance...

  4. 14 CFR 435.9 - Issuance of a reentry license.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV... reentry license authorizes a licensee to reenter a reentry vehicle and payload, if any, in accordance...

  5. 14 CFR 435.9 - Issuance of a reentry license.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV... reentry license authorizes a licensee to reenter a reentry vehicle and payload, if any, in accordance...

  6. 14 CFR 435.9 - Issuance of a reentry license.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV... reentry license authorizes a licensee to reenter a reentry vehicle and payload, if any, in accordance...

  7. The Development of High Order Numerical Techniques for Reentry Simulation of Hypersonic Spacecraft

    NASA Technical Reports Server (NTRS)

    Sanders, Richard

    1991-01-01

    The primary difficulty encountered when simulating hypersonic flow is that the flow normally includes strong nonlinear discontinuities. These discontinuities fall into three broad classes: shocks, slip-lines, and rarefaction waves. Moreover, in the hypersonic flow regime, the chemistry of hot gases plays a vital role and can not be neglected. These facts combine to make the numerical treatment of spacecraft reentry a most challenging problem. In this work, we develop a class of finite difference schemes that accurately resolve discontinuous solutions to spacecraft reentry flow and are simple to incorporate into existing spacecraft reentry codes.

  8. Reentry trajectory optimization and control

    NASA Astrophysics Data System (ADS)

    Strohmaier, P.; Kiefer, A.; Burkhardt, D.; Horn, K.

    1990-06-01

    There are several possible methods to increase the cross range capability of a winged reentry vehicle, for instance, skip trajectories, a powered cruise phase, or high lift/drag ratio flight. However, most of these alternative descent strategies have not yet been investigated sufficiently with respect to aero-thermodynamic effects and the design of the thermal protection system. This problem is treated by two different means. First, a nominal reentry trajectory is generated based on a phase concept, and then the same problem is again solved using a numerical optimization code to determine the control functions. The nominal reentry trajectory design presented first subdivides the total reentry trajectory into several segments with partially constant control/state parameters such as maximum heat flux and deceleration. The optimal conditions for a given segment can then be selected. In contrast, the parameterized optimization code selects the control functions freely. Both approaches consider a mass point simulation which uses realistic model assumptions for atmosphere, earth and gravity. Likewise, both approaches satisfy all flight regime limitations and boundary conditions such as thermal constraints throughout the flight path and specified speed and altitude at the final time. For the optimization of high cross reentry trajectories the cross range per total absorbed heat represents an appropriate cost function. The optimization code delivers quite a different flight strategy than that usually generated by the nominal reentry design program, first flying longer along the temperature boundary at highest possible angle of attack (AOAs) (utilizing higher average turn rates), and afterwards performing flare-dive segments to reduce heat flux and to increase range. Finally, the aspect of guiding the nominal or optimized reentry trajectory during a cross range flight is considered. The vertical guidance is performed with both angles of attack and roll angle control. The

  9. Implantable micromechanical parylene-based pressure sensors for unpowered intraocular pressure sensing

    NASA Astrophysics Data System (ADS)

    Chen, Po-Jui; Rodger, Damien C.; Agrawal, Rajat; Saati, Saloomeh; Meng, Ellis; Varma, Rohit; Humayun, Mark S.; Tai, Yu-Chong

    2007-10-01

    This paper presents the first implantable, unpowered, parylene-based microelectromechanical system (MEMS) pressure sensor for intraocular pressure (IOP) sensing. From in situ mechanical deformation of the compliant spiral-tube structures, this sensor registers pressure variations without electrical or powered signal transduction of any kind. Micromachined high-aspect-ratio polymeric hollow tubes with different geometric layouts are implemented to obtain high-sensitivity pressure responses. An integrated device packaging method has been developed toward enabling minimally invasive suture-less needle-based implantation of the device. Both in vitro and ex vivo device characterizations have successfully demonstrated mmHg resolution of the pressure responses. In vivo animal experiments have also been conducted to verify the biocompatibility and functionality of the implant fixation method inside the eye. Using the proposed implantation scheme, the pressure response of the implant can be directly observed from outside the eye under visible light, with the goal of realizing convenient, direct and faithful IOP monitoring in glaucoma patients.

  10. Long-term frequency aging for unpowered space-class oscillators.

    PubMed

    Bloch, Martin; Ho, John; Mancini, Oleandro; Terracciano, Louis; Mallette, Leo A

    2009-10-01

    Very little data exists regarding the long-term aging performance of space-rated oscillators in the non-operating mode. This paper provides empirical evidence that may be used to estimate the performance of unpowered oscillators for long-term space missions, as well as an aid in validating the worst-case analyses that are routinely performed on these oscillators. The proper operation of any space vehicle is dependent on the performance of the onboard master oscillator. For maximum reliability, the onboard clock is often provided as a dual-or triple-redundant ensemble, with one active oscillator. The backup oscillator(s) are usually powered off and may be off for a significant percentage of the mission. A significant parameter of importance for oscillator performance is the aging rate. Papers have been presented on the aging performance of active oscillators in space, but very little data exists regarding the long-term aging performance of oscillators in the nonoperating mode. The aging rate data are extremely important for predicting the expected performance of these backup oscillators after 10 or 15 years in of non-operation in space. This paper presents performance data derived from temperature controlled crystal oscillators and oven controlled crystal oscillators that have been dormant for decades.

  11. 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.

  12. Test Cases for Reentry Survivability Modeling

    NASA Astrophysics Data System (ADS)

    Ailor, W.; Hallman, W.; Steckel, G.; Weaver, M.

    2012-01-01

    One approved approach for minimizing the long-term hazards posed by space debris is to reenter space hardware into the atmosphere at end-of-mission or to place hardware in an orbit with a relatively short lifetime. Selection of a short lifetime orbit vice a deorbited reentry into a safe area depends on predictions of the hazards posed by random reentry of the object. If the object is left in orbit, what is the casualty expectation associated with its eventual reentry? Clearly, having high confidence in reentry hazard prediction tools is important to this decision-making process and the final choice can have significant mission and cost impacts. This paper describes a set of test cases that can be used to validate reentry hazard models. The test cases were assembled from reentry cases where "known" and tracked objects reentered the atmosphere and debris from the reentries was subsequently found on the ground and was analyzed. The test cases include best estimates of the state, mass properties, and physical description of each object prior to reentry, the wind profile through which the debris fell (for one case), and the impact location and physical description of each surviving object. The report also summarizes results of metallurgical analyses conducted on surviving debris, which places limits on the maximum temperatures reached during reentry. Details on a specific reentry are included as an example.

  13. Reducing the energy cost of human walking using an unpowered exoskeleton.

    PubMed

    Collins, Steven H; Wiggin, M Bruce; Sawicki, Gregory S

    2015-06-11

    With efficiencies derived from evolution, growth and learning, humans are very well-tuned for locomotion. Metabolic energy used during walking can be partly replaced by power input from an exoskeleton, but is it possible to reduce metabolic rate without providing an additional energy source? This would require an improvement in the efficiency of the human-machine system as a whole, and would be remarkable given the apparent optimality of human gait. Here we show that the metabolic rate of human walking can be reduced by an unpowered ankle exoskeleton. We built a lightweight elastic device that acts in parallel with the user's calf muscles, off-loading muscle force and thereby reducing the metabolic energy consumed in contractions. The device uses a mechanical clutch to hold a spring as it is stretched and relaxed by ankle movements when the foot is on the ground, helping to fulfil one function of the calf muscles and Achilles tendon. Unlike muscles, however, the clutch sustains force passively. The exoskeleton consumes no chemical or electrical energy and delivers no net positive mechanical work, yet reduces the metabolic cost of walking by 7.2 ± 2.6% for healthy human users under natural conditions, comparable to savings with powered devices. Improving upon walking economy in this way is analogous to altering the structure of the body such that it is more energy-effective at walking. While strong natural pressures have already shaped human locomotion, improvements in efficiency are still possible. Much remains to be learned about this seemingly simple behaviour. PMID:25830889

  14. Reducing the energy cost of human walking using an unpowered exoskeleton.

    PubMed

    Collins, Steven H; Wiggin, M Bruce; Sawicki, Gregory S

    2015-06-11

    With efficiencies derived from evolution, growth and learning, humans are very well-tuned for locomotion. Metabolic energy used during walking can be partly replaced by power input from an exoskeleton, but is it possible to reduce metabolic rate without providing an additional energy source? This would require an improvement in the efficiency of the human-machine system as a whole, and would be remarkable given the apparent optimality of human gait. Here we show that the metabolic rate of human walking can be reduced by an unpowered ankle exoskeleton. We built a lightweight elastic device that acts in parallel with the user's calf muscles, off-loading muscle force and thereby reducing the metabolic energy consumed in contractions. The device uses a mechanical clutch to hold a spring as it is stretched and relaxed by ankle movements when the foot is on the ground, helping to fulfil one function of the calf muscles and Achilles tendon. Unlike muscles, however, the clutch sustains force passively. The exoskeleton consumes no chemical or electrical energy and delivers no net positive mechanical work, yet reduces the metabolic cost of walking by 7.2 ± 2.6% for healthy human users under natural conditions, comparable to savings with powered devices. Improving upon walking economy in this way is analogous to altering the structure of the body such that it is more energy-effective at walking. While strong natural pressures have already shaped human locomotion, improvements in efficiency are still possible. Much remains to be learned about this seemingly simple behaviour.

  15. Incarceration, Prisoner Reentry, and Communities

    PubMed Central

    Morenoff, Jeffrey D.; Harding, David J.

    2014-01-01

    Since the mid-1970s the United States has experienced an enormous rise in incarceration and accompanying increases in returning prisoners and in post-release community correctional supervision. Poor urban communities are disproportionately impacted by these phenomena. This review focuses on two complementary questions regarding incarceration, prisoner reentry, and communities:(1) whether and how mass incarceration has affected the social and economic structure of American communities, and (2) how residential neighborhoods affect the social and economic reintegration of returning prisoners. These two questions can be seen as part of a dynamic process involving a pernicious “feedback” loop, in which mass incarceration undermines the structure and social organization of some communities, thus creating more criminogenic environments for returning prisoners and further diminishing their prospects for successful reentry and reintegration. PMID:25400321

  16. 14 CFR 435.3 - Types of reentry licenses.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV... authorizes a licensee to reenter one model or type of reentry vehicle, other than an RLV, to a reentry site... authorizes a licensee to reenter any of a designated family of reentry vehicles, other than an RLV,...

  17. 14 CFR 435.3 - Types of reentry licenses.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV... authorizes a licensee to reenter one model or type of reentry vehicle, other than an RLV, to a reentry site... authorizes a licensee to reenter any of a designated family of reentry vehicles, other than an RLV,...

  18. 14 CFR 435.3 - Types of reentry licenses.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV... authorizes a licensee to reenter one model or type of reentry vehicle, other than an RLV, to a reentry site... authorizes a licensee to reenter any of a designated family of reentry vehicles, other than an RLV,...

  19. 14 CFR 435.3 - Types of reentry licenses.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV... authorizes a licensee to reenter one model or type of reentry vehicle, other than an RLV, to a reentry site... authorizes a licensee to reenter any of a designated family of reentry vehicles, other than an RLV,...

  20. 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.

  1. 14 CFR 435.7 - Payload reentry determination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV... transport a payload to Earth on a reentry vehicle unless the proposed payload is exempt from payload...

  2. 14 CFR 435.7 - Payload reentry determination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV... transport a payload to Earth on a reentry vehicle unless the proposed payload is exempt from payload...

  3. 14 CFR 435.7 - Payload reentry determination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV... transport a payload to Earth on a reentry vehicle unless the proposed payload is exempt from payload...

  4. 14 CFR 435.7 - Payload reentry determination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV... transport a payload to Earth on a reentry vehicle unless the proposed payload is exempt from payload...

  5. 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.

  6. 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…

  7. 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.

  8. Controller performance improvements for reentry through Earth's atmosphere for low L/D spacecraft

    NASA Astrophysics Data System (ADS)

    Kline, Eric Michael

    Development of space-based industry created on the International Space Station is limited by reentry through Earth's atmosphere. The Lyapunov method is applied to improve reentry controller performance through Earth's atmosphere. A Predictor Corrector controller (PCCPA) derived from the Apollo program reentry guidance is the baseline against which candidate controllers are compared. Controllers designed to guide the reentry vehicle to within 1nm of the final target while satisfying a 51.55 BTU/ft2/sec heat rate constraint and a 4 g load constraint are evaluated in a six degree of freedom simulation environment. Three Lyapunov controllers developed in the initial design phase are subjected to variations in vehicle L/D. Controller gains are iteratively determined to satisfy reentry requirements for nominal reentry. However, different controller gain sets have different levels of performance robustness. Only one controller, the Lyapunov Controller, Gain Set 3, satisfies reentry requirements over a larger range of L/D variations than the PCCPA. In the final design phase, three hybrid reentry controllers are developed by combining Lyapunov based guidance routines with PCCPA transition logic and are evaluated for variations in vehicle L/D, weight and initial flight path angle (gamma0). The Hybrid Predictor Corrector/Lyapunov Controller #1 demonstrates the greatest performance robustness and satisfies all reentry requirements over a larger range of L/D, weight, and gamma 0 variations than the PCCPA. The hybrid controller, #3, meets all reentry requirements for a larger range of L/D variations than the PCCPA. The hybrid controller, #2, fails to outperform the PCCPA. All seven reentry controllers are linearized at four operating points and linear robust control analysis techniques are employed to quantify controller performance. Two robustness parameters, eta, a guaranteed domain of stability, and Jw, a measure of system performance to the worst possible direction of the

  9. STS-30 deorbit and reentry ground track

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Rockwell International (RI) supplied artist concept titled 'STS-30 Deorbit and Reentry Track' shows Atlantis, Orbiter Vehicle (OV) 104, deorbit and reentry ground track. Ground track and map portray OV-104's deorbit over Madagascar, atmospheric reentry maneuvers, approach to the California coast, and landing at Edwards Air Force Base (EAFB), California. the transport trailer of the Payload Environmental Transportation System (PETS). Magellan, destined for unprecedented studies of Venusian topographic features, will be deployed by the crew of NASA's STS-30 mission in April 1989. View provided by KSC with alternate number KSC-88PC-1086.

  10. Joule heating induced thermomigration failure in un-powered microbumps due to thermal crosstalk in 2.5D IC technology

    NASA Astrophysics Data System (ADS)

    Li, Menglu; Kim, Dong Wook; Gu, Sam; Parkinson, Dilworth Y.; Barnard, Harold; Tu, K. N.

    2016-08-01

    Thermal-crosstalk induced thermomigration failure in un-powered microbumps has been found in 2.5D integrated circuit (IC) circuit. In 2.5D IC, a Si interposer was used between a polymer substrate and a device chip which has transistors. The interposer has no transistors. If transistors are added to the interposer chip, it becomes 3D IC. In our test structure, there are two Si chips placed horizontally on a Si interposer. The vertical connections between the interposer and the Si chips are through microbumps. We powered one daisy chain of the microbumps under one Si chip; however, the un-powered microbumps in the neighboring chip are failed with big holes in the solder layer. We find that Joule heating from the powered microbumps is transferred horizontally to the bottom of the neighboring un-powered microbumps, and creates a large temperature gradient, in the order of 1000 °C/cm, through the un-powered microbumps in the neighboring chip, so the latter failed by thermomigration. In addition, we used synchrotron radiation tomography to compare three sets of microbumps in the test structure: microbumps under electromigration, microbumps under thermomigration, and microbumps under a constant temperature thermal annealing. The results show that the microbumps under thermomigration have the largest damage. Furthermore, simulation of temperature distribution in the test structure supports the finding of thermomigration.

  11. 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.

  12. A calculation of carbon ablation on a reentry body during supersonic/subsonic flight

    NASA Astrophysics Data System (ADS)

    Hunter, L. W.; Perini, L. L.; Conn, D. W.; Brenza, P. T.

    1985-06-01

    A simplified but accurate procedure is presented for calculating carbon recession and temperature histories of reentry bodies designed to slow down to subsonic speeds before impact. The method accounts for finite-rate chemistry and predicts results substantially different from diffusion-limited ablation calculations.

  13. Women offenders and reentry issues.

    PubMed

    Taylor, S D

    1996-01-01

    Women parallel men in their profile of physical disease, psychosocial configuration, addictive patterns, and criminal deviance. For women offenders in particular, the prison environment reinforces a victim role that originated in childhood and adolescence. In addition, such settings discourage both emotional expression (except for aggression) and responsibility, since basic needs such as food, lodging, and clothing are provided. Incarcerated women have significant treatment issues, including the lack of social and vocational role definition, psychological dependence and psychic craving, poorly developed social skills, and conflicts in social, family, and intimate relationships. This article describes the unique psychoeducational and skills-training needs of women offenders as they adjust to community living, and outlines specific treatment interventions that have proven to effect successful patient outcomes. Case studies are used to illustrate the reentry experiences of three women offenders with distinct backgrounds. One example illustrates how a woman who had been involved in the criminal justice system for 24 years overcame her addiction and self-confidence issues. A second case study profiles an offender with three children who had experienced sexual trauma during her childhood and adult years. A third case reports on an African-American woman whose crack-cocaine addiction resulted in the birth of a drug-exposed son. The treatment model tested in all three cases emphasized the practical and often overlooked treatment issues of incarcerated women.

  14. Women offenders and reentry issues.

    PubMed

    Taylor, S D

    1996-01-01

    Women parallel men in their profile of physical disease, psychosocial configuration, addictive patterns, and criminal deviance. For women offenders in particular, the prison environment reinforces a victim role that originated in childhood and adolescence. In addition, such settings discourage both emotional expression (except for aggression) and responsibility, since basic needs such as food, lodging, and clothing are provided. Incarcerated women have significant treatment issues, including the lack of social and vocational role definition, psychological dependence and psychic craving, poorly developed social skills, and conflicts in social, family, and intimate relationships. This article describes the unique psychoeducational and skills-training needs of women offenders as they adjust to community living, and outlines specific treatment interventions that have proven to effect successful patient outcomes. Case studies are used to illustrate the reentry experiences of three women offenders with distinct backgrounds. One example illustrates how a woman who had been involved in the criminal justice system for 24 years overcame her addiction and self-confidence issues. A second case study profiles an offender with three children who had experienced sexual trauma during her childhood and adult years. A third case reports on an African-American woman whose crack-cocaine addiction resulted in the birth of a drug-exposed son. The treatment model tested in all three cases emphasized the practical and often overlooked treatment issues of incarcerated women. PMID:8714337

  15. 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.

  16. 14 CFR 435.15 - Rights not conferred by reentry license.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV) General § 435.15 Rights not conferred by reentry license. Issuance of a reentry license...

  17. 14 CFR 435.15 - Rights not conferred by reentry license.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV) General § 435.15 Rights not conferred by reentry license. Issuance of a reentry license...

  18. 14 CFR 435.15 - Rights not conferred by reentry license.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV) General § 435.15 Rights not conferred by reentry license. Issuance of a reentry license...

  19. 14 CFR 435.15 - Rights not conferred by reentry license.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV) General § 435.15 Rights not conferred by reentry license. Issuance of a reentry license...

  20. German experiments developed for reentry missions

    NASA Astrophysics Data System (ADS)

    Auweter-Kurtz, M.; Hald, H.; Koppenwallner, G.; Speckmann, H.-D.

    1996-01-01

    For the development of reentry technology it is essential that the knowledge gained from ground test facilities and numerical methods is tested and broadened in real reentry flights. The first of such projects was the space reentry capsule EXPRESS, which was designed as a German—Japanese enterprise for both microgravity research and reentry experiments. The capsule was built by the Russian company DB Saljut as part of the Khrunichev State Research and Production Space Center and modified by DASA. The capsule was launched from Kagoshima by a Japanese M-3 SII rocket in January 1995. Due to a failure of the rocket, the nominal orbital altitude could not be reached, which led to an early reentry of the capsule in Ghana after two and a half orbits. In the stagnation region of the reentry module an experiment was planned with a fibre reinforced ceramic tile of 300 mm in diameter integrated in the ablative heat shield. This experiment, called "CETEX", was designed by the German Aerospace Research Establishment (DLR) in Stuttgart. The aim of CETEX is to qualify lightweight fibre reinforced ceramics and related structural concepts in terms of heat shield applications for space vehicles as well as to compare the erosion behaviour shown in flight experiments and ground tests. An integral part of the CETEX experiment is the PYREX experiment of the University of Stuttgart. With PYREX a pyrometer shall be qualified, which is designed for high precision temperature measurement of heat shield materials made of fibre reinforced ceramic compounds during the reentry phase of space vehicles and probes. A third German experiment, RAFLEX, projected by Hyperschall Technologie Göttingen (HTG), was also integrated in the CETEX tile. RAFLEX is designed for the measurement of dynamic and static pressures and heat transfer at various positions on the EXPRESS capsule. Two small SiC tubes are fed through the CETEX tile for the RAFLEX and RTEX experiments. RTEX is a Japanese spectroscopy

  1. 14 CFR 435.43 - Payload reentry review requirements and procedures.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV) Payload Reentry Review and Determination § 435.43 Payload reentry review requirements and... shall apply to the payload reentry review conducted for a license to reenter a reentry vehicle...

  2. 14 CFR 435.43 - Payload reentry review requirements and procedures.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV) Payload Reentry Review and Determination § 435.43 Payload reentry review requirements and... shall apply to the payload reentry review conducted for a license to reenter a reentry vehicle...

  3. 14 CFR 435.43 - Payload reentry review requirements and procedures.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV) Payload Reentry Review and Determination § 435.43 Payload reentry review requirements and... shall apply to the payload reentry review conducted for a license to reenter a reentry vehicle...

  4. 14 CFR 435.43 - Payload reentry review requirements and procedures.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE (RLV) Payload Reentry Review and Determination § 435.43 Payload reentry review requirements and... shall apply to the payload reentry review conducted for a license to reenter a reentry vehicle...

  5. Communication with reentry vehicle through modulated plasma

    NASA Astrophysics Data System (ADS)

    Hesse, Philip W.; Uhm, Han S.; Choe, Joon

    1994-05-01

    Signal antennae are mounted on the casing wall between forward nose and rear tail ends of an aerospace launched vehicle for radio communication through a conducting sheath of plasma formed thereon by atmospheric ionization during descent of the vehicle along a non-gliding reentry path. The reentry path is maintained by vehicle guidance at a steep angle in response to data transmitted to the antennae through the plasma of the conducting sheath which is thereby maintained in complete surrounding relation to the vehicle and modulated to enhance data transmission during the entire duration of vehicle descent.

  6. YPF uses horizontal reentry to aid thin bed production

    SciTech Connect

    Acosta, M.R.; Leiro, F.A.; Sesano, G.S.; Hill, D.

    1997-01-01

    Reentry and horizontal drilling/completion techniques have proven themselves useful in exploiting thin beds. A pilot horizontal reentry contracted by Yacimiento Petroliferos Fiscales (YPF) for a marginal well in its Lomita Sur field resulted in decreased water coning and production rates four times greater than expected. Further horizontal reentries in this thin-bed field are planned.

  7. 14 CFR 435.13 - Transfer of a reentry license.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Transfer of a reentry license. 435.13 Section 435.13 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE...

  8. 14 CFR 435.13 - Transfer of a reentry license.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Transfer of a reentry license. 435.13 Section 435.13 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE...

  9. 14 CFR 435.13 - Transfer of a reentry license.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Transfer of a reentry license. 435.13 Section 435.13 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE...

  10. 14 CFR 435.13 - Transfer of a reentry license.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Transfer of a reentry license. 435.13 Section 435.13 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING REENTRY OF A REENTRY VEHICLE OTHER THAN A REUSABLE LAUNCH VEHICLE...

  11. Robust adaptive backstepping control for reentry reusable launch vehicles

    NASA Astrophysics Data System (ADS)

    Wang, Zhen; Wu, Zhong; Du, Yijiang

    2016-09-01

    During the reentry process of reusable launch vehicles (RLVs), the large range of flight envelope will not only result in high nonlinearities, strong coupling and fast time-varying characteristics of the attitude dynamics, but also result in great uncertainties in the atmospheric density, aerodynamic coefficients and environmental disturbances, etc. In order to attenuate the effects of these problems on the control performance of the reentry process, a robust adaptive backstepping control (RABC) strategy is proposed for RLV in this paper. This strategy consists of two-loop controllers designed via backstepping method. Both the outer and the inner loop adopt a robust adaptive controller, which can deal with the disturbances and uncertainties by the variable-structure term with the estimation of their bounds. The outer loop can track the desired attitude by the design of virtual control-the desired angular velocity, while the inner one can track the desired angular velocity by the design of control torque. Theoretical analysis indicates that the closed-loop system under the proposed control strategy is globally asymptotically stable. Even if the boundaries of the disturbances and uncertainties are unknown, the attitude can track the desired value accurately. Simulation results of a certain RLV demonstrate the effectiveness of the control strategy.

  12. Assessment of the ATV-1 Re-Entry Observation Campaign for Future Re-Entry Missions

    NASA Astrophysics Data System (ADS)

    Lips, T.; Lohle, S.; Marynowsky, T.; Rees, D.; Stenbeak-Nielsen, H. C.; Beks, M. L.; Hatton, J.

    2010-09-01

    This paper summarizes the midterm results of the currently ongoing ESA study “Assessment of the ATV-1 Reentry Observation Campaign for Future Re-entry Missions”. The primary objective of this study is to investigate the data obtained during a joint ESA/NASA airborne observation campaign of the destructive re-entry of ATV-1 Jules Verne which occurred on September 29, 2008. The presented results are focused on spectroscopic fragment characterization(material identification), frame-by-frame fragment tracking(manual and automatic) for various video recordings, 3D triangulation of the tracked fragments, and fragment propagation until complete demise or ground impact, including the actual size and location of the ATV-1 debris footprint. Fragment propagation analyses comprise also the derivation of aerodynamic fragment properties and potential delta velocities. These parameters are of high importance for the re-entry safety analysis for ATV-2 Johannes Kepler.

  13. Optimal nonlinear guidance for a reentry vehicle

    NASA Astrophysics Data System (ADS)

    Harel, D.; Guelman, M.

    Using the exact nonlinear equations of motion an optimal guidance law for a reentry vehicle to achieve at impact a zero miss and a predefined flight path angle is derived. The application of the optimal guidance law in feedback form is based on the on-line solution of a nonlinear algebraic equation. Numerical results are presented.

  14. Re-Entry Women: Annotated Bibliography.

    ERIC Educational Resources Information Center

    Porterfield, Patricia Lamb

    This is an annotated bibliography on topics related to reentry women. Topic categories include general and administrative issues, programs and services, needs assessment and evaluation, counseling and personal development, career planning and job placement, curriculum and instruction, admissions and recruiting, and financial aid. Annotations cite…

  15. Prisoner Reentry Programming: Who Recidivates and when?

    ERIC Educational Resources Information Center

    Severson, Margaret E.; Bruns, Kimberly; Veeh, Christopher; Lee, Jaehoon

    2011-01-01

    This article provides the results of a multi-year evaluation of one state's prison reentry program and its impact on the success of offender participants as measured by certain recidivism outcomes, defined here as yielding a positive urinalysis, returning to prison, and having a new conviction. Using propensity score matching, the recidivism…

  16. Reusable Reentry Satellite (RRS): Launch tradeoff study

    NASA Technical Reports Server (NTRS)

    1990-01-01

    A goal of the Phase B study is to define the launch system interfaces for the reusable reentry satellite (RRS) program. The focus of the launch tradeoff study, documented in this report, is to determine which expendable launch vehicles (ELV's) are best suited for the RRS application by understanding the impact of all viable launch systems on RRS design and operation.

  17. 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…

  18. 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.

  19. Spacecraft Orbital Debris Reentry: Aerothermal Analysis

    NASA Technical Reports Server (NTRS)

    Rochelle, Wm. C.; Kinsey, Robin E.; Reid, Ethan A.; Reynolds, Robert C.; Johnson, Nicholas L.

    1997-01-01

    In the past 40 years, thousands of objects have been placed in Earth orbit and are being tracked. Space hardware reentry survivability must be evaluated to assess risks to human life and property on the ground. The objective of this paper is to present results of a study to determine altitude of demise (burn-up) or survivability of reentering objects. Two NASA/JSC computer codes - Object Reentry Survival Analysis Tool (ORSAT) and Miniature ORSAT (MORSAT) were used to determine trajectories, aerodynamic aerothermal environment, and thermal response of selected spacecraft components. The methodology of the two codes is presented, along with results of a parametric study of reentering objects modeled as spheres and cylinders. Parameters varied included mass, diameter, wall thickness, ballistic coefficient, length, type of material, and mode of tumbling/spinning. Two fragments of a spent Delta second stage undergoing orbital decay, stainless steel cylindrical propellant tank and titanium pressurization sphere, were evaluated with ORSAT and found to survive entry, as did the actual objects. Also, orbital decay reentry predictions of the Japanese Advanced Earth Observing Satellite (ADEOS) aluminum and nickel box-type components and the Russian COSMOS 954 satellite beryllium cylinders were made with MORSAT. These objects were also shown to survive reentry.

  20. A hypersonic parachute for low-temperature reentry

    NASA Astrophysics Data System (ADS)

    Krischke, M.; Lorenzini, E.; Sabath, D.

    1992-08-01

    Results are presented on a simulations of the atmospheric reentry from LEO of the Small Expendable Tether Deployer (described by Grumbly and Harrison, 1991), a capsule with an attached heat-resistant tether that can act as a hypersonic parachute for returning spacecraft. Results obtained for the endmass reentry with different tethers show that a tether, which can reduce the heat loads of reentry by an order of magnitude, replaces the retromotor for the initiation of the reentry and simplifies the necessary heat protection of the reentry capsule. A heat-resistant tether would be very advantageous for sample returns from the Space Station and for manned Mars missions.

  1. An activation-repolarization time metric to predict localized regions of high susceptibility to re-entry

    PubMed Central

    Child, Nicholas; Bishop, Martin J.; Hanson, Ben; Coronel, Ruben; Opthof, Tobias; Bourkens, Bastiaan; Walton, Richard; Efimov, Igor; Bostock, Julian; Hill, Yolanda; Rinaldi, Christopher A; Razavi, Reza; Gill, Jaswinder; Taggart, Peter

    2015-01-01

    Background Initiation of re-entrant ventricular tachycardia (VT) involves complex interactions between activation and repolarization wavefronts. Recent experimental work has identified the time interval between S2 repolarization proximal to a line of functional block and the activation at the adjacent distal side, as a critical determinant of re-entry. Objective We hypothesized: (1) an algorithm could be developed which would generate a spatial map of this interval (designated the “re-entry vulnerability index”-RVI); (2) that this would accurately identify a pathway of re-entry as well as rotor formation in animal experiments and in a computational model; and, (3) that it would be possible to generate an RVI map in humans during routine clinical procedures and co-register with anatomical and electrophysiological features. Methods and Results An algorithm was developed which sampled all points on a multielectrode grid and calculated RVI between all pairs of electrodes within a given radius. The algorithm successfully identified the spatial region with increased susceptibility to re-entry in an established Langendorff pig heart model and the site of re-entry and rotor formation in an optically mapped sheep heart model and corresponding computational simulations. The feasibility of RVI mapping was evaluated during a clinical procedure by co-registering with the anatomy and physiology in a patient undergoing a VT ablation. Conclusions We developed an algorithm to calculate a re-entry vulnerability index from intervals between local repolarization and activation times at all adjacent points over a multielectrode grid. The algorithm accurately identified the region of re-entry in two animal models of functional re-entry. The possibility of clinical application was demonstrated in a patient with VT. PMID:25863160

  2. Feasibility of Structural and Functional MRI Acquisition with Unpowered Implants in Argus II Retinal Prosthesis Patients: A Case Study

    PubMed Central

    Cunningham, Samantha I.; Shi, Yonggang; Weiland, James D.; Falabella, Paulo; Olmos de Koo, Lisa C.; Zacks, David N.; Tjan, Bosco S.

    2015-01-01

    Purpose Magnetic resonance imaging (MRI) can measure the effects of vision loss and recovery on brain function and structure. In this case study, we sought to determine the feasibility of acquiring anatomical and functional MRI data in recipients of the Argus II epiretinal prosthesis system. Methods Following successful implantation with the Argus II device, two retinitis pigmentosa (RP) patients completed MRI scans with their implant unpowered to measure primary visual cortex (V1) functional responses to a tactile task, whole-brain morphometry, V1 cortical thickness, and diffusion properties of the optic tract and optic radiation. Measurements in the subjects with the Argus II implant were compared to measurements obtained previously from RP patients and sighted individuals. Results The presence of the Argus II implant resulted in artifacts that were localized around the patient's implanted eye and did not extend into cortical regions or white matter tracts associated with the visual system. Structural data on V1 cortical thickness and the retinofugal tract obtained from the two Argus II subjects fell within the ranges of sighted and RP groups. When compared to the RP and sighted subjects, Argus II patients' tactile-evoked cross-modal functional MRI (fMRI) blood oxygen level-dependent (BOLD) responses in V1 also fell within the range of either sighted or RP groups, apparently depending on time since implantation. Conclusions This study demonstrates that successful acquisition and quantification of structural and functional MR images are feasible in the presence of the inactive implant and provides preliminary information on functional changes in the brain that may follow sight restoration treatments. Transitional Relevance Successful MRI and fMRI acquisition in Argus II recipients demonstrates feasibility of using MRI to study the effect of retinal prosthesis use on brain structure and function. PMID:26693097

  3. Evaluation of Reentry Breakup and Debris Generation

    NASA Astrophysics Data System (ADS)

    Nyman, R. L.

    2012-01-01

    Orbital missions launching from Cape Canaveral typically overfly Europe or African before achieving orbital insertion and pose a risk that must be evaluated as part of the overall mission casualty expectation. During the downrange overflight phase, the vehicle is well above the atmosphere and has achieved near orbital velocity, consequently a loss of thrust, loss of control or high altitude breakup will bring either the intact upper stage or smaller secondary debris fragments into the atmosphere and subject them to intense aerodynamic heating. In order to make reasonable risk estimates, it is necessary to first predict the reentry breakup characteristics and the survival of debris fragments. ACTA has developed the Coupled Aeroheating and Thermal Network Solver (CATNS) code to help range safety analysts evaluate reentry breakup and demise.

  4. Landing Energy Dissipation for Manned Reentry Vehicles

    NASA Technical Reports Server (NTRS)

    1960-01-01

    Landing Energy Dissipation for Manned Reentry Vehicles. The film shows experimental investigations to determine the landing-energy-dissipation characteristics for several types of landing gear for manned reentry vehicles. The landing vehicles are considered in two categories: those having essentially vertical-descent paths, the parachute-supported vehicles, and those having essentially horizontal paths, the lifting vehicles. The energy-dissipation devices include crushable materials such as foamed plastics and honeycomb for internal application in couch-support systems, yielding metal elements as part of the structure of capsules or as alternates for oleos in landing-gear struts, inflatable bags, braking rockets, and shaped surfaces for water impact. [Entire movie available on DVD from CASI as Doc ID 20070030945. Contact help@sti.nasa.gov

  5. Shadowgraph Images of Re-entry Vehicles

    NASA Technical Reports Server (NTRS)

    1960-01-01

    These four shadowgraph images represent early re-entry vehicle concepts. A shadowgraph is a process that makes visible the disturbances that occur in a fluid flow at high velocity, in which light passing through a flowing fluid is refracted by the density gradients in the fluid resulting in bright and dark areas on a screen placed behind the fluid.H. Julian Allen pioneered and developed the Blunt Body Theory which made possible the heat shield designs that were embodied in the Mercury, Gemini and Apollo space capsules, enabling astronauts to survive the firey re-entry into Earth's atmosphere. A blunt body produces a shockwave in front of the vehicle--visible in the photo--that actually shields the vehicle from excessive heating. As a result, blunt body vehicles can stay cooler than pointy, low drag vehicles.

  6. Reusable Reentry Satellite (RRS): Configuration trade study

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The overall Reusable Reentry Satellite (RRS) Phase B Study objective is to design a relatively inexpensive satellite to access space for extended periods of time, with eventual recovery of experiments on Earth. The expected principal use for such a system is research on the effects of variable gravity (0-1.5 g) and radiation on small animals, plants, lower life forms, tissue samples, and materials processes. The RRS will be capable of: (1) being launched by a variety of expendable launch vehicles; (2) operating in low earth orbit as a free flying unmanned laboratory; and (3) executing independent atmospheric reentry and soft landing. The RRS will be designed to be refurbished and reused up to three times a year for a period of 10 years. The information provided in this report describes the process involved in the evolution of the RRS overall configuration. This process considered reentry aerodynamics, aerothermodynamics, internal equipment layout, and vehicle mass properties. This report delineates the baseline design decisions that were used to initiate the RRS design effort. As a result, there will be deviations between this report and the RRS Final Report. In those instances, the RRS Final Report shall be considered to be the definitive reference.

  7. EV13 Genesis Reentry Observations and Data Analysis

    NASA Technical Reports Server (NTRS)

    Swift, Wesley R.; Suggs, Robert M.

    2006-01-01

    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 which 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 which could be used during future reentries. This report 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.

  8. Re-entry survivability and risk

    NASA Astrophysics Data System (ADS)

    Fudge, Michael L.

    1998-11-01

    This paper is the culmination of the research effort which was reported on last year while still in-progress. As previously reported, 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 reentering 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 demonstrated in dramatic fashion in January 1997 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 report details reentry survivability estimation methodology, including the specific methodology used by ITT Systems' (formerly Kaman Sciences) 'SURVIVE' model. The major change to the model in the last twelve months has been the increase in the fidelity with which upper- atmospheric aerodynamics has been modeled. This has resulted in an adjustment in the factor relating the amount of kinetic energy loss to the amount of heating entering and reentering body, and also validated and removed the necessity for certain empirically-based adjustments made to the theoretical heating expressions. Comparisons between empirical results (observations of objects which have been recovered on Earth after surviving reentry) and SURVIVE

  9. The secret of guided missile re-entry

    NASA Astrophysics Data System (ADS)

    Chen, Jingzhong; An, Sehua

    1986-06-01

    The history and development of reentry vehicles especially as related to guided missiles is studied. The development of fiber reinforced composites to avoid the combustion of reentry vehicle heads is described. The ionization of molecules caused by high temperature friction with the air during high speed reeentry is briefly described. Reentry remote sensing as an important basis for developing configuration and predicting accuracy of point of impact of the guided missile is also discussed.

  10. Effective reentry methods reduce costs and optimize production

    SciTech Connect

    Szutiak, G.; Walker, D.

    1996-10-21

    Favorable oil prices and tax incentives have spawned an increase in reentry drilling, adding new life to fields once abandoned in Canada. (The provincial government in Alberta has stimulated reentry drilling in western Canada by its tax royalty relief and incentives.) A review of four reentry projects covering 19 horizontal wells in western Canada illustrates a number of planning considerations that can save an operator money while ensuring optimization of the production. The paper recommends several standard steps in planning and executing slim hole reentries drawn from these projects.

  11. Orbital decay analysis, reentry predictions and risk assessment for the GOCE satellite

    NASA Astrophysics Data System (ADS)

    Pardini, Carmen; Anselmo, Luciano

    the critical use of this information for civil protection evaluations. However, after an initial period of test and analysis, reasonably conservative criteria were elaborated and applied, with good and consistent results through the end of the reentry prediction campaign. Being the attention of the Italian civil protection authorities focused on the national territory, during the last three days of satellite residual lifetime, reentries where 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 current uncertainty windows. Only 14 hours before reentry it was possible to exclude any residual risk of debris fall on the Italian territory and the GOCE fragments eventually plunged into the Southern Atlantic Ocean, between the Falkland Islands and the coast of Argentina, on 11 November 2013, around 00:24 - 00:40 UTC.

  12. Optimal guidance for reentry vehicles based on indirect Legendre pseudospectral method

    NASA Astrophysics Data System (ADS)

    Tian, Bailing; Zong, Qun

    2011-04-01

    Development of a feasible guidance scheme for reentry vehicles is a challenge because of its significant nonlinearity and multi-constraints. A method for the implementation of three-degree-of-freedom guidance for constrained reentry vehicle is presented in the paper. First, the constrained trajectory is generated by Legendre pseudospectral method (LPM) and then the feasibily of the trajectory is validated. Based on the obtained reference trajectory, the guidance problem is converted into a trajectory state regulation problem which is a linear time varying system. A robust state feedback guidance law is generated in real time using indirect Legendre pseudospectral feedback method. Finally, simulation results illustrate that the overall guidance scheme can lead to a very accurately controlled flight with all the constraints satisfied even in the presence of initial state uncertainty.

  13. Thermal stress analysis of space shuttle orbiter subjected to reentry aerodynamic heating

    NASA Technical Reports Server (NTRS)

    Ko, William L.; Fields, Roger A.

    1987-01-01

    A structural performance and resizing (SPAR) finite-element computer program and NASA structural analysis (NASTRAN) finite-element computer programs were used in the thermal stress analysis of the space shuttle orbiter subjected to reentry aerodynamic heating. A SPAR structural model was set up for the entire left wing of the orbiter, and NASTRAN structural models were set up for: (1) a wing segment located at midspan of the orbiter left wing, and (2) a fuselage segment located at midfuselage. The thermal stress distributions in the orbiter structure were obtained and the critical high thermal stress regions were identified. It was found that the thermal stresses induced in the orbiter structure during reentry were relatively low. The thermal stress predictions from the whole wing model were considered to be more accurate than those from the wing segment model because the former accounts for temperature and stress effects throughout the entire wing.

  14. 75 FR 75619 - Waiver of Acceptable Mission Risk Restriction for Reentry and a Reentry Vehicle

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-06

    ... waiver concerns two petitions for waiver submitted to the FAA by Space Exploration Technologies Corp. (SpaceX): A petition to waive the requirement that a waiver petition be submitted at least sixty days... Space Transportation Reusable Launch Vehicle and Reentry Licensing Regulations, NPRM, 64 FR 19626,...

  15. 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

    ... Commercial Space Transportation Reusable Launch Vehicle and Reentry Licensing Regulations, 64 FR 19626, 19645..., 2010 launch date planned at the time of the filing of the petition. However, in its petition, SpaceX... left in orbit to reenter randomly at some later time. SpaceX's mitigation measures are of...

  16. 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…

  17. 14 CFR 431.57 - Information requirements for payload reentry review.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE (RLV) Payload Reentry Review and Determination § 431.57 Information requirements for...

  18. 14 CFR 431.61 - Incorporation of payload reentry determination in license application.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE (RLV) Payload Reentry Review and Determination § 431.61 Incorporation of...

  19. 14 CFR 431.61 - Incorporation of payload reentry determination in license application.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE (RLV) Payload Reentry Review and Determination § 431.61 Incorporation of...

  20. 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 VEHICLE (RLV) Payload Reentry Review and Determination § 431.57 Information requirements for...

  1. 14 CFR 431.61 - Incorporation of payload reentry determination in license application.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE (RLV) Payload Reentry Review and Determination § 431.61 Incorporation of...

  2. 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 VEHICLE (RLV) Payload Reentry Review and Determination § 431.57 Information requirements for...

  3. 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 VEHICLE (RLV) Payload Reentry Review and Determination § 431.57 Information requirements for...

  4. 14 CFR 431.61 - Incorporation of payload reentry determination in license application.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE (RLV) Payload Reentry Review and Determination § 431.61 Incorporation of...

  5. Status of 'HIMES' reentry flight test project

    NASA Astrophysics Data System (ADS)

    Inatani, Yoshifumi; Kawaguchi, Jun'ichiro; Yonemoto, Koichi

    1990-10-01

    The salient features of the Highly Maneuverable Experimental Space (HIMES) vehicle which is being developed by the Institute of Space and Astronautical Science of Japan are discussed together with the results of tests conducted. Analytical studies carried out so far include system analyses, aerodynamic design, the navigation/guidance and control systems, the propulsion system, and structural studies. Results of flight tests conducted to verify these analyses include the low-speed gliding flight test and the atmospheric reentry flight test, as well as a ground firing test of the hydrogen-fueled propulsion system. Diagrams are presented of the HIMES vehicle and its propulsion engines.

  6. Nonlinear and adaptive estimation in reentry.

    NASA Technical Reports Server (NTRS)

    Jazwinski, A. H.

    1972-01-01

    The problem of real-time estimation of a lifting reentry vehicle trajectory of the shuttle orbiter type is considered. Simulations feature large position and velocity uncertainties at radar acquisition and realistic model errors in lift, drag and other model parameters. Radar tracking and accelerometer data are simulated. Significant nonlinearities are found to exist on spacecraft acquisition. An iterated nonlinear filter is shown to perform optimally during the radar acquisition phase. An adaptive filter is shown to track time-varying model errors, such as errors in the lift and drag coefficients, down to the noise level. Such real-time model tracking (identification) is frequently required for guidance and control implementation.

  7. Landing Energy Dissipation for Manned Reentry Vehicles

    NASA Technical Reports Server (NTRS)

    Fisher, Loyd. L.

    1960-01-01

    The film shows experimental investigations to determine the landing-energy-dissipation characteristics for several types of landing gear for manned reentry vehicles. The landing vehicles are considered in two categories: those having essentially vertical-descent paths, the parachute-supported vehicles, and those having essentially horizontal paths, the lifting vehicles. The energy-dissipation devices include crushable materials such as foamed plastics and honeycomb for internal application in couch-support systems, yielding metal elements as part of the structure of capsules or as alternates for oleos in landing-gear struts, inflatable bags, braking rockets, and shaped surfaces for water impact.

  8. Kiernan reentry measurements system on Kwajalein atoll

    SciTech Connect

    Roth, K.R.; Austin, M.E.; Frediani, D.J.; Knittel, G.H.; Mrstik, A.V.

    1989-01-01

    The Kiernan Reentry Measurements System (KREMS), located on Kwajalein Atoll in the Pacific, is the United States' most sophisticated and important research and development radar site. Consisting of four one-of-a-kind instrumentation radars, KREMS has played a major role for the past 25 years in the collection of data associated with ICBM testing. Furthermore, it has served as an important space-surveillance facility that provides an early U.S. view of many Soviet and Chinese satellite launches. Finally, the system is slated to play a key role in Strategic Defense Initiative experiments.

  9. 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…

  10. Reentry in Ohio Corrections: A Catalyst for Change

    ERIC Educational Resources Information Center

    Wilkinson, Reginald A.; Rhine, Edward E.; Henderson-Hurley, Martha

    2006-01-01

    In 2002, the Ohio Department of Rehabilitation and Correction (DRC) published The Ohio Plan for Productive Offender Reentry and Recidivism Reduction. The document listed forty-four recommendations designed to contribute significantly to the development of a reentry transition system that providing a seamless service and program delivery beginning…

  11. 40 CFR 161.390 - Reentry protection data requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR REGISTRATION OF ANTIMICROBIAL PESTICIDES Data Requirement Tables § 161.390 Reentry protection data requirements. (a) Table. Sections 161.100 through 161.102 describe how to use this table to determine the reentry protection data requirements and the substance to...

  12. 40 CFR 161.390 - Reentry protection data requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR REGISTRATION OF ANTIMICROBIAL PESTICIDES Data Requirement Tables § 161.390 Reentry protection data requirements. (a) Table. Sections 161.100 through 161.102 describe how to use this table to determine the reentry protection data requirements and the substance to...

  13. 40 CFR 161.390 - Reentry protection data requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR REGISTRATION OF ANTIMICROBIAL PESTICIDES Data Requirement Tables § 161.390 Reentry protection data requirements. (a) Table. Sections 161.100 through 161.102 describe how to use this table to determine the reentry protection data requirements and the substance to...

  14. 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…

  15. 14 CFR 431.55 - Payload reentry review.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Payload reentry review. 431.55 Section 431.55 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE (RLV) Payload...

  16. 14 CFR 431.59 - Issuance of payload reentry determination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Issuance of payload reentry determination. 431.59 Section 431.59 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE...

  17. 14 CFR 431.55 - Payload reentry review.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Payload reentry review. 431.55 Section 431.55 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE (RLV) Payload...

  18. 14 CFR 431.59 - Issuance of payload reentry determination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Issuance of payload reentry determination. 431.59 Section 431.59 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE...

  19. 14 CFR 431.55 - Payload reentry review.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Payload reentry review. 431.55 Section 431.55 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE (RLV) Payload...

  20. 14 CFR 431.55 - Payload reentry review.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Payload reentry review. 431.55 Section 431.55 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE (RLV) Payload...

  1. 14 CFR 431.59 - Issuance of payload reentry determination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Issuance of payload reentry determination. 431.59 Section 431.59 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE...

  2. 14 CFR 431.59 - Issuance of payload reentry determination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Issuance of payload reentry determination. 431.59 Section 431.59 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE...

  3. An Evaluation Guide for College Women's Re-entry Programs.

    ERIC Educational Resources Information Center

    Mezirow, Jack; Rose, Amy D.

    Since 1970, over 300 community colleges have established re-entry programs designed especially for women who are either continuing their education or entering the job market after an extended hiatus. Re-entry programs vary in scope and in the nature of services provided, with some offering specific skills on vocational training, and others…

  4. Reentry Body Stability Tests Conducted in Langley Spin Tunnel

    NASA Technical Reports Server (NTRS)

    1958-01-01

    Reentry Body Stability Tests Conducted in Langley Spin Tunnel. Reentry body stability tests were conducted in an initial configuration, with a small drogue chute, with an extendable flare, and in an alternate configuration with a covered flare. [Entire movie available on DVD from CASI as Doc ID 20070030957. Contact help@sti.nasa.gov

  5. The International Association of Reentry: Mission and Future

    ERIC Educational Resources Information Center

    Wilkinson, Reginald A.; Rhine, Edward E.

    2005-01-01

    There is a growing national movement in corrections embracing offender reentry. In a very brief period of time, innovative and ambitious initiatives have been launched at all levels of government and by untold groups and community organizations to build more effective responses to the myriad of challenges presented by reentry. The International…

  6. Female Arab-Muslim nursing students' reentry transitions.

    PubMed

    McDermott-Levy, Ruth

    2013-01-01

    As nursing students are increasingly studying abroad and returning to their home countries to practice, it is important to identify international nursing students' reentry transition to understand their reentry needs. Phenomenological inquiry was used to describe the reentry experience of seven Omani nurses after studying in the United States. The nurses' reentry experience was influenced by the personal and professional transformation from studying abroad and included themes of adaptation to cultural differences and service to themselves, their profession, and their nation. These nurses returned home to resume previous roles; they were changed and this required them to redefine and adapt to their roles within their families and workplace. Nurses returning from international study could benefit from a formal reentry program to assist their transition to family, community, and professional life and to enhance the nurses' contribution from their international education. PMID:23832951

  7. Female Arab-Muslim nursing students' reentry transitions.

    PubMed

    McDermott-Levy, Ruth

    2013-07-04

    As nursing students are increasingly studying abroad and returning to their home countries to practice, it is important to identify international nursing students' reentry transition to understand their reentry needs. Phenomenological inquiry was used to describe the reentry experience of seven Omani nurses after studying in the United States. The nurses' reentry experience was influenced by the personal and professional transformation from studying abroad and included themes of adaptation to cultural differences and service to themselves, their profession, and their nation. These nurses returned home to resume previous roles; they were changed and this required them to redefine and adapt to their roles within their families and workplace. Nurses returning from international study could benefit from a formal reentry program to assist their transition to family, community, and professional life and to enhance the nurses' contribution from their international education.

  8. Orbit re-entry experiment vehicle development

    NASA Astrophysics Data System (ADS)

    Yamamoto, Masataka; Yamawaki, Kouji; Akimoto, Toshio; Murakami, Atsushi; Inaba, Motoyuki; Kaneko, Yutaka; Shimoda, Takayuki; Ishii, Yasuo; Izumi, Tatsushi; Kawano, Isao

    1992-08-01

    An overview of the Orbital Re-entry Experiment (OREX) vehicle development, including detail design, analyses on the overall system, guidance and control, propulsion, and data acquisition systems is presented. The outline of the experiment vehicle is shown. OREX flight is analyzed and the splash down point variance ellipse is shown. Vehicle body aerodynamic characteristics were analyzed and validated by supersonic wind tunnel and dynamically balanced wind tunnel tests. Analyses on onboard equipment environmental resistance, controllability from on orbit to re-entry phases and navigation and guidance of the space plane were conducted. It was confirmed that there was no problem on the guidance and control system. Review on the propellant volume and analyses on the propulsion system performance, propulsion system heat exchanger performance, and thruster and piping system temperature were conducted and possibility of hard starting of the 150 N hydrazine thruster was noticed. RF (Radio Frequency) link analyses were conducted around Tanegashima, Ogasawara, and the splash down area and prospect of continuously acquiring good link margin for 300 seconds was obtained. Semi unitized structure of truncated cone shape with main body made of aluminum alloy, which has application record for rockets, laid with skin, stringers, and frames was employed for the structure. Data acquisition systems for tracking and operation, including those at Tanegashima, Ogasawara, Christmas, down range ship, and airplane tracking stations were studied.

  9. Statistical Issues for Calculating Reentry Hazards

    NASA Technical Reports Server (NTRS)

    Matney, Mark; Bacon, John

    2016-01-01

    A number of statistical tools have been developed over the years for assessing the risk of reentering object to human populations. These tools make use of the characteristics (e.g., mass, shape, size) of debris that are predicted by aerothermal models to survive reentry. This information, combined with information on the expected ground path of the reentry, is used to compute the probability that one or more of the surviving debris might hit a person on the ground and cause one or more casualties. The statistical portion of this analysis relies on a number of assumptions about how the debris footprint and the human population are distributed in latitude and longitude, and how to use that information to arrive at realistic risk numbers. This inevitably involves assumptions that simplify the problem and make it tractable, but it is often difficult to test the accuracy and applicability of these assumptions. This paper builds on previous IAASS work to re-examine many of these theoretical assumptions, including the mathematical basis for the hazard calculations, and outlining the conditions under which the simplifying assumptions hold. This study also employs empirical and theoretical information to test these assumptions, and makes recommendations how to improve the accuracy of these calculations in the future.

  10. Statistical Issues for Calculating Reentry Hazards

    NASA Technical Reports Server (NTRS)

    Bacon, John B.; Matney, Mark

    2016-01-01

    A number of statistical tools have been developed over the years for assessing the risk of reentering object to human populations. These tools make use of the characteristics (e.g., mass, shape, size) of debris that are predicted by aerothermal models to survive reentry. This information, combined with information on the expected ground path of the reentry, is used to compute the probability that one or more of the surviving debris might hit a person on the ground and cause one or more casualties. The statistical portion of this analysis relies on a number of assumptions about how the debris footprint and the human population are distributed in latitude and longitude, and how to use that information to arrive at realistic risk numbers. This inevitably involves assumptions that simplify the problem and make it tractable, but it is often difficult to test the accuracy and applicability of these assumptions. This paper builds on previous IAASS work to re-examine one of these theoretical assumptions.. This study employs empirical and theoretical information to test the assumption of a fully random decay along the argument of latitude of the final orbit, and makes recommendations how to improve the accuracy of this calculation in the future.

  11. Advanced validation of CFD-FDTD combined method using highly applicable solver for reentry blackout prediction

    NASA Astrophysics Data System (ADS)

    Takahashi, Yusuke

    2016-01-01

    An analysis model of plasma flow and electromagnetic waves around a reentry vehicle for radio frequency blackout prediction during aerodynamic heating was developed in this study. The model was validated based on experimental results from the radio attenuation measurement program. The plasma flow properties, such as electron number density, in the shock layer and wake region were obtained using a newly developed unstructured grid solver that incorporated real gas effect models and could treat thermochemically non-equilibrium flow. To predict the electromagnetic waves in plasma, a frequency-dependent finite-difference time-domain method was used. Moreover, the complicated behaviour of electromagnetic waves in the plasma layer during atmospheric reentry was clarified at several altitudes. The prediction performance of the combined model was evaluated with profiles and peak values of the electron number density in the plasma layer. In addition, to validate the models, the signal losses measured during communication with the reentry vehicle were directly compared with the predicted results. Based on the study, it was suggested that the present analysis model accurately predicts the radio frequency blackout and plasma attenuation of electromagnetic waves in plasma in communication.

  12. Low-Speed Wind-Tunnel Test of an Unpowered High-Speed Stoppable Rotor Concept in Fixed-Wing Mode

    NASA Technical Reports Server (NTRS)

    Lance, Michael B.; Sung, Daniel Y.; Stroub, Robert H.

    1991-01-01

    An experimental investigation of the M85, a High Speed Rotor Concept, was conducted at the NASA Langley 14 x 22 foot Subsonic Tunnel, assisted by NASA-Ames. An unpowered 1/5 scale model of the XH-59A helicopter fuselage with a large circular hub fairing, two rotor blades, and a shaft fairing was used as a baseline configuration. The M85 is a rotor wing hybrid aircraft design, and the model was tested with the rotor blade in the fixed wing mode. Assessments were made of the aerodynamic characteristics of various model rotor configurations. Variation in configurations were produced by changing the rotor blade sweep angle and the blade chord length. The most favorable M85 configuration tested included wide chord blades at 0 deg sweep, and it attained a system lift to drag ratio of 8.4.

  13. Statistical Issues for Uncontrolled Reentry Hazards

    NASA Technical Reports Server (NTRS)

    Matney, Mark

    2008-01-01

    A number of statistical tools have been developed over the years for assessing the risk of reentering objects to human populations. These tools make use of the characteristics (e.g., mass, shape, size) of debris that are predicted by aerothermal models to survive reentry. The statistical tools use this information to compute the probability that one or more of the surviving debris might hit a person on the ground and cause one or more casualties. The statistical portion of the analysis relies on a number of assumptions about how the debris footprint and the human population are distributed in latitude and longitude, and how to use that information to arrive at realistic risk numbers. This inevitably involves assumptions that simplify the problem and make it tractable, but it is often difficult to test the accuracy and applicability of these assumptions. This paper looks at a number of these theoretical assumptions, examining the mathematical basis for the hazard calculations, and outlining the conditions under which the simplifying assumptions hold. In addition, this paper will also outline some new tools for assessing ground hazard risk in useful ways. Also, this study is able to make use of a database of known uncontrolled reentry locations measured by the United States Department of Defense. By using data from objects that were in orbit more than 30 days before reentry, sufficient time is allowed for the orbital parameters to be randomized in the way the models are designed to compute. The predicted ground footprint distributions of these objects are based on the theory that their orbits behave basically like simple Kepler orbits. However, there are a number of factors - including the effects of gravitational harmonics, the effects of the Earth's equatorial bulge on the atmosphere, and the rotation of the Earth and atmosphere - that could cause them to diverge from simple Kepler orbit behavior and change the ground footprints. The measured latitude and longitude

  14. A NLP Based Reentry Flight Guidance Algorithm

    NASA Astrophysics Data System (ADS)

    Gräßlin, M.; Schöttle, U.

    A major cost driving factor for space transportation systems, especially for reusable systems, are the operation costs. The Guidance, Navigation and Control (GNC) system of a vehicle determines the amount of autonomy and ground support required. Current systems demand high manpower effort from the ground, which makes a mission costly and inflexible. Next generation space transportation systems demand a high cost saving in order to be commercially successful. One possibility to cut down costs is a highly autonomous and flexible guidance system. The paper addresses an approach to achieve this goal by using onboard flight path prediction in combination with numerical optimisation routines to guide a vehicle in its reentry mission. Some numerical results are given to demonstrate the capabilities of such an approach.

  15. Thermoacoustic environments to simulate reentry conditions

    NASA Technical Reports Server (NTRS)

    Bayerdoerfer, Gerhard

    1994-01-01

    Aerothermal environments as encountered during the reentry of spaceplanes or during the cruise of hypersonic aircrafts represent complex loading conditions for the external structures of those vehicles. In order to shield against the aerodynamic heating a special Thermal Protection System (TPS) is required which is designed as a light weight structure to reduce the weight penalty. TPS is therefore vulnerable to vibroacoustic fatigue caused by the pressure fluctuations of the environment. Because of the complex interactions between the loading forces and the resulting structural response which make an analytical treatment difficult and in order to provide means for fatigue testing IABG has designed and built a thermoacoustic facility which recently became operational. The facility is capable to produce surface temperatures up to 1.300 C at sound pressure levels up to 160 dB. This paper describes the design of the facility, some operational test work it also deals with problems associated with the facility instrumentation.

  16. Investigating a Novel Activation-Repolarisation Time Metric to Predict Localised Vulnerability to Reentry Using Computational Modelling

    PubMed Central

    Hill, Yolanda R.; Child, Nick; Hanson, Ben; Wallman, Mikael; Coronel, Ruben; Plank, Gernot; Rinaldi, Christopher A.; Gill, Jaswinder; Smith, Nicolas P.; Taggart, Peter; Bishop, Martin J.

    2016-01-01

    Exit sites associated with scar-related reentrant arrhythmias represent important targets for catheter ablation therapy. However, their accurate location in a safe and robust manner remains a significant clinical challenge. We recently proposed a novel quantitative metric (termed the Reentry Vulnerability Index, RVI) to determine the difference between activation and repolarisation intervals measured from pairs of spatial locations during premature stimulation to accurately locate the critical site of reentry formation. In the clinic, the method showed potential to identify regions of low RVI corresponding to areas vulnerable to reentry, subsequently identified as ventricular tachycardia (VT) circuit exit sites. Here, we perform an in silico investigation of the RVI metric in order to aid the acquisition and interpretation of RVI maps and optimise its future usage within the clinic. Within idealised 2D sheet models we show that the RVI produces lower values under correspondingly more arrhythmogenic conditions, with even low resolution (8 mm electrode separation) recordings still able to locate vulnerable regions. When applied to models of infarct scars, the surface RVI maps successfully identified exit sites of the reentrant circuit, even in scenarios where the scar was wholly intramural. Within highly complex infarct scar anatomies with multiple reentrant pathways, the identified exit sites were dependent upon the specific pacing location used to compute the endocardial RVI maps. However, simulated ablation of these sites successfully prevented the reentry re-initiation. We conclude that endocardial surface RVI maps are able to successfully locate regions vulnerable to reentry corresponding to critical exit sites during sustained scar-related VT. The method is robust against highly complex and intramural scar anatomies and low resolution clinical data acquisition. Optimal location of all relevant sites requires RVI maps to be computed from multiple pacing

  17. Investigating a Novel Activation-Repolarisation Time Metric to Predict Localised Vulnerability to Reentry Using Computational Modelling.

    PubMed

    Hill, Yolanda R; Child, Nick; Hanson, Ben; Wallman, Mikael; Coronel, Ruben; Plank, Gernot; Rinaldi, Christopher A; Gill, Jaswinder; Smith, Nicolas P; Taggart, Peter; Bishop, Martin J

    2016-01-01

    Exit sites associated with scar-related reentrant arrhythmias represent important targets for catheter ablation therapy. However, their accurate location in a safe and robust manner remains a significant clinical challenge. We recently proposed a novel quantitative metric (termed the Reentry Vulnerability Index, RVI) to determine the difference between activation and repolarisation intervals measured from pairs of spatial locations during premature stimulation to accurately locate the critical site of reentry formation. In the clinic, the method showed potential to identify regions of low RVI corresponding to areas vulnerable to reentry, subsequently identified as ventricular tachycardia (VT) circuit exit sites. Here, we perform an in silico investigation of the RVI metric in order to aid the acquisition and interpretation of RVI maps and optimise its future usage within the clinic. Within idealised 2D sheet models we show that the RVI produces lower values under correspondingly more arrhythmogenic conditions, with even low resolution (8 mm electrode separation) recordings still able to locate vulnerable regions. When applied to models of infarct scars, the surface RVI maps successfully identified exit sites of the reentrant circuit, even in scenarios where the scar was wholly intramural. Within highly complex infarct scar anatomies with multiple reentrant pathways, the identified exit sites were dependent upon the specific pacing location used to compute the endocardial RVI maps. However, simulated ablation of these sites successfully prevented the reentry re-initiation. We conclude that endocardial surface RVI maps are able to successfully locate regions vulnerable to reentry corresponding to critical exit sites during sustained scar-related VT. The method is robust against highly complex and intramural scar anatomies and low resolution clinical data acquisition. Optimal location of all relevant sites requires RVI maps to be computed from multiple pacing

  18. Second-order analytic solutions for re-entry trajectories

    NASA Astrophysics Data System (ADS)

    Kim, Eun-Kyou

    1993-01-01

    With the development of aeroassist technology, either for near-earth orbital transfer with or without a plane change or for planetary aerocapture, it is of interest to have accurate analytic solutions for reentry trajectories in an explicit form. Starting with the equations of motion of a non-thrusting aerodynamic vehicle entering a non-rotating spherical planetary atmosphere, a normalization technique is used to transform the equations into a form suitable for an analytic integration. Then, depending on the type of planar entry modes with a constant angle-of-attack, namely, ballistic fly-through, lifting skip, and equilibrium glide trajectories, the first-order solutions are obtained with the appropriate simplification. By analytic continuation, the second-order solutions for the altitude, speed, and flight path angle are derived. The closed form solutions lead to explicit forms for the physical quantities of interest, such as the deceleration and aerodynamic heating rates. The analytic solutions for the planar case are extended to three-dimensional skip trajectories with a constant bank angle. The approximate solutions for the heading and latitude are developed to the second order. In each type of trajectory examined, explicit relations among the principal variables are in a form suitable for guidance and navigation purposes. The analytic solutions have excellent agreement with the numerical integrations. They also provide some new results which were not reported in the existing classical theory.

  19. Characteristics of the Shuttle Orbiter Leeside Flow During A Reentry Condition

    NASA Technical Reports Server (NTRS)

    Kleb, William L.; Weilmuenster, K. James

    1992-01-01

    A study of the leeside flow characteristics of the Shuttle Orbiter is presented for a reentry flight condition. The flow is computed using a point-implicit, finite-volume scheme known as the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA). LAURA is a second-order accurate, laminar Navier-Stokes solver, incorporating finite-rate chemistry with a radiative equilibrium wall temperature distribution and finite-rate wall catalysis. The resulting computational solution is analyzed in terms of salient flow features and the surface quantities are compared with flight data.

  20. ISS Update: ATV-3 ReEntry Breakup Recorder

    NASA Video Gallery

    ISS Update Commentator Pat Ryan talks with Dr. William Ailor, Principal Investigator for the ReEntry Breakup Recorder (REBR) for The Aerospace Corporation. Ailor talks about capturing data as Europ...

  1. Controlled reentry of the Gamma Ray Observatory (GRO)

    NASA Astrophysics Data System (ADS)

    Brown, Evette R.

    1988-09-01

    Reentry of the GRO satellite must be controlled because it is expected that a great portion of the massive spacecraft would survive the reentry into the earth's atmosphere with the debris possibly causing harm to human life and property. The intent of this paper is to present a technique, results, and conclusion for a controlled reentry scenario for GRO. The planned impact would occur in an uninhabited portion of the South Pacific Ocean. Two major areas were analyzed. First, targeting analysis examined conditions under which the orbital maneuver study was done. Finally, the debris scatter involved analyzing effects of the breakup of the spacecraft on the impact area. These two areas were the basis from which the controlled reentry study was accomplished.

  2. 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.

  3. Critical role of inhomogeneities in pacing termination of cardiac reentry

    NASA Astrophysics Data System (ADS)

    Sinha, Sitabhra; Stein, Kenneth M.; Christini, David J.

    2002-09-01

    Reentry around nonconducting ventricular scar tissue, a cause of lethal arrhythmias, is typically treated by rapid electrical stimulation from an implantable cardioverter defibrillator. However, the dynamical mechanisms of termination (success and failure) are poorly understood. To elucidate such mechanisms, we study the dynamics of pacing in one- and two-dimensional models of anatomical reentry. In a crucial realistic difference from previous studies of such systems, we have placed the pacing site away from the reentry circuit. Our model-independent results suggest that with such off-circuit pacing, the existence of inhomogeneity in the reentry circuit is essential for successful termination of tachycardia under certain conditions. Considering the critical role of such inhomogeneities may lead to more effective pacing algorithms.

  4. 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.

  5. 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.

  6. 14 CFR 431.7 - Payload and payload reentry determinations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE (RLV... launch a payload unless the proposed payload is exempt from payload review under § 415.53 of this...

  7. 14 CFR 431.7 - Payload and payload reentry determinations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE (RLV... launch a payload unless the proposed payload is exempt from payload review under § 415.53 of this...

  8. 14 CFR 431.7 - Payload and payload reentry determinations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE (RLV... launch a payload unless the proposed payload is exempt from payload review under § 415.53 of this...

  9. 14 CFR 431.7 - Payload and payload reentry determinations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH AND REENTRY OF A REUSABLE LAUNCH VEHICLE (RLV... launch a payload unless the proposed payload is exempt from payload review under § 415.53 of this...

  10. 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.

  11. 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. PMID:24574929

  12. 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

  13. A hypersonic parachute for low-temperature re-entry

    NASA Astrophysics Data System (ADS)

    Krischke, M.; Lorenzini, E. C.; Sabath, D.

    1995-09-01

    Atmospheric re-entry, even when initiated from a circular low-Earth orbit, requires heavy heat shields, ablative materials or radiative dissipation techniques. Semi-analytical and numerical simulations of the atmospheric re-entry from low-Earth orbits of a capsule with a 20-km, attached, heat resistant tether have shown that the thermal input flux on the capsule is reduced by more than one order of magnitude with respect to a comparable re-entry without tether. Long tethers have low ballistic coefficients and a large surface for heat dissipation. Moreover, a long tether is stabilized by gravity gradient and consequently tends to maintain a high angle of attack with respect to the wind velocity. The exposed surface of a 20-km-long 1-mm diameter tether is 20 m 2, which is much larger than the cross section of a re-entry capsule. The resulting strong drag decelerates the capsule during re-entry like a conceivable hypersonic parachute would do. This paper describes the methods and results of the simulation of the SEDS endmass re-entry with different tethers.

  14. Evaluation of Ceramic Foams and Simulated Reentry Environments

    NASA Technical Reports Server (NTRS)

    Stackpoole, Mairead

    2003-01-01

    NASA and Ames is conducting ongoing research in lower density reusable TPS material for future reentry vehicles. Ceramic foams from pre ceramic polymer routes have potential for use in both acreage TPS and as tile leading edges for reentry vehicles. One of the key factors to investigate, when developing new materials for reentry applications, is their oxidation behavior in the appropriate reentry environment whrch can be simulated using ground based arc jet (plasma jet) testing. Studies have shown that oxidation rates of materials will differ when exposed to either monatomatic or molecular oxygen and the amount of monoatomic oxygen depends on the conditions particular to a given test situation. Monoatomic oxygen is always present in reentry environment, therefore arc jet testing is required to provide the appropriate conditions (stagnation pressures, heat fluxes, enthalpies, heat loads and atmospheres) encountered during flight. This preliminary 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 materials response.

  15. Water Landing Characteristics of a Reentry Capsule

    NASA Technical Reports Server (NTRS)

    1958-01-01

    Water Landing Characteristics of a Reentry Capsule. Experimental and theoretical investigations have been made to determine the water-landing characteristics of a conical-shaped reentry capsule having a segment of a sphere as the bottom. For the experimental portion of the investigation, a 1/12-scale model capsule and a full-scale capsule were tested for nominal flight paths of 65 deg and 90 deg (vertical), a range of contact attitudes from -30 deg to 30 deg, and a full-scale vertical velocity of 30 feet per second at contact. Accelerations were measured by accelerometers installed at the centers of gravity of the model and full-scale capsules. For the model test the accelerations were measured along the X-axis (roll) and Z-axis (yaw) and for the full-scale test they were measured along the X-axis (roll), Y-axis (pitch), and Z-axis (yaw). Motions and displacements of the capsules that occurred after contact were determined from high-speed motion pictures. The theoretical investigation was conducted to determine the accelerations that might occur along the X-axis when the capsule contacted the water from a 90 deg flight path at a 0 deg attitude. Assuming a rigid body, computations were made from equations obtained by utilizing the principle of the conservation of momentum. The agreement among data obtained from the model test, the full-scale test, and the theory was very good. The accelerations along the X-axis, for a vertical flight path and 0 deg attitude, were in the order of 40g. For a 65 deg flight path and 0 deg attitude, the accelerations along the X-axis were in the order of 50g. Changes in contact attitude, in either the positive or negative direction from 0 deg attitude, considerably reduced the magnitude of the accelerations measured along the X-axis. Accelerations measured along the Y- and Z-axes were relatively small at all test conditions. [Entire movie available on DVD from CASI as Doc ID 20070030955. Contact help@sti.nasa.gov

  16. Landing Energy Dissipation for Manned Reentry Vehicles

    NASA Technical Reports Server (NTRS)

    Fisher, Lloyd J., Jr.

    1960-01-01

    Analytical and experimental investigations have been made to determine the landing-energy-dissipation characteristics for several types of landing gear for manned reentry vehicles. The landing vehicles are considered in two categories: those having essentially vertical-descent paths, the parachute-supported vehicles, and those having essentially horizontal paths, the lifting vehicles. The energy-dissipation devices discussed are crushable materials such as foamed plastics and honeycomb for internal application in couch-support systems, yielding metal elements as part of the structure of capsules or as alternates for oleos in landing-gear struts, inflatable bags, braking rockets, and shaped surfaces for water impact. It appears feasible to readily evaluate landing-gear systems for internal or external application in hard-surface or water landings by using computational procedures and free-body landing techniques with dynamic models. The systems investigated have shown very interesting energy-dissipation characteristics over a considerable range of landing parameters. Acceptable gear can be developed along lines similar to those presented if stroke requirements and human-tolerance limits are considered.

  17. Water Landing Characteristics of a Reentry Capsule

    NASA Technical Reports Server (NTRS)

    1958-01-01

    Experimental and theoretical investigations have been made to determine the water-landing characteristics of a conical-shaped reentry capsule having a segment of a sphere as the bottom. For the experimental portion of the investigation, a 1/12-scale model capsule and a full-scale capsule were tested for nominal flight paths of 65 deg and 90 deg (vertical), a range of contact attitudes from -30 deg to 30 deg, and a full-scale vertical velocity of 30 feet per second at contact. Accelerations were measured by accelerometers installed at the centers of gravity of the model and full-scale capsules. For the model test the accelerations were measured along the X-axis (roll) and Z-axis (yaw) and for the full-scale test they were measured along the X-axis (roll), Y-axis (pitch), and Z-axis (yaw). Motions and displacements of the capsules that occurred after contact were determined from high-speed motion pictures. The theoretical investigation was conducted to determine the accelerations that might occur along the X-axis when the capsule contacted the water from a 90 deg flight path at a 0 deg attitude. Assuming a rigid body, computations were made from equations obtained by utilizing the principle of the conservation of momentum. The agreement among data obtained from the model test, the full-scale test, and the theory was very good. The accelerations along the X-axis, for a vertical flight path and 0 deg attitude, were in the order of 40g. For a 65 deg flight path and 0 deg attitude, the accelerations along the X-axis were in the order of 50g. Changes in contact attitude, in either the positive or negative direction from 0 deg attitude, considerably reduced the magnitude of the accelerations measured along the X-axis. Accelerations measured along the Y- and Z-axes were relatively small at all test conditions.

  18. Reusable Reentry Satellite (RRS) system design study

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Reusable Reentry Satellite (RRS) is intended to provide investigators in several biological disciplines with a relatively inexpensive method to access space for up to 60 days with eventual recovery on Earth. The RRS will permit totally intact, relatively soft, recovery of the vehicle, system refurbishment, and reflight with new and varied payloads. The RRS is to be capable of three reflights per year over a 10-year program lifetime. The RRS vehicle will have a large and readily accessible volume near the vehicle center of gravity for the Payload Module (PM) containing the experiment hardware. The vehicle is configured to permit the experimenter late access to the PM prior to launch and rapid access following recovery. The RRS will operate in one of two modes: (1) as a free-flying spacecraft in orbit, and will be allowed to drift in attitude to provide an acceleration environment of less than 10(exp -5) g. the acceleration environment during orbital trim maneuvers will be less than 10(exp -3) g; and (2) as an artificial gravity system which spins at controlled rates to provide an artificial gravity of up to 1.5 Earth g. The RRS system will be designed to be rugged, easily maintained, and economically refurbishable for the next flight. Some systems may be designed to be replaced rather than refurbished, if cost effective and capable of meeting the specified turnaround time. The minimum time between recovery and reflight will be approximately 60 days. The PMs will be designed to be relatively autonomous, with experiments that require few commands and limited telemetry. Mass data storage will be accommodated in the PM. The hardware development and implementation phase is currently expected to start in 1991 with a first launch in late 1993.

  19. 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.

  20. Maternal distress and women's reentry into family and community life.

    PubMed

    Arditti, Joyce; Few, April

    2008-09-01

    This paper advances conceptualization of maternal distress following incarceration. We utilized a multiple case study methodology based on interviews with 10 mothers who demonstrated various permutations of "the triple threat" (depression, domestic violence, and substance abuse; Arditti & Few, 2006). Findings suggest that depressive symptomology persisted and worsened for mothers in our study and that maternal distress was indicative not only of women's psychological state, but also a relational and situational construct that embodied women's core experience. Maternal distress was largely characterized by health challenges, dysfunctional intimate relationships, loss related trauma, guilt and worry over children, and economic inadequacy. Further, maternal distress seemed to be intensified by the punitive traumatic context of prison and lessened by rehabilitation opportunities as well as support by kin and probation officers after reentry. Recommendations for clinicians and professionals who work with reentry mothers center around the need to alleviate maternal distress and better address women's emotional and physical health needs during incarceration and reentry.

  1. 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.

  2. 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.

  3. 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.

  4. An Explicit Reentry Guidance Law Using Bezier Curves

    NASA Astrophysics Data System (ADS)

    Esmaelzadeh, Reza; Naghash, Abolghasem; Mortazavi, Mehdi

    An explicit guidance law is developed for a reentry vehicle. Motion is constrained to a three-dimensional Bezier curve. Acceleration commands are derived by solving an inverse problem related to Bezier parameters. A comparison with pure proportional navigation shows the same accuracy, but a higher capability for optimal trajectory to some degree. Other advantages such as trajectory representation with minimum parameters, applicability to any reentry vehicle configuration and any control scheme, and Time-to-Go independency make this guidance approach more favorable.

  5. Guidance and Control During Direct-Descent Parabolic Reentry

    NASA Technical Reports Server (NTRS)

    Foudriat, Edwin C.; Wingrove, Rodney C.

    1961-01-01

    The results of studies of four reentry guidance and control techniques for the energy management of vehicles returning to the earth at escape speeds are compared in this paper. The reentry trajectories are constrained to those of direct descent, that is, where the vehicle does not leave that portion of the atmosphere where useful aerodynamic forces are available after its initial entry. The guidance techniques compared are: (1) a piloted simulator study reference trajectory techniques; 2) An automatic controller using reference trajectory techniques; 3) A predictor system employing linear prediction (perturbation) techniques; and 4) A repetitive prediction system employing rapid-time computer techniques.

  6. School reentry for children with acquired central nervous systems injuries.

    PubMed

    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 education is not necessarily a special classroom, but an individualized set of educational needs, determined by a multidisciplinary school team, to promote educational success. The purpose of this article is to inform those pediatricians and pediatric allied health professionals treating children with CNS injury of the systems in place to support successful school reentry and their role in contributing to developing an appropriate educational plan. PMID:19489086

  7. Who Goes Back to Prison; Who Does Not: A Multiyear View of Reentry Program Participants

    ERIC Educational Resources Information Center

    Severson, Margaret E.; Veeh, Christopher; Bruns, Kimberly; Lee, Jaehoon

    2012-01-01

    Existing studies of reentry programs in the United States focus on the successes and failures of reentering offenders when compared to matched reentering offenders who did not receive structured reentry services. Little attention has been focused solely on the reentry participants themselves, and on how the level of program exposure may be related…

  8. A Qualitative Study of Returning Study Abroad Students: The Critical Role of Reentry Support Programs

    ERIC Educational Resources Information Center

    Arouca, Raquel Alexandra de Moura

    2013-01-01

    Reentry Shock had been studied through psychological symptoms and inter-relationship problems. Previous research also focused on quantitative data of post-experience questionnaires. This dissertation examines how reentry support programs help students during the reentry process and how participants integrate the study abroad experience into their…

  9. Adapting to Bad News: Lessons from the Harlem Parole Reentry Court

    ERIC Educational Resources Information Center

    Hamilton, Zachary K.

    2011-01-01

    The reentry court model was created to address the risks and needs of offenders returning to the community during the period immediately following release. While there is growing interest in reentry courts, research to date has been limited. This study utilized a quasi-experimental design, comparing reentry court participants with traditional…

  10. 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…

  11. 38 CFR 21.8022 - Entry and reentry.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... reentry. (a) Date of program entry. VA may not enter a child into a vocational training program or provide an evaluation or any training, services, or assistance under this subpart before the date VA first...) VOCATIONAL REHABILITATION AND EDUCATION Vocational Training and Rehabilitation for Certain Children...

  12. 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…

  13. 40 CFR 161.390 - Reentry protection data requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... crop Nonfood Greenhouse Food crop Nonfood Forestry Domestic outdoor Indoor Test substance Data to... oncogenic effects or other adverse effects as evidenced by subchronic, chronic, and reproduction studies... could cause adverse effects on persons entering treated sites. In the last situation, reentry...

  14. 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.

  15. Planned Flight of the Terrestrial HIAD Orbital Reentry (THOR)

    NASA Technical Reports Server (NTRS)

    Dillman, Robert; Hughes, Stephen; DiNonno, John; Bodkin, Richard; White, Joseph; DelCorso, Joseph; Cheatwood, F. M.

    2014-01-01

    The Terrestrial HIAD Orbital Reentry (THOR) is planned for flight in 2016 as a secondary payload on an Orbital Sciences commercial resupply mission to the International Space Station. THOR will launch with its Hypersonic Inflatable Aerodynamic Decelerator (HIAD) stowed as a small cylinder between the second stage motor and the launch vehicle fairing. Once the Cygnus cargo vehicle has separated from the second stage, THOR will likewise separate, autonomously re-orient itself, perform a deorbit burn, then inflate the HIAD to a 3.5m diameter cone before atmospheric interface. THOR is a follow-on mission to the IRVE-3 flight test of 2012. The high energy of orbital reentry will allow THOR to demonstrate the performance of its improved, second-generation inflatable structure and flexible TPS materials, in a more energetic entry environment than previous suborbital test flights.This paper discusses the sequence of events planned to occur as part of the THOR mission. Specific topics will include the THOR mission concept, reentry vehicle design for the expected flight environment, the on-board sensors that will allow quantification of vehicle performance, and how we intend to retrieve the flight data from a reentry vehicle splashing down in international waters.

  16. 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.

  17. Reusable Reentry Satellite (RRS): Thermal control trade study

    NASA Technical Reports Server (NTRS)

    Wallace, Clark

    1990-01-01

    The design and assessment work performed in defining the on-orbit Thermal Control Subsystem (TCS) requirements for the Reusable Reentry Satellite (RRS) is discussed. Specifically, it describes the hardware and design measures necessary for maintaining the Payload Module (PM) Environmental Control Life Support System (ECLSS) heat exchanger, the hydrazine propellant, and PM water supply within their required temperature limits.

  18. 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.

  19. Study Abroad Reentry: Behavior, Affect, and Cultural Distance

    ERIC Educational Resources Information Center

    Gray, Kelsey M.; Savicki, Victor

    2015-01-01

    Reentry has become a more focused aspect of study abroad in recent years as the field has moved away from a laissez-faire approach and toward an emphasis on intervention and support of study abroad students in their efforts to make sense of their experiences (Vande Berg, Paige & Lou, 2012). Although not a new concept (Brathurst & La Brack,…

  20. 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…

  1. 38 CFR 21.8022 - Entry and reentry.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Entry and reentry. 21.8022 Section 21.8022 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Vocational Training and Rehabilitation for Certain Children of Vietnam Veterans and Veterans with...

  2. 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…

  3. 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)

  4. 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…

  5. Thermal protection of reentry vehicles by actively cooled nosetips

    NASA Technical Reports Server (NTRS)

    Walker, R. E.; Hidahl, J. W.

    1980-01-01

    Analytical modeling efforts and clear-air ground test results of a transportation-cooled nosetips (TCNT) design are presented. The discrete water injection platelet TCNT described was conceived and created to achieve the performance requirements for severe reentry vehicle trajectories. Thermal performance computer modeling techniques, combing both local heat blockage and boundary layer recovery enthalpy reduction are outlined.

  6. Calibration of Radar Based Re-Entry Predictions

    NASA Astrophysics Data System (ADS)

    Lemmens, S.; Bastida Virgili, B.; Flohrer, T.; Gini, F.; Krag, H.; Steiger, C.

    2015-03-01

    The availability of GPS observations via the telemetry during GOCE’s (Gravity Field and Steady-State Ocean Circulation Explorer) entire re-entry campaign enabled the generation of high quality orbit products which can be used as input to re-entry predictions. These high precision orbits can be used as reference to assess the quality of orbits generated from other sources. Here we verify the accuracy of orbits based on radar tracking data, obtained by dedicated observations with the Tracking & Imaging Radar system from the Fraunhofer High Frequency Physics and Radar Techniques institute, with respect to the a post-processed GPS based reference orbit. This leads to time-depended quantification of the orbit determination uncertainties on the re-entry predictions. Furthermore, the ballistic coefficient determined by the orbit determination and its time dependent evolution can be used to a priori estimate the attitude behaviour of GOCE, which can be compared to the telemetry. The attitude behaviour can be analysed by the use of inverse synthetic aperture radar (ISAR) images, also obtained by dedicated observation by TIRA. The effect of adding this knowledge on the attitude evolution to the re-entry predictions is evaluated.

  7. Motion and Heating During Atmosphere Reentry of Space Vehicles

    NASA Technical Reports Server (NTRS)

    Wong, Thomas J.; Goodwin, Glen; Slye, Robert E.

    1960-01-01

    The results of an analysis of the motion and heating during atmospheric reentry of manned space vehicles has shown the following: 1. Flight-corridor depths which allow reentry in a single pass decrease rapidly as the reentry speed increases if the maximum deceleration is limited to 10 g. 2. Use of aerodynamic lift can result in a three-to five fold increase in corridor depth over that available to a ballistic vehicle for the same deceleration limits. 3. Use of aerodynamic lift to widen these reentry corridors causes a heating penalty which becomes severe for values of the lift-drag ratio greater than unity for constant lift-drag entry. 4. In the region of most intense convective heating the inviscid flow is generally in chemical equilibrium but the boundary-layer flows are out of equilibrium. Heating rates for the nonequilibrium boundary layer are generally lower than for the corresponding equilibrium case. 5. Radiative heating from the hot gas trapped between the shock wave and the body stagnation region may be as severe as the convective heating and unfortunately occurs at approximately the same time in the flight.

  8. 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.

  9. Controlled Re-Entry of the H-IIB Launch Vehicle Upper Stage with the Use of the Re-Entry Safety System

    NASA Astrophysics Data System (ADS)

    Ida, K.; Mori, S.; Sakamoto, K.; Ikeda, S.; Sato, T.; Kawabata, H.

    2012-01-01

    On January 22, 2011, during flight No. 2 of the H-IIB launch vehicle, the Japan Aerospace Exploration Agency (JAXA) succeeded in performing a controlled re-entry experiment for the upper stage. This is the first time this has been done for the upper stage of a Japanese launch vehicle. For flight No. 1, the upper stage performed a random re- entry. With a view to avoiding debris generation and debris-related impact accidents, JAXA resolved to develop a more refined re-entry process. Consequently, the "Re-entry Safety System" was developed in order to achieve controlled re-entry with certainty. After one orbit, while executing controlled re-entry, the Re-entry Safety System monitored the upper stage's function and orbit. Subsequently, a command disengaging the lockout of the deorbit manoeuvre was issued from ground and re-entry commenced. The details of the Re-entry Safety System, which facilitated the controlled re-entry, are described herein.

  10. The Role of Prevention in Promoting Continuity of Health Care in Prisoner Reentry Initiatives

    PubMed Central

    Lanza, A. Stephen; Dyson, William; Gordon, Derrick M.

    2013-01-01

    Most incarcerated individuals will return to the community, and their successful reentry requires consideration of their health and how their health will affect their families and communities. We propose the use of a prevention science framework that integrates universal, selective, and indicated strategies to facilitate the successful reentry of men released from prison. Understanding how health risks and disparities affect the transition from prison to the community will enhance reentry intervention efforts. To explore the application of the prevention rubric, we evaluated a community-based prisoner reentry initiative. The findings challenge all involved in reentry initiatives to reconceptualize prisoner reentry from a program model to a prevention model that considers multilevel risks to and facilitators of successful reentry. PMID:23488516

  11. A real-time digital computer program for the simulation of automatic spacecraft reentries

    NASA Technical Reports Server (NTRS)

    Kaylor, J. T.; Powell, L. F.; Powell, R. W.

    1977-01-01

    The automatic reentry flight dynamics simulator, a nonlinear, six-degree-of-freedom simulation, digital computer program, has been developed. The program includes a rotating, oblate earth model for accurate navigation calculations and contains adjustable gains on the aerodynamic stability and control parameters. This program uses a real-time simulation system and is designed to examine entries of vehicles which have constant mass properties whose attitudes are controlled by both aerodynamic surfaces and reaction control thrusters, and which have automatic guidance and control systems. The program has been used to study the space shuttle orbiter entry. This report includes descriptions of the equations of motion used, the control and guidance schemes that were implemented, the program flow and operation, and the hardware involved.

  12. Analysis of Damped Oscillations during Reentry: A New Approach to Evaluate Cardiac Restitution☆

    PubMed Central

    Munteanu, Adelina; Kondratyev, Aleksandar A.; Kucera, Jan P.

    2008-01-01

    Abstract Reentry is a mechanism underlying numerous cardiac arrhythmias. During reentry, head-tail interactions of the action potential can cause cycle length (CL) oscillations and affect the stability of reentry. We developed a method based on a difference-delay equation to determine the slopes of the action potential duration and conduction velocity restitution functions, known to be major determinants of reentrant arrhythmogenesis, from the spatial period P and the decay length D of damped CL oscillations. Using this approach, we analyzed CL oscillations after the induction of reentry and the resetting of reentry with electrical stimuli in rings of cultured neonatal rat ventricular myocytes grown on microelectrode arrays and in corresponding simulations with the Luo-Rudy model. In the experiments, P was larger and D was smaller after resetting impulses compared to the induction of reentry, indicating that reentry became more stable. Both restitution slopes were smaller. Consistent with the experimental findings, resetting of simulated reentry caused oscillations with gradually increasing P, decreasing D, and decreasing restitution slopes. However, these parameters remained constant when ion concentrations were clamped, revealing that intracellular ion accumulation stabilizes reentry. Thus, the analysis of CL oscillations during reentry opens new perspectives to gain quantitative insight into action potential restitution. PMID:17921218

  13. Inflatable Re-entry Vehicle Experiment (IRVE-4) Overview

    NASA Technical Reports Server (NTRS)

    Litton, Daniel K.; Bose, David M.; Cheatwood, F. McNeil; Hughes, Stephen; Wright, Henry S.; Lindell, Michael C.; Derry, Stephen D.; Olds, Aaron

    2011-01-01

    The suite of Inflatable Re-Entry Vehicle Experiments (IRVE) is designed to further our knowledge and understanding of Hypersonic Inflatable Aerodynamic Decelerators (HIADs). Before infusion into a future mission, three challenges need to be addressed: surviving the heat pulse during re-entry, demonstrating system performance at relevant scales, and demonstrating controllability in the atmosphere. IRVE-4 will contribute to a better understanding of controllability by characterizing how a HIAD responds to a set of controlled inputs. The ability to control a HIAD is vital for missions that are g-limited, require precision targeting and guidance for aerocapture or entry, descent, and landing. The IRVE-4 flight test will focus on taking a first look into controlling a HIAD. This paper will give an overview of the IRVE-4 mission including the control response portion of the flight test sequence, and will provide a review of the mission s development.

  14. Reentry Programming for High-Risk Offenders: Insights From Participants.

    PubMed

    Bender, Kimberly A; Cobbina, Jennifer E; McGarrell, Edmund F

    2016-10-01

    The mass increase in imprisonment of the last two decades has led to an increasing number of adults released from prison. Scholarly accounts of prisoner reentry have demonstrated that incarcerated individuals face barriers on release from prison and that intervention programs are necessary to assist their transition to the community. Here, we build from the insights of previous research by examining how high-risk offenders perceive a reentry program. Using a qualitative approach, our findings suggest that procedural and substantive justice affect their satisfaction and involvement with the program. This study highlights the importance of providing employment opportunities, social support, and fair and respectful delivery of services to assist incarcerated individuals transitioning to the community.

  15. Reentry control of a low-lift maneuverable spacecraft

    NASA Astrophysics Data System (ADS)

    Roenneke, Axel J.; Well, Klaus H.

    1992-08-01

    Commercial operation of space laboratories will rely on small, unmanned reentry capsules to retrieve experimental products independent from Shuttle services. An example for such a concept is the Space Mail system studied by the ESA. This paper presents a trajectory control system based on linear state feedback to guide and control the reentry glide of low-lifting capsules. A technique to design a time-varying controller is derived and applied. Simulation results of spatial flights over a rotating earth show that the designed controller effectively responds to entry condition offsets on several reference trajectories. Also, the controller is capable of tolerating modified vehicle parameters as well as atmospheric disturbances, and the same controller gain functions are successfully applied to different reference trajectories.

  16. Upper atmospheric disturbance effects on reentry satellite landing accuracy

    NASA Astrophysics Data System (ADS)

    Seyler, T. A.; Florence, D. E.

    1992-08-01

    Upper atmosphere disturbances can seriously affect the landing accuracy of a reentry satellite, causing it to miss its target by possibly hundreds of miles. Specifically, geomagnetic storms typically can cause significant density variation in the upper atmosphere, as much as double, for periods of up to a week. The effect of this density variation on groundtrack synchronization for the terminal recovery phase of the orbital mission is examined. Fuel synchronization requirements for a nominal life sciences mission vehicle, the RRS (Reusable Reentry Satellite), are determined for a case of moderately high geomagnetic activity occurring for seven days before landing. A simple strategy for making the necesary corrections and the associated propellant expenditure are presented.

  17. Radioactive satellites - Intact reentry and breakup by debris impact

    NASA Technical Reports Server (NTRS)

    Anz-Meador, P. D.; Potter, A. E., Jr.

    1991-01-01

    There is a substantial mass of radioactive material in nuclear reactors or radioisotope thermal generators (RTGs) in orbit about the earth. This paper examines the reentry of intact nuclear fuel cores and RTGs and the fragmentation and subsequent radioactive debris cloud deposition and evolution resulting from the impact of orbital debris upon an orbiting reactor, fuel core, or RTG. To assess the intact reentry, decay rates and a predicted decay date using historical and projected orbital decay data, are estimated. The current NASA debris environment model is utilized to estimate impact rates and debris cloud evolution of a fragmentation event. Results of these analyses are compared and concepts are tendered which would tend to minimize the radiological debris hazard to personnel and structures both on the earth's surface and in low earth orbit.

  18. Impact of space shuttle orbiter reentry on mesospheric NOx.

    NASA Technical Reports Server (NTRS)

    Stolarski, R. S.; Cicerone, R. J.; Nagy, A. F.

    1973-01-01

    Shuttle orbiter reentry will produce large amounts of nitric oxide (NO) through shock heating at mesospheric altitudes. The effects of this reentry are modeled by considering an impulsive source of NO in time-dependent equations including photochemistry and transport. The model uses an odd-nitrogen approach similar to Strobel's. Parameterized flux boundary conditions are imposed at the mesopause and stratopause and concentrations of the odd nitrogen species (NO, NO2, NO+, N(4S) and N(2D) are found numerically by a finite difference scheme. A localized disturbance can last many hours, depending on the effectiveness of eddy transport. Although the model is one-dimensional, effects of horizontal transport are also included approximately.

  19. Reentry survival analysis of tumbling metallic hollow cylinder

    NASA Astrophysics Data System (ADS)

    Sim, Hyung-seok; Kim, Kyu-hong

    2011-09-01

    The survival of orbital debris reentering the Earth's atmosphere is considered. The numerical approach of NASA's Object Reentry Survival Analysis Tool (ORSAT) is reviewed, and a new equation accounting for reradiation heat loss of hollow cylindrical objects is presented. Based on these, a code called Survivability Analysis Program for Atmospheric Reentry (SAPAR) has been developed, and the new equation for reradiation heat loss is validated. Using this equation in conjunction with the formulation used in ORSAT, a comparative case study on the Delta-II second stage cylindrical tank is given, demonstrating that the analysis using the proposed equation is in good agreement with the actual recovered object when a practical value for thermal emissivity is used. A detailed explanation of the revised formulation is given, and additional simulation results are presented. Finally, discussions are made to address the applicability of the proposed equation to be incorporated in future survival analyses of orbital debris.

  20. Analysis of catalysis effects for orbital reentry vehicles

    NASA Astrophysics Data System (ADS)

    Bisceglia, Stefano; Grasso, Francesco; Ranuzzi, Giuliano

    2004-11-01

    An analisys of the hypersonic flow in thermochemical nonequilibrium around the forebody of the Orbital Reentry Experiment (OREX) is presented for typical reentry conditions. The numerical approach relies on a k-ɛ turbulence model that accounts for the coupling of turbulence with chemistry. The numerical fluxes are computed with a 2nd order TVD scheme incorporating finite-rate chemistry with costant wall temperature and finite-rate wall catalysis by means of Scott's model. The computed flow fields are analyzed by considering the most relevant flow properties and comparing grid converged solutions with stagnation heat flux data. In order to investigate the effect of molecule production due to recombination and its contribution to catalytic process, numerical studies with both fully catalytic and non-catalytic wall boundary conditions have been carried out.

  1. Design of a recovery system for a reentry vehicle

    NASA Technical Reports Server (NTRS)

    Von Eckroth, Wulf; Garrard, William L.; Miller, Norman

    1993-01-01

    Engineers are often required to design decelerator systems which are deployed in cross-wind orientations. If the system is not designed to minimize 'line sail', damage to the parachutes could result. A Reentry Vehicle Analysis Code (RVAC) and an accompanying graphics animation software program (DISPLAY) are presented in this paper. These computer codes allow the user to quickly apply the Purvis line sail modeling technique to any vehicle and then observe the relative motion of the vehicle, nose cap, suspension lines, pilot and drogue bags and canopies on a computer screen. Data files are created which allow plots of velocities, spacial positions, and dynamic pressures versus time to be generated. The code is an important tool for the design engineer because it integrates two degrees of freedom (DOF) line sail equations with a three DOF model of the reentry body and jettisoned nose cap to provide an animated output.

  2. Comparison of laser gyro IMU configurations for reentry systems

    NASA Astrophysics Data System (ADS)

    Majure, Robert G.; Robinson, Thomas A.

    An evaluation is made of future system accuracy requirements, physical criteria, and environmental constraints for ring laser gyro systems that are to be used in reentry vehicles. Attention is given to the configurational issues of inertial measurement unit (IMU) orientation in the vehicle, size and weight reduction, ring laser gyro selection, and tradeoffs of potential integration options for the IMU and the processor. A minimization of external interfaces is accomplished by IMU/data processor integration.

  3. A study on method of reentry guidance for manned spacecraft

    NASA Astrophysics Data System (ADS)

    Zhao, Hanyuan; Xie, Xiaoquan

    In this paper, the methods of reentry guidance for manned spacecraft are chiefly studied. To the longitudinal guidance law, the method of choosing feedback gains coefficients k1, k2, and k3 is given. As for the lateral guidance law, the bang-bang control method similar to the 'funnel' is discussed. Calculation indicates that the guidance precision of these means is satisfied with the index of demand.

  4. Reentry control to a drag vs. energy profile

    NASA Astrophysics Data System (ADS)

    Roenneke, Axel J.; Markl, Abert

    We present trajectory control for a winged re-entry vehicle based on drag versus energy guidance. A linear control law is derived to track the drag reference guaranteeing satisfactory drag error dynamics. For the controller design, the vehicle's motion in the vertical plane is transformed into a drag state space, and the transformed system is linearized along the drag reference. Flight simulation results show that the control system operates effectively while subject to considerable atmospheric variations.

  5. Aerodynamic characteristics of reentry vehicles at supersonic velocities

    NASA Astrophysics Data System (ADS)

    Adamov, N. P.; Kharitonov, A. M.; Chasovnikov, E. A.; Dyad'kin, A. A.; Kazakov, M. I.; Krylov, A. N.; Skorovarov, A. Yu.

    2015-09-01

    Models of promising reentry vehicles, experimental equipment, and test program are described. The method used to determine the total aerodynamic characteristics of these models on the AB-313 mechanical balance in the T-313 supersonic wind tunnel and the method used for simulations are presented. The aerodynamic coefficients of the examined objects in wide ranges of Mach numbers and angles of attack are obtained. The experimental data are compared with the results of simulations.

  6. 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.

  7. The concept of reentry in the addicted anesthesia provider.

    PubMed

    Valdes, Jorge A

    2014-04-01

    Substance abuse among healthcare providers is a serious issue affecting patient care and patient outcomes. Substance abuse among anesthesia providers is of extreme concern because of the type of drugs and easy access providers are granted. Impaired anesthesia providers jeopardize not only their own safety but also the safety of their patients. Accidental death of either the healthcare provider or the patient is often the unfortunate first sign of addiction among anesthesia providers. Most states, in the United States offer treatment programs for anesthesia providers as an option to disciplinary action, and on completion of the Substance abuse is the primary occupational program, the provider is allowed to reenter practice. Successful reentry is sometimes rare, and providers are plagued with the stigma of abuse, shame, and a high incidence of relapse. This article is an analysis of the concept of reentry into anesthesia practice, using Walker and Avant's model of concept analysis. Tenets of successful reentry are discussed. Implications for further concept analysis, practice, and research are presented. PMID:24902450

  8. 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.

  9. Reentry safety for the Topaz II Space Reactor: Issues and analyses

    SciTech Connect

    Connell, L.W.; Trost, L.C.

    1994-03-01

    This report documents the reentry safety analyses conducted for the TOPAZ II Nuclear Electric Propulsion Space Test Program (NEPSTP). Scoping calculations were performed on the reentry aerothermal breakup and ground footprint of reactor core debris. The calculations were used to assess the risks associated with radiologically cold reentry accidents and to determine if constraints should be placed on the core configuration for such accidents. Three risk factors were considered: inadvertent criticality upon reentry impact, atmospheric dispersal of U-235 fuel, and the Special Nuclear Material Safeguards risks. Results indicate that the risks associated with cold reentry are very low regardless of the core configuration. Core configuration constraints were therefore not established for radiologically cold reentry accidents.

  10. ELECTRA © Launch and Re-Entry Safety Analysis Tool

    NASA Astrophysics Data System (ADS)

    Lazare, B.; Arnal, M. H.; Aussilhou, C.; Blazquez, A.; Chemama, F.

    2010-09-01

    French Space Operation Act gives as prime objective to National Technical Regulations to protect people, properties, public health and environment. In this frame, an independent technical assessment of French space operation is delegated to CNES. To perform this task and also for his owns operations CNES needs efficient state-of-the-art tools for evaluating risks. The development of the ELECTRA© tool, undertaken in 2007, meets the requirement for precise quantification of the risks involved in launching and re-entry of spacecraft. The ELECTRA© project draws on the proven expertise of CNES technical centers in the field of flight analysis and safety, spaceflight dynamics and the design of spacecraft. The ELECTRA© tool was specifically designed to evaluate the risks involved in the re-entry and return to Earth of all or part of a spacecraft. It will also be used for locating and visualizing nominal or accidental re-entry zones while comparing them with suitable geographic data such as population density, urban areas, and shipping lines, among others. The method chosen for ELECTRA© consists of two main steps: calculating the possible reentry trajectories for each fragment after the spacecraft breaks up; calculating the risks while taking into account the energy of the fragments, the population density and protection afforded by buildings. For launch operations and active re-entry, the risk calculation will be weighted by the probability of instantaneous failure of the spacecraft and integrated for the whole trajectory. ELECTRA©’s development is today at the end of the validation phase, last step before delivery to users. Validation process has been performed in different ways: numerical application way for the risk formulation; benchmarking process for casualty area, level of energy of the fragments entries and level of protection housing module; best practices in space transportation industries concerning dependability evaluation; benchmarking process for

  11. 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.

  12. In Depth Analysis of AVCOAT TPS Response to a Reentry Flow

    SciTech Connect

    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 is 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.

  13. 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.

  14. 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.

  15. Coronas-F Orbit Monitoring and Re-Entry Prediction

    NASA Technical Reports Server (NTRS)

    Ivanov, N. M.; Kolyuka, Yu. F.; Afanasieva, T. I.; Gridchina, T. A.

    2007-01-01

    Russian scientific satellite CORONAS-F was launched on July, 31, 2001. The object was inserted in near-circular orbit with the inclination 82.5deg and a mean altitude approx. 520 km. Due to the upper atmosphere drag CORONAS-F was permanently descended and as a result on December, 6, 2005 it has finished the earth-orbital flight, having lifetime in space approx. 4.5 years. The satellite structural features and its flight attitude control led to the significant variations of its ballistic coefficient during the flight. It was a cause of some specific difficulties in the fulfillment of the ballistic and navigation support of this space vehicle flight. Besides the main mission objective CORONAS-F also has been selected by the Inter-Agency Space Debris Coordination Committee (IADC) as a target object for the next regular international re-entry test campaign on a program of surveillance and re-entry prediction for the hazard space objects within their de-orbiting phases. Spacecraft (S/C) CORONAS-F kept its working state right up to the end of the flight - down to the atmosphere entry. This fact enabled to realization of the additional research experiments, concerning with an estimation of the atmospheric density within the low earth orbits (LEO) of the artificial satellites, and made possible to continue track the S/C during final phase of its flight by means of Russian regular command & tracking system, used for it control. Thus there appeared a unique possibility of using for tracking S/C at its de-orbiting phase not only passive radar facilities, belonging to the space surveillance systems and traditionally used for support of the IADC re-entry test campaigns, but also more precise active trajectory radio-tracking facilities from the ground control complex (GCC) applied for this object. Under the corresponding decision of the Russian side such capability of additional high-precise tracking control of the CORONAS-F flight in this period of time has been implemented

  16. 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.

  17. Adaptive Guidance and Control Algorithms applied to the X-38 Reentry Mission

    NASA Astrophysics Data System (ADS)

    Graesslin, M.; Wallner, E.; Burkhardt, J.; Schoettle, U.; Well, K. H.

    inversion renders a scheduled controller. Throughout the reentry, varying sets of actuators are available for control. Depending on which set is available, different inversion schemes are applied. With at least three controls effectors, decoupled control of the attitude angles can be achieved via a successive inversion which exploits the time-scale separation inherent in the attitude dynamics. However, during a flight phase where control needs to be achieved with only two body flaps, internal dynamics must be taken into account. To this end, a redefinition of the controlled variables is carried out so that the internal dynamics are stabilized while satisfactory tracking performance is achieved. The objectives of the present paper are to discuss the guidance and control approach taken, and asses the per- formance of the concepts by numerical flight simulations. For this purpose results obtained by means of a nu- merical flight simulator (CREDITS), that accurately models the characteristics of the X-38 vehicle, are presented to demonstrate the performance and effectiveness of the guidance and control design. Sensitivities to non- nominal flight conditions have been evaluated by Monte-Carlo analyses comprising motion simulations in both three and six degree of freedom. The results show that the mission requirements are met.

  18. Electrophysiology of postinfarction ventricular tachycardia: a paradigm of stable reentry.

    PubMed

    Richardson, A W; Callans, D J; Josephson, M E

    1999-09-01

    Sustained monomorphic ventricular tachycardia (VT) is a paradigm of a stable reentrant rhythm. The hallmark of stable reentry is the presence of an excitable gap, which in reentrant VT composes 15% to 45% of the tachycardia cycle length. Resetting allows definition of the extent and pattern of the excitable gap. Site-specific resetting responses suggest that the VT circuit has both functionally and anatomically derived characteristics. Entrainment provides information regarding the effects of overdrive pacing on properties of the tissue composing the circuit rather than on properties of the tachycardia itself. These data help us to understand the mechanisms of pharmacologic agents and to direct ablation of reentrant VT.

  19. Conceptual study of a small semiballistic reentry experiment vehicle

    NASA Astrophysics Data System (ADS)

    Schoettle, U. M.; Bregman, E. R.; Hillesheimer, M.; Inatani, Y.

    1990-10-01

    A semiballistic reentry capsule is proposed as testbed for flight experiments to validate computational prediction methods for aerothermochemical effects encountered during hypersonic flights and vehicle performance and to verify new guidance and control concepts. This paper addresses aspects of mission and vehicle requirements as derived from numerical simulations. A critical design problem is guiding and controlling the vehicle of limited lift capabilities to a predetermined recovery site. A predictive guidance scheme using flight state information obtained by means of the GPS is examined and the dynamic performance discussed. In spite of its drawback of information loss during the blackout phase, GPS navigation is found to be a viable option for vehicle guidance.

  20. Heat Transfer of Reentry Vehicles During Atmosphere Flight

    NASA Astrophysics Data System (ADS)

    Churakov, D. A.; Gorshkov, A. B.; Kovalev, R. V.; Vlasov, V. I.; Beloshitsky, A. V.; Dyadkin, A. A.; Zhurin, S. V.

    2009-01-01

    An atmosphere reentry of a winged space vehicle was investigated with a specially profiled windward surface in order to attain a reduced heat flux to wing edges in comparison with conventional airplane configurations as "Buran" and "Space Shuttle". Aerodynamics forces acting on the space vehicle were determined and it was shown that the considered vehicle configuration secures necessary aerodynamics characteristics in main parts of the trajectory. Heat transfer calculations were made for equilibrium and nonequilibrium air approaches using two methods: in the frame of Navier-Stokes equations and Euler equations with an approximate integral method of local similarity.

  1. Reentry thermal protection from Pioneer F RTG insulation material

    NASA Technical Reports Server (NTRS)

    Vorreiter, J. W.

    1972-01-01

    Ablation tests were performed on the insulation material used in the Pioneer F radioisotope thermoelectric generator (RTG) in the Ames Arc-Heated Planetary-Gas Wind Tunnel. Test results indicate that the material, trade name Min-K 1301, should experience little ablation for heat transfer rates below 40 BTU/sq ft-sec. If the current design were to be changed so that the various pieces of Min-K were fastened or interlocked together the total amount of heat delivered to the RTG heat source during an earth orbital decay reentry would be reduced by at least 22.7%.

  2. Flap effectiveness appraisal for winged re-entry vehicles

    NASA Astrophysics Data System (ADS)

    de Rosa, Donato; Pezzella, Giuseppe; Donelli, Raffaele S.; Viviani, Antonio

    2016-05-01

    The interactions between shock waves and boundary layer are commonplace in hypersonic aerodynamics. They represent a very challenging design issue for hypersonic vehicle. A typical example of shock wave boundary layer interaction is the flowfield past aerodynamic surfaces during control. As a consequence, such flow interaction phenomena influence both vehicle aerodynamics and aerothermodynamics. In this framework, the present research effort describes the numerical activity performed to simulate the flowfield past a deflected flap in hypersonic flowfield conditions for a winged re-entry vehicle.

  3. New tool allows selective multi-lateral re-entry

    SciTech Connect

    1997-05-01

    This article overviews the world`s first application of a downhole tool installed after the drilling and completion of a lateral borehole from a larger backbone casing, to allow future access to the lateral using through-tubing, coiled tubing operations. The system described is based on the Multi Lateral Selective Re-Entry System, or MLR (trademark), supplied by Pressure Control Engineering Ltd. (PCE) of Poole, Dorset, England. Primary equipment used in creating the lateral completion and its tieback to the backbone liner was supplied by Sperry Sun.

  4. A conceptual design study of the reusable reentry satellite

    NASA Technical Reports Server (NTRS)

    Swenson, Byron L.; Mascy, Alfred C.; Carter, Bruce; Cartledge, Alan; Corridan, Robert E.; Edsinger, Larry E.; Jackson, Robert W.; Keller, Robert; Murbach, Marcus S.; Wercinski, Paul F.

    1988-01-01

    Experimentation leading to an understanding of life processes under reduced and extremely low gravitational forces will profoundly contribute to the success of future space missions involving humans. In addition to research on gravitational biology, research on the effects of cosmic radiation and the interruption and change of circadian rhythms on life systems is also of prime importance. Research in space, however, is currently viewed by biological scientists as an arena that is essential, yet largely inaccessible to them for their experimentation. To fulfill this need, a project and spacecraft system described as the Reusuable Reentry Satellite or Lifesat has been proposed by NASA.

  5. Some Landing Studies Pertinent to Glider-Reentry Vehicles

    NASA Technical Reports Server (NTRS)

    Houbolt, John C.; Batterson, Sidney A.

    1960-01-01

    Results are presented of some landing studies that may serve as guidelines in the consideration of landing problems of glider-reentry configurations. The effect of the initial conditions of sinking velocity, angle of attack, and pitch rate on impact severity and the effect of locating the rear gear in various positions are discussed. Some information is included regarding the influence of landing-gear location on effective masses. Preliminary experimental results on the slideout phase of landing include sliding and rolling friction coefficients that have been determined from tests of various skids and all-metal wheels.

  6. Successful Reentry: The Perspective of Private Correctional Health Care Providers

    PubMed Central

    Greifinger, Robert B.

    2006-01-01

    Due to public health and safety concerns, discharge planning is increasingly prioritized by correctional systems when preparing prisoners for their reintegration into the community. Annually, private correctional health care vendors provide $3 billion of health care services to inmates in correctional facilities throughout the U.S., but rarely are contracted to provide transitional health care. A discussion with 12 people representing five private nationwide correctional health care providers highlighted the barriers they face when implementing transitional health care and what templates of services health care companies could provide to state and counties to enhance the reentry process. PMID:17131191

  7. Alternans amplification following a two-stimulus protocol in a one-dimensional cardiac ionic model of reentry: From annihilation to double-wave quasiperiodic reentry

    NASA Astrophysics Data System (ADS)

    Comtois, P.; Vinet, A.

    2007-06-01

    Electrical pacing is a common procedure in both experimental and clinical settings to study and/or annihilate anatomical reentry. A previous study [Comtois and Vinet, Chaos 12, 903 (2002)] has described new ways to terminate reentry in a one-dimensional loop model by a protocol consisting of only two stimulations. Annihilation of the reentrant activity was much more likely with these new scenarios than through a unidirectional block. This paper investigates the sensitivity of these scenarios of annihilation to the length of the pathway. It shows that double-pulse stimulation can stop the reentry if the circuit is shorter than a limiting length. Beyond this upper limit, stimulation rather yields sustained double-wave reentry. The same dynamical mechanism, labeled alternans amplification, is found to be responsible for these two types of post-stimulus dynamics.

  8. 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…

  9. 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…

  10. 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…

  11. Balancing Act: The Adaptation of Traditional Judicial Roles in Reentry Court

    ERIC Educational Resources Information Center

    Taylor, Caitlin J.

    2012-01-01

    While research has confirmed their role adaptation and importance in reducing recidivism in drug courts, little research has documented the role of the judge in reentry courts. Based on interviews with participants and the workgroup, court observations, and a document analysis, this study revealed that judges in a federal reentry court program…

  12. Reflections on Reentry after Teaching in China. Occasional Papers in Intercultural Learning, Number 14.

    ERIC Educational Resources Information Center

    Miller, Marcia D.

    The shock of reentry for any sojourner upon returning to their native land may be as great, if not greater, than the initial adjustment period that occurs upon arrival in the foreign country. Intercultural travelers should prepare for the reentry process and the resultant cultural lag upon their return home with the same care that they practiced…

  13. 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:…

  14. 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…

  15. 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…

  16. Statistical Issues for Uncontrolled Reentry Hazards Empirical Tests of the Predicted Footprint for Uncontrolled Satellite Reentry Hazards

    NASA Technical Reports Server (NTRS)

    Matney, Mark

    2011-01-01

    A number of statistical tools have been developed over the years for assessing the risk of reentering objects to human populations. These tools make use of the characteristics (e.g., mass, material, shape, size) of debris that are predicted by aerothermal models to survive reentry. The statistical tools use this information to compute the probability that one or more of the surviving debris might hit a person on the ground and cause one or more casualties. The statistical portion of the analysis relies on a number of assumptions about how the debris footprint and the human population are distributed in latitude and longitude, and how to use that information to arrive at realistic risk numbers. Because this information is used in making policy and engineering decisions, it is important that these assumptions be tested using empirical data. This study uses the latest database of known uncontrolled reentry locations measured by the United States Department of Defense. The predicted ground footprint distributions of these objects are based on the theory that their orbits behave basically like simple Kepler orbits. However, there are a number of factors in the final stages of reentry - including the effects of gravitational harmonics, the effects of the Earth s equatorial bulge on the atmosphere, and the rotation of the Earth and atmosphere - that could cause them to diverge from simple Kepler orbit behavior and possibly change the probability of reentering over a given location. In this paper, the measured latitude and longitude distributions of these objects are directly compared with the predicted distributions, providing a fundamental empirical test of the model assumptions.

  17. FLPP IXV Re-Entry Vehicle, Aerodynamic Characterisation

    NASA Astrophysics Data System (ADS)

    Belmont, J.-P.; Cantinaud, O.; Tribot, J.-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 improving 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 and thick body. 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. The AEDB includes nominal aerodynamic data, a new set of free molecular aerodynamic coefficients as well as aerodynamic uncertainties. Through the phase B2/C1, complementary computations were performed (CFSE, EPFL, ASTRIUM, TAS, DAA) as well as wind tunnel tests such as ONERA S4ma, DLR H2K, DNW/NLR SST, FOI T1500. All data were analyzed and compared enabling the consolidation of the nominal aerodynamic and aerodynamic uncertainties as well. The paper presents the logic of work based on the system engineering plan with emphasis on the different prediction tools used aiming the final aerodynamic characterization of the IXV configuration.

  18. Investigations of Control Surface Seals for Re-entry Vehicles

    NASA Technical Reports Server (NTRS)

    Dunlap, Patrick H., Jr.; Steinetz, Bruce M.; Curry, Donald M.; DeMange, Jeffrey J.; Rivers, H. Kevin; Hsu, Su-Yuen

    2002-01-01

    Re-entry vehicles generally require control surfaces (e.g., rudders, body flaps) to steer them during flight. Control surface seals are installed along hinge lines and where control surface edges move close to the vehicle body. These seals must operate at high temperatures and limit heat transfer to underlying structures to prevent them from overheating and causing possible loss of vehicle structural integrity. This paper presents results for thermal analyses and mechanical testing conducted on the baseline rudder/fin seal design for the X-38 re-entry vehicle. Exposure of the seals in a compressed state at the predicted peak seal temperature of 1900 F resulted in loss of seal resiliency. The vertical Inconel rudder/fin rub surface was re-designed to account for this loss of resiliency. Room temperature compression tests revealed that seal unit loads and contact pressures were below limits set to protect Shuttle thermal tiles on the horizontal sealing surface. The seals survived an ambient temperature 1000 cycle scrub test over sanded Shuttle tiles and were able to disengage and re-engage the tile edges during testing. Arc jet tests confirmed the need for seals in the rudder/fin gap location because a single seal caused a large temperature drop (delta T = 1710 F) in the gap.

  19. Atomic and molecular data for spacecraft re-entry plasmas

    NASA Astrophysics Data System (ADS)

    Celiberto, R.; Armenise, I.; Cacciatore, M.; Capitelli, M.; Esposito, F.; Gamallo, P.; Janev, R. K.; Laganà, A.; Laporta, V.; Laricchiuta, A.; Lombardi, A.; Rutigliano, M.; Sayós, R.; Tennyson, J.; Wadehra, J. M.

    2016-06-01

    The modeling of atmospheric gas, interacting with the space vehicles in re-entry conditions in planetary exploration missions, requires a large set of scattering data for all those elementary processes occurring in the system. A fundamental aspect of re-entry problems is represented by the strong non-equilibrium conditions met in the atmospheric plasma close to the surface of the thermal shield, where numerous interconnected relaxation processes determine the evolution of the gaseous system towards equilibrium conditions. A central role is played by the vibrational exchanges of energy, so that collisional processes involving vibrationally excited molecules assume a particular importance. In the present paper, theoretical calculations of complete sets of vibrationally state-resolved cross sections and rate coefficients are reviewed, focusing on the relevant classes of collisional processes: resonant and non-resonant electron-impact excitation of molecules, atom–diatom and molecule–molecule collisions as well as gas-surface interaction. In particular, collisional processes involving atomic and molecular species, relevant to Earth (N2, O2, NO), Mars (CO2, CO, N2) and Jupiter (H2, He) atmospheres are considered.

  20. 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... 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,...

  1. Comparison of ORSAT and SCARAB reentry analysis tools for a generic satellite test case

    NASA Astrophysics Data System (ADS)

    Kelley, Robert; Hill, Nicole; Rochelle, William; Johnson, Nicholas L.; Lips, Tobias

    Reentry analysis is essential to understanding the consequences of the full life cycle of a space-craft. Since reentry is a key factor in spacecraft development, NASA and ESA have separately developed tools to assess the survivability of objects during reentry. Criteria such as debris casualty area and impact energy are particularly important to understanding the risks posed to people on Earth. Therefore, NASA and ESA have undertaken a series of comparison studies of their respective reentry codes for verification and improvements in accuracy. The NASA Object Reentry Survival Analysis Tool (ORSAT) and the ESA Spacecraft Atmospheric Reen-try and Aerothermal Breakup (SCARAB) reentry analysis tools serve as standard codes for reentry survivability assessment of satellites. These programs predict whether an object will demise during reentry and calculate the debris casualty area of objects determined to survive, establishing the reentry risk posed to the Earth's population by surviving debris. A series of test cases have been studied for comparison and the most recent uses "Testsat," a conceptual satellite composed of generic parts, defined to use numerous simple shapes and various materials for a better comparison of the predictions of these two codes. This study is an improvement on the others in this series because of increased consistency in modeling techniques and variables. The overall comparison demonstrated that the two codes arrive at similar results. Either most objects modeled resulted in close agreement between the two codes, or if the difference was sig-nificant, the variance could be explained as a case of semantics in the model definitions. This paper presents the main results of ORSAT and SCARAB for the Testsat case and discusses the sources of any discovered differences. Discussion of the results of previous comparisons is made for a summary of differences between the codes and lessons learned from this series of tests.

  2. Reentry Preparedness among Soon-to-be-Released Inmates and the Role of Time Served

    PubMed Central

    Wolff, Nancy; Shi, Jing; Schumann, Brooke E.

    2014-01-01

    Purpose While reentry funding is flowing into states, its target efficiency and effectiveness depends on whether it goes to the right people in the right ways. The purpose of this study was to examine whether and how the amount of time incarcerated affects reentry readiness. Materials and Methods A population-based survey was conducted. Approximately 4000 soon-to-be-released male inmates were drawn from a state correctional system. Readiness is described in terms of feeling ready and material, social, and treatment resources available for reentry by time served on current conviction (episode effect) and since age 18 (cumulative effect). Generalized hierarchical linear models were used to estimate the effects of demographic, criminological, and time served variables on reentry readiness outcomes. Results Reentry vulnerability increased with time served since turning 18 (cumulative effect) but not with time served on the current conviction (episode effect). Inmates serving more than 10 years since turning 18 were at greatest reentry risk. Conclusions The findings indicate that inmates who have served more prison time over their lifetime have more pronounced needs and risks suggesting that reentry funding be targeted towards those who have served more time over the course of their lifetime. PMID:24431474

  3. Spacecraft destruction during re-entry - latest results and development of the SCARAB software system

    NASA Astrophysics Data System (ADS)

    Lips, T.; Fritsche, B.; Koppenwallner, G.; Klinkrad, H.

    2004-01-01

    The calculation of destructive re-entries and the prediction of the related ground risk potential due to fragment objects reaching the ground have become of high interest in the past years. This was also evident during the re-entry of the MIR space station in 2001. In 1995, under ESA contract, HTG started an international cooperation with other companies and institutes to develop the SCARAB software system (Spacecraft Atmospheric Re-Entry and Aerothermal Break-Up). SCARAB is a quasi-deterministic tool, modeling a re-entry object down to sub-system level. The resulting aerodynamic parameters and mass distribution allow calculating a realistic 6D re-entry trajectory. Geometry and mass are continuously updated during calculation. Multi-level fragmentations due to different destruction processes are considered. The SCARAB software has been applied to several projects, namely ATV (ESA), ROSAT (Germany), Ariane-5 (ESA) and BeppoSAX (Italy). The practical application of SCARAB to project work has been demonstrated. In addition SCARAB has been compared with NASA's ORSAT code. It has also been verified with experimental data gained from re-entry vehicles, break-up observations and wind-tunnel tests. SCARAB is now on the way to become the European standard software for re-entry destruction analysis.

  4. 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.

  5. 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

  6. Ascent and reentry guidance concept based on NLP-methods

    NASA Astrophysics Data System (ADS)

    Gräßlin, M. H.; Telaar, J.; Schöttle, U. M.

    2004-08-01

    This paper addresses the application of an autonomous guidance concept to the ascent flight of the reusable launch vehicle Hopper, and to the reentry mission of the space plane X-38. Presently, the guidance requirements with respect to autonomy, accuracy and mission flexibility have been increased steadily for RLV applications. Nonlinear Programming (NLP)-based guidance strategies have been proposed that offer the potential to meet these demands. The autonomous guidance is achieved by combining onboard flight path prediction and NLP methods for flight optimization. Such guidance strategies hold promise for reduced pre-mission analyses for trajectory planning, and for improved adaptability to non-nominal mission conditions. Its applicability, autonomy and performance will be discussed showing numerical results obtained with a flight-simulation environment.

  7. Trajectory control for a low-lift maneuverable reentry vehicle

    NASA Astrophysics Data System (ADS)

    Roenneke, Axel J.; Cornwell, Phillip J.

    1992-02-01

    To operate laboratories in space, unmanned vehicles are necessary to carry experimental products to the ground. An example for such a concept is the European developed Space Mail capsule with a lift-to-drag ratio of about 0.5. This report presents a system model to describe the reentry flight of a maneuverable space capsule over a rotating planet and the development of a guidance and control concept using a reference trajectory. A technique to design a time-varying path controller is effectively applied to the Space Mail capsule. The controller design is based on linear state feedback of three states that are crucial for the problem: the errors in distance, speed, and flight path angle. The proposed controller can compensate for initial entry speed offsets of +/- 5 percent from the nominal entry speed.

  8. Fixed-trim re-entry guidance analysis

    NASA Technical Reports Server (NTRS)

    Gracey, C.; Cliff, E. M.; Lutze, F. H.; Kelley, H. J.

    1981-01-01

    The terminal guidance problem for a fixed-trim re-entry body is formulated with the objective of synthesizing a closed-loop steering law. A transformation of variables and subsequent linearization of the motion, with the sight-line to the target as a reference, reduces the order of the state system for the guidance problem. The reduced order system, although nonlinear and time-varying, is simple enough to lend itself to synthesis of a class of guidance laws. A generalization of the feedforward device of classical control theory is successfully employed for compensation of roll autopilot lags. The proposed steering law exhibits superior miss-distance performance in a computational comparison with existing fixed-trim guidance laws.

  9. Laminar-to-turbulent transitions over an ablating reentry capsule

    NASA Astrophysics Data System (ADS)

    Komurasaki, Kimiya; Candler, Graham V.

    2000-11-01

    The aerodynamic mechanism of early transition phenomena over an ablating reentry capsule has been analytically examined. A two-equation turbulence model ( k- ɛ model) was coupled with Reynolds averaged Navier-Stokes equations. Low-Reynolds-number effects on the solid wall were taken into account by modifying the Chien's correction. As a result, transition occurred at the lower Reynolds number with higher ablation rate. The predicted transition-point Reynolds number was 3×10 4 at the surface-mass-injection rate of 100 g/sm 2. The principal mechanism of this early transition is thought as follows; the viscosity damping effects are reduced and re-laminarization is prevented in the downstream of the capsule surface, due to the turbulence on the surface and due to the pushing out of near-surface stream-lines from the surface by successive mass injection.

  10. Reentry-F Flowfield Solutions at 80,000 ft.

    NASA Technical Reports Server (NTRS)

    Wood, William A.; Riley, Christopher J.; Cheatwood, F. McNeil

    1997-01-01

    Three equilibrium-air numerical solutions are presented for the Reentry-F flight-test vehicle at Mach 20, 80,000 Ft. conditions, including turbulent flow predictions. The three solutions are from a thin-layer Navier-Stokes code, coupled thin-layer and parabolized Navier-Stokes codes, and an approximate viscous shock-layer code. Boundary-layer and shock-layer profiles are presented and compared between the three solutions, revealing close agreement between the three solution methods. Notable exceptions to the close agreement, with 7-10 percent discrepancies, occur in the density profiles at the boundary-layer edge, in the boundary-layer velocity profiles, and in the shock-layer profiles in regions influenced by the nose bluntness.

  11. Non-intrusive flow measurements on a reentry vehicle

    NASA Technical Reports Server (NTRS)

    Miles, R. B.; Satavicca, D. A.; Zimmermann, G. M.

    1983-01-01

    This study evaluates the utility of various non-intrusive techniques for the measurement of the flow field on the windward side of the Space Shuttle or a similar re-entry vehicle. Included are linear (Rayleigh, Raman, Mie, Laser Doppler Velocimetry, Resonant Doppler Velocimetry) and nonlinear (Coherent Anti-Stokes Raman, Laser Induced Fluorescence) light scattering, electron beam fluorescence, thermal emission and mass spectroscopy. Flow field properties are taken from a nonequilibrium flow model by Shinn, Moss and Simmonds at NASA Langley. Conclusions are, when possible, based on quantitative scaling of known laboratory results to the conditions projected. Detailed discussion with researchers in the field contributed further to these conclusions and provided valuable insights regarding the experimental feasibility of each of the techniques.

  12. 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.

  13. Landing Characteristics of a Lenticular-Shaped Reentry Vehicle

    NASA Technical Reports Server (NTRS)

    Blanchard, Ulysse J.

    1961-01-01

    An experimental investigation was made of the landing characteristics of a 1/9-scale dynamic model of a lenticular-shaped reentry vehicle having extendible tail panels for control after reentry and for landing control (flare-out). The landing tests were made by catapulting a free model onto a hard-surface runway and onto water. A "belly-landing" technique in which the vehicle was caused to skid and rock on its curved undersurface (heat shield), converting sinking speed into angular energy, was investigated on a hard-surface runway. Landings were made in calm water and in waves both with and without auxiliary landing devices. Landing motions and acceleration data were obtained over a range of landing attitudes and initial sinking speeds during hard-surface landings and for several wave conditions during water landings. A few vertical landings (parachute letdown) were made in calm water. The hard-surface landing characteristics were good. Maximum landing accelerations on a hard surface were 5g and 18 radians per sq second over a range of landing conditions. Horizontal landings on water resulted in large violent rebounds and some diving in waves. Extreme attitude changes during rebound at initial impact made the attitude of subsequent impact random. Maximum accelerations for water landings were approximately 21g and 145 radians per sq second in waves 7 feet high. Various auxiliary water-landing devices produced no practical improvement in behavior. Reduction of horizontal speed and positive control of impact attitude did improve performance in calm water. During vertical landings in calm water maximum accelerations of 15g and 110 radians per sq second were measured for a contact attitude of -45 deg and a vertical velocity of 70 feet per second.

  14. Impact of tidal density variability on orbital and reentry predictions

    NASA Astrophysics Data System (ADS)

    Leonard, J. M.; Forbes, J. M.; Born, G. H.

    2012-12-01

    Since the first satellites entered Earth orbit in the late 1950's and early 1960's, the influences of solar and geomagnetic variability on the satellite drag environment have been studied, and parameterized in empirical density models with increasing sophistication. However, only within the past 5 years has the realization emerged that "troposphere weather" contributes significantly to the "space weather" of the thermosphere, especially during solar minimum conditions. Much of the attendant variability is attributable to upward-propagating solar tides excited by latent heating due to deep tropical convection, and solar radiation absorption primarily by water vapor and ozone in the stratosphere and mesosphere, respectively. We know that this tidal spectrum significantly modifies the orbital (>200 km) and reentry (60-150 km) drag environments, and that these tidal components induce longitude variability not yet emulated in empirical density models. Yet, current requirements for improvements in orbital prediction make clear that further refinements to density models are needed. In this paper, the operational consequences of longitude-dependent tides are quantitatively assessed through a series of orbital and reentry predictions. We find that in-track prediction differences incurred by tidal effects are typically of order 200 ± 100 m for satellites in 400-km circular orbits and 15 ± 10 km for satellites in 200-km circular orbits for a 24-hour prediction. For an initial 200-km circular orbit, surface impact differences of order 15° ± 15° latitude are incurred. For operational problems with similar accuracy needs, a density model that includes a climatological representation of longitude-dependent tides should significantly reduce errors due to this source.

  15. Application of Plasma on Reentry Vehicle Communication and Interplanetary Spacecraft Sterilization

    NASA Astrophysics Data System (ADS)

    Fenstermacher, Jarrod J.

    In order to gain a better understanding of the reactions occurring during reentry at the gas-surface interface, a reactive ion etch (RIE) plasma device was augmented to more accurately represent how material may paralyze in the presence of plasma. The device inflow was augmented to include a nitrogen line, and the outflow augmented to allow chemical analysis. A nichrome resistor heater was added to raise sample temperatures to pyrolysis levels. Cryo-focusing was performed on pyrolysis gases in order to test the ability to quantify compounds released during heating. This was done using liquid nitrogen prior to compounds entering the gas chromatography column. The nitrogen line also allowed initial study into the use of the RIE machine for planetary protection experiments due to the biocidal properties of Nitrogen/Oxygen plasma. This included static build-up experiments on equipment sensitive to electrostatic discharge. Experiments were also carried out using George Washington University's Vacuum Arc Thruster (VAT). The VAT was used in an attempt to catalyze spallation from a silicon phenolic thermal protection system material (TPS).

  16. CARINA - A space vehicle with re-entry capabilities for microgravity experiments

    NASA Astrophysics Data System (ADS)

    Borriello, G.; Sansone, A.; Ricciardi, A.

    1992-08-01

    An Italian autonomous space vehicle with recovery capabilities, named CARINA (Capsula di Rientro Non Abitata), is described with special attention given to the technological developments in areas pertaining to the reentry system, including reentry aerothermodynamics and the design of the thermal protection system. Consideration is also given to the configuration of the CARINA vehicle (comprised of the expendable Service Module and the Apollo-like Reentry Module), the subsystems and their performances, the mission life cycle, the microgravity utilization aspects, and the programmatic aspects.

  17. 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.

  18. Ablative performance of carbon-carbon nosetips in simulated re-entry environments

    NASA Technical Reports Server (NTRS)

    Nestler, D. E.

    1977-01-01

    A summary is presented of ablation performance data for carbon-carbon nosetip models obtained over a range of pressures from 10 to 168 atm. Two classes of tests are reviewed: (1) steady state, in which a constant environment is imposed on the model, and (2) ramp, in which the pressure is increased from 10 to 80 atmospheres to simulate re-entry pressure history. Comparison of arc test parameters with typical reentry vehicle parameters is included, to assess the adequacy of the test simulation. Based on this comparison, recommendations are made for facility developments which would yield improved simulation capability for reentry vehicle nosetip ablative performance.

  19. Model for oxygen recombination on silicon-dioxide surfaces. II - Implications toward reentry heating

    NASA Technical Reports Server (NTRS)

    Jumper, E. J.; Seward, W. A.

    1992-01-01

    This paper briefly reviews the model for recombination of oxygen on a silicon-dioxide surface presented in detail in a previous paper. New data supporting the model is also presented. The ramifications of the model toward the production of excited molecular oxygen is examined as it pertains to surface heating. A reentry simulation is given and compared to STS-2 reentry data, and conclusions are drawn as to the implications of the recombination model toward reentry heating. A possible buffering of the heating above a critical temperature associated with the physics of the model is also discussed.

  20. The Development of a CO2 Test Capability in the NASA JSC ARCJet for Mars Reentry Simulation

    NASA Technical Reports Server (NTRS)

    DelPapa, Steven V.; Suess, Leonard; Shafer, Brian

    2011-01-01

    The Atmospheric Reentry Materials and Structures Evaluation Facility (ARMSEF) located at NASA Johnson Space Center is used for simulating the extreme environment experienced upon reentry for the development and certification of thermal protection systems (TPS). The facility supports a large variety of programs and was heavily leveraged for the certification and operational support of the TPS for the Orbiter and, more recently, the development of the heat shield for CEV. This paper will provide more detail into the heritage of the facility. Unique attributes of the facility include a modular aerodynamically stabilized arc heater and independently controlled O2 and N2 for the test gases. When combining the O2 and N2 in a 23:77 mass ratio respectively the Earth s atmosphere is accurately simulated and via modification of this ratio the investigation of the effects of atomic oxygen on a material s response is possible. In the summer of 2010 a development effort was started to add CO2 as a third independently controlled test gas such that, when combined with N2, opens up the possibility of accurately simulating a Martian reentry environment. This paper will discuss the test facility, especially the arc heater, in more detail. Initial testing involved relatively low concentrations of CO2 combined with N2 for the primary purpose of gathering data to answer two pressing safety concerns. The first being the rate of production of carbon monoxide (CO) within the ejector vacuum system. The main concern was that CO can be flammable and possibly explosive at high enough concentrations and pressures. The hazard control during the development phase involved the use of injecting N2 inside the test chamber diffuser to dilute and reduce the concentration of any and all CO present. A residual gas analyzer (RGA) was used to determine the relative amount of CO in the exhaust gas and provide a conversion rate of CO2 to CO. This paper will discuss in more detail the results of the RGA

  1. Mechanisms of Familial Influence on Reentry among Formerly Incarcerated Latino Men.

    PubMed

    Lee, Jane Jean-Hee; Guilamo-Ramos, Vincent; Muñoz-Laboy, Miguel; Lotz, Kevin; Bornheimer, Lindsay

    2016-07-01

    In the United States more than 10,000 people are released from state and federal prisons every week and often reenter the communities in which they were arrested. Formerly incarcerated individuals face considerable challenges to securing employment and housing. Subsequently, approximately two-thirds of former prisoners are rearrested within three years of their release. Latino men represent the fastest growing ethnic group of prisoners in the United States with unique cultural and social needs during the reentry process. The present study examined the role of the family in the reentry process through in-depth interviews (N = 16) with formerly incarcerated Latino men (FILM). The authors sought to identify familial processes specific to Latino men with potential to affect engagement and participation in reentry programs. Findings suggest that family mechanisms of social control and social support influence FILM's reentry. Social work practitioners who work with this growing population can engage familial processes to prevent recidivism and promote desistance. PMID:27501637

  2. Planet Earth Set to Broil: Thermal Radiation from Chicxulub Ejecta Reentry

    NASA Astrophysics Data System (ADS)

    Goldin, T. J.; Melosh, H. J.

    2009-03-01

    We model the thermal radiation transfer due to the atmospheric reentry of hypervelocity Chicxulub impact ejecta. Self-shielding of downward radiation by the spherules limits the magnitude and duration of the thermal pulse at the Earth’s surface.

  3. The Reentry Adult College Student: An Exploration of the Black Male Experience

    ERIC Educational Resources Information Center

    Rosser-Mims, Dionne; Palmer, Glenn A.; Harroff, Pamela

    2014-01-01

    This chapter shares findings from a qualitative study on reentry adult Black males' postsecondary education experiences and identifies strategies to help this population matriculate through college and graduate.

  4. 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).

  5. Pedagogy of Individual Choice and Female Inmate Reentry in the U.S. Southwest

    PubMed Central

    Kellett, Nicole Coffey; Willging, Cathleen Elizabeth

    2011-01-01

    Much of the mental health, substance use, and educational programming within a particular women’s prison in the southwestern United States promotes individual choice and agency. Incarcerated women from rural areas are told that their ability to succeed outside prison is primarily dependent upon their personal choices. Comparably little attention is given to preparing women for their upcoming release or to overcoming structural barriers that could undermine successful reentry within rural communities. As a result, these returning citizens, many of whom grapple with mental illness and alcohol or drug dependence, blame themselves for their inability to surmount these barriers. In this qualitative research, we draw upon the perspectives of 99 incarcerated women to clarify how ideologies of individual choice promulgated in reentry pedagogy clash with contextual factors within rural communities to derail the reentry process. We also consider community reentry from Amartya Sen’s capabilities framework and discuss how this model could inform needed interventions. PMID:21864909

  6. A re-entry tachycardia triggered by the spontaneous interruption of an atrial tachycardia.

    PubMed

    Buttà, Carmelo; Tuttolomondo, Antonino; Di Raimondo, Domenico; Giarrusso, Lucia; Miceli, Giuseppe; Cuttitta, Francesco; La Rosa, Donata; Licata, Giuseppe; Pinto, Antonio

    2015-01-01

    The common atrioventricular nodal re-entry tachycardia is the most common form of paroxysmal supraventricular tachycardia. It starts frequently with a supraventricular ectopic beat that, on finding the fast pathway in refractory period, travels in the slow pathway as to appear as a prolongation of the PR interval on the ECG. In this study, we show a singular case of a common atrioventricular nodal re-entry tachycardia triggered by the spontaneous interruption of an atrial tachycardia.

  7. An uncommon case of spontaneous conversion from AV re-entry tachycardia to AV nodal re-entry tachycardia in a patient with dual tachycardia.

    PubMed

    Zeljković, Ivan; Benko, Ivica; Manola, Šime; Radeljić, Vjekoslav; Pavlović, Nikola

    2015-01-01

    We report the case of a 46-year old patient in whom an electrophysiology study (EP) was performed due to paroxysmal supraventricular tachycardia documented in 12-lead ECG. During the EP study, supraventricular tachycardia was induced easily and it corresponded to orthodromic AV reentry tachycardia (AVRT) using a concealed left free wall accessory pathway. However, during the study AVRT spontaneously and repeatedly converted to the typical slow-fast AV node reentry tachycardia (AVNRT). Both accessory and AV nodal slow pathways were ablated, due to the finding that both AVRT and AVNRT were independently inducible during the EP study. PMID:27134441

  8. An uncommon case of spontaneous conversion from AV re-entry tachycardia to AV nodal re-entry tachycardia in a patient with dual tachycardia

    PubMed Central

    Zeljković, Ivan; Benko, Ivica; Manola, Šime; Radeljić, Vjekoslav; Pavlović, Nikola

    2016-01-01

    We report the case of a 46-year old patient in whom an electrophysiology study (EP) was performed due to paroxysmal supraventricular tachycardia documented in 12-lead ECG. During the EP study, supraventricular tachycardia was induced easily and it corresponded to orthodromic AV reentry tachycardia (AVRT) using a concealed left free wall accessory pathway. However, during the study AVRT spontaneously and repeatedly converted to the typical slow-fast AV node reentry tachycardia (AVNRT). Both accessory and AV nodal slow pathways were ablated, due to the finding that both AVRT and AVNRT were independently inducible during the EP study. PMID:27134441

  9. The technology for wireline re-entry of deep ocean boreholes employed for the Dianaut Program

    NASA Astrophysics Data System (ADS)

    Floury, Luc; Gable, Robert

    1992-03-01

    More than 850 holes have been drilled in the world's oceans over the past 24 years, in connection with the Deep Sea Drilling Project (DSDP) and the Ocean Drilling Program (ODP). At least 45 of these holes were fitted with a re-entry cone and many were cased through the sedimentary and unconsolidated layers, allowing hole re-entry with a drill string from a drilling vessel and wireline logging to the drill stem. Re-entry of seafloor drill holes with a wireline logger positioned on the seabed was first successfully accomplished during the FARE program. The DIANAUT program was a scientific application of seafloor wireline re-entry utilizing the logging shuttle ‘Nadia’ in combination with the manned submersible ‘Nautile’. The Nadia re-entry logging system was successfully seated in drill re-entry cones of three boreholes in the Atlantic Ocean (water depths of 1666, 4485, and, 4976 m) and logging operations with different probes (temperature, heat-pulse flowmeter, BHTV, fluid sampler, magnetometer) were performed from the seafloor with full logging control and data acquisition from the Nautile. In the near future the logging shuttle ‘Nadia’ could be developed into a support facility for long-term downhole measurements and later into an unmanned seafloor logging system.

  10. Vulnerability to reentry in a regionally ischemic tissue: a simulation study.

    PubMed

    Trénor, Beatriz; Romero, Lucía; Ferrero, José María; Sáiz, Javier; Moltó, Germán; Alonso, José Miguel

    2007-10-01

    Sudden cardiac death is mainly provoked by arrhythmogenic processes. During myocardial ischemia many malignant arrhythmias, such as reentry, take place and can degenerate into ventricular fibrillation. It is thus of great interest to unravel the intricate mechanisms underlying the initiation and maintenance of a reentry. In this computational study, we analyze the probability of reentry during different stages of the acute phase of ischemia. We also aimed at the understanding of the role of its main components: hypoxia, hyperkalemia, and acidosis analyzing the intricate ionic mechanisms responsible for reentry generation. We simulated the electrical activity of a ventricular tissue affected by regional ischemia based on a modified version of the Luo-Rudy model (LRd00). The ischemic conditions were varied to simulate different stages of this pathology. After premature stimulation, we evaluated the vulnerability to reentry. We obtained an unimodal behavior for the vulnerable window as ischemia progressed, peaking at the eighth minute after the onset of ischemia where the vulnerable window yielded 58 ms. Under more severe conditions the vulnerable window decreased and became zero for minute 8.75. The present work provides insight into the mechanisms of reentry generation during ischemia, highlighting the role of acidosis and hypoxia when hyperkalemia is present.

  11. Analytical and experimental heat transfer and flow-field prediction on a rectangular reentry module

    SciTech Connect

    Laganelli, A.L.

    1980-02-05

    A General Purpose Heat Source (GPHS) has been designed for the purpose of supplying power to a radioisotope thermal generator intended for interplanetary missions. The baseline configuration, nominally 2 in. x 4 in. x 4 in. with sharp edges and corners, is required to survive accidental earth reentry as well as terminal impact velocities. Several problems have been identified relative to survival criteria during reentry. This paper is concerned with the flow field and reentry heating for a broad face-on or side-on reentry orientation. Moreover, the analysis considers convective heat transfer in the absence of roughness or ablation effects during the supersonic/hypersonic regime of reentry. The anaytical results are compared with wind tunnel data. From these studies it was concluded that heat transfer distributions for non-circular shapes ca be obtained for reentry conditions using wind tunnel data for the surface distributions and a stagnation value based on a reference sphere condition. The distributions obtained at a fixed Mach number (M > 1) appear valid over an extended range of Mach numbers. The above required definition of a proper velocity gradient, and definition of an area aspect ratio. Flowfield predictions (inviscid) using the CM2DT program provide a proper definition of pressure and shock characteristics for non-similar (viscous) solutions. (LCL)

  12. Longitudinal stability analysis of a suborbital re-entry demonstrator for a deployable capsule

    NASA Astrophysics Data System (ADS)

    Iacovazzo, Michele; Carandente, Valerio; Savino, Raffaele; Zuppardi, Gennaro

    2015-01-01

    In the field of atmospheric re-entry technology several research and industrial projects are based on the design of deployable, umbrella-like Thermal Protection Systems (TPSs) and aero-brakes. These systems are made of flexible, high temperature resistant fabrics, folded at launch and deployed in space for de-orbit and re-entry operations. This technology is very promising for low cost research and industrial applications, but requires to be validated by experimental flight tests. The University of Naples "Federico II" is currently working on the development of different down-scaled technological demonstrators for this kind of capsule to be launched by different classes of sounding rockets. In the present work an aerodynamic longitudinal stability analysis for a possible, suborbital re-entry demonstrator, has been performed in continuum and rarefied regimes. The longitudinal stability behavior of the capsule, along the entire re-entry path, has been investigated in the whole range of angle of attack and, in particular, around the nominal and the reverse equilibrium re-entry attitudes (i.e. around 0° and 180°, respectively) to implement a proper re-entry strategy able not to compromise the effectiveness of the flying system.

  13. GPK-2 re-entry and deepening -- a technical report

    SciTech Connect

    Baumgartner, J.; Gerard, A.; Barla, R.; Socomine, S.A.

    1999-01-01

    Between mid February to end of May 1999 (in 104 days) the well GPK2 at the Soultz HDR site was successfully re-entered and deepened from 3876 m to a final depth of 5084 m and fully completed. Re-entry included the pulling of the existing 321 1 m long internal 9 5/8-inch by 7-inch casing string, fishing of a submersible pump and some 150 m of 2 3/8-inch tubing, sealing of a major loss zone and opening of a 6 1/4-inch well section in granite (3211-3876 m) to 8 1/2-inch hole size. The well was extended to 5048 m in 8 1/2'' hole size and again completed with a floating 9 5/8-inch by 7-inch casing string. The casing shoe is at 4431 m. A bottom hole core was taken in the depth range 5048-5051 m. The core recovery was app. 40%. A pilot hole in 6 1/4-inch was drilled from 5051-5084 m for in situ stress measurements using the hydraulic fracturing technique. The re-entry and deepening of the well GPK2 was accompanied by several technical developments. New casing packer elements based on inflatable metal shells were developed in a close cooperation between SOCOMINE and MeSy GmbH (patent pending). These packer elements were successfully integrated into the completion of the well. The full weight of the casing string is supported by these elements which are filled with and imbedded in cement. High temperature cementing strategies (up to 170-190 C) for the complex saline fluids encountered in Soultz (High Magnesium Resistant Cements) were developed in a cooperation between Schlumberger Dowell (Vechta), SOCOMINE, SII of Houston, Ruhr-University Bochum, BGR Hannover and IFP Paris. The development of several high temperature logging tools (200 C range, 6-arm caliper, PTF probe) was initiated with CSMA (Cornwall) during the preparation of the deepening of GPK2. Initial scientific investigations included borehole logging (NGS, CLIPER, ARI, UBI, TEMPERATURE), geological investigations (cuttings, core) and seismic monitoring while drilling. During the first temperature log performed

  14. Hayabusa Re-Entry: Trajectory Analysis and Observation Mission Design

    NASA Technical Reports Server (NTRS)

    Cassell, Alan M.; Winter, Michael W.; Allen, Gary A.; Grinstead, Jay H.; Antimisiaris, Manny E.; Albers, James; Jenniskens, Peter

    2011-01-01

    On June 13th, 2010, the Hayabusa sample return capsule successfully re-entered Earth s atmosphere over the Woomera Prohibited Area in southern Australia in its quest to return fragments from the asteroid 1998 SF36 Itokawa . The sample return capsule entered at a super-orbital velocity of 12.04 km/sec (inertial), making it the second fastest human-made object to traverse the atmosphere. The NASA DC-8 airborne observatory was utilized as an instrument platform to record the luminous portion of the sample return capsule re-entry (60 sec) with a variety of on-board spectroscopic imaging instruments. The predicted sample return capsule s entry state information at 200 km altitude was propagated through the atmosphere to generate aerothermodynamic and trajectory data used for initial observation flight path design and planning. The DC- 8 flight path was designed by considering safety, optimal sample return capsule viewing geometry and aircraft capabilities in concert with key aerothermodynamic events along the predicted trajectory. Subsequent entry state vector updates provided by the Deep Space Network team at NASA s Jet Propulsion Laboratory were analyzed after the planned trajectory correction maneuvers to further refine the DC-8 observation flight path. Primary and alternate observation flight paths were generated during the mission planning phase which required coordination with Australian authorities for pre-mission approval. The final observation flight path was chosen based upon trade-offs between optimal viewing requirements, ground based observer locations (to facilitate post-flight trajectory reconstruction), predicted weather in the Woomera Prohibited Area and constraints imposed by flight path filing deadlines. To facilitate sample return capsule tracking by the instrument operators, a series of two racetrack flight path patterns were performed prior to the observation leg so the instruments could be pointed towards the region in the star background where

  15. The SRB heat shield: Aeroelastic stability during reentry

    NASA Technical Reports Server (NTRS)

    Ventres, C. S.; Dowell, E. H.

    1977-01-01

    Wind tunnel tests of a 3% scale model of the aft portion of the SRB equipped with partially scaled heat shields were conducted for the purpose of measuring fluctuating pressure levels in the aft skirt region. During these tests, the heat shields were observed to oscillate violently, the oscillations in some instances causing the heat shields to fail. High speed films taken during the tests reveal a regular pattern of waves in the fabric starting near the flow stagnation point and progressing around both sides of the annulus. The amplitude of the waves was too great, and their pattern too regular, for them to be attributed to the fluctuating pressure levels measured during the tests. The cause of the oscillations observed in the model heat shields, and whether or not similar oscillations will occur in the full scale SRB heat shield during reentry were investigated. Suggestions for modifying the heat shield so as to avoid the oscillations are provided, and recommendations are made for a program of vibration and wind tunnel tests of reduced-scale aeroelastic models of the heat shield.

  16. ARV Re-Entry Module Aerodynmics And Aerothermodynamics

    NASA Astrophysics Data System (ADS)

    Scheer, Heloise; Tran, Philippe; Berthe, Philippe

    2011-05-01

    Astrium-ST is the prime contractor of ARV phase A and is especially in charge of designing the Reentry Module (RM). The RM aeroshape has been defined following a trade-off. High level system requirements were derived with particular attention paid on minimum lift-over-drag ratio, trim incidence, centre-of-gravity lateral off-set and box size, volumetric efficiency, attitude at parachute deployment, flight heritage and aeroheating. Since moderate cross-range and thus L/D ratio were required, the aeroshape trade-off has been performed among blunt capsule candidates. Two front- shield families were considered: spherical (Apollo/ARD/Soyuz type) and sphero-conical (CTV type) segment front-shield. The rear-cone angle was set to 20° for internal pressurized volume and accommodation purposes. Figures of merit were assessed and a spherical front- shield of ARD type with a 20° rear-cone section was selected and proposed for further investigations. Maximum benefits will be taken from ARD flight heritage. CFD and WTT campaigns plans will be presented including preliminary results.

  17. Maneuverable reentry vehicle trajectory footprints: Calculation and properties

    SciTech Connect

    Handler, F.A.

    1987-11-20

    We have obtained an analytical solution of MAneuverable Reentry Vehicle (MARV) trajectory equations that provides useful estimates of a MARV's potential impact footprint on the ground. We concentrate on quick footprint estimation, as required for battle management of a terminal strategic defense system, but we also present other applications such as evaluating tradeoffs between MARV trajectories, design capabilities, and resulting footprints. We estimate the footprint by analytically solving three types of maximal maneuvering trajectories in which the MARV combines maximal turns, lifts or dives through specified angles, finally attempting to extend level flight as long as possible. We display several quantitative results, for a range of MARV capabilities, including variation of footprint area with trajectory incidence angle, altitude, and lift capability. We find that footprint area decreases rapidly as altitude decreases due to the exponentially increasing atmospheric drag. Further, the eccentricity of the footprints depends sensitively on the altitude, incidence angle and velocity, ranging from 0.1 to 0.8. Footprint area increases as lift capability of the MARV increases, roughly as the 3/2 power of lift for a trajectory with incidence angle of 20 degrees. 2 refs., 14 figs.

  18. Reentry heat transfer analysis of the space shuttle orbiter

    NASA Astrophysics Data System (ADS)

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

    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.

  19. 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

  20. Spacecraft destruction during re-entry - latest results and developments of the SCARAB software system

    NASA Astrophysics Data System (ADS)

    Lips, T.; Fritsche, B.; Koppenwallner, G.; Klinkrad, H.

    Not only since the re-entry of the MIR space station in 2001 the calculation of destructive re-entry and the prediction of ground risk potential due to space debris objects reaching the ground have become of high interest. Already in 1995 HTG started in an international cooperation with other companies and institutes under ESA contract the development of the SCARAB software system (SpaceCraft Atmospheric Re-entry and Aerothermal Break-up). SCARAB is a deterministic tool. The re-entry object is completely modelled down to sub-system level. The resulting aerodynamic parameters and mass distribution allow calculating a realistic 6D re-entry trajectory. Geometry and mass are continuously updated during calculation. Multi-level fragmentations due to different destruction processes are considered. The SCARAB software has been applied to several projects, namely ATV (Europe), ROSAT (Germany), Ariane-5 (Europe) and BeppoSAX (Italy). The practical application of SCARAB to project work has been demonstrated. In addition SCARAB has been tested against the NASA ORSAT code. It has also been verified with experimental data gained from re-entry vehicles, break-up observations and wind-tunnel tests. SCARAB is now on the way to become the European standard software for re-entry destruction analysis. This paper will give an overview of the latest results of applications of the software and a description of the interactive development process to fit the different needs of each project. The key features of planned future releases will be presented.

  1. 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.

  2. A new technique for calculating reentry base heating. [analysis of laminar base flow field of two dimensional reentry body

    NASA Technical Reports Server (NTRS)

    Meng, J. C. S.

    1973-01-01

    The laminar base flow field of a two-dimensional reentry body has been studied by Telenin's method. The flow domain was divided into strips along the x-axis, and the flow variations were represented by Lagrange interpolation polynomials in the transformed vertical coordinate. The complete Navier-Stokes equations were used in the near wake region, and the boundary layer equations were applied elsewhere. The boundary conditions consisted of the flat plate thermal boundary layer in the forebody region and the near wake profile in the downstream region. The resulting two-point boundary value problem of 33 ordinary differential equations was then solved by the multiple shooting method. The detailed flow field and thermal environment in the base region are presented in the form of temperature contours, Mach number contours, velocity vectors, pressure distributions, and heat transfer coefficients on the base surface. The maximum heating rate was found on the centerline, and the two-dimensional stagnation point flow solution was adquate to estimate the maximum heating rate so long as the local Reynolds number could be obtained.

  3. 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

  4. NOx production and rainout from Chicxulub impact ejecta reentry

    NASA Astrophysics Data System (ADS)

    Parkos, Devon; Alexeenko, Alina; Kulakhmetov, Marat; Johnson, Brandon C.; Melosh, H. Jay

    2015-12-01

    The Chicxulub impact 66.0 Ma ago initiated the second biggest extinction in the Phanerozoic Eon. The cause of the concurrent oceanic nitrogen isotopic anomaly, however, remains elusive. The Chicxulub impactor struck the Yucatán peninsula, ejecting 2 × 1015 kg of molten and vaporized rock that reentered globally as approximately 1023 microscopic spherules. Here we report that modern techniques indicate that this ejecta generates 1.5 × 1014 moles of NOx, which is enough to cause the observed nitrogen enrichment of the basal layer. Additionally, reentry-based NO production would explain the anomalously heavy isotopic composition of the observed nitrogen. We include N, O, N2, O2, and NO species in simulations of nonequilibrium chemically reacting flow around a reentering spherule. We then determine the net production of NO from all the spherules and use turbulence models to determine how quickly this yield diffuses through the atmosphere. Upon reaching the stratosphere and troposphere, cloud moisture absorbs the NOx and forms nitric acid. We model this process and determine the acidity of the resulting precipitation, which peaks about 1 year after the impact. The precipitation ultimately reaches the upper ocean, where we assume that the well-mixed surface layer is 100 m deep. We then model the naturally occurring carbonate/bicarbonate buffer and determine the net pH. We find that insufficient NOx reaches the ocean to directly cause the observed end-Cretaceous oceanic extinction via acidification and buffer removal. However, the resulting nitrates are sufficient to explain the concurrent nitrogen isotopic anomaly and facilitate an end-Cretaceous algae bloom.

  5. Water-Landing Characteristics of a Reentry Capsule

    NASA Technical Reports Server (NTRS)

    McGehee, John R.; Hathaway, Melvin E.; Vaughan, Victor L., Jr.

    1959-01-01

    Experimental and theoretical investigations have been made to determine the water-landing characteristics of a conical-shaped reentry capsule having a segment of a sphere as the bottom. For the experimental portion of the investigation, a 1/12-scale model capsule and a full-scale capsule were tested for nominal flight paths of 65 deg and 90 deg (vertical), a range of contact attitudes from -30 deg to 30 deg, and a full-scale vertical velocity of 30 feet per second at contact. Accelerations were measured by accelerometers installed at the centers of gravity of the model and full-scale capsules. For the model test the accelerations were measured along the X-axis (roll) and Z-axis (yaw) and for the full-scale test they were measured along the X-axis (roll), Y-axis (pitch), and Z-axis (yaw). Motions and displacements of the capsules that occurred after contact were determined from high-speed motion pictures. The theoretical investigation was conducted to determine the accelerations that might occur along the X-axis when the capsule contacted the water from a 90 deg flight path at a 0 deg attitude. Assuming a rigid body, computations were made from equations obtained by utilizing the principle of the conservation of momentum. The agreement among data obtained from the model test, the full-scale test, and the theory was very good. The accelerations along the X-axis, for a vertical flight path and 0 deg attitude, were in the order of 40g. For a 65 deg flight path and 0 deg attitude, the accelerations along the X-axis were in the order of 50g. Changes in contact attitude, in either the positive or negative direction from 0 deg attitude, considerably reduced the magnitude of the accelerations measured along the X-axis. Accelerations measured along the Y- and Z-axes were relatively small at all test conditions.

  6. Passivity analysis for a winged re-entry vehicle

    SciTech Connect

    Mooij, E.

    2014-12-10

    Application of simple adaptive control (SAC) theory to the design of guidance and control systems for winged re-entry vehicles has been proven successful. To apply SAC to these non-linear and non-stationary systems, it needs to be Almost Strictly Passive (ASP), which is an extension of the Almost Strictly Positive Real (ASPR) condition for linear, time-invariant systems. To fulfill the ASP condition, the controlled, non-linear system has to be minimum-phase (i.e., the zero dynamics is stable), and there is a specific condition for the product of output and input matrix. Earlier studies indicate that even the linearised system is not ASPR. The two problems at hand are: 1) the system is non-minimum phase when flying with zero bank angle, and 2) whenever there is hybrid control, e.g., yaw control is established by combined reaction and aerodynamic control for the major part of flight, the second ASPR condition cannot be met. In this paper we look at both issues, the former related to the guidance system and the latter to the attitude-control system. It is concluded that whenever the nominal bank angle is zero, the passivity conditions can never be met, and guidance should be based on nominal commands and a redefinition of those whenever the error becomes too large. For the remaining part of the trajectory, the passivity conditions are marginally met, but it is proposed to add feedforward compensators to alleviate these conditions. The issue of hybrid control is avoided by redefining the controls with total control moments and adding a so-called control allocator. Deriving the passivity conditions for rotational motion, and evaluating these conditions along the trajectory shows that the (non-linear) winged entry vehicle is ASP. The sufficient conditions to apply SAC for attitude control are thus met.

  7. Passivity analysis for a winged re-entry vehicle

    NASA Astrophysics Data System (ADS)

    Mooij, E.

    2014-12-01

    Application of simple adaptive control (SAC) theory to the design of guidance and control systems for winged re-entry vehicles has been proven successful. To apply SAC to these non-linear and non-stationary systems, it needs to be Almost Strictly Passive (ASP), which is an extension of the Almost Strictly Positive Real (ASPR) condition for linear, time-invariant systems. To fulfill the ASP condition, the controlled, non-linear system has to be minimum-phase (i.e., the zero dynamics is stable), and there is a specific condition for the product of output and input matrix. Earlier studies indicate that even the linearised system is not ASPR. The two problems at hand are: 1) the system is non-minimum phase when flying with zero bank angle, and 2) whenever there is hybrid control, e.g., yaw control is established by combined reaction and aerodynamic control for the major part of flight, the second ASPR condition cannot be met. In this paper we look at both issues, the former related to the guidance system and the latter to the attitude-control system. It is concluded that whenever the nominal bank angle is zero, the passivity conditions can never be met, and guidance should be based on nominal commands and a redefinition of those whenever the error becomes too large. For the remaining part of the trajectory, the passivity conditions are marginally met, but it is proposed to add feedforward compensators to alleviate these conditions. The issue of hybrid control is avoided by redefining the controls with total control moments and adding a so-called control allocator. Deriving the passivity conditions for rotational motion, and evaluating these conditions along the trajectory shows that the (non-linear) winged entry vehicle is ASP. The sufficient conditions to apply SAC for attitude control are thus met.

  8. 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.

  9. 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.

  10. 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.

  11. A Spatial Analysis of Risks and Resources for Reentry Youth in Los Angeles County

    PubMed Central

    Abrams, Laura S.; Freisthler, Bridget

    2012-01-01

    Research on youth reentering the community following incarceration has largely focused on individual risks for negative outcomes and in doing so, has overlooked the potential importance of the neighborhood context(s) where youth return. Addressing this research gap, this study explores associations between neighborhood risks and resources and rates of youth reentering the community following incarceration. Examining archival data from 272 zip codes in Los Angeles County, spatial analysis detected positive associations between rates of youth reentry and unemployment, poverty, and ethnic minority concentration. Reentry rates were also positively associated with neighborhood risks including density of off-premise alcohol outlets and level of community violence. Examining resources on their own, specifically designated youth services were positively associated with reentry rates, whereas education and mental health/substance abuse services were negatively associated. However, none of these resources were significantly associated with reentry rates when neighborhood risks were simultaneously considered. The results of this study highlight the relevance of neighborhood context in youth reentry research and lead to several directions for future study. PMID:23304429

  12. 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. PMID:16131635

  13. Aerothermodynamic and stability analyses of a deployable re-entry capsule

    NASA Astrophysics Data System (ADS)

    Carandente, Valerio; Zuppardi, Gennaro; Savino, Raffaele

    2014-01-01

    Recent research projects, in the field of atmospheric re-entry technology, are focused on the design of deployable, umbrella-like Thermal Protection Systems (TPSs). These TPSs are made of flexible high temperature resistant fabrics, folded at launch and deployed in space for de-orbit and re-entry operations. In the present paper two possible sphere-cone configurations for the TPS have been investigated from an aerodynamic point of view. The analyzed configurations are characterized by the same reentry mass and maximum diameter, but have different half-cone angles (45° and 60°). The analyses involve both the evaluation of thermal and aerodynamic loads and the assessment of the capsule longitudinal stability. The aerothermodynamic analysis has been performed for the completely deployed heat shield in transitional and continuum regimes, while the longitudinal stability has been analyzed in free molecular, transitional and continuum regimes, also taking into consideration the heat shield deployment sequence at high altitudes.

  14. Study on adaptive BTT reentry speed depletion guidance law based on BP neural network

    NASA Astrophysics Data System (ADS)

    Zheng, Zongzhun; Wang, Yongji; Wu, Hao

    2007-11-01

    Reentry guidance is one of the key technologies in hypersonic vehicle research field. In addition to the constraints on its final position coordinates, the vehicle must also impact the target from a specified direction with high precision. And therefore the adaptability of guidance law is critical to control the velocity of hypersonic vehicle and firing accuracy properly in different surroundings of large airspace. In this paper, a new adaptive guidance strategy based on Back Propagation (BP) neural network for the reentry mission of a generic hypersonic vehicle is presented. Depending on the nicer self-learn ability of BP neural network, the guidance law considers the influence of biggish mis-modeling of aerodynamics, structure error and other initial disturbances on the flight capability of vehicle. Consequently, terminal position accuracy and velocity are guaranteed, while many constraints are satisfied. Numerical simulation results clearly bring out the fact that the proposed reentry guidance law based on BP neural network is rational and effective.

  15. 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.

  16. 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

  17. 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.

  18. 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 obtain a…

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

    SciTech Connect

    Watkinson, A. F.

    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.

  20. 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

    ... permits, refugee travel documents, and Form I-551. 211.3 Section 211.3 Aliens and Nationality DEPARTMENT... Expiration of immigrant visas, reentry permits, refugee travel documents, and Form I-551. An immigrant visa, reentry permit, refugee travel document, or Form I-551 shall be regarded as unexpired if the...

  1. Effect of surface catalycity on high-altitude aerothermodynamics of reentry vehicles

    NASA Astrophysics Data System (ADS)

    Molchanova, A. N.; Kashkovsky, A. V.; Bondar, Ye. A.

    2016-10-01

    This work is aimed at the development of surface chemistry models for the Direct Simulation Monte Carlo (DSMC) method applicable to non-equilibrium high-temperature flows about reentry vehicles. Probabilities of the surface processes dependent on individual properties of each particular molecule are determined from the macroscopic reaction rate data. Two different macroscopic finite rate sets are used for construction of DSMC surface recombination models. The models are implemented in the SMILE++ software system for DSMC computations. A comparison with available experimental data is performed. Effects of surface recombination on the aerothermodynamics of a blunt body at high-altitude reentry conditions are numerically studied with the DSMC method.

  2. Reentry-vehicle flight testing and recovery techniques. Paper AIAA-80-1455

    SciTech Connect

    Rigali, D.J.; Sterk, M.W.; Randmaa, J.

    1980-01-01

    A technique to soft-recover high ballistic coefficient reentry vehicles from ICBM reentry conditions has been developed and demonstrated. To date, two different types of vehicles have been soft-recovered, utilizing the mass jettison, parachute recovery technique described. The fabrication and assembly of two additional RVs of different designs are presently underway in preparation for flight test. A technique to allow an increase in the severity of the environment from which an RV can be recovered is presently being analyzed and ground-tested with plans to flight-test it within two years. Descriptions of all of these vehicles and a summary of the flight-test results are presented.

  3. Campagne FARE: Wireline reentry of DSDP Hole 396B using the NADIA System

    NASA Astrophysics Data System (ADS)

    Legrand, Jacques; Echardour, André; Floc'h, Henri; Floury, Luc; Harmegnies, François; Loaec, Gerard; Raer, Yves; Stephen, Ralph; Gieskes, Joris; Pozzi, Jean-Pierre

    This paper describes the successful field test of the NADIA (Navette de Diagraphie, which means logging shuttle) wireline reentry system, an apparatus designed and built by IFREMER (Institut Francaise de Recherche pour l'Exploitation de la Mer) to place instruments and to carry out well logging in boreholes in the deep sea without a drill ship. The Campagne FARE (Faisabilite Re-Entree) field tests in July 1988 in DSDP (Deep Sea Drilling Project) Hole 396B (near the Kane Fracture Zone at the Mid-Atlantic Ridge (Figure 1)) demonstrated the feasibility of routine reentry and logging in a water depth of 4455 m.

  4. Supersonic aerodynamic characteristics of some reentry concepts for angles of attack to 90 deg

    NASA Technical Reports Server (NTRS)

    Spearman, M. L.

    1985-01-01

    Past studies of reentry vehicles tested to high angles of attack (up to 90 deg) in the Mach number range from 2 to 4.8 are reviewed. Two basic planforms are considered: highly-swept deltas and circular. The delta concepts include variations in cross section (and thus volume) and in camber distribution. The effectiveness of various types of aerodynamic control devices is also included. The purpose of the paper is to examine the characteristics of the vehicles with a view toward the potential usefulness of such concepts in a flight regime that would include reentry from space into the atmosphere followed by a transition to sustained atmospheric flight.

  5. 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.

  6. Inflatable Re-Entry Vehicle Experiment (IRVE) Design Overview

    NASA Technical Reports Server (NTRS)

    Hughes, Stephen J.; Dillman, Robert A.; Starr, Brett R.; Stephan, Ryan A.; Lindell, Michael C.; Player, Charles J.; Cheatwood, F. McNeil

    2005-01-01

    Inflatable aeroshells offer several advantages over traditional rigid aeroshells for atmospheric entry. Inflatables offer increased payload volume fraction of the launch vehicle shroud and the possibility to deliver more payload mass to the surface for equivalent trajectory constraints. An inflatable s diameter is not constrained by the launch vehicle shroud. The resultant larger drag area can provide deceleration equivalent to a rigid system at higher atmospheric altitudes, thus offering access to higher landing sites. When stowed for launch and cruise, inflatable aeroshells allow access to the payload after the vehicle is integrated for launch and offer direct access to vehicle structure for structural attachment with the launch vehicle. They also offer an opportunity to eliminate system duplication between the cruise stage and entry vehicle. There are however several potential technical challenges for inflatable aeroshells. First and foremost is the fact that they are flexible structures. That flexibility could lead to unpredictable drag performance or an aerostructural dynamic instability. In addition, durability of large inflatable structures may limit their application. They are susceptible to puncture, a potentially catastrophic insult, from many possible sources. Finally, aerothermal heating during planetary entry poses a significant challenge to a thin membrane. NASA Langley Research Center and NASA's Wallops Flight Facility are jointly developing inflatable aeroshell technology for use on future NASA missions. The technology will be demonstrated in the Inflatable Re-entry Vehicle Experiment (IRVE). This paper will detail the development of the initial IRVE inflatable system to be launched on a Terrier/Orion sounding rocket in the fourth quarter of CY2005. The experiment will demonstrate achievable packaging efficiency of the inflatable aeroshell for launch, inflation, leak performance of the inflatable system throughout the flight regime, structural

  7. Users manual for Aerospace Nuclear Safety Program six-degree-of-freedom reentry simulation (TMAGRA6C)

    SciTech Connect

    Sharbaugh, R.C.

    1990-02-01

    This report documents the updated six-degree-of-freedom reentry simulation TMAGRA6C used in the Aerospace Nuclear Safety Program, ANSP. The simulation provides for the inclusion of the effects of ablation on the aerodynamic stability and drag of reentry bodies, specifically the General Purpose Heat Source, GPHS. The existing six-degree-of-freedom reentry body simulations (TMAGRA6A and TMAGRA6B) used in the JHU/APL Nuclear Safety Program do not include aerodynamic effects resulting from geometric changes to the configuration due to ablation from reentry flights. A wind tunnel test was conducted in 1989 to obtain the effects of ablation on the hypersonic aerodynamics of the GPHS module. The analyzed data were used to form data sets which are included herein in tabular form. These are used as incremental aerodynamic inputs in the new TMAGRA6C six-degree-of-freedom reentry simulation. 20 refs., 13 figs., 2 tabs.

  8. Accurate monotone cubic interpolation

    NASA Technical Reports Server (NTRS)

    Huynh, Hung T.

    1991-01-01

    Monotone piecewise cubic interpolants are simple and effective. They are generally third-order accurate, except near strict local extrema where accuracy degenerates to second-order due to the monotonicity constraint. Algorithms for piecewise cubic interpolants, which preserve monotonicity as well as uniform third and fourth-order accuracy are presented. The gain of accuracy is obtained by relaxing the monotonicity constraint in a geometric framework in which the median function plays a crucial role.

  9. Accurate Finite Difference Algorithms

    NASA Technical Reports Server (NTRS)

    Goodrich, John W.

    1996-01-01

    Two families of finite difference algorithms for computational aeroacoustics are presented and compared. All of the algorithms are single step explicit methods, they have the same order of accuracy in both space and time, with examples up to eleventh order, and they have multidimensional extensions. One of the algorithm families has spectral like high resolution. Propagation with high order and high resolution algorithms can produce accurate results after O(10(exp 6)) periods of propagation with eight grid points per wavelength.

  10. Breaking down Barriers: A Case Study of Juvenile Justice Personnel Perspectives on School Reentry

    ERIC Educational Resources Information Center

    Cole, Heather; Cohen, Rebecca

    2013-01-01

    This article utilizes a qualitative case study to explore juvenile justice personnel perspectives on school reentry. Juvenile justice personnel are a little tapped into source of information on the inner workings of the school-to-prison pipeline. They provide a unique perspective as firsthand observers of the pipeline, offering a different voice…

  11. 14 CFR 440.12 - Duration of coverage for licensed reentry; modifications.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... small that financial responsibility is no longer necessary, as determined by the FAA through the risk... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING FINANCIAL RESPONSIBILITY Financial Responsibility for...) For reentry, insurance coverage required under § 440.9, or other form of financial...

  12. 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].

  13. Effects of Personality Correlates on Achievement Motivation in Traditional and Reentry College Women.

    ERIC Educational Resources Information Center

    Johnson, Carolyn H.

    There is little literature comparing personality differences between traditional (under age 25) and reentry women students (aged 25 and older). The purpose of the present study is to examine these differences. A background questionnaire and five additional scales: (1) the Work and Family Orientation Questionnaire (WOFO-3); (2) the…

  14. 19 CFR 123.29 - Procedure on arrival at port of reentry.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... initials. (b) Vessels and rail shipments continuing in-transit movement—(1) Vessels. In the case of a... in-transit rail shipment arriving at an intermediate port of reentry or exit intended for further in...; DEPARTMENT OF THE TREASURY CBP RELATIONS WITH CANADA AND MEXICO Shipments in Transit Through Canada or...

  15. 19 CFR 123.29 - Procedure on arrival at port of reentry.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... initials. (b) Vessels and rail shipments continuing in-transit movement—(1) Vessels. In the case of a... in-transit rail shipment arriving at an intermediate port of reentry or exit intended for further in...; DEPARTMENT OF THE TREASURY CBP RELATIONS WITH CANADA AND MEXICO Shipments in Transit Through Canada or...

  16. 19 CFR 123.29 - Procedure on arrival at port of reentry.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... initials. (b) Vessels and rail shipments continuing in-transit movement—(1) Vessels. In the case of a... in-transit rail shipment arriving at an intermediate port of reentry or exit intended for further in...; DEPARTMENT OF THE TREASURY CBP RELATIONS WITH CANADA AND MEXICO Shipments in Transit Through Canada or...

  17. 19 CFR 123.29 - Procedure on arrival at port of reentry.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... initials. (b) Vessels and rail shipments continuing in-transit movement—(1) Vessels. In the case of a... in-transit rail shipment arriving at an intermediate port of reentry or exit intended for further in...; DEPARTMENT OF THE TREASURY CBP RELATIONS WITH CANADA AND MEXICO Shipments in Transit Through Canada or...

  18. Improving Career Re-entry Outcomes for People with Multiple Sclerosis: A Comparison of Two Approaches.

    ERIC Educational Resources Information Center

    Rumrill, Phillip D.; Roessler, Richard T.; Cook, Bryan G.

    1998-01-01

    Reentry workers with multiple sclerosis (n=23) participated with employers and rehabilitation counselors in training seminars; 14 received traditional job search intervention. After 16 weeks, 11 of the 37 had reentered the labor force. Most already had high self-efficacy and career maturity. (SK)

  19. 14 CFR 440.12 - Duration of coverage for licensed reentry; modifications.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... determination that risk to third parties and Government property as a result of licensed reentry is sufficiently small that financial responsibility is no longer necessary, as determined by the FAA through the risk analysis conducted to determine MPL and specified in a license order. (b) Financial responsibility...

  20. Adult Learners in Cyberspace: A Collective Case Study of Reentry Women in a Virtual Learning Community

    ERIC Educational Resources Information Center

    Howard, Brian R.

    2010-01-01

    The purpose of this collective case study is to describe and explore a virtual learning community as experienced by women reentering higher education in an online graduate degree program. The grand tour question for this study was: How do reentry women in an online graduate program describe their experience in a virtual learning community? …

  1. Exploring Efficacy in Negotiating Support: Women Re-Entry Students in Higher Education

    ERIC Educational Resources Information Center

    Filipponi-Berardinelli, Josephine Oriana

    2013-01-01

    The existing literature on women re-entry students reveals that women students concurrently struggle with family, work, and sometimes health issues. Women students often do not receive adequate support from their partners or from other sources in helping manage the multiple roles that compete for their time, and often face constraints that affect…

  2. Development of the parachute recovery system for the LBRV-2 reentry vehicle

    SciTech Connect

    Pepper, W.B.

    1983-11-01

    A single-stage 6.44-ft-dia ribbon parachute has been developed for deceleration and recovery of a 130-lb nose cone. Recovery procedures begin with jettisoning a part of the initial reentry mass before the parachute is deployed. An operational RV flight resulted in recovery of the payload (in two pieces) and the undamaged parachute.

  3. Experimental simulation of reentry shots using a skin-gelatine composite model.

    PubMed

    Grosse Perdekamp, M; Pollak, S; Thierauf, A; Strassburger, E; Hunzinger, M; Vennemann, B

    2009-09-01

    A bullet that has passed in and out of one body segment may continue its way into another part of the body causing a second entrance ("reentry") wound, which is often said to have an atypical and sometimes confusing appearance. To analyze this problem in a systematical approach, 9-mm Parabellum full metal-jacketed projectiles were fired at skin-gelatine composite models simulating the consecutive passage of a bullet through two parts of a body. When there was a distance between the two segments, the primary exit and the reentry skin wounds did not show any distinctive features differing from usual gunshot injuries. In the case of contact between exit and reentry site, the corresponding skin wounds resembled each other as both had central tissue defects surrounded by abrasion areas. The subsequent investigation of the simulant revealed that skin particles from both the exit and the adjacent reentry site had been displaced in the direction of the shot along the whole bullet track of the second segment. The morphological findings are presented and discussed with respect to the pertinent literature, and possible physical ballistic explanations are suggested. PMID:19636582

  4. 77 FR 40068 - Draft Guidance for Industry: Recommendations for Donor Questioning, Deferral, Reentry, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-06

    ... Questioning, Deferral, Reentry, and Product Management To Reduce the Risk of Transfusion-Transmitted Malaria...-Transmitted Malaria'' dated June 2012. The draft guidance document provides blood establishments that collect... malaria. This guidance replaces the draft guidance entitled ``Guidance for Industry: Recommendations...

  5. Assessing Children with Traumatic Brain Injury during Rehabilitation: Promoting School and Community Reentry.

    ERIC Educational Resources Information Center

    Farmer, Janet E.; And Others

    1996-01-01

    Evaluating children with traumatic brain injury (TBI) in order to facilitate their transition to school is reviewed. A process-oriented approach to assessing TBI children during rehabilitation is suggested. The major areas of functioning important to school reentry are discussed. The need for families and professionals to communicate about the…

  6. Mentoring Formerly Incarcerated Adults: Insights from the Ready4Work Reentry Initiative. Field Report Series

    ERIC Educational Resources Information Center

    Bauldry, Shawn; Korom-Djakovic, Danijela; McClanahan, Wendy S.; McMaken, Jennifer; Kotloff, Lauren J.

    2009-01-01

    This report explores mentoring as a tool for supporting the successful reintegration of formerly incarcerated individuals within the context of a larger reentry strategy--in this case, the "Ready4Work" model. "Ready4Work" was a three-year national demonstration designed to address the needs of the growing ex-prisoner population and to test the…

  7. Reentry thermal testing of a general purpose heat source fueled clad

    SciTech Connect

    Peterson, D.E.; Frantz, C.E.

    1982-03-01

    A General Purpose Heat Source (GPHS) module was exposed to heat treatments simulating an isothermal prelaunch condition, followed by thermal pulses corresponding to atmospheric reentry. Helium release rates were determined during each heating and modeled after simple diffusion theory. Following the tests, the module was examined metallurgically with no evidence of swelling of the cladding nor degradation of the fuel.

  8. Recognition of Tacit Skills: Sustaining Learning Outcomes in Adult Learning and Work Re-Entry

    ERIC Educational Resources Information Center

    Evans, Karen; Kersh, Natasha; Kontiainen, Seppo

    2004-01-01

    This paper is based on the project "Recognition of Tacit Skills and Knowledge in Work Re-entry" carried out as a part of the ESRC-funded Research Network "Improving Incentives to Learning in the Workplace". The network aims to contribute to improved practice among a wide range of practitioners. The study has investigated the part played by tacit…

  9. Northern Kentucky University ReEntry Center, 1980-1990. 10 Year Anniversary Celebration.

    ERIC Educational Resources Information Center

    Northern Kentucky Univ., Highland Heights.

    The original poems and articles contained in this publication were submitted by individuals who have either been through the programs offered by the ReEntry Center at Northern Kentucky University or have otherwise had their lives touched and changed by the center's existence. They are intended to illustrate the growth and achievement that these…

  10. Continuing Education: Reentry and the Mature Woman--Annotated Selected References and Resources. Bibliography Series: 2.

    ERIC Educational Resources Information Center

    Cirksena, Kathy, Comp.; And Others

    This bibliography, second in a series of three to be issued by the Women's Educational Equity Communications Network (WEECN), contains ninety-three selected information resources (articles, papers, separately published bibliographies, and monographs) in the area of continuing education and the reentry woman. These materials, alphabetized according…

  11. 19 CFR 123.29 - Procedure on arrival at port of reentry.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...; DEPARTMENT OF THE TREASURY CUSTOMS RELATIONS WITH CANADA AND MEXICO Shipments in Transit Through Canada or Mexico § 123.29 Procedure on arrival at port of reentry. (a) Presentation of documents. At the first port in the United States after transportation through Canada or Mexico under the provisions of...

  12. Learning to Resist: Educational Counter-Narratives of Black College Reentry Mothers

    ERIC Educational Resources Information Center

    Sealey-Ruiz, Yolanda

    2013-01-01

    Background: College reentry women are often older than the traditional college student, and in this study are distinguished from other students because of their parental status as mothers (Johnson-Bailey, 2000; Sealey-Ruiz, 2007). As one of the the fastest growing populations in colleges and universities across the nation, it is alarming that many…

  13. Re-entry Women: Part-Time Enrollment, Full-Time Commitment. Field Evaluation Draft.

    ERIC Educational Resources Information Center

    Hall, Roberta M.

    Barriers re-entry women often face as they enroll, or attempt to enroll, in undergraduate and graduate degree programs on a part-time basis are discussed, and recommendations for change are offered. A wide range of possible actions is outlined so that institutions can pursue those most appropriate to their individual circumstances. Suggestions on…

  14. Re-Entry Women: A Selective Review of the Educational Process, Career Choice, and Interest Measurement

    ERIC Educational Resources Information Center

    Tittle, Carol Kehr; Denker, Elenor Rubin

    1977-01-01

    Some factors related to the reentry of adult females to post secondary education, as reported in recent literature, are reviewed. Barriers and opportunities in continuing education, current theories and research on career choice for women, and sex bias in counseling and interest inventories are discussed. (GDC)

  15. Control of a high beta maneuvering reentry vehicle using dynamic inversion.

    SciTech Connect

    Watts, Alfred Chapman

    2005-05-01

    The design of flight control systems for high performance maneuvering reentry vehicles presents a significant challenge to the control systems designer. These vehicles typically have a much higher ballistic coefficient than crewed vehicles like as the Space Shuttle or proposed crew return vehicles such as the X-38. Moreover, the missions of high performance vehicles usually require a steeper reentry flight path angle, followed by a pull-out into level flight. These vehicles then must transit the entire atmosphere and robustly perform the maneuvers required for the mission. The vehicles must also be flown with small static margins in order to perform the required maneuvers, which can result in highly nonlinear aerodynamic characteristics that frequently transition from being aerodynamically stable to unstable as angle of attack increases. The control system design technique of dynamic inversion has been applied successfully to both high performance aircraft and low beta reentry vehicles. The objective of this study was to explore the application of this technique to high performance maneuvering reentry vehicles, including the basic derivation of the dynamic inversion technique, followed by the extension of that technique to the use of tabular trim aerodynamic models in the controller. The dynamic inversion equations are developed for high performance vehicles and augmented to allow the selection of a desired response for the control system. A six degree of freedom simulation is used to evaluate the performance of the dynamic inversion approach, and results for both nominal and off nominal aerodynamic characteristics are presented.

  16. International Space Station as an Observation Platform for Hypersonic Re-Entry of its Visiting Vehicles

    NASA Technical Reports Server (NTRS)

    Bacon, John B.

    2001-01-01

    The International Space Station (ISS) will receive an armada of visiting supply vehicles during its life in orbit. Over 500 tons of material will be destroyed in targeted re-entries of these vehicles. Because all such re-entries lie in the same orbital plane of the station, and because the visiting vehicles typically deorbit within a few hours of departure, the ISS will usually be within sight of the re-entry process, at a range of only 300-600 kilometers. This vantage point offers an unprecedented opportunity for systematically measuring hypersonic destructive processes. This paper examines the integrated operational constraints of the ISS, its supply vehicles, and candidate sensors which can be employed in the scientific observation of the re-entry process. It is asserted the ISS program has the potential to reduce the worldwide risks from future deorbiting spacecraft, through systematic experimental characterization of the factors which affect the rupture, debris survival, and footprint size of its visiting vehicle fleet.

  17. 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…

  18. 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.

  19. 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.

  20. Development of a Sheathed Miniature Aerothermal Reentry Thermocouple for Thermal Protection System Materials

    NASA Technical Reports Server (NTRS)

    Martinez, Edward R.; Weber, Carissa Tudryn; Oishi, Tomo; Santos, Jose; Mach, Joseph

    2011-01-01

    The Sheathed Miniature Aerothermal Reentry Thermocouple is a micro-miniature thermocouple for high temperature measurement in extreme environments. It is available for use in Thermal Protection System materials for ground testing and flight. This paper discusses the heritage, and design of the instrument. Experimental and analytical methods used to verify its performance and limitations are described.

  1. 14 CFR 437.63 - Agreements with other entities involved in a launch or reentry.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Agreements with other entities involved in a launch or reentry. 437.63 Section 437.63 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING EXPERIMENTAL PERMITS Safety Requirements § 437.63 Agreements with other...

  2. 14 CFR 437.63 - Agreements with other entities involved in a launch or reentry.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Agreements with other entities involved in a launch or reentry. 437.63 Section 437.63 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING EXPERIMENTAL PERMITS Safety Requirements § 437.63 Agreements with other...

  3. 14 CFR 437.63 - Agreements with other entities involved in a launch or reentry.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Agreements with other entities involved in a launch or reentry. 437.63 Section 437.63 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING EXPERIMENTAL PERMITS Safety Requirements § 437.63 Agreements with other...

  4. 14 CFR 437.63 - Agreements with other entities involved in a launch or reentry.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Agreements with other entities involved in a launch or reentry. 437.63 Section 437.63 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING EXPERIMENTAL PERMITS Safety Requirements § 437.63 Agreements with other...

  5. 14 CFR 437.63 - Agreements with other entities involved in a launch or reentry.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Agreements with other entities involved in a launch or reentry. 437.63 Section 437.63 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING EXPERIMENTAL PERMITS...

  6. Side Jet/Cross Flow Interaction at Hypersonic Re-entry Conditions

    NASA Astrophysics Data System (ADS)

    Adeli, R.; Seiler, F.

    Since decades control jets are commonly used for steering re-entry vehicles, e.g. the Apollo capsules, the Space Shuttles and were also used for the "SpaceShipOne" mission and recently direct to the flight path of missiles.

  7. 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.

  8. Aerothermodynamics of generic re-entry vehicle with a series of aerospikes at nose

    NASA Astrophysics Data System (ADS)

    Yadav, Rajesh; Velidi, Gurunadh; Guven, Ugur

    2014-03-01

    Re-entry of a blunt nosed vehicle is one of the most intriguing problems in any space programme. Especially in light of various space tourism possibilities, there are many works concerning re-entry of commercial blunt nosed space vehicles. In this paper, a generic blunt body re-entry model represented by a hemisphere-cylinder, fitted axisymmetrically with an aerodisk aerospike at the nose is investigated numerically with commercially available control volume based axisymmetric flow solver. The scaled down re-entry model has a base diameter of 40 mm and an overall length of 100 mm. A 6 mm diameter aerospike fitted axisymmetrically at the nose has a hemispherical cap from which another aerospike of 4 mm diameter protrudes which again has a hemispherical cap. Two dimensional compressible, axisymmetric Navier Stokes Equations are solved for a turbulent hypersonic flow of a 5 species, chemically reacting air in thermal equilibrium with free stream conditions of Mach no., static pressure and temperature of 10.1, 16,066 Pa and 216.65 K, respectively. The results are compared with that of re-entry model without any aerospike. Among the cases investigated, the spiked blunt body having two aerospikes in series with lengths l1 and l2 equal to 30 and 20 respectively and overall length-to-diameter ratio of 1.5 showed a favourable reduction in the peak reattachment heat flux along with high reduction in aerodynamic drag and thus stands as a prospective case for blunt body nose configuration for hypersonic flight.

  9. Connection to mental health care upon community reentry for detained youth: a qualitative study

    PubMed Central

    2014-01-01

    Background Although detained youth evidence increased rates of mental illness, relatively few adolescents utilize mental health care upon release from detention. Thus, the goal of this study is to understand the process of mental health care engagement upon community reentry for mentally-ill detained youth. Methods Qualitative interviews were conducted with 19 youth and caregiver dyads (39 participants) recruited from four Midwest counties affiliated with a state-wide mental health screening project. Previously detained youth (ages 11–17), who had elevated scores on a validated mental health screening measure, and a caregiver were interviewed 30 days post release. A critical realist perspective was used to identify themes on the detention and reentry experiences that impacted youth mental health care acquisition. Results Youth perceived detention as a crisis event and having detention-based mental health care increased their motivation to seek mental health care at reentry. Caregivers described receiving very little information regarding their child during detention and felt “out of the loop,” which resulted in mental health care utilization difficulty. Upon community reentry, long wait periods between detention release and initial contact with court or probation officers were associated with decreased motivation for youth to seek care. However, systemic coordination between the family, court and mental health system facilitated mental health care connection. Conclusions Utilizing mental health care services can be a daunting process, particularly for youth upon community reentry from detention. The current study illustrates that individual, family-specific and systemic issues interact to facilitate or impair mental health care utilization. As such, in order to aid youth in accessing mental health care at detention release, systemic coordination efforts are necessary. The systematic coordination among caregivers, youth, and individuals within the justice

  10. Accurate quantum chemical calculations

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    1989-01-01

    An important goal of quantum chemical calculations is to provide an understanding of chemical bonding and molecular electronic structure. A second goal, the prediction of energy differences to chemical accuracy, has been much harder to attain. First, the computational resources required to achieve such accuracy are very large, and second, it is not straightforward to demonstrate that an apparently accurate result, in terms of agreement with experiment, does not result from a cancellation of errors. Recent advances in electronic structure methodology, coupled with the power of vector supercomputers, have made it possible to solve a number of electronic structure problems exactly using the full configuration interaction (FCI) method within a subspace of the complete Hilbert space. These exact results can be used to benchmark approximate techniques that are applicable to a wider range of chemical and physical problems. The methodology of many-electron quantum chemistry is reviewed. Methods are considered in detail for performing FCI calculations. The application of FCI methods to several three-electron problems in molecular physics are discussed. A number of benchmark applications of FCI wave functions are described. Atomic basis sets and the development of improved methods for handling very large basis sets are discussed: these are then applied to a number of chemical and spectroscopic problems; to transition metals; and to problems involving potential energy surfaces. Although the experiences described give considerable grounds for optimism about the general ability to perform accurate calculations, there are several problems that have proved less tractable, at least with current computer resources, and these and possible solutions are discussed.

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

    PubMed Central

    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

    2015-01-01

    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. PMID:26416244

  12. 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.

  13. A vehicle health monitoring system for the Space Shuttle Reaction Control System during reentry. M.S. Thesis - Massachusetts Inst. of Technology

    NASA Technical Reports Server (NTRS)

    Rosello, Anthony David

    1995-01-01

    A general two tier framework for vehicle health monitoring of Guidance Navigation and Control (GN&C) system actuators, effectors, and propulsion devices is presented. In this context, a top level monitor that estimates jet thrust is designed for the Space Shuttle Reaction Control System (RCS) during the reentry phase of flight. Issues of importance for the use of estimation technologies in vehicle health monitoring are investigated and quantified for the Shuttle RCS demonstration application. These issues include rate of convergence, robustness to unmodeled dynamics, sensor quality, sensor data rates, and information recording objectives. Closed loop simulations indicate that a Kalman filter design is sensitive to modeling error and robust estimators may reduce this sensitivity. Jet plume interaction with the aerodynamic flowfield is shown to be a significant effect adversely impacting the ability to accurately estimate thrust.

  14. Accurate Optical Reference Catalogs

    NASA Astrophysics Data System (ADS)

    Zacharias, N.

    2006-08-01

    Current and near future all-sky astrometric catalogs on the ICRF are reviewed with the emphasis on reference star data at optical wavelengths for user applications. The standard error of a Hipparcos Catalogue star position is now about 15 mas per coordinate. For the Tycho-2 data it is typically 20 to 100 mas, depending on magnitude. The USNO CCD Astrograph Catalog (UCAC) observing program was completed in 2004 and reductions toward the final UCAC3 release are in progress. This all-sky reference catalogue will have positional errors of 15 to 70 mas for stars in the 10 to 16 mag range, with a high degree of completeness. Proper motions for the about 60 million UCAC stars will be derived by combining UCAC astrometry with available early epoch data, including yet unpublished scans of the complete set of AGK2, Hamburg Zone astrograph and USNO Black Birch programs. Accurate positional and proper motion data are combined in the Naval Observatory Merged Astrometric Dataset (NOMAD) which includes Hipparcos, Tycho-2, UCAC2, USNO-B1, NPM+SPM plate scan data for astrometry, and is supplemented by multi-band optical photometry as well as 2MASS near infrared photometry. The Milli-Arcsecond Pathfinder Survey (MAPS) mission is currently being planned at USNO. This is a micro-satellite to obtain 1 mas positions, parallaxes, and 1 mas/yr proper motions for all bright stars down to about 15th magnitude. This program will be supplemented by a ground-based program to reach 18th magnitude on the 5 mas level.

  15. 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.; Okazaki, R.; Zolensky, M.; Sandford, S.; Ireland, T.; Ueno, M.; Mukai, T.; Yoshikawa, M.; Yamada, T.; Kuninaka, H.; Kawaguchi, J.

    2011-01-01

    The "Hayabusa" re-entry capsule was safely carried into the clean room of Sagamihara Planetary Sample Curation Facility in JAXA on June 18, 2010. After executing computed tomographic (CT) scanning, removal of heat shield, and surface cleaning of sample container, the sample container was enclosed into the clean chamber. After opening the sample container and residual gas sampling in the clean chamber, optical observation, sample recovery, sample separation for initial analysis will be performed. This curation work is continuing for several manths with some selected member of Hayabusa Asteroidal Sample Preliminary Examination Team (HASPET). We report here on the 'Hayabusa' capsule recovery operation, and transportation and acceptance at the curation facility of the Hayabusa re-entry capsule.

  16. Measuring the spectral emissivity of thermal protection materials during atmospheric reentry simulation

    NASA Technical Reports Server (NTRS)

    Marble, Elizabeth

    1996-01-01

    Hypersonic spacecraft reentering the earth's atmosphere encounter extreme heat due to atmospheric friction. Thermal Protection System (TPS) materials shield the craft from this searing heat, which can reach temperatures of 2900 F. Various thermophysical and optical properties of TPS materials are tested at the Johnson Space Center Atmospheric Reentry Materials and Structures Evaluation Facility, which has the capability to simulate critical environmental conditions associated with entry into the earth's atmosphere. Emissivity is an optical property that determines how well a material will reradiate incident heat back into the atmosphere upon reentry, thus protecting the spacecraft from the intense frictional heat. This report describes a method of measuring TPS emissivities using the SR5000 Scanning Spectroradiometer, and includes system characteristics, sample data, and operational procedures developed for arc-jet applications.

  17. 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.

  18. Reentry Near the Percolation Threshold in a Heterogeneous Discrete Model for Cardiac Tissue

    NASA Astrophysics Data System (ADS)

    Alonso, Sergio; Bär, Markus

    2013-04-01

    Arrhythmias in cardiac tissue are related to irregular electrical wave propagation in the heart. Cardiac tissue is formed by a discrete cell network, which is often heterogeneous. A localized region with a fraction of nonconducting links surrounded by homogeneous conducting tissue can become a source of reentry and ectopic beats. Extensive simulations in a discrete model of cardiac tissue show that a wave crossing a heterogeneous region of cardiac tissue can disintegrate into irregular patterns, provided the fraction of nonconducting links is close to the percolation threshold of the cell network. The dependence of the reentry probability on this fraction, the system size, and the degree of excitability can be inferred from the size distribution of nonconducting clusters near the percolation threshold.

  19. 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.

  20. Laboratory-experiments on shear-flow instabilities in a re-entry sheath

    NASA Astrophysics Data System (ADS)

    Niemann, C.; Ashour-Abdalla, M.; Clark, S. E.; Niehoff, D.; Schaeffer, D. B.; Constantin, C. G.; Schriver, D.; El Alaoui, M.; Sotnikov, V. I.

    2013-10-01

    Shear-flow instabilities in the plasma sheath surrounding re-entry vehicles and hypersonic aircraft can be detrimental to radio-communication but have not been investigated experimentally in detail. We present measurements of plasma-fluctuations in the lower-hybrid range, created in a laser-produced plasma plume that closely resembles a reentry sheath (1011-1013 cm-3, 1-20 eV). Shear-flow instabilities form in the diamagnetic current layer of the laser-produced plasma (20 J) exploding at hypersonic speed (M > 10) into a preformed magnetic field (400 G). Electric- and magnetic-field gradients are characterized with magnetic flux probes over large spatial (20 cm) and temporal scales, while the plasma parameters are measured via optical Thomson scattering. The frequency spectrum of plasma pulsations is investigated with biased Langmuir probes. The data is compared to simulations performed with a 2D PIC Darwin code. Work supported by the AFRL.

  1. Direct Monte Carlo Simulations of the Intermediate Experimental Vehicle at Early Stages of Reentry

    NASA Astrophysics Data System (ADS)

    Banyai, T.; Torres, E.; Kashkovsky, A. V.; Vashchenkov, P. V.; Ivanov, M. S.; Rambaud, P.

    2011-05-01

    Within the European Space Agency (ESA) framework program FLPP Next Generation Launcher (NGL) preparatory activities on System, In-Flight Experimentation and Aerothermodynamics Period 1, Step 2, von Karman Institute (VKI) has to perform ground testing and numerical simulations to contribute to the aerothermodynamic database of the Intermediate eXperimental Vehicle (IXV) along its trajectory during re-entry. The present article summarizes the part of these activities in relation with the evaluation of the aerodynamic properties in the early stages of reentry. Due to the rarefied nature of the higher atmosphere, the computations were carried out by means of Direct Simulation of Monte Carlo (DSMC) method. The aim of this work was to a., validate the methodology used at VKI, b., perform computations at several points along the trajectory and c., assess the feasibility of joint simulation of rarefied flow and thrusters.

  2. 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.

  3. 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.

  4. Effect of shock interactions on the attitude stability of a toroidal ballute for reentry vehicles

    NASA Astrophysics Data System (ADS)

    Otsu, Hirotaka; Abe, Takashi

    2016-03-01

    The effect of shock interactions on the attitude stability of a reentry vehicle system with a toroidal ballute was investigated. The hypersonic wind tunnel experimental results showed that when the shock interaction occurred near or outside the ballute, an unstable oscillation of the ballute was observed. This was caused by the local high-pressure region on the ballute surface created by the shock interaction between the shock from the reentry capsule and the shock from the ballute. To avoid this unstable oscillation, the radius of the ballute should be designed to be large enough so that the shock from the capsule will be located inside the ballute, which can avoid the local high-pressure region on the ballute surface.

  5. Human subject experiments to estimate reentry periods for monocrotophos-treated tobacco.

    PubMed

    Guthrie, F E; Domanski, J J; Chasson, A L; Bradway, D E; Monroe, R J

    1976-01-01

    Thirteen to fifteen human volunteers worked for eight-hr periods in tobacco fields treated 96, 72, and 48 hr previously with monocrotophos (3-hydroxy-N-methyl-cis-crotonamide dimethyl phosphate). At the 48-hr reentry period, during which time no rainfall occurred, both post-exposure plasma and red blood cell cholinesterase levels of the worker group were depressed from pre-exposure levels although the decline was less than 9% in both cases. Rainfall in excess of one inch fell during the 96- and 72-hr reentry intervals, and no important change in cholinesterase levels was noted. Experiments with mice were in general agreement with the human tests. Dimethyl phosphoric acid in urine of the worker group collected prior to, and three hr after, exposure was unchanged in all cases. Rain appeared to have markedly reduced dislodgable residues.

  6. REENTRY OF YOUNG OFFENDERS FROM THE JUSTICE SYSTEM: A Developmental Perspective

    PubMed Central

    Steinberg, Laurence; Chung, He Len; Little, Michelle

    2009-01-01

    This article presents a developmental perspective on the reentry of young offenders into the community. We begin with a discussion of the psychosocial tasks of late adolescence. Next, we discuss contextual influences on the successful negotiation of these psychosocial tasks. Third, we examine whether and to what extent the contexts to which young offenders are exposed in the justice system are likely to facilitate normative psychosocial development. Finally, we argue that the psychosocial development of youthful offenders is disrupted, or “arrested,” by their experiences within the justice system. Interventions designed to facilitate the successful reentry of young offenders into the community must be informed by what we know about healthy psychosocial development in late adolescence. PMID:20119512

  7. AN EMPIRICAL PORTRAIT OF COMMUNITY REENTRY AMONG SERIOUS JUVENILE OFFENDERS IN TWO METROPOLITAN CITIES

    PubMed Central

    CHUNG, HE LEN; SCHUBERT, CAROL A.; MULVEY, EDWARD P.

    2009-01-01

    This study examined the community reentry process among 413 serious adolescent offenders released from juvenile court commitments in two metropolitan areas. Data are provided about postrelease court supervision and community-based services (CBSs) during the first 6 months in the community as well as indicators of antisocial activity, formal system involvement, school attendance, and employment. Findings indicate that a far greater proportion of offenders reported receiving supervision than CBSs, but when utilized, the frequency of CBS use was high, and intensive services reduced the odds of formal system involvement. In addition, court supervision increased the likelihood of positive adjustment during community reentry. These results held after controlling for social context variables, including peer deviance, parental monitoring, and contact with caring adults. PMID:19997526

  8. Stimulus-induced critical point. Mechanism for electrical initiation of reentry in normal canine myocardium.

    PubMed Central

    Frazier, D W; Wolf, P D; Wharton, J M; Tang, A S; Smith, W M; Ideker, R E

    1989-01-01

    The hypothesis was tested that the field of a premature (S2) stimulus, interacting with relatively refractory tissue, can create unidirectional block and reentry in the absence of nonuniform dispersion of recovery. Simultaneous recordings from a small region of normal right ventricular (RV) myocardium were made from 117 to 120 transmural or epicardial electrodes in 14 dogs. S1 pacing from a row of electrodes on one side of the mapped area generated parallel activation isochrones followed by uniform parallel isorecovery lines. Cathodal S2 shocks of 25 to 250 V lasting 3 ms were delivered from a mesh electrode along one side of the mapped area to scan the recovery period, creating isogradient electric field lines perpendicular to the isorecovery lines. Circus reentry was created following S2 stimulation; initial conduction was distant from the S2 site and spread towards more refractory tissue. Reentry was clockwise for right S1 (near the septum) with top S2 (near the pulmonary valve) and for left S1 with bottom S2; and counterclockwise for right S1 with bottom S2 and left S1 with top S2. The center of the reentrant circuit for all S2 voltages and coupling intervals occurred at potential gradients of 5.1 +/- 0.6 V/cm (mean +/- standard deviation) and at preshock intervals 1 +/- 3 ms longer than refractory periods determined locally for a 2 mA stimulus. Thus, when S2 field strengths and tissue refractoriness are uniformally dispersed at an angle to each other, circus reentry occurs around a "critical point" where an S2 field of approximately 5 V/cm intersects tissue approximately at the end of its refractory period. Images PMID:2921316

  9. A preliminary study of the air data sensing problem on a re-entry vehicle

    NASA Astrophysics Data System (ADS)

    Hettena, E.

    1995-03-01

    A brief review of different measurement techniques for speed, pressure, and temperature on a re-entry vehicle is given in order to evaluate their applicability and limitations to the design of an air data system. A pressure-sensors based air data system is then assumed and an engineering aerodynamic model is used to investigate the influence of the measurement errors on the relevant air data parameters necessary for light guidance and control.

  10. Development of the parachute recovery system for the LBRV-2 reentry vehicle

    SciTech Connect

    Pepper, W.B.

    1983-10-01

    A 6.44-ft-dia ribbon parachute with no reefing has been developed for recovery for the 130-lb LBRV-2 reentry nose cone. This report presents the results of five sled-launched, free-flight tests and of an operational recovery at velocities of 600 to 875 ft/s with corresponding dynamic pressures of 340 to 766 lb/ft/sup 2/.

  11. Functional reentry and circus movement arrhythmias in the small intestine of normal and diabetic rats.

    PubMed

    Lammers, Wim J E P; Stephen, B; Karam, S M

    2012-04-01

    In a few recent studies, the presence of arrhythmias based on reentry and circus movement of the slow wave have been shown to occur in normal and diseased stomachs. To date, however, reentry has not been demonstrated before in any other part of the gastrointestinal system. No animals had to be killed for this study. Use was made of materials obtained during the course of another study in which 11 rats were treated with streptozotocin and housed with age-matched controls. After 3 and 7 mo, segments of duodenum, jejunum, and ileum were isolated and positioned in a tissue bath. Slow wave propagation was recorded with 121 extracellular electrodes. After the experiment, the propagation of the slow waves was reconstructed. In 10 of a total of 66 intestinal segments (15%), a circus movement of the slow wave was detected. These reentries were seen in control (n = 2) as well as in 3-mo (n = 2) and 7-mo (n = 6) diabetic rats. Local conduction velocities and beat-to-beat intervals during the reentries were measured (0.42 ± 0.15 and 3.03 ± 0.67 cm/s, respectively) leading to a wavelength of 1.3 ± 0.5 cm and a circuit diameter of 4.1 ± 1.5 mm. This is the first demonstration of a reentrant arrhythmia in the small intestine of control and diabetic rats. Calculations of the size of the circuits indicate that they are small enough to fit inside the intestinal wall. Extrapolation based on measured velocities and rates indicate that reentrant arrhythmias are also possible in the distal small intestine of larger animals including humans.

  12. Evaluating and Addressing Potential Hazards of Fuel Tanks Surviving Atmospheric Reentry

    NASA Technical Reports Server (NTRS)

    Kelley, Robert L.; Johnson, Nicholas L.

    2011-01-01

    In order to ensure reentering spacecraft do not pose an undue risk to the Earth's population it is important to design satellites and rocket bodies with end of life considerations in mind. In addition to considering the possible consequences of deorbiting a vehicle, consideration must also be given to the possible risks associated with a vehicle failing to become operational or reach its intended orbit. Based on recovered space debris and numerous reentry survivability analyses, fuel tanks are of particular concern in both of these considerations. Most spacecraft utilize some type of fuel tank as part of their propulsion system. These fuel tanks are most often constructed using stainless steel or titanium and are filled with potentially hazardous substances such as hydrazine and nitrogen tetroxide. For a vehicle which has reached its scheduled end of mission the contents of the tanks are typically depleted. In this scenario the use of stainless steel and titanium results in the tanks posing a risk to people and property do to the high melting point and large heat of ablation of these materials leading to likely survival of the tank during reentry. If a large portion of the fuel is not depleted prior to reentry, there is the added risk of hazardous substance being released when the tank impact the ground. This paper presents a discussion of proactive methods which have been utilized by NASA satellite projects to address the risks associated with fuel tanks reentering the atmosphere. In particular it will address the design of a demiseable fuel tank as well as the evaluation of off the shelf designs which are selected to burst during reentry.

  13. Analysis of the inadvertent reentry of the Cassini Spacecraft's Radioisotope Thermoelectric Generators

    NASA Astrophysics Data System (ADS)

    Frank, Michael V.; Ailor, William H.

    1999-01-01

    As part of the launch approval process, the Interagency Nuclear Safety Review Panel (INSRP) provides an independent safety assessment of space missions, such as the Cassini mission, that carry a significant amount of nuclear materials. This paper describes potential accident scenarios that might lead to release of Plutonium from an accidental reentry during an Earth swingby maneuver. Because of large extrapolations from the current knowledge base, the analysis emphasized treatment of uncertainties.

  14. Atrioventricular Nodal Re-entry Tachycardia in Identical Twins: A Case Report and Literature Review.

    PubMed

    Barake, Walid; Caldwell, Jane; Baranchuk, Adrian

    2013-01-01

    This report details the case of 17 year old identical twins who both presented with paroxysmal supraventricular tachycardia (PSVT). Electrophysiological studies revealed atrioventricular nodal reentry tachycardia (AVNRT) in both twins. Successful but technically challenging slow pathway ablation was performed in both twins. This is the first reported case of confirmed AVNRT in identical twins which adds strong evidence to heritability of the dual AV node physiology and AVNRT. A review of the current literature regarding PSVT in monozygotic twins is provided. PMID:23329875

  15. Analysis of video imagery of the reentry and breakup of the STS-31 external tank

    NASA Technical Reports Server (NTRS)

    Snyder, Michael W.; Pitts, David E.

    1992-01-01

    Some of the major questions concerning the reentry and breakup of the STS-31 external tank (ET), which had a deactivated tumble valve, are addressed. The time of breakup, the altitude, and the geographic location of the ET at breakup were determined. The tumble rate was estimated to be between 8.59 deg and 8.84 deg/s. The ET broke up into at least 50 pieces 7 s after initial rupture.

  16. Test of Re-Entry Systems at Estrange Using Sounding Rockets and Stratospheric Balloons

    NASA Astrophysics Data System (ADS)

    Lockowandt, C.; Abrahamsson, M.; Florin, G.

    2015-09-01

    Stratospheric balloons and sounding rockets can provide an ideal in-flight platform for performing re-entry and other high speed tests off different types of vehicles and techniques. They are also ideal platforms for testing different types of recovery systems such as airbrakes and parachutes. This paper expands on some examples of platforms and missions for drop tests from balloons as well as sounding rockets launched from Esrange Space Center, a facility run by Swedish Space Corporation SSC in northern Sweden.

  17. Atrioventricular Nodal Re-entry Tachycardia in Identical Twins: A Case Report and Literature Review

    PubMed Central

    Barake, Walid; Caldwell, Jane; Baranchuk, Adrian

    2013-01-01

    This report details the case of 17 year old identical twins who both presented with paroxysmal supraventricular tachycardia (PSVT). Electrophysiological studies revealed atrioventricular nodal reentry tachycardia (AVNRT) in both twins. Successful but technically challenging slow pathway ablation was performed in both twins. This is the first reported case of confirmed AVNRT in identical twins which adds strong evidence to heritability of the dual AV node physiology and AVNRT. A review of the current literature regarding PSVT in monozygotic twins is provided. PMID:23329875

  18. 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

  19. Reentry produced by small-scale heterogeneities in a discrete model of cardiac tissue

    NASA Astrophysics Data System (ADS)

    Alonso, Sergio; Bär, Markus

    2016-06-01

    Reentries are reexcitations of cardiac tissue after the passing of an excitation wave which can cause dangerous arrhythmias like tachycardia or life-threatening heart failures like fibrillation. The heart is formed by a network of cells connected by gap junctions. Under ischemic conditions some of the cells lose their connections, because gap junctions are blocked and the excitability is decreased. We model a circular region of the tissue where a fraction of connections among individual cells are removed and substituted by non-conducting material in a two-dimensional (2D) discrete model of a heterogeneous excitable medium with local kinetics based on electrophysiology. Thus, two neighbouring cells are connected (disconnected) with a probability ϕ (1 – ϕ). Such a region is assumed to be surrounded by homogeneous tissue. The circular heterogeneous area is shown to act as a source of new waves which reenter into the tissue and reexcitate the whole domain. We employ the Fenton-Karma equations to model the action potential for the local kinetics of the discrete nodes to study the statistics of the reentries in two dimensional networks with different topologies. We conclude that the probability of reentry is determined by the proximity of the fraction of disrupted connections between neighboring nodes (“cells”) in the heterogeneous region to the percolation threshold.

  20. Reentry produced by small-scale heterogeneities in a discrete model of cardiac tissue

    NASA Astrophysics Data System (ADS)

    Alonso, Sergio; Bär, Markus

    2016-06-01

    Reentries are reexcitations of cardiac tissue after the passing of an excitation wave which can cause dangerous arrhythmias like tachycardia or life-threatening heart failures like fibrillation. The heart is formed by a network of cells connected by gap junctions. Under ischemic conditions some of the cells lose their connections, because gap junctions are blocked and the excitability is decreased. We model a circular region of the tissue where a fraction of connections among individual cells are removed and substituted by non-conducting material in a two-dimensional (2D) discrete model of a heterogeneous excitable medium with local kinetics based on electrophysiology. Thus, two neighbouring cells are connected (disconnected) with a probability ϕ (1 - ϕ). Such a region is assumed to be surrounded by homogeneous tissue. The circular heterogeneous area is shown to act as a source of new waves which reenter into the tissue and reexcitate the whole domain. We employ the Fenton-Karma equations to model the action potential for the local kinetics of the discrete nodes to study the statistics of the reentries in two dimensional networks with different topologies. We conclude that the probability of reentry is determined by the proximity of the fraction of disrupted connections between neighboring nodes (“cells”) in the heterogeneous region to the percolation threshold.

  1. Engagement processes in model programs for community reentry from prison for people with serious mental illness.

    PubMed

    Angell, Beth; Matthews, Elizabeth; Barrenger, Stacey; Watson, Amy C; Draine, Jeffrey

    2014-01-01

    Linking prisoners with mental illness with treatment following release is critical to preventing recidivism, but little research exists to inform efforts to engage them effectively. This presentation compares the engagement process in two model programs, each representing an evidence-based practice for mental health which has been adapted to the context of prison reentry. One model, Forensic Assertive Community Treatment (FACT), emphasizes a long-term wrap-around approach that seeks to maximize continuity of care by concentrating all services within one interdisciplinary team; the other, Critical Time Intervention (CTI), is a time-limited intervention that promotes linkages to outside services and bolsters natural support systems. To compare engagement practices, we analyze data from two qualitative studies, each conducted in a newly developed treatment program serving prisoners with mental illness being discharged from prisons to urban communities. Findings show that the working relationship in reentry services exhibits unique features and is furthered in both programs by the use of practitioner strategies of engagement, including tangible assistance, methods of interacting with consumers, and encouragement of service use via third parties such as families and parole officers. Nevertheless, each program exhibited distinct cultures and rituals of reentry that were associated with fundamental differences in philosophy and differences in resources available to each program.

  2. Engagement Processes in Model Programs for Community Reentry from Prison for People with Serious Mental Illness

    PubMed Central

    Angell, Beth; Matthews, Elizbeth; Barrenger, Stacey; Watson, Amy C.; Draine, Jeffrey

    2014-01-01

    Linking prisoners with mental illness with treatment following release is critical to preventing recidivism, but little research exists to inform efforts to engage them effectively. This presentation compares the engagement process in two model programs, each representing an evidence-based practice for mental health which has been adapted to the context of prison reentry. One model, Forensic Assertive Community Treatment (FACT), emphasizes a long-term wrap-around approach that seeks to maximize continuity of care by concentrating all services within one interdisciplinary team; the other, Critical Time Intervention (CTI), is a time-limited intervention that promotes linkages to outside services and bolsters natural support systems. To compare engagement practices, we analyze data from two qualitative studies, each conducted in a newly developed treatment program serving prisoners with mental illness being discharged from prisons to urban communities. Findings show that the working relationship in reentry services exhibits unique features and is furthered in both programs by the use of practitioner strategies of engagement, including tangible assistance, methods of interacting with consumers, and encouragement of service use via third parties such as families and parole officers. Nevertheless, each program exhibited distinct cultures and rituals of reentry that were associated with fundamental differences in philosophy and differences in resources available to each program. PMID:24650496

  3. Re-Entries: New strategies in development zones at the Orinoco Oil Belt

    SciTech Connect

    Gonzalez, R.; Briceno, M.; Figueroa, J.; Bolanos, C.

    1996-08-01

    Drilling of horizontal wells in Venezuela began in the Orinoco Oil Belt with the wells CI-87 and CI-97 in the J-20 block, drilled in 1989 and 1990, respectively. Well CI-87 produces up to 1000 BPD without steam injection. Due to the success of this well, the exploitation strategy was oriented toward re-entry and sidetracking wells with mechanical problems, high water cut and low potential. The purpose of this programme was to enhance drainage patterns, access new reservoirs through existing bores, and increase oil production while reducing per-barrel costs. Eighteen (18) wells were re-drilled in different pay zones such as O-12, O-13, O-14 and O-15 with horizontal sections between a thousand feet and one thousand six hundred feet. Those wells were completed with progressive cavity pumps, sucker rod beam pumps and electrical submersible pumps. Presented in this paper are the results of the re-entries at the Orinoco Oil Belt and the future re-entry strategy.

  4. The effects of bedrest on crew performance during simulated shuttle reentry. Volume 2: Control task performance

    NASA Technical Reports Server (NTRS)

    Jex, H. R.; Peters, R. A.; Dimarco, R. J.; Allen, R. W.

    1974-01-01

    A simplified space shuttle reentry simulation performed on the NASA Ames Research Center Centrifuge is described. Anticipating potentially deleterious effects of physiological deconditioning from orbital living (simulated here by 10 days of enforced bedrest) upon a shuttle pilot's ability to manually control his aircraft (should that be necessary in an emergency) a comprehensive battery of measurements was made roughly every 1/2 minute on eight military pilot subjects, over two 20-minute reentry Gz vs. time profiles, one peaking at 2 Gz and the other at 3 Gz. Alternate runs were made without and with g-suits to test the help or interference offered by such protective devices to manual control performance. A very demanding two-axis control task was employed, with a subcritical instability in the pitch axis to force a high attentional demand and a severe loss-of-control penalty. The results show that pilots experienced in high Gz flying can easily handle the shuttle manual control task during 2 Gz or 3 Gz reentry profiles, provided the degree of physiological deconditioning is no more than induced by these 10 days of enforced bedrest.

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

    SciTech Connect

    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 routes 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.

  6. Study on Mini Re-Entry System Using Deployable Membrane Aeroshell

    NASA Astrophysics Data System (ADS)

    Koyama, Masashi; Suzuki, Kojiro; Imamura, Osamu; Yamada, Kazuhiko

    An aeroshell made from membrane material have an advantage of reduction in the aerodynamic heating, because its small mass and large area enable us to make the low-ballistic-coefficient flight, in which the vehicle decelerates at very high altitude with low atmospheric density. In this paper, we propose a new concept of mini re-entry system for small satellites. This vehicle is called "FEATHER" (Flexible Expanded Aeroshell with Tiny payload Harness for Entry and Recovery). "FEATHER" is a novel re-entry and recovery system, featuring the autonomous aeroshell deployment, the low-ballistic-coefficient re-entry with less severe aerodynamicc heating and so on. FEATHER is composed of the membrane aeroshell made from the high-temperature cloth called ZYLON®, an outer frame made of Shape Memory Alloy (SMA) and a payload. When the aeroshell receives the aerodynamic heating, the temperature of SMA frame rises and restores the circular shape as memorized beforehand. Then the membrane aeroshell is automatically deployed. Therefore the vehicle can achieve the low-ballistic-coefficient flight with a drastic reduction in the aerodynamic heating without any additional sensors, controllers and actuators. The preliminary studies made on FEATHER system so far including the hypersonic wind tunnel experiments are presented in this paper.

  7. 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.

  8. Analytical Predictions of Thermal Stress in the Stardust PICA Heatshield Under Reentry Flight Conditions

    NASA Technical Reports Server (NTRS)

    Squire, Thomas; Milos, Frank; Agrawal, Parul

    2009-01-01

    We performed finite element analyses on a model of the Phenolic Impregnated Carbon Ablator (PICA) heatshield from the Stardust sample return capsule (SRC) to predict the thermal stresses in the PICA material during reentry. The heatshield on the Stardust SRC was a 0.83 m sphere cone, fabricated from a single piece of 5.82 cm-thick PICA. The heatshield performed successfully during Earth reentry of the SRC in January 2006. Material response analyses of the full, axisymmetric PICA heatshield were run using the Two-Dimensional Implicit Ablation, Pyrolysis, and Thermal Response Program (TITAN). Peak surface temperatures were predicted to be 3385K, while the temperature at the PICA backface remained at the estimated initial cold-soak temperature of 278K. Surface recession and temperature distribution results from TITAN, at several points in the reentry trajectory, were mapped onto an axisymmetric finite element model of the heatshield. We used the finite element model to predict the thermal stresses in the PICA from differential thermal expansion. The predicted peak compressive stress in the PICA heatshield was 1.38 MPa. Although this level of stress exceeded the chosen design limit for compressive stresses in PICA tiles for the design of the Orion crew exploration vehicle heatshield, the Stardust heatshield exhibited no obvious mechanical failures from thermal stress. The analyses of the Stardust heatshield were used to assess and adjust the level of conservatism in the finite element analyses in support of the Orion heatshield design.

  9. Analysis of the inadvertent reentry of the Cassini Spacecraft's Radioisotope Thermoelectric Generators

    NASA Astrophysics Data System (ADS)

    Daywitt, James E.; Bhutta, Bilal A.; Vacek, Daniel J.; Letts, William R.; Tobery, E. Wayne

    1999-01-01

    A rigorous multi-discipline approach has been developed to compute the aero/thermal/structural response of the Cassini Spacecraft's G_eneral P_urpose H_eat S_ource (GPHS) modules in the unlikely event of accidental reentry of the spacecraft during its Earth gravity-assist maneuver. A new r_eacting, a_blating, c_hemical e_quilibrium/nonequilibrium with r_adiation (RACER) full Navier-Stokes code is applied, along with an in-depth, transient-heating code, a nonlinear structural analysis code, and a six-degree-of-freedom flight-dynamics code. Attention is focused on the GPHS modules that would breakaway from the R_adioisotope T_hermoelectric G_enerators (RTGs) at high altitude. In addition, detailed analyses are performed to determine the survival/failure of the Graphite Impact Shells that would be released if the GPHS fails. The reentry velocity of the GPHS module (20 km/sec) is higher than any previously analyzed Earth reentry trajectory.

  10. Analysis of the inadvertent reentry of the Cassini Spacecraft{close_quote}s Radioisotope Thermoelectric Generators

    SciTech Connect

    Tobery, E.W.; Bhutta, B.A.

    1999-01-01

    A rigorous multi-discipline approach has been developed to compute the aero/thermal/structural response of the Cassini Spacecraft{close_quote}s G{underscore}eneral P{underscore}urpose H{underscore}eat S{underscore}ource (GPHS) modules in the unlikely event of accidental reentry of the spacecraft during its Earth gravity-assist maneuver. A new r{underscore}eacting, a{underscore}blating, c{underscore}hemical e{underscore}quilibrium/nonequilibrium with r{underscore}adiation (RACER) full Navier-Stokes code is applied, along with an in-depth, transient-heating code, a nonlinear structural analysis code, and a six-degree-of-freedom flight-dynamics code. Attention is focused on the GPHS modules that would breakaway from the R{underscore}adioisotope T{underscore}hermoelectric G{underscore}enerators (RTGs) at high altitude. In addition, detailed analyses are performed to determine the survival/failure of the Graphite Impact Shells that would be released if the GPHS fails. The reentry velocity of the GPHS module (20 km/sec) is higher than any previously analyzed Earth reentry trajectory. {copyright} {ital 1999 American Institute of Physics.}

  11. Reusable Reentry Satellite (RRS) system design study: System cost estimates document

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Reusable Reentry Satellite (RRS) program was initiated to provide life science investigators relatively inexpensive, frequent access to space for extended periods of time with eventual satellite recovery on earth. The RRS will provide an on-orbit laboratory for research on biological and material processes, be launched from a number of expendable launch vehicles, and operate in Low-Altitude Earth Orbit (LEO) as a free-flying unmanned laboratory. SAIC's design will provide independent atmospheric reentry and soft landing in the continental U.S., orbit for a maximum of 60 days, and will sustain three flights per year for 10 years. The Reusable Reentry Vehicle (RRV) will be 3-axis stabilized with artificial gravity up to 1.5g's, be rugged and easily maintainable, and have a modular design to accommodate a satellite bus and separate modular payloads (e.g., rodent module, general biological module, ESA microgravity botany facility, general botany module). The purpose of this System Cost Estimate Document is to provide a Life Cycle Cost Estimate (LCCE) for a NASA RRS Program using SAIC's RRS design. The estimate includes development, procurement, and 10 years of operations and support (O&S) costs for NASA's RRS program. The estimate does not include costs for other agencies which may track or interface with the RRS program (e.g., Air Force tracking agencies or individual RRS experimenters involved with special payload modules (PM's)). The life cycle cost estimate extends over the 10 year operation and support period FY99-2008.

  12. EntrySat: A 3U CubeStat to study the reentry atmospheric environment

    NASA Astrophysics Data System (ADS)

    Anthony, Sournac; Raphael, Garcia; David, Mimoun; Jeremie, Chaix

    2016-04-01

    ISAE France Entrysat has for main scientific objective the study of uncontrolled atmospheric re-entry. This project, is developed by ISAE in collaboration with ONERA and University of Toulouse, is funded by CNES, in the overall frame of the QB50 project. This nano-satellite is a 3U Cubesat measuring 34*10*10 cm3, similar to secondary debris produced during the break up of a spacecraft. EntrySat will collect the external and internal temperatures, pressure, heat flux, attitude variations and drag force of the satellite between ≈150 and 90 km before its destruction in the atmosphere, and transmit them during the re-entry using the IRIDIUM satellite network. The result 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. In order to fulfil the scientific objectives, the satellite will acquire 18 re-entry sensors signals, convert them and compress them, thanks to an electronic board developed by ISAE students in cooperation with EREMS. In order to transmit these data every second during the re-entry phase, the satellite will use an IRIDIUM connection. In order to keep a stable enough attitudes during this phase, a simple attitude orbit and control system using magnetotorquers and an inertial measurement unit (IMU) is developed at ISAE by students. A commercial GPS board is also integrated in the satellite into Entry Sat to determine its position and velocity which are necessary during the re-entry phase. This GPS will also be used to synchronize the on-board clock with the real-time UTC data. During the orbital phase (≈2 year) EntrySat measurements will be recorded transmitted through a more classical "UHF/VHF" connection. Preference for presentation: Poster Most suitable session: Author for correspondence: Dr Raphael F. Garcia ISAE 10, ave E. Belin, 31400 Toulouse, France Raphael.GARCIA@isae.fr +33 5 61 33 81 14

  13. Dynamics of circus movement re-entry across canine Purkinje fibre-muscle junctions.

    PubMed

    Gilmour, R F; Watanabe, M

    1994-05-01

    1. To determine the cellular electrophysiological mechanisms for unidirectional conduction block and re-entrant excitation, single cycles of circus movement re-entry were induced in canine Purkinje fibre-papillary muscle preparations containing two Purkinje fibre-muscle junctions (PMJs). The preparations were mounted in a partitioned tissue bath that permitted independent superfusion of each PMJ. The pre-existing dispersion of refractoriness between PMJs was accentuated by superfusing PMJ1 with normal Tyrode solution or Tyrode solution containing 6-8 mM KCl and superfusing PMJ2 with Tyrode solution containing 0.5 mM heptanol and 4-10 mM KCl. 2. Premature stimuli delivered to the Purkinje fibre induced unidirectional anterograde conduction block at PMJ2. Conduction proceeded from Purkinje cells to papillary muscle at PMJ1 and from papillary muscle retrogradely across the previously blocked PMJ2. 3. The difference in refractory periods between the two PMJs defined a range of premature coupling intervals within which re-entry was inducible. Conduction block at the PMJ occurred in papillary muscle at short coupling intervals and in the Purkinje fibre at longer intervals. 4. Once initiated, re-entry could be reset or annihilated by properly timed subthreshold current pulses delivered to cells at the PMJ. 5. To define better the mechanisms for conduction block and re-entry, an analytical model was developed using non-linear regression analysis to derive equations from the experimental results. Varying parameters within the constraints of the model reproduced the key features of the rate-dependent conduction block observed experimentally. Critical elements of the model included the induction of significant activation delays at short diastolic intervals and a reduction in the rate of action potential duration restitution after exposure to heptanol. 6. These results help to establish the conditions necessary for induction of one-dimensional circus movement re-entry and to

  14. Reentry response of the lightweight radioisotope heater unit resulting from a Cassini Venus-Venus-Earth-Jupiter gravity assist maneuver accident

    SciTech Connect

    1996-12-01

    Reentry analyses consisting of ablation response, thermal response and thermal stress response have been conducted on the Lightweight Radioisotope Heater Unit (LWRHU) for Cassini/Venus-Venus-Earth-Jupiter-Gravity-Assist (VVEJGA) reentry conditions. Sequential ablation analyses of the LWRHU aeroshell, and the fuel pellet have been conducted in reentry regimes where the aeroshell has been deemed to fail. The failure criterion for ablation is generally assumed to be recession corresponding to 75% and 100% of the wall thickness. The 75% recession failure criteria allows for uncertainties that result mainly because of the high energies involved in the VVEJGA reentries compared to orbital decay reentries. Risk evaluations should consider the fact that for shallow flight paths the unit may disassemble at high-altitude as a result of ablation or may remain intact with a clad that had been molten. Within the limitations of the methodologies and assumptions of the analyses, the results indicate that: (1) For a side-on stable LWRHU reentry, aeroshell ablation failures occur for all reentry angles. (2)For a side-on spinning LWRHU reentry, aeroshell ablation failures are minimal. (3) For the tumbling LWRHU reentry, the aeroshell survives for most angles. (4) For the thermostructural analyses, using both a 1% and 5% allowable strain, all reentry angles and orientations examined resulted in small localized failures, but aeroshell breach is not predicted for any case. The analyses included in this report concentrate on VVEJGA reentry scenarios. Analyses reported previously have demonstrated that the LWRHU has adequate design margin to survive reentry from orbital decay scenarios and most injection scenarios at speeds up to escape speeds. The exception is a narrow range of flight path angles that produce multiple skip trajectories which may have excessive ablation.

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

    PubMed

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

    1988-01-01

    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 x g maximum, respectively) and of two versions of NASA's proposed materials research Re-usable Re-entry Satellite (8 x g maximum in one case and 4 x 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.

  16. 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.

  17. GPHS motion studies for heat pulse intervals of reentries from gravity-assist trajectories. Aerospace Nuclear Safety Program

    SciTech Connect

    Lucero, E.F.; Sharbaugh, R.C.

    1990-03-01

    Motion studies of the General Purpose Heat Source Module, GPHS, were conducted in the heat pulse interval associated with entries from earth gravity assist trajectories. The APL six-degree-of-freedom reentry program designated TMAGRA6C was used. The objectives of the studies were to (1) determine the effect of ablation on GPHS motion, and (2) determine whether the GPHS module entering the earth`s atmosphere from an earth-gravity-assist trajectory has a preferred orientation during the heat pulse phase of reentry. The results are given in summary form for easy visualization of the initial conditions investigated and to provide a quick-look of the resulting motion. Detail of the motion is also given for the parameters of interest for each case studied. Selected values of initial pitch rate, roll rate, and combinations of these within the range 0{degree} to 1000{degrees}/sec were investigated for initial reentry angles of -7{degrees} (shallow) and -90{degrees} (steep) and initial angles of attack of 0{degree} (broadface to the wind) and 90{degrees}. Although the studies are not exhaustive, a sufficient number of reentry conditions (initial altitude, reentry angle, angle of attack, rotational motion) have been investigated to deduce certain trends. The results also provide information on additional reentry conditions that need to be investigated. The present results show four GPHS orientations that predominate - all with some pitch oscillations and rolling motion. These are: angles of attack, {alpha}{sub R} of 0{degree}, 30{degrees}, 90{degrees} and tumbling. It should be assumed that all these orientations are equally probable because only combinations of two initial reentry angles, {gamma}{sub 0}, and two values of {alpha}{sub R}. have been investigated. Further the probability for any given initial rate on orientation is not known.

  18. GPHS motion studies for heat pulse intervals of reentries from gravity-assist trajectories. [General Purpose Heat Source Module (GPHS)

    SciTech Connect

    Lucero, E.F.; Sharbaugh, R.C.

    1990-03-01

    Motion studies of the General Purpose Heat Source Module, GPHS, were conducted in the heat pulse interval associated with entries from earth gravity assist trajectories. The APL six-degree-of-freedom reentry program designated TMAGRA6C was used. The objectives of the studies were to (1) determine the effect of ablation on GPHS motion, and (2) determine whether the GPHS module entering the earth's atmosphere from an earth-gravity-assist trajectory has a preferred orientation during the heat pulse phase of reentry. The results are given in summary form for easy visualization of the initial conditions investigated and to provide a quick-look of the resulting motion. Detail of the motion is also given for the parameters of interest for each case studied. Selected values of initial pitch rate, roll rate, and combinations of these within the range 0[degree] to 1000[degrees]/sec were investigated for initial reentry angles of -7[degrees] (shallow) and -90[degrees] (steep) and initial angles of attack of 0[degree] (broadface to the wind) and 90[degrees]. Although the studies are not exhaustive, a sufficient number of reentry conditions (initial altitude, reentry angle, angle of attack, rotational motion) have been investigated to deduce certain trends. The results also provide information on additional reentry conditions that need to be investigated. The present results show four GPHS orientations that predominate - all with some pitch oscillations and rolling motion. These are: angles of attack, [alpha][sub R] of 0[degree], 30[degrees], 90[degrees] and tumbling. It should be assumed that all these orientations are equally probable because only combinations of two initial reentry angles, [gamma][sub 0], and two values of [alpha][sub R]. have been investigated. Further the probability for any given initial rate on orientation is not known.

  19. Reentry-Vehicle Shape Optimization Using a Cartesian Adjoint Method and CAD Geometry

    NASA Technical Reports Server (NTRS)

    Nemec, Marian; Aftosmis, Michael J.

    2006-01-01

    A DJOINT solutions of the governing flow equations are becoming increasingly important for the development of efficient analysis and optimization algorithms. A well-known use of the adjoint method is gradient-based shape. Given an objective function that defines some measure of performance, such as the lift and drag functionals, its gradient is computed at a cost that is essentially independent of the number of design variables (e.g., geometric parameters that control the shape). Classic aerodynamic applications of gradient-based optimization include the design of cruise configurations for transonic and supersonic flow, as well as the design of high-lift systems. are perhaps the most promising approach for addressing the issues of flow solution automation for aerodynamic design problems. In these methods, the discretization of the wetted surface is decoupled from that of the volume mesh. This not only enables fast and robust mesh generation for geometry of arbitrary complexity, but also facilitates access to geometry modeling and manipulation using parametric computer-aided design (CAD). In previous work on Cartesian adjoint solvers, Melvin et al. developed an adjoint formulation for the TRANAIR code, which is based on the full-potential equation with viscous corrections. More recently, Dadone and Grossman presented an adjoint formulation for the two-dimensional Euler equations using a ghost-cell method to enforce the wall boundary conditions. In Refs. 18 and 19, we presented an accurate and efficient algorithm for the solution of the adjoint Euler equations discretized on Cartesian meshes with embedded, cut-cell boundaries. Novel aspects of the algorithm were the computation of surface shape sensitivities for triangulations based on parametric-CAD models and the linearization of the coupling between the surface triangulation and the cut-cells. The accuracy of the gradient computation was verified using several three-dimensional test cases, which included design

  20. Reentry in survived subepicardium coupled to depolarized and inexcitable midmyocardium: Insights into arrhythmogenesis in ischemia phase 1B

    PubMed Central

    Jie, Xiao; Rodríguez, Blanca; de Groot, Joris R.; Coronel, Ruben; Trayanova, Natalia

    2010-01-01

    BACKGROUND Delayed ventricular arrhythmias during acute myocardial ischemia (1B arrhythmias) are associated with an increase in tissue impedance and are most likely sustained in a thin subepicardial layer. OBJECTIVE The goal of this study was to test the hypothesis that heterogeneous uncoupling between depolarized midmyocardium and surviving subepicardium results in heterogeneous refractoriness in the latter, providing the reentry substrate after a premature beat. METHODS A 3-dimensional bidomain slab was constructed comprising a normal subepicardial layer coupled to a slightly depolarized (−80 to −60 mV) but inexcitable midmyocardium. Experimentally measured tissue impedance served as input for the model. Four stages of heterogeneous uncoupling between the 2 layers were simulated, each corresponding to an experimental ischemic impedance value. Effective refractory periods (ERP), conduction velocities, and inducibility of reentry were examined. RESULTS Heterogeneous uncoupling resulted in subepicardial ERP dispersion, allowing reentry to occur. The minimum ERP dispersion needed to induce reentry was 28 ms. Reentry induction was only possible in this model at the 2 intermediate stages of uncoupling, and only when midmyocardial resting membrane potential was more negative than −60 mV. Complete uncoupling of the layers resulted in normal subepicardial conduction without arrhythmias. The minimum length of the reentrant pathway was 2.5 cm, comparable to 2.4 cm reported in previous experiments. CONCLUSION Heterogeneous uncoupling to a negative sink such as depressed inexcitable midmyocardium may be a substrate for ischemia 1B arrhythmias. Total uncoupling removes the arrhythmogenic substrate. PMID:18598961

  1. Modulation of conduction and refractoriness in atrioventricular junctional reentrant circuit. Effect on reentry initiated by atrial extrastimulus.

    PubMed Central

    Mahmud, R; Denker, S T; Tchou, P J; Jazayeri, M; Akhtar, M

    1988-01-01

    The importance of activation sequence of an atrioventricular junctional reentrant (AVJRe) circuit, before delivery of an extrastimulus, has received little attention in studies concerned with clinical tachycardias. In this study a change in activation sequence was accomplished using bidirectional activation (V-A sequential pacing) during the basic drive (V1A1-V1A1). It was noted that, compared with an atrial extrastimulus (A2) after an atrial drive (A1-A1), earlier activation (by V1 impulse of the V1A1-V1A1 drive) consistently improved conduction, or decreased refractoriness, or both, in the anterograde as well as the retrograde pathway of the AVJRe circuit. In all patients, five with AV nodal reentry and six with Wolff-Parkinson-White syndrome, reentrant tachycardia could be prevented during V-A sequential pacing. In four of eleven patients, reentry was prevented despite achieving the so-called critical atrioventricular nodal delays that had previously caused reentry during control study. This finding suggested that conduction delay necessary for reentry was related to the site of block, which in turn was affected by V-A sequential pacing. We concluded that changing the activation sequence during basic drive modulates conduction and refractoriness in AVJRe circuits, and allows the study of a wide range of electrophysical factors that prevent or permit reentry. Images PMID:3335641

  2. Reentry response of the light weight radioisotope heater unit resulting from a Venus-Earth-Earth Gravity Assist maneuver accident

    SciTech Connect

    Hagan, J.C.

    1988-10-01

    Reentry analyses consisting of ablation response, thermal response and thermal stress response have been conducted on the Light Weight Radioisotope Heater Unit for Galileo/VEEGA reentry conditions. Sequential ablation analyses of the LWRHU aeroshell, the fuel clad, and the fuel pellet have been conducted in reentry regimes where the aeroshell has been deemed to fail. The failure criterion for ablation is assumed to be recession corresponding to 50% of the wall thickness (the design criterion recommended in the DOE Overall Safety Manual). Although the analyses have been carried far beyond this limit (as presented and discussed herein), JHU/APL endorses the position that failure may occur at the time that this recession is achieved or at lower altitudes within the heat pulse considering the uncertainties in the aerodynamic, thermodynamic, and thermo-structural analyses and modeling. These uncertainties result mainly because of the high energies involved in the VEEGA reentries compared to orbital decay reentries. Risk evaluations should consider the fact that for shallow flight paths the unit may disassemble at high-altitude as a result of ablation or may remain intact until it impacts with a clad that had been molten. 80 refs., 46 figs., 16 tabs.

  3. Empirical Tests of the Predicted Footprint for Uncontrolled Satellite Reentry Hazards

    NASA Technical Reports Server (NTRS)

    Matney, Mark

    2011-01-01

    A number of statistical tools have been developed over the years for assessing the risk of reentering object to human populations. These tools make use of the characteristics (e.g., mass, material, shape, size) of debris that are predicted by aerothermal models to survive reentry. The statistical tools use this information to compute the probability that one or more of the surviving debris might hit a person on the ground and cause one or more casualties. The statistical portion of the analysis relies on a number of assumptions about how the debris footprint and the human population are distributed in latitude and longitude, and how to use that information to arrive at realistic risk numbers. Because this information is used in making policy and engineering decisions, it is important that these assumptions be tested using empirical data. This study uses the latest database of known uncontrolled reentry locations measured by the United States Department of Defense. The predicted ground footprint distributions of these objects are based on the theory that their orbits behave basically like simple Kepler orbits. However, there are a number of factors in the final stages of reentry - including the effects of gravitational harmonics, the effects of the Earth s equatorial bulge on the atmosphere, and the rotation of the Earth and atmosphere - that could cause them to diverge from simple Kepler orbit behavior and possibly change the probability of reentering over a given location. In this paper, the measured latitude and longitude distributions of these objects are directly compared with the predicted distributions, providing a fundamental empirical test of the model assumptions.

  4. Flow Redistribution Between Legs and Brain During STS 93 Re-Entry and Landing

    NASA Technical Reports Server (NTRS)

    Arbeille, P.; Meck, J.; Porcher, M.; Benavides, E.; Martin, D. S.; South, D. A.; Ribeiro, C.; Westover, A.

    2003-01-01

    The objective was to quantify bit by bit the arterial hemodynamic response to the successive acceleration induced fluid shifts during re-entry and landing. Method: The astronaut instrumented himself with a flat Doppler probe fixed on the skin, a blood pressure arm cuff, and 3 ECG electrodes. The ICMS (integrated cardiovascular monitoring system, 15x15x25 cu cm, battery powered) designed to monitor Blood pressure, ECG, cerebral and femoral flows was fixed below the astronaut sit in the middeck. Recordings started 5 minutes before de-orbiting (TIG) and stopped 5 min after wheels stop. Results. During re-entry blood pressure increased by 20% at TIG, and then by 25 to 30% during the highest Gz accelerations (approx 1 S g ) . The cerebral flow remained decreased by 10 to 15% below inflight value all during the Entry and landing phases. Conversely the femoral flow increased at TIG and entry ( + l0 to 20%), recovered at 0.lg, and then decreased in proportion with the Gz acceleration (-10% to -40% from 0.5g to 1.5g). The reduction in Femoral flow was associated with an opposite variation in lower limb vascular resistance. Consequently the cerebral flow/femoral flow ratio decreased at TIG and entry (-20%), and then increased according to the Gz acceleration level ( + l0 to +40% from 0.5 to 1.5g). Conclusion: During orthostatic tests (Stand LBNP tests) the cerebral to femoral flow ratio allowed to quantify the efficiency of the flow redistribution between these 2 areas and predicted orthostatic intolerance. In the present case the astronaut was found orthostatically tolerant at postflight tilt tests, but we suggest that during re-entry this parameter could predict the occurrence of syncope in severely disadapted astronauts.

  5. '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.

  6. Closed loop reentry guidance law of a spaceplane - Application to Hermes

    NASA Astrophysics Data System (ADS)

    Jouhaud, F.

    1991-10-01

    A closed loop guidance law has been synthesised for the whole reentry trajectory of a space plane. The principle of this guidance consisted in determining at each time, as a function of observed position and velocity deviations from a reference trajectory, the accelerations to apply to the vehicle that nullify the deviations at the final time in order to exactly fulfill position and speed final constraints needed for landing. This new guidance law was evaluated in terms of the sensitivity of the final position and heatings to various perturbations or error causes.

  7. NLP reentry guidance - Developing a strategy for low L/D vehicles

    NASA Astrophysics Data System (ADS)

    Cramer, Evin J.; Bradt, Jerre E.; Hardtla, John W.

    Problems in developing a strategy for design of a nonlinear programming (NLP) guidance algorithm for a low L/D reentry vehicle are discussed. The fundamental issue considered in the design of the guidance algorithm is the formulation of the mathematical description of the guidance problem for an NLP guidance algorithm. It is shown that properly defining the problem is of importance in being able to handle large atmospheric density and wind uncertainties. A method of solution is also presented along with results showing the effectiveness of the algorithm.

  8. Advanced particulate fibrous composite for thermal control of re-entry vehicles

    NASA Technical Reports Server (NTRS)

    White, Susan; Lee, Siu-Chun; Grzesik, Jan

    1993-01-01

    Combining the selectively reflective properties of particulate reflective coatings with the low density and high temperature capability of ceramic fibrous materials results in a novel composite material with useful optical properties. Numerical predictions of the radiative properties of zirconia and silica composites for a range of mixture fractions and wavelengths show the improvements attainable by dispersing spheres throughout a fiber matrix. The radiation conductance is controlled by the percentage of spheres in the composite. Results show that specific wavelength domains are controlled by either the spheres or the fibers, so the optical properties can be tailored for reentry applications.

  9. Analysis of ECLSS performance during reentry after loss of one ammonia tank

    NASA Technical Reports Server (NTRS)

    Steines, G. J.

    1976-01-01

    An analysis was performed to determine whether, in case of a loss of one of the ammonia tanks, the Ammonia Boiler System can provide adequate heat rejection for the orbiter ECLSS during reentry. Results indicate that temperatures can be maintained as long as NH3 is available, but that one tank does not contain sufficient NH3 to complete all missions. A recommendation is made to investigate incorporation of onboard NH3 quantity calculations, and/or addition of a third NH3 tank.

  10. OVERFLOW Simulations of Space Shuttle Orbiter Reentry Based on As-Built Geometry

    NASA Technical Reports Server (NTRS)

    Ma, Edward C.; Vicker, Darby J.; Campbell, Charles H.; Wilson, Brad; Pavek, Mike; Berger, Karen

    2012-01-01

    The Space Shuttle Orbiters Discovery and Endeavor have been digitally scanned to obtain outer mold line surfaces. Using these scans, the existing overset computational fluid dynamics (CFD) grid system will be modified by projecting the grid points to the scanned geometry. Simulations will be performed using the OVERFLOW solver and the results compared to previous OVERFLOW results on the theoretical geometry and the aerodynamic databook. The "bent airframe" term will be compared between the aerodynamic databook and the computations over a range of reentry conditions.

  11. An Overview of JAXA's Ground-Observation Activities for HAYABUSA Reentry

    NASA Astrophysics Data System (ADS)

    Fujita, Kazuhisa; Yamamoto, Masa-Yuki; Abe, Shinsuke; Ishihara, Yoshiaki; Iiyama, Ohmi; Kakinami, Yoshihiro; Hiramatsu, Yoshihiro; Furumoto, Muneyoshi; Takayanagi, Hiroki; Suzuki, Toshiyuki; Yanagisawa, Toshifumi; Kurosaki, Hirohisa; Shoemaker, Michael; Ueda, Masayoshi; Shiba, Yasuo; Suzuki, Masaharu

    2011-10-01

    On 2010 June 13, the HAYABUSA asteroid explorer returned to Earth and underwent a super-orbital atmospheric reentry. In order to recover the sample return capsule and to take ground-based measurements, the Japan Aerospace Exploration Agency organized a ground-observation team and performed optical tracking of the capsule, spectroscopy of the fireball, and measurements of infrasounds and shock waves generated by the fireball. In this article, an overview of the ground-based observation is presented, and an outline of the preliminary results derived from observations is reported.

  12. Sensor Fusion of Gaussian Mixtures for Ballistic Target Tracking in the Re-Entry Phase.

    PubMed

    Lu, Kelin; Zhou, Rui

    2016-01-01

    A sensor fusion methodology for the Gaussian mixtures model is proposed for ballistic target tracking with unknown ballistic coefficients. To improve the estimation accuracy, a track-to-track fusion architecture is proposed to fuse tracks provided by the local interacting multiple model filters. During the fusion process, the duplicate information is removed by considering the first order redundant information between the local tracks. With extensive simulations, we show that the proposed algorithm improves the tracking accuracy in ballistic target tracking in the re-entry phase applications. PMID:27537883

  13. Electrophysiological actions of somatostatin on the atrioventricular junction in sinus rhythm and reentry tachycardia.

    PubMed Central

    Webb, S C; Krikler, D M; Hendry, W G; Adrian, T E; Bloom, S R

    1986-01-01

    Because somatostatin, a neuroregulatory peptide, is found in abundance in the atria and atrioventricular node, its electrophysiological and antiarrhythmic properties were compared with those of verapamil in ten patients with paroxysmal atrioventricular tachycardia. During sinus rhythm, intravenous somatostatin slowed the heart rate whereas verapamil increased it. Though both agents prolonged atrioventricular conduction time and refractoriness, verapamil was more potent. They were equally effective at terminating reentry atrioventricular tachycardia, restoring sinus rhythm in six of seven patients. Whereas verapamil consistently blocked conduction in the atrioventricular node, somatostatin usually induced ventricular extrasystoles at the time of conversion. Somatostatin may have physiological importance in the neurohumoral control of cardiac impulse formation and conduction. PMID:2875723

  14. An aerodynamic model for a hemispherically-capped biconic reentry vehicle with six drag flaps

    SciTech Connect

    Jordan, T.M.; Buffington, R.J.

    1987-01-01

    The development of an aerodynamic model for a hemispherically-capped biconic reentry vehicle with six drag flaps is presented. The aerodynamic model is primarily based on wind tunnel test results, with the use of computational fluid dynamic codes. For Mach numbers from 4 to 15, the inviscid axial force coefficient was computed for drag flap deflections from 6 to 36. Axial force coefficient was found to vary significantly with ablating flap shape as well as with changing flight conditions. The aerodynamic model can be used for input to vehicle recovery trajectory simulations.

  15. Sensor Fusion of Gaussian Mixtures for Ballistic Target Tracking in the Re-Entry Phase

    PubMed Central

    Lu, Kelin; Zhou, Rui

    2016-01-01

    A sensor fusion methodology for the Gaussian mixtures model is proposed for ballistic target tracking with unknown ballistic coefficients. To improve the estimation accuracy, a track-to-track fusion architecture is proposed to fuse tracks provided by the local interacting multiple model filters. During the fusion process, the duplicate information is removed by considering the first order redundant information between the local tracks. With extensive simulations, we show that the proposed algorithm improves the tracking accuracy in ballistic target tracking in the re-entry phase applications. PMID:27537883

  16. Bundle-branch reentry ventricular tachycardia after transcatheter aortic valve replacement

    PubMed Central

    de la Rosa Riestra, Adriana; Rubio Caballero, José Amador; Freites Estévez, Alfonso; Alonso Belló, Javier; Botas Rodríguez, Javier

    2016-01-01

    An 83-year-old male suffering from severe symptomatic aortic valve stenosis received an implant of a biological aortic prosthesis through the femoral artery without complications. Seven days after dischargement he experienced a syncope. The patient was wearing an ECG holter monitor that day, which showed a wide QRS complex tachycardia of 300 beats per minute. The electrophysiological study revealed a bundle-branch reentry ventricular tachycardia as the cause of the syncope. Radio-frequency was applied on the right-bundle branch. Twelve months later, the patient has remained asymptomatic. PMID:27134443

  17. The reentry to Earth as a valuable option at the end-of-life of Libration Point Orbit missions

    NASA Astrophysics Data System (ADS)

    Alessi, Elisa Maria

    2015-06-01

    Nowadays the mission design must comprise the implementation of end-of-life disposal solutions to preserve the space environment and for the sustainability of the project as a whole. In this work, the Earth's reentry is presented as a disposal strategy that it is worth investigating also for Libration Point Orbit missions. Following a recent ESA study, the analysis is performed first in the Circular Restricted Three-Body Problem, and then considering a high-fidelity model. The test cases selected are Herschel, SOHO and Gaia. Attention is paid not only to the Δv -budget, but also to the reentry angle, the time of flight and the regions on the surface of the Earth involved. A review on the known cases of hypervelocity reentries and the corresponding physics is given in order to find a reasonable approach to avoid dangerous fragmentations at low altitudes.

  18. 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.

  19. NNLOPS accurate associated HW production

    NASA Astrophysics Data System (ADS)

    Astill, William; Bizon, Wojciech; Re, Emanuele; Zanderighi, Giulia

    2016-06-01

    We present a next-to-next-to-leading order accurate description of associated HW production consistently matched to a parton shower. The method is based on reweighting events obtained with the HW plus one jet NLO accurate calculation implemented in POWHEG, extended with the MiNLO procedure, to reproduce NNLO accurate Born distributions. Since the Born kinematics is more complex than the cases treated before, we use a parametrization of the Collins-Soper angles to reduce the number of variables required for the reweighting. We present phenomenological results at 13 TeV, with cuts suggested by the Higgs Cross section Working Group.

  20. 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.

  1. Re-Entry Women Students in Higher Education: A Model for Non-Traditional Support Programs in Counseling and Career Advisement.

    ERIC Educational Resources Information Center

    Karr-Kidwell, PJ

    A model program of support for non-traditional women students has been developed at Texas Woman's University (TWU). Based on a pilot study, several steps were taken to assist these re-entry students at TWU. For example, in spring semester of 1983, a committee for re-entry students was established, with a student organization--Women in…

  2. Mission analysis and guidance, navigation, and control design for rendezvous and docking phase of advanced reentry vehicle mission

    NASA Astrophysics Data System (ADS)

    Strippoli, L.; Colmenarejo, P.; Strauch, H.

    2013-12-01

    Advanced Reentry Vehicle (ARV) belongs to the family of vehicles designed to perform rendezvous and docking (RvD) with the International space station (ISS) [1]. Differently from its predecessor ATV (Automated Transfer Vehicle), the ARV will transport a reentry capsule, equipped with a heatshield and able to bring back cargo, experiments, or, as a possible future development, even crew, being this latter scenario very attracting in view of the Space Shuttle retirement. GMV, as subcontractor of EADS-Astrium Germany, is in charge of the RvD and departure mission analysis and GNC (Guidance, Navigation, and Control) design of ARV mission. This paper will present the main outcomes of the study.

  3. Application of numerical methods to extend capabilities for optimal rocket guidance: report on reentry guidance of shuttle orbiter

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Analytical models are presented for optimal trajectories and reentry guidance of the space shuttle orbiter. Major emphasis is placed on the development of a "footprint', which refers to a set of reachable destination positions attainable by the shuttle at a specified terminal altitude. An unconstrained reentry footprint was calculated for a shuttle vehicle which enters the earth's atmosphere at 93 km initial altitude after a deboost from a near earth orbit. The method of computation is briefly described, and graphs are presented which illustrate the footprint and the variation of state and control variables along it. The effects of constraints and of variations in initial state upon the footprint are discussed.

  4. Follow-up investigations of GPHS motion during heat pulse intervals of reentries from gravity-assist trajectories

    SciTech Connect

    Sharbaugh, R.C.

    1992-03-23

    Motion studies of the General Purpose Heat Source Module, GPHS, which were conducted in the heat pulse intervals associated with entries from earth gravity assist trajectories. The APL six-degree-of-freedom reentry program designated TMAGRA6C was used. The objectives of the studies were to (1) determine whether the GPHS module entering the earth's atmosphere from an earth-gravity-assist trajectory has a preferred orientation during the heat pulse of reentry, (2) determine the effect of magnus force on the roll rate and angle of attack of the GPHS during an EGA entry, (3) determine the effect of the magnitude of pitch and roll damping on the GPHS motion.

  5. 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

  6. SHEFEX II - Aerodynamic Re-Entry Controlled Sharp Edge Flight Experiment

    NASA Astrophysics Data System (ADS)

    Longo, J. M. A.; Turner, J.; Weihs, H.

    2009-01-01

    In this paper the basic goals and architecture of the SHEFEX II mission is presented. Also launched by a two staged sounding rocket system SHEFEX II is a consequent next step in technology test and demonstration. Considering all experience and collected flight data obtained during the SHEFEX I Mission, the test vehicle has been re-designed and extended by an active control system, which allows active aerodynamic control during the re-entry phase. Thus, ceramic based aerodynamic control elements like rudders, ailerons and flaps, mechanical actuators and an automatic electronic control unit has been implemented. Special focus is taken on improved GNC Elements. In addition, some other experiments including an actively cooled thermal protection element, advanced sensor equipment, high temperature antenna inserts etc. are part of the SHEFEX II experimental payload. A final 2 stage configuration has been selected considering Brazilian solid rocket boosters derived from the S 40 family. During the experiment phase a maximum entry velocity of Mach around 10 is expected for 50 seconds. Considering these flight conditions, the heat loads are not representative for a RLV re-entry, however, it allows to investigate the principal behaviour of such a facetted ceramic TPS, a sharp leading edge at the canards and fins and all associated gas flow effects and their structural response.

  7. Instrumentation Of C-Sic Tiles To Quantify Their Mechanical Behavior During Atmospheric Re-Entry

    NASA Astrophysics Data System (ADS)

    Pereira, C.; Romano, R.; Walz, S.; Schwarz, R.; Fremont, E.; Girard, F.

    2011-05-01

    The windward surfaces of re-entry vehicles are exposed to large thermal gradients and pressure loadings which result in changes to the surface topology and high transient loading of fixation elements. In particular positive steps result in local aero-thermodynamic effects with increased thermal loading of the adjacent tiles. An objective of the in-flight instrumentation of IXV is to document the aerodynamic and thermal loads on the tiles including deflection and the evolution of steps along the vehicle. To this end a combination of high temperature strain gauges and thermocouples will be placed at the metallic stand-offs behind the highest loaded tiles and on one half of the nose cap attachments. The deflection at the edges of the tiles and the steps will be measured using linear variable differential sensors (L VDT). This paper presents background information, the rationale for the chosen measurement points, the design evolution and the validation of the instrumentation both in terms of functionality and ability to withstand the launch and re-entry environment of the IXV

  8. Thermographic Imaging of the Space Shuttle During Re-Entry Using a Near Infrared Sensor

    NASA Technical Reports Server (NTRS)

    Zalameda, Joseph N.; Horvath, Thomas J.; Kerns, Robbie V.; Burke, Eric R.; Taylor, Jeff C.; Spisz, Tom; Gibson, David M.; Shea, Edward J.; Mercer, C. David; Schwartz, Richard J.; Tack, Steve; Bush, Brett C.; Dantowitz, Ronald F.; Kozubal, Marek J.

    2012-01-01

    High resolution calibrated near infrared (NIR) imagery of the Space Shuttle Orbiter was obtained during hypervelocity atmospheric re-entry of the STS-119, STS-125, STS-128, STS-131, STS-132, STS-133, and STS-134 missions. This data has provided information on the distribution of surface temperature and the state of the airflow over the windward surface of the Orbiter during descent. The thermal imagery complemented data collected with onboard surface thermocouple instrumentation. The spatially resolved global thermal measurements made during the Orbiter s hypersonic re-entry will provide critical 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 critical for the validation of physics-based, semi-empirical boundary-layer transition prediction methods as well as stimulating the validation of laminar numerical chemistry models and the development of turbulence models supporting NASA s next-generation spacecraft. In this paper we provide details of the NIR imaging system used on both air and land-based imaging assets. The paper will discuss calibrations performed on the NIR imaging systems that permitted conversion of captured radiant intensity (counts) to temperature values. Image processing techniques are presented to analyze the NIR data for vignetting distortion, best resolution, and image sharpness. Keywords: HYTHIRM, Space Shuttle thermography, hypersonic imaging, near infrared imaging, histogram analysis, singular value decomposition, eigenvalue image sharpness

  9. 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.

  10. Phase-2 reentry in cardiac tissue: Role of the slow calcium pulse

    NASA Astrophysics Data System (ADS)

    Cantalapiedra, Inma R.; Peñaranda, Angelina; Echebarria, Blas; Bragard, Jean

    2010-07-01

    Phase-2 re-entry is thought to underlie many causes of idiopathic ventricular arrhythmias as, for instance, those occurring in Brugada syndrome. In this paper, we study under which circumstances a region of depolarized tissue can re-excite adjacent regions that exhibit shorter action potential duration (APD), eventually inducing reentry. For this purpose, we use a simplified ionic model that reproduces well the ventricular action potential. With the help of this model, we analyze the conditions that lead to very short action potentials (APs), as well as possible mechanisms for re-excitation in a cable. We then study the induction of re-entrant waves (spiral waves) in simulations of AP propagation in the heart ventricles. We show that re-excitation takes place via a slow pulse produced by calcium current that propagates into the region of short APs until it encounters excitable tissue. We calculate analytically the speed of the slow pulse, and also give an estimate of the minimal tissue size necessary for allowing reexcitation to take place.

  11. Assessment of thermochemical nonequilibrium and slip effects for Orbital Reentry Experiment (OREX)

    NASA Technical Reports Server (NTRS)

    Gupta, Roop N.; Moss, James N.; Price, Joseph M.

    1996-01-01

    Results are provided from a viscous shock layer (VSL) analysis of the reentry flowfield around the forebody of the Japanese Orbital Reentry Experiment (OREX) vehicle. This vehicle is a 50 deg. spherically blunted cone with a nose radius of 1.35 m and a base diameter of 3.4 m. Calculations are done for the OREX trajectory from 105 to 48.4 km altitude range. A 7-species chemical model is found adequate for the flowfield analysis. However, for altitudes greater than 84 km, the low density effects (such as thermal nonequilibrium and slip) are to be implemented for good agreement between the predictions and flight inferred heat-transfer rate data. Further, at altitudes lower than 84 km, a finite surface recombination probability is to be employed in place of a non-catalytic surface for better comparison between the calculations and data. VSL results are also compared with the direct simulation Monte Carlo (DSMC) predictions at high altitudes (greater than 80 km) and the electron number density data for three altitudes in the OREX trajectory. Overall, there is a good comparison between the flight data and calculated results. With the ongoing refinements in data extraction procedures, the OREX data should prove valuable for validating theoretical models employed in flowfield codes for calculation of reacting-gas flowfields.

  12. Simulation of Ectopic Pacemakers in the Heart: Multiple Ectopic Beats Generated by Reentry inside Fibrotic Regions

    PubMed Central

    Gouvêa de Barros, Bruno; Weber dos Santos, Rodrigo; Lobosco, Marcelo; Alonso, Sergio

    2015-01-01

    The inclusion of nonconducting media, mimicking cardiac fibrosis, in two models of cardiac tissue produces the formation of ectopic beats. The fraction of nonconducting media in comparison with the fraction of healthy myocytes and the topological distribution of cells determines the probability of ectopic beat generation. First, a detailed subcellular microscopic model that accounts for the microstructure of the cardiac tissue is constructed and employed for the numerical simulation of action potential propagation. Next, an equivalent discrete model is implemented, which permits a faster integration of the equations. This discrete model is a simplified version of the microscopic model that maintains the distribution of connections between cells. Both models produce similar results when describing action potential propagation in homogeneous tissue; however, they slightly differ in the generation of ectopic beats in heterogeneous tissue. Nevertheless, both models present the generation of reentry inside fibrotic tissues. This kind of reentry restricted to microfibrosis regions can result in the formation of ectopic pacemakers, that is, regions that will generate a series of ectopic stimulus at a fast pacing rate. In turn, such activity has been related to trigger fibrillation in the atria and in the ventricles in clinical and animal studies. PMID:26583127

  13. Reusable Reentry Satellite (RRS): Telemetry, Tracking, and Command (TT/C) Coverage Tradeoff Study

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Reusable Reentry Satellite (RRS) Telemetry, Tracking & Command (TT&C) Coverage Tradeoff Study described herein was performed during Part 1 of the RRS Phase B contract. This report is one of several that describes the results of various trade studies performed to arrive at a recommended design for the RRS satellite system. The overall RRS Phase B Study objective is to design a relatively inexpensive satellite to access space for extended periods of time, with eventual recovery of experiments on Earth. The RRS will be capable of: (1) being launched by a variety of expendable launch vehicles; (2) operating in low earth orbit as a free flying unmanned laboratory; and (3) executing an independent atmospheric reentry and soft landing. The RRS will be designed to be refurbished and reused up to three times a year for a period of 10 years. The expected principal use for such a system is research on the effects of variable gravity (0 to 1.5 g) and radiation on small animals, plants, lower life forms, tissue samples, and materials processes. This Summary Report provides a description of the RRS Telemetry, Tracking & Command Analysis performed to study the ground station coverage available to meet RRS requirements. Concepts were considered that used off-the-shelf technology, had generous margins of capability, and high reliability, were easily maintained, cost effective, and were compatible with existing support networks. From this study, a recommended RRS TT&C configuration will be developed.

  14. Dynamics of sustained reentry in a loop model with discrete gap junction resistances

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Potse, Mark; Vinet, Alain

    2007-08-01

    The dynamics of reentry is studied in a one-dimensional loop of model cardiac cells with discrete intercellular gap junction resistance (R) . Each cell is represented by a continuous cable with ionic current given by a modified Beeler-Reuter formulation. For R below a limiting value, propagation is found to change from period-1 to quasiperiodic (QP) at a critical loop length (Lcrit) that decreases with R . Quasiperiodic reentry exists from Lcrit to a minimum length (Lmin) , which also shortens with R . The decrease of Lcrit(R) is not a simple scaling, but the bifurcation can still be predicted from the slope of the restitution curve giving the duration of the action potential as a function of the diastolic interval. However, the shape of the restitution curve changes with R . An increase of R does not seem to increase the number of possible QP solutions since, as in the continuous cable, only two QP modes of propagation were found despite an extensive search through alternative initial conditions.

  15. Introduction to the Dianaut Program: A scientific wireline re-entry in deep ocean boreholes

    NASA Astrophysics Data System (ADS)

    Robert Gable; DIANAUT Shipboard Party

    1992-03-01

    Downhole measurements were successfully made, during the DIANAUT program, in three Deep Sea Drilling Project (DSDP) holes in the North Atlantic, utilizing the wireline re-entry capability of the French logging shuttle Nadia which, seated in the drill re-entry cone, provides a completely stable platform with precise control of depth and logging speed. Logging activities included temperature profiles, borehole televiewer logs, flowmeter measurements, fluid sampling, and a three-component magnetometer profile. The different parameters were measured to study the heat transfer regime and hydrogeological processes within the oceanic crust as a function of age and distance from the ridge axis. Interpretation of the data obtained from holes 333A, 395A, and 534A, drilled in rocks ranging in age from 3.5 to 154 m.y., provide evidence of cold seawater circulation in the upper permeable layer of the young crust (sites 333A and 395A), thus maintaining very low temperatures and heat flow; higher temperatures were obtained from the older crust at site 534A.

  16. Introduction to the DIANAUT program: A scientific wireline re-entry in deep ocean boreholes

    NASA Astrophysics Data System (ADS)

    Gable, Robert

    1992-03-01

    Downhole measurements were successfully made, during the DIANAUT program, in three Deep Sea Drilling Project (DSDP) holes in the North Atlantic, utilizing the wireline re-entry capability of the French logging shuttle Nadia which, seated in the drill re-entry cone, provides a completely stable platform with precise control of depth and logging speed. Logging activities included temperature profiles, borehole televiewer logs, flowmeter measurements, fluid sampling, and a three-component magnetometer profile. The different parameters were measured to study the heat transfer regime and hydrogeological processes within the oceanic crust as a function of age and distance from the ridge axis. Interpretation of the data obtained from holes 333A, 395A, and 534A, drilled in rocks ranging in age from 3.5 to 154 m.y., provide evidence of cold seawater circulation in the upper permeable layer of the young crust (sites 333A and 395A), thus maintaining very low temperatures and heat flow; higher temperatures were obtained from the older crust at site 534A.

  17. Sonic-boom ground pressure measurements from the launch and reentry of Apollo 16

    NASA Technical Reports Server (NTRS)

    Henderson, H. R.; Hilton, D. A.

    1974-01-01

    Sonic-boom pressure signatures recorded during the launch and reentry phases of the Apollo 16 mission are presented. Five measurements were obtained along the vehicle ground track: 69 km (37.3 n. mi.) 92 km (49.8 n. mi.), and 130 km (70.3 n. mi.) down range from the launch site during ascent, and at 185 km (100 n. mi.) and approximately 5.5 km (3 n. mi.) from the splash-down point during reentry. Tracings of the measured signatures are included along with values of the overpressure, impulse, time duration, and rise times. Also included are brief descriptions of the launch and recovery test areas in which the measurements were obtained, the sonic-boom instrumentation deployment, flight profiles, and operating conditions for the launch vehicle and spacecraft, surface weather information at the measuring sites, and high-altitude weather information for the general measurement areas. Comparisons of the sonic-boom overpressures from Apollo 15 and 16 along with those from current aircraft are also presented.

  18. Influences of Turbulent Reentry Plasma Sheath on Wave Scattering and Propagation

    NASA Astrophysics Data System (ADS)

    Liu, Zhiwei; Bao, Weimin; Li, Xiaoping; Shi, Lei; Liu, Donglin

    2016-06-01

    The randomness of turbulent reentry plasma sheaths can affect the propagation and scattering properties of electromagnetic waves. This paper developed algorithms to estimate the influences. With the algorithms and typical reentry data, influences of GPS frequency and Ka frequency are studied respectively. Results show that, in terms of wave scattering, the scattering loss caused by the randomness of the turbulent plasma sheath increases with the increase of the ensemble average electron density, ensemble average collision frequency, electron density fluctuation and turbulence integral scale respectively. Also the scattering loss is much smaller than the dielectric loss. The scattering loss of Ka frequency is much less than that of the GPS frequency. In terms of wave propagation, the randomness arouses the fluctuations of amplitude and phase of waves. The fluctuations change with altitudes that when the altitude is below 30 km, fluctuations increase with altitude increasing, and when the altitude is above 30 km, fluctuations decrease with altitude increasing. The fluctuations of GPS frequency are strong enough to affect the tracking, telemetry, and command at appropriate conditions, while the fluctuations of Ka frequency are much more feeble. This suggests that the Ka frequency suffers less influences of the randomness of a turbulent plasma sheath. supported by the National Basic Research Program of China (No. 2014CB340205) and National Natural Science Foundation of China (Nos. 61301173 and 61473228)

  19. The induction of reentry in cardiac tissue. The missing link: How electric fields alter transmembrane potential

    NASA Astrophysics Data System (ADS)

    Roth, Bradley J.; Krassowska, Wanda

    1998-03-01

    This review examines the initiation of reentry in cardiac muscle by strong electric shocks. Specifically, it concentrates on the mechanisms by which electric shocks change the transmembrane potential of the cardiac membrane and create the physiological substrate required by the critical point theory for the initiation of rotors. The mechanisms examined include (1) direct polarization of the tissue by the stimulating current, as described by the one-dimensional cable model and its two- and three-dimensional extensions, (2) the presence of virtual anodes and cathodes, as described by the bidomain model with unequal anisotropy ratios of the intra- and extracellular spaces, (3) polarization of the tissue due to changing orientation of cardiac fibers, and (4) polarization of individual cells or groups of cells by the electric field ("sawtooth potential"). The importance of these mechanisms in the initiation of reentry is examined in two case studies: the induction of rotors using successive stimulation with a unipolar electrode, and the induction of rotors using cross-field stimulation. These cases reveal that the mechanism by which a unipolar stimulation induces arrhythmias can be explained in the framework of the bidomain model with unequal anisotropy ratios. In contrast, none of the examined mechanisms provide an adequate explanation for the induction of rotors by cross-field stimulation. Hence, this study emphasizes the need for further experimental and theoretical work directed toward explaining the mechanism of field stimulation.

  20. 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.

  1. Hypothetical Reentry Thermostructural Performance of Space Shuttle Orbiter With Missing or Eroded Thermal Protection Tiles

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    This report deals with hypothetical reentry thermostructural performance of the Space Shuttle orbiter with missing or eroded thermal protection system (TPS) tiles. The original STS-5 heating (normal transition at 1100 sec) and the modified STS-5 heating (premature transition at 800 sec) were used as reentry heat inputs. The TPS missing or eroded site is assumed to be located at the center or corner (spar-rib juncture) of the lower surface of wing midspan bay 3. For cases of missing TPS tiles, under the original STS-5 heating, the orbiter can afford to lose only one TPS tile at the center or two TPS tiles at the corner (spar-rib juncture) of the lower surface of wing midspan bay 3. Under modified STS-5 heating, the orbiter cannot afford to lose even one TPS tile at the center or at the corner of the lower surface of wing midspan bay 3. For cases of eroded TPS tiles, the aluminum skin temperature rises relatively slowly with the decreasing thickness of the eroded central or corner TPS tile until most of the TPS tile is eroded away, and then increases exponentially toward the missing tile case.

  2. Near-Optimal Re-Entry Trajectories for Reusable Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Chou, H.-C.; Ardema, M. D.; Bowles, J. V.

    1997-01-01

    A near-optimal guidance law for the descent trajectory for earth orbit re-entry of a fully reusable single-stage-to-orbit pure rocket launch vehicle is derived. A methodology is developed to investigate using both bank angle and altitude as control variables and selecting parameters that maximize various performance functions. The method is based on the energy-state model of the aircraft equations of motion. The major task of this paper is to obtain optimal re-entry trajectories under a variety of performance goals: minimum time, minimum surface temperature, minimum heating, and maximum heading change; four classes of trajectories were investigated: no banking, optimal left turn banking, optimal right turn banking, and optimal bank chattering. The cost function is in general a weighted sum of all performance goals. In particular, the trade-off between minimizing heat load into the vehicle and maximizing cross range distance is investigated. The results show that the optimization methodology can be used to derive a wide variety of near-optimal trajectories.

  3. Dynamic and Static High Temperature Resistant Ceramic Seals for X- 38 re-Entry Vehicle

    NASA Astrophysics Data System (ADS)

    Handrick, Karin E.; Curry, Donald M.

    2002-01-01

    In a highly successful partnership, NAS A, ESA, DLR (German Space Agency) and European industry are building the X-38, V201 re-entry spacecraft, the prototype of the International Space Station's Crew Return Vehicle (CRV). This vehicle would serve both as an ambulance for medical emergencies and as an evacuation vehicle for the Space Station. The development of essential systems and technologies for a reusable re-entry vehicle is a first for Europe, and sharing the development of an advanced re-entry spacecraft with foreign partners is a first for NASA. NASA, in addition to its subsystem responsibilities, is performing overall X-38 vehicle system engineering and integration, will launch V201 on the Space Shuttle, deliver flight data for post-flight analysis and assessment and is responsible for development and manufacture of structural vehicle components and thermal protection (TPS) tiles. The major European objective for cooperation with NASA on X-38 was to establish a clear path through which key technologies needed for future space transportation systems could be developed and validated at affordable cost and with controlled risk. Europe has taken the responsibility to design and manufacture hot control surfaces like metallic rudders and ceramic matrix composites (CMC) body flaps, thermal protection systems such as CMC leading edges, the CMC nose cap and -skirt, insulation, landing gears and elements of the V201 primary structure. Especially hot control surfaces require extremely high temperature resistant seals to limit hot gas ingestion and transfer of heat to underlying low-temperature structures to prevent overheating of these structures and possible loss of the vehicle. Complex seal interfaces, which have to fulfill various, tight mission- and vehicle-related requirements exist between the moveable ceramic body flaps and the bottom surface of the vehicle, between the rudder and fin structure and the ceramic leading edge panel and TPS tiles. While NASA

  4. Infrasound and Seismic Observation of Hayabusa Reentry as An Artificial Meteorite Fall

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    The Hayabusa, the world first sample-return minor body explorer, came back to the Earth, and reentered into the Earth's atmosphere on June 13, 2010. Following the reentries of the Genesis in 2004 and the Stardust in 2006, the return of the Hayabusa Sample Return Capsule (H-SRC) was the third direct reentry event from the interplanetary transfer orbit to the Earth at a velocity of over 11.2 km/s. In addition, it was the world first case of the direct reentry of the spacecraft (H-S/C) itself from the interplanetary transfer orbit. The H-SRC and the H-S/C reentries are very good analogue for studying bolide size meteors and meteorite falls. We, therefore, conducted a ground observation campaign for aspects of meteor sciences. We carried out multi-site ground observations of the Hayabusa reentry in the Woomera Prohibited Area (WPA), Australia. The observations were configured with optical imaging with still and video recordings, spectroscopies, and shockwave detection with infrasound and seismic sensors. In this study, we report details of the infrasound/seismic observations and those results. To detect shockwaves from the H-SRC and the H-S/C, we installed three small aperture infrasound/seismic arrays as the main stations. In addition, we also installed three single component seismic sub stations and an audible sound recorder. The infrasound and seismic sensors clearly recorded sonic boom type shockwaves from the H-SRC and disrupted fragments of the H-S/C itself. The audible recording also detected those shockwave sounds in the human audible band. Positive overpressure values of shockwaves (corresponding to the H-SRC) recorded at three main stations are 1.3 Pa, 1.0 Pa, and 0.7 Pa with the slant distance of 36.9 km, 54.9 km, and 67.8 km (i.e., the source altitude of 36.5 km, 38.9km, and 40.6 km), respectively. These amplitudes of shockwave overpressures are systematically smaller than those of theoretical predictions. We tried to identify the sources of shockwaves

  5. Evaluation of the Seattle Public Schools' 1983-84 Re-Entry Program. Report No. 84-13.

    ERIC Educational Resources Information Center

    Ramey, Madelaine

    This report evaluates the Seattle Public School District's 1983-84 re-entry program for suspended and expelled students in terms of seven expected student behavioral outcomes and Outreach/Intake Services Unit objectives. The program's purpose is to assist these students in improving the attitudes and/or behaviors which lead to disciplinary action.…

  6. A Qualitative Investigation of the College Choice Experiences and Reentry Expectations of U.S. American Third Culture Kids

    ERIC Educational Resources Information Center

    Thurston-Gonzalez, Sara J.

    2009-01-01

    The focus of this qualitative study is on U.S. third culture kids (TCKs), youth who have grown up abroad because of their parent's work, and their college choice experiences and reentry expectations. Through a background questionnaire and personal interviews with eleven students transitioning from two international secondary schools in a…

  7. STD 105: Process Groups as an Instructional Medium for Re-entry Women at Paul D. Camp Community College.

    ERIC Educational Resources Information Center

    Creamer, Elizabeth; Duggin, Molly; Kidd, Ronald

    1999-01-01

    An effective team-based, group-oriented personal development from a woman's perspective course explores the effects of several issues on the re-entry woman: the role that society and culture play in influencing women's vocational choices; women's roles; the economic necessity of work; stress; and relationships. A team-based approach provides a…

  8. 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.…

  9. An Exploration of Factors Reducing Recidivism Rates of Formerly Incarcerated Youth with Disabilities Participating in a Re-Entry Intervention

    ERIC Educational Resources Information Center

    Unruh, Deanne K.; Gau, Jeff M.; Waintrup, Miriam G.

    2009-01-01

    Juvenile offenders are costly to our society in terms of the monetary and social expenditures from the legal system, victims' person costs, and incarceration. The re-entry and community reintegration outcomes for formerly incarcerated youth with a disabling condition are bleak compared to peers without disabilities. In this study, we examined the…

  10. A Leadership Opportunity for School Social Workers: Bridging the Gaps in School Reentry for Juvenile Justice System Youths

    ERIC Educational Resources Information Center

    Goldkind, Lauri

    2011-01-01

    Social work is frequently missing when policy and practice conversations turn to juvenile justice system youths. However, school social workers are well positioned to have a vital role in the readmission and reentry process for these young people. Formerly incarcerated youths present unique challenges for themselves, their families, and…

  11. Does Offender Gambling on the inside Continue on the outside? Insights from Correctional Professionals on Gambling and Re-Entry

    ERIC Educational Resources Information Center

    Williams, D. J.; Walker, Gordon J.

    2009-01-01

    This study brings to light a neglected topic of particular importance--offender gambling issues within the context of re-entry into the community. Fifteen correctional professionals from Nevada (high gambling availability) and Utah (no legalized gambling) participated in semi-structured interviews to provide insights into how gambling may impact…

  12. Report on Annual Women's Re-Entry Program Workshop (4th, Albuquerque, New Mexico, July 31, 1981).

    ERIC Educational Resources Information Center

    Maria, Arietta

    This report briefly describes presentations made at a re-entry workshop which was sponsored by the New Mexico Commission on the Status of Women. The 45 participants included representatives from post-secondary programs and institutions throughout the state. The purpose of this workshop was to provide information to state institutions and agencies…

  13. 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…

  14. 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…

  15. The relative role of refractoriness and source-sink relationship in reentry generation during simulated acute ischemia.

    PubMed

    Romero, Lucía; Trénor, Beatriz; Alonso, José M; Tobón, Catalina; Saiz, Javier; Ferrero, José M

    2009-08-01

    During acute myocardial ischemia, reentrant episodes may lead to ventricular fibrillation (VF), giving rise to potentially mortal arrhythmias. VF has been traditionally related to dispersion of refractoriness and more recently to the source-sink relationship. Our goal is to theoretically investigate the relative role of dispersion of refractoriness and source-sink mismatch in vulnerability to reentry in the specific situation of regional myocardial acute ischemia. The electrical activity of a regionally ischemic tissue was simulated using a modified version of the Luo-Rudy dynamic model. Ischemic conditions were varied to simulate the time-course of acute ischemia. Our results showed that dispersion of refractoriness increased with the severity of ischemia. However, no correlation between dispersion of refractoriness and the width of the vulnerable window was found. Additionally, in approximately 50% of the reentries, unidirectional block (UDB) took place in cells completely recovered from refractoriness. We examined patterns of activation after premature stimulation and they were intimately related to the source-sink relationship, quantified by the safety factor (SF). Moreover, the isoline where the SF dropped below unity matched the area where propagation failed. It was concluded that the mismatch of the source-sink relationship, rather than solely refractoriness, was the ultimate cause of the UDB leading to reentry. The SF represents a very powerful tool to study the mechanisms responsible for reentry.

  16. Career Assessment, Remediation, Education, Employment, and Re-entry Program (CAREER). El Paso Community College Career Grant. Final Report.

    ERIC Educational Resources Information Center

    LaFleur, Carol A.

    Objectives of the Career Assessment, Remediation, Education, Employment, and Re-entry (CAREER) project were to establish a series of intensive, short-term job training programs using competency-based instruction to serve Hispanic persons who were economically disadvantaged, displaced, unemployed, or underemployed, as well as Hispanic females who…

  17. Vocational Interest as a Correlate of Re-Entry of Girls into School in Edo State, Nigeria: Implications for Counselling

    ERIC Educational Resources Information Center

    Alika, Ijeoma Henrietta; Egbochuku, Elizabeth Omotunde

    2012-01-01

    The study investigated the relationship between vocational interest socio-economic status and re-entry of girls into school in Edo State. The research design adopted was correlational because it sought to establish the relationship between the independent variable and the dependent variable. A sample size of 306 girls who re-enrolled in institutes…

  18. The Role of the Center for Innovation in Teaching the Handicapped in Project PRIME. (Programmed Reentry into Mainstream Education.

    ERIC Educational Resources Information Center

    Semmel, Melvyn I.; Adler, Meredith

    Described is the role of the Center for Innovation in Teaching the Handicapped (CITH) in Project PRIME (Programmed Reentry into Mainstream Education), which attempted to assess the efficacy of mainstreaming for 1,035 emotionally disturbed, educable mentally retarded, and language/learning disabled Texas pupils in grades 3-5. The behavior…

  19. Probabilities of escape, re-entry, and orbit decay due to misdirected injection maneuvers

    NASA Astrophysics Data System (ADS)

    Longuski, James M.

    1992-04-01

    Whenever a space vehicle is injected from low earth orbit to high orbit or to escape, there is a small probability of misdirection. Once misdirection is assumed, then up to three major families of trajectories may result: escape, re-entry, or orbit decay. Analytic models of these trajectories provide contours on the injection sphere. Analytic integration of the areas between the contours gives the relative probability of each family occurring. The approximate analytic models are much faster in providing solutions than the numerical methods currently in use and have comparable accuracy. The new method provides a useful tool in the safety analysis of both single and multistage injection maneuvers. Recent applications have included analysis of the Galileo and the Ulysses injections into interplanetary trajectories.

  20. Trajectory optimization and guidance for a Hermes-type reentry vehicle

    NASA Astrophysics Data System (ADS)

    Jaensch, C.; Markl, A.

    Trajectory-optimization principles are applied to the reentry of a vehicle in a low-earth orbit, and a related guidance algorithm is developed. The approach calls for the substitution of linearization by on-line optimization for range control. The on-line technique, an extension of the Space Shuttle guidance algorithm, employs fully nonlinear dynamics and low parameterization for the velocity-dependent drag profile. A mathematical model for the aerothermodynamics and the thermal-protection-system heating model are developed, and the extensions of the Space Shuttle algorithm are listed. The method accounts for path constraints by including bounds for the parameters in the optimization algorithm, and the algorithm is used to derive trajectories that minimize the weight of thermal protection. The algorithm compares well with open-loop optimal trajectories for the same angle of attack, and when the angle of attack is an optimal control, the integrated heat flux can also be optimized.

  1. Guidance and control law for automatic landing flight experiment of reentry space vehicle

    NASA Astrophysics Data System (ADS)

    Miyazawa, Yoshikazu; Ishikawa, Kazutoshi; Fujii, Kenji

    An automatic landing flight experiment with a sub-scale model is being prepared for a planned future reentry space vehicle by the National Aerospace Laboratory and the National Space Development Agency of Japan. The subscale model is dropped from a helicopter at a 1500-m altitude, and, controlled by an on-board navigation, guidance, and control system, it automatically lands on a 1000-m runway. This paper discusses preliminary study results obtained from numerical simulation. The guidance and control law was designed using a multiple delay model and multiple design point approach. Control system robustness against uncertain and time varying dynamics is especially considered in this approach. The control performances are evaluated with appropriately defined quadratic indices of tracking error. Simple control structures are assumed and parameters are obtained with numerical optimization. The approach was successfully applied to the design, and feasibility of the experiment has been verified with numerical simulations.

  2. Pre-flight physical simulation test of HIMES reentry test vehicle

    NASA Astrophysics Data System (ADS)

    Kawaguchi, Jun'ichiro; Inatani, Yoshifumi; Yonemoto, Koichi; Hosokawa, Shigeru

    ISAS is now developing a small reentry test vehicle, which is 2m long with a 1.5m wing span and weighs about 170 kg, for the purpose of exploring high angle-of-attack aerodynamic attitude control issue in supersonic and hypersonic speed. The flight test, employing 'Rockoon' launch system, is planned as a preliminary design verification for a fully reusable winged rocket named HIMES (Highly Maneuverable Experimental Space) vehicle. This paper describes the results of preflight ground test using a motion table system. This ground system test is called 'physical simulation' aimed at: (1) functional verification of side-jet system, aerodynamic surface actuators, battery and onboard avionics; and (2) guidance and control law evaluation, in total hardware-in-the-loop system. The pressure of side-jet nozzles was measured to provide exact thrust characteristics of reaction control. The dynamics of vehicle motion was calculated in real-time by the ground simulation computer.

  3. European Experimental Re-Entry Testbed EXPERT: Qualification of Payloads for Flight

    NASA Astrophysics Data System (ADS)

    Ratti, F.; Gavira, J.; Thirkettle, A. C.; Erba, F.; Muylaert, J.-M.; Walpot, L.; Rembiasz, J. M.

    2009-01-01

    The European Experimental Re-entry Test-bed EXPERT is developed by the European Space Agency (ESA) as part of its General Technological Research Program (GSTP). The aim of EXPERT is to improve the understanding of critical aero-thermodynamic phenomena associated with hypersonic re-entry flights. The EXPERT project provides an opportunity to the scientific community and industries throughout Europe to propose and perform experiments in order to obtain aero-thermodynamic data for the validation of numerical models and of ground to flight extrapolation methodologies. During the last years an intense activity has been performed at ESA in order to select the most suitable experiments, bring them to a mature design, manufacture the qualification model and qualify the experiments for flight. ESA staffs coordinated and supported the work of the principal investigators of the experiments from European institutions and industrial organizations in order to maximize the scientific output in compliance with the budget resources made available to the EXPERT project and the programmatic constraints. EXPERT is a re-entry capsule having the shape of a blunted cone. The front part consists of a nose made of ceramic material developed at DLR Stuttgart. No ablative material is implemented so as not to contaminate the specific measurements of Payloads on board. The ceramic nose hosts a set of experiments: the Flush Air Data System (FADS) developed by HTG aiming at collecting free flow data required for post flight analysis, the pyrometer PYREX developed at IRS in Stuttgart collecting data on the temperature and heat flux of the ceramic nose, and the IRS spectrometer RESPECT aiming at resolving the different species generated in the plasma region during re-entry. The sides of the blunted cone are protected by a metallic thermal protection system in which several experiments are located. Two Payloads developed by IRS and VKI are dedicated to the measurement of catalytic effects. One aims

  4. From the ideal to the real world: a phenomenological inquiry into student sojourners' reentry adaptation.

    PubMed

    Hsiao, Feilin

    2011-01-01

    This phenomenological study examines the thematic structure of reentry transition for international music therapy graduates who have returned home after studying in the United States. Emphasis is placed upon career development. Standardized open-ended interviews were used to obtain rich and in-depth descriptions of the participants' experiences. Ten music therapists from six countries participated in the study. The themes that emerged from the data include moving from the ideal to the real world, shifting from the role of student to professional, confronting reality and working through challenges, and achieving personal growth and self-transformation. The dynamics of cross-cultural comparison, confronting the home culture, and redefining music therapy and professional identities within the local cultural context are illustrated via quotations from the participants. Implications and recommendations for music therapy education and career preparation for international graduates are discussed. PMID:22506298

  5. Violence and Victimization During Incarceration: Relations to Psychosocial Adjustment During Reentry to the Community.

    PubMed

    Schappell, Ashley; Docherty, Meagan; Boxer, Paul

    2016-01-01

    We surveyed male ex-offenders (N = 100) about their experiences during and prior to incarceration to assess the role of these factors in psychosocial adjustment postrelease. Participants completed measures of preincarceration mental health problems and severe victimization and feelings of safety during incarceration; they also self-reported emotional distress, antisocial behavior, and posttraumatic stress (PTS). Moderator analyses of PTS outcomes revealed two key interactions between preincarceration mental health problems and severe victimization during incarceration as well as preincarceration mental health problems by feelings of safety during incarceration. In those without preincarceration mental health problems, victimization and PTS were significantly positively related; this was not the case for those with preexisting mental problems. Furthermore, the positive relation between feeling unsafe and PTS was stronger among those with preexisting mental problems. Findings are discussed with respect to implications for reentry services. PMID:26830297

  6. Gravity wave structure between 60 and 90 km inferred from Space Shuttle reentry data

    NASA Technical Reports Server (NTRS)

    Fritts, David C.; Blanchard, Robert C.; Coy, Lawrence

    1989-01-01

    Density fluctuations obtained along seven Space Shuttle reentry tracks are used to examine the horizontal structure and the vertical distribution of density variance in the mesosphere and lower thermosphere. The tracks lie primarily over open ocean at middle and low latitudes and represent the only measurements of horizontal atmospheric structure at these heights available to date. The density fluctuations are interpreted in terms of gravity-wave motions and reveal significant density (and velocity) variance at horizontal scales ranging from about 10 to 1000 km. Fluctuation amplitudes are used to infer corresponding velocity perturbations and characteristic vertical scales and frequencies of the wave spectrum. Results suggest that the mean velocity variance is smaller over the Pacific ocean than over major land masses, and that the variance increases with height in a manner consistent with that expected in the present of wave saturation processes.

  7. Social bonds and change during incarceration: testing a missing link in the reentry research.

    PubMed

    Rocque, Michael; Bierie, David M; MacKenzie, Doris L

    2011-08-01

    Research examining prisoner reentry has demonstrated negative impacts of incarceration on social bonds. However, this research is limited in two ways. First, it generally examines outcomes after release, paying less attention to processes occurring in prison. Second, this work tends to examine "incarceration" as a whole, regarding prisons as homogenous. This study uses data from an experiment in which offenders were randomly assigned to incarceration at one of two prisons polarized across a number of structural characteristics that research suggests affect social bonds (a traditional prison vs. a correctional boot camp). Groups were compared with respect to commitment, belief, attachment, and in terms of changes among their relationships during incarceration. The data showed that the boot camp improved prosocial beliefs, but few differences emerged in terms of commitment and attachment. Similarly, the data showed few differences in attachment regardless of the prosocial or antisocial orientation of the inmate's friends or family.

  8. Peri-implantitis Treatment with a Regenerative Approach: Clinical Outcomes on Reentry.

    PubMed

    Parma-Benfenati, Stefano; Roncati, Marisa; Galletti, Primo; Tinti, Carlo

    2015-01-01

    This case series presents clinical outcomes on reentry using regenerative submerged and nonsubmerged approaches in peri-implant defects; pre- and posttreatment assessments of nine implants in six patients are presented. A mean bone fill value of 91.3% with a 4.88-mm mean bone gain was obtained. Neither approach led to additional bone loss or required additional bone augmentation procedures. Strict methods of implant surface decontamination and detoxification were used on all patients, regardless of implant surface characteristics. The regenerative procedure was effective in the treatment of moderate to advanced peri-implantitis lesions without compromising the previous fixed implant-supported prostheses. These preliminary results are reasonably encouraging in that all cases showed bone gains. Nevertheless, caution must be exercised when determining reosseointegration, because it is not possible to ascertain it in clinical practice.

  9. The use of inflatable structures for re-entry of orbiting vehicles

    NASA Astrophysics Data System (ADS)

    Kendall, Robert T.; Maddox, Arthur R.

    1990-10-01

    Inflatable recovery systems offer the unique advantage that a large high-drag shape can be stored initially in a relatively small package. The resulting shapes decelerate rapidly with lower heating inputs than other types of re-entry vehicles. Recent developments have led to some light-weight materials, with little thermal protection, can withstand the heating inputs to such vehicles. As a result, inflatable recovery vehicles offer a simple, reliable and economical way to return various vehicles from orbit. This paper examines the application of this concept to a large and a small vehicle with the accompanying dynamics that might be expected. More complex systems could extend the concept to emergency personnel escape systems, payload abort and satellite recovery systems.

  10. Inflatable re-Entry and Descent Technology - Results of the IRDT-2 Mission and Future Applications

    NASA Astrophysics Data System (ADS)

    Walther, S.

    2002-01-01

    This paper will present the results of the second IRDT flight, a mission which is planned for May 2002. The first testflight successfully demonstrated its performance in 2000. The Inflatable Re-entry and Descent Technology (IRDT), an innovative lightweight return technology, is designed to provide significant mass and cost savings compared to conventionally fixed heat shield and parachute systems for returning elements from space. This technology is highly attractive for a broad range of applications, e.g. return of small capsules, larger objects like ATV or launcher elements from an Earth orbit and may also be used for planetary missions. IRDT can be adapted to existing vehicles or be used as baseline for new vehicles. Potential future application scenarios, e.g. a Download System to return payload from the ISS, will also be described.

  11. Evaluation of non-intrusive flow measurement techniques for a re-entry flight experiment

    NASA Technical Reports Server (NTRS)

    Miles, R. B.; Santavicca, D. A.; Zimmermann, M.

    1983-01-01

    This study evaluates various non-intrusive techniques for the measurement of the flow field on the windward side of the Space Shuttle orbiter or a similar reentry vehicle. Included are linear (Rayleigh, Raman, Mie, Laser Doppler Velocimetry, Resonant Doppler Velocimetry) and nonlinear (Coherent Anti-Stokes Raman, Laser-Induced Fluorescence) light scattering, electron-beam fluorescence, thermal emission, and mass spectroscopy. Flow-field properties were taken from a nonequilibrium flow model by Shinn, Moss, and Simmonds at the NASA Langley Research Center. Conclusions are, when possible, based on quantitative scaling of known laboratory results to the conditions projected. Detailed discussion with researchers in the field contributed further to these conclusions and provided valuable insights regarding the experimental feasibility of each of the techniques.

  12. The application of some lifting-body reentry concepts to missile design

    NASA Technical Reports Server (NTRS)

    Spearman, M. L.

    1985-01-01

    The aerodynamic characteristics of some lifting-body concepts are examined with a view to the applicability of such concepts to the design of missiles. A considerable amount of research has been done in past years with vehicle concepts suitable for manned atmospheric-entry and atmospheric flight. Some of the concepts appear to offer some novel design approaches for missiles for a variety of missions and flight profiles, including long-range orbital/reentry with transatmospheric operation for strategic penetration, low altitude penetration, and battlefield tactical. The concepts considered include right triangular pyramidal configurations, a lenticular configuration, and various 75-degree triangular planform configurations with variations in body camber and control systems. The aerodynamic features are emphasized but some observations are also made relative to other factors such as heat transfer, structures, carriage, observability, propulsion, and volumetric efficiency.

  13. The Advanced Re-Entry Vehicle (ARV) a Development Step from ATV Toward Manned Transportation Systems

    NASA Astrophysics Data System (ADS)

    Bottacini, M.; Berthe, P.; Vo, X.; Pietsch, K.

    2011-08-01

    The Advanced Re-entry Vehicle (ARV) programme has been undertaken by Europe with the objective to contribute to the preparation of a future European crew transportation system, while providing a valuable logistic support to the ISS through an operational cargo return system. This development would allow: - the early acquisition of critical technologies; - the design, development and testing of elements suitable for the follow up human rated transportation system. These vehicles should also serve future LEO infrastructures and exploration missions. With the aim to satisfy the above objectives a team composed by major European industries and led by EADS Astrium Space Transportation is currently conducting the phase A of the programme under contract with the European Space Agency (ESA). Two vehicle versions are being investigated: a Cargo version, transporting cargo only to/from the ISS, and a Crew version, which will allow the transfer of both crew and cargo to/from the ISS. The ARV Cargo version, in its present configuration, is composed of three modules. The Versatile Service Module (VSM) provides to the system the propulsion/GNC for orbital manoeuvres and attitude control and the orbital power generation. Its propulsion system and GNC shall be robust enough to allow its use for different launch stacks and different LEO missions in the future. The Un-pressurised Cargo Module (UCM) provides the accommodation for about 3000 kg of un-pressurised cargo and is to be sufficiently flexible to ensure the transportation of: - orbital infrastructure components (ORU's); - scientific / technological experiments; - propellant for re-fuelling, re-boost (and deorbiting) of the ISS. The Re-entry Module (RM) provides a pressurized volume to accommodate active/passive cargo (2000 kg upload/1500 kg download). It is conceived as an expendable conical capsule with spherical heat- hield, interfacing with the new docking standard of the ISS, i.e. it carries the IBDM docking system, on a

  14. The Advanced Re-Entry Vehicle (ARV) A Development Step From ATV Toward Manned Transportation Systems

    NASA Astrophysics Data System (ADS)

    Bottacini, Massimiliano; Berthe, Philippe; Vo, Xavier; Pietsch, Klaus

    2011-05-01

    The Advanced Re-entry Vehicle (ARV) programme has been undertaken by Europe with the objective to contribute to the preparation of a future European crew transportation system, while providing a valuable logistic support to the ISS through an operational cargo return system. This development would allow: - the early acquisition of critical technologies; - the design, development and testing of elements suitable for the follow up human rated transportation system. These vehicles should also serve future LEO infrastructures and exploration missions. With the aim to satisfy the above objectives a team composed by major European industries and led by EADS Astrium Space Transportation is currently conducting the phase A of the programme under contract with the European Space Agency (ESA). Two vehicle versions are being investigated: a Cargo version, transporting cargo only to/from the ISS, and a Crew version, which will allow the transfer of both crew and cargo to/from the ISS. The ARV Cargo version, in its present configuration, is composed of three modules. The Versatile Service Module (VSM) provides to the system the propulsion/GNC for orbital manoeuvres and attitude control and the orbital power generation. Its propulsion system and GNC shall be robust enough to allow its use for different launch stacks and different LEO missions in the future. The Un-pressurised Cargo Module (UCM) provides the accommodation for about 3000 kg of unpressurised cargo and is to be sufficiently flexible to ensure the transportation of: - orbital infrastructure components (ORU’s); - scientific / technological experiments; - propellant for re-fuelling, re-boost (and de-orbiting) of the ISS. The Re-entry Module (RM) provides a pressurized volume to accommodate active/passive cargo (2000 kg upload/1500 kg download). It is conceived as an expendable conical capsule with spherical heat-shield, interfacing with the new docking standard of the ISS, i.e. it carries the IBDM docking system, on

  15. Probabilistic analysis of the inadvertent reentry of the Cassini spacecraft's radioisotope thermoelectric generators.

    PubMed

    Frank, M V

    2000-04-01

    As part of the launch approval process, the Interagency Nuclear Safety Review Panel provides an independent safety assessment of space missions--such as the Cassini mission--that carry a significant amount of nuclear materials. This survey article describes potential accident scenarios that might lead to release of fuel from an accidental reentry during an Earth swingby maneuver, the probabilities of such scenarios, and their consequences. To illustrate the nature of calculations used in this area, examples are presented of probabilistic models to obtain both the probability of scenario events and the resultant source terms of such scenarios. Because of large extrapolations from the current knowledge base, the analysis emphasizes treatment of uncertainties.

  16. Multiblock analysis for Shuttle Orbiter reentry heating from Mach 24 to Mach 12

    NASA Technical Reports Server (NTRS)

    Gnoffo, Peter A.; Weilmuenster, K. James; Alter, Stephen J.

    1994-01-01

    A multiblock, laminar heating analysis for the shuttle orbiter at three trajectory points ranging from Mach 24.3 to Mach 12.86 on reentry is described. The analysis is performed using the Langley Aerothermodynamic Upwind Relaxation Algorithm with a seven species chemical nonequilibrium model. A finite-catalytic-wall model appropriate for shuttle tiles at a radiative equilibrium wall temperature is applied. Computed heating levels are generally in good agreement with the flight data, although a few rather large discrepancies remain unexplained. The multiblock relaxation strategy partitions the flowfield into manageable blocks requiring a fraction of the computational resources (time and memory) required by a full domain approach. In fact, the computational cost for a solution at even a single trajectory point would be prohibitively expensive at the given resolution without the multiblock approach. Converged blocks are reassembled to enable a fully coupled converged solution over the entire vehicle, starting from a nearly converged initial condition.

  17. Static mechanical strain induces capillary endothelial cell cycle re-entry and sprouting

    NASA Astrophysics Data System (ADS)

    Zeiger, A. S.; Liu, F. D.; Durham, J. T.; Jagielska, A.; Mahmoodian, R.; Van Vliet, K. J.; Herman, I. M.

    2016-08-01

    Vascular endothelial cells are known to respond to a range of biochemical and time-varying mechanical cues that can promote blood vessel sprouting termed angiogenesis. It is less understood how these cells respond to sustained (i.e., static) mechanical cues such as the deformation generated by other contractile vascular cells, cues which can change with age and disease state. Here we demonstrate that static tensile strain of 10%, consistent with that exerted by contractile microvascular pericytes, can directly and rapidly induce cell cycle re-entry in growth-arrested microvascular endothelial cell monolayers. S-phase entry in response to this strain correlates with absence of nuclear p27, a cyclin-dependent kinase inhibitor. Furthermore, this modest strain promotes sprouting of endothelial cells, suggesting a novel mechanical ‘angiogenic switch’. These findings suggest that static tensile strain can directly stimulate pathological angiogenesis, implying that pericyte absence or death is not necessarily required of endothelial cell re-activation.

  18. 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.

  19. Ceramic Adhesive and Methods for On-Orbit Repair of Re-Entry Vehicles

    NASA Technical Reports Server (NTRS)

    Riedell, James A.; Easler, Timothy E.

    2013-01-01

    This adhesive is capable of repairing damaged leading edge components of reentry vehicles while in space, and is novel with regard to its ability to be applied in the vacuum of space, and in a microgravity environment. Once applied, the adhesive provides thermal and oxidation protection to the substrate (in this case, reinforced carbon/carbon composites, RCCs) during re-entry of a space vehicle. Although there may be many formulations for repair adhesives, at the time of this reporting, this is the first known adhesive capable of an on-orbit repair. The adhesive is an engineered ceramic material composed of a pre-ceramic polymer and refractory powders in the form of a paste or putty that can be applied to a scratched, cracked, or fractured composite surface, covering and protecting the damaged area. The adhesive is then "cured" with a heat cycle, thereby cross-linking the polymer into a hardened material and bonding it to the substrate. During the heat of reentry, the material is converted to a ceramic coating that provides thermal and oxidative stability to the repaired area, thus allowing the vehicle to pass safely from space into the upper atmosphere. Ceramic powders such as SiC, ZrB2 and Y2O3 are combined with allylhydridopolycarbosilane (AHPCS) resin, and are mixed to form a paste adhesive. The material is then applied to the damaged area by brush, spatula, trowel, or other means to fill cracks, gaps, and holes, or used to bond patches onto the damaged area. The material is then cured, in a vacuum, preferably at 250F (approximately equal to 121C) for two hours. The re-entry heating of the vehicle at temperatures in excess of 3,000F (approximately equal to 1,650C) then converts this material into a ceramic coating. This invention has demonstrated advantages in resistance to high temperatures, as was demonstrated in more than 100 arc-jet tests in representative environments at NASA. Extensive testing verified oxidation protection for the repaired substrate (RCC

  20. Application of DSMC Electronic Excitation Modeling to Radiation Calculation of Hypersonic Reentry Flows

    NASA Astrophysics Data System (ADS)

    Li, Zheng; Sohn, Ilyoup; Levin, Deborah A.; Modest, Michael F.

    2011-05-01

    The current work implemented excited levels of atomic N and corresponding electron impact excitation/de-excitation and ionization processes in DSMC. Results show that when excitation models are included, the Stardust 68.9 km re-entry flow has an observable change in the ion number densities and electron temperature. Adding in the excited levels of atoms improves the degree of ionization by providing additional intermediate steps to ionization. The extra ionization reactions consume the electron energy and reduce the electron temperature. The DSMC results of number densities of excited levels are lower than the prediction of quasi steady state calculation. Comparison of radiation calculations using electronic excited populations from DSMC and QSS indicates that, at the stagnation point, there is about 20% difference of the radiative heat flux between DSMC and QSS.

  1. Supraventricular tachycardia in Lown-Ganong-Levine syndrome: atrionodal versus intranodal reentry.

    PubMed

    Josephson, M E; Kastor, J A

    1977-10-01

    The mechanism of the abbreviated atrioventricular (A-V) nodal conduction time and paroxysmal supraventricular tachycardia in the Lown-Ganong-Levine syndrome was evaluated in six patients. In each the A-H interval increased in response to rapid atrial pacing and atrial extrastimuli; typical dual A-V nodal pathways were demonstrated. In five patients studied at two cycle lengths prolongation of conduction and refractoriness of the "fast" pathway was noted at the shorter basic cycle length. Propranolol prolonged conduction and refractoriness of the "fast" pathway in three patients and in one produced Wenckebach conduction during atrial pacing which did not occur prior to its administration. In three patients the atrium did not appear necessary to sustain supraventricular tachycardia. These findings suggest that preferential rapidly conducting A-V nodal fibers and intranodal reentry are the responsible mechanisms in those patients with Lown-Ganong-Levine syndrome and reciprocating tachycardia.

  2. Viscous code prediction of re-entry vehicle roll torque based on ablated surface topology

    NASA Astrophysics Data System (ADS)

    Szostowski, D. J.; Lowe, D. L.; Nestler, D. E.

    1982-06-01

    A new approach is developed for modeling roll torque due to ablated surface features of tape-wrapped, carbon-phenolic heatshields. The approach stems from preferential and random asymmetric topological characteristics observed on material specimens from ground test models and recovered re-entry vehicles. Roll torque contributions from each type of surface feature are determined from aerodynamic models coupled to an integral viscous technique. The dominant roll-producing mechanisms are shown to be warp yarn bias surface roughness and the formation of asymmetric char ledges. Comparisons with flight test roll histories validate the framework for the roll modeling technique, including predictions for a class of vehicle differing substantially from the one for which the model was developed.

  3. Measurement of lateral launch loads on re-entry vehicles using SWAT

    SciTech Connect

    Mayes, R.L.

    1993-11-01

    The Sum of Weighted Accelerations Technique (SWAT) has been developed at Sandia National Laboratories to infer dynamic forces acting on free elastic structures from acceleration measurements. A derivative of SWAT known as SWAT TEEM (Sum of Weighted Accelerations using Tome Eliminated Elastic Modes) is utilized. This paper describes experiments demonstrating how this technology can be applied to measure lateral launch loads on Re-entry Vehicle (RV) payloads. A technique to determine the number of sensors and best locations is described. Experiments are performed to excite a structure to which a mockup RV is mounted. Acceleration measurements on the RV are used to reconstruct the lateral force acting at the RV base, and these results are compared to measured results.

  4. Numerical Flight Mechanics Analysis Of The SHEFEX I Ascent And Re-Entry Phases

    NASA Astrophysics Data System (ADS)

    Bartolome Calvo, Javier; Eggers, Thino

    2011-08-01

    The SHarp Edge Flight EXperiment (SHEFEX) I provides a huge amount of scientific data to validate numerical tools in hypersonic flows. These data allow the direct comparison of flight measurements with the current numerical tools available at DLR. Therefore, this paper is devoted to apply a recently developed direct coupling between aerodynamics and flight dynamics to the SHEFEX I flight. In a first step, mission analyses are carried out using the trajectory optimization program REENT 6D coupled to missile DATCOM. In a second step, the direct coupling between the trajectory program and the DLR TAU code, in which the unsteady Euler equations including rigid body motion are solved, is applied to analyze some interesting parts of ascent and re-entry phases of the flight experiment. The agreement of the numerical predictions with the obtained flight data is satisfactory assuming a variable fin deflection angle.

  5. 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

  6. Heatshield material selection for advanced ballistic reentry vehicles. [rayon fiber cloth impregnated with phenolic resin

    NASA Technical Reports Server (NTRS)

    Legendre, P. J.; Holtz, T.; Sikra, J. C.

    1980-01-01

    The Performance of staple rayon fiber and AVTEX continuous rayon fiber was evaluated as precursor materials for heatshields. The materials studied were referenced to the IRC FM5055A heatshield materials flown during the past decade. Three different arc jet facilities were used to simulate portions of the reentry environment. The IRC FM5055A and the AVTEX FM5055G, both continuous rayon fiber woven materials having the phenolic impregnant filled with carbon particles were compared. The AVTEX continuous fiber, unfilled material FM5822A was also examined to a limited extent. Test results show that the AVTEX FM5055G material provided a close substitute for the IRC FM5055A material both in terms of thermal protection and roll torque performance.

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

    SciTech Connect

    Fritts, D.C. ); Dingyi Wang ); Blanchard, R.C. )

    1993-03-15

    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 [approximately]90 km. The rate of amplitude growth decreases at greater heights, however, and appears to cease above [approximately]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.

  8. Interplanetary and Interstellar Dust Particles: Reentry Heating and Capture in Aerogel

    NASA Technical Reports Server (NTRS)

    Szydlik, Paul P.

    1996-01-01

    Studies of interplanetary and interstellar dust can provide significant information on the evolution of the solar system or stars, respectively. However, for reliable analysis it is crucial to know how the particles have been modified during reentry (in the case of interplanetary dust particles, or [DP's) and impact into the capture medium. In the case of stratospheric capture, particles will be heated by atmospheric drag. Subsequent capture of the particles will result in heating, ablation, accretion of the capture medium and possible fragmentation. Modeling of these processes is a useful way of assessing their effects on the interpretation of the compositional data for these particles. Previous work on reentry heating has shown that heat diffusion alone cannot adequately account for temperature gradients observed in IDP's. In fact, for any reasonable thermal parameters, calculations show the particles to be nearly isothermal. Here we extend those studies to include phase transitions. These preliminary results are promising and show a significant temperature gradient for a 100 micron (diameter) particle. The actual capture of the particles in silica aerogel is being modeled using a comprehensive shock hydrodynamic code (called CTH). Various options of this code were investigated to attempt to make the most appropriate choice of methods of impact, equations of state, and processes of energy transfer from capture material to particle. The initial calculations with the code used only 'reasonable' estimates for the physical parameters of silica aerogel. Through the literature searches and personal contacts with the knowledgeable scientists, the best possible mechanical and thermal data have been made available for these computations.

  9. The Double-Blind Stick-and-Swap Technique for True Lumen Reentry After Subintimal Crossing of Coronary Chronic Total Occlusions.

    PubMed

    Christopoulos, Georgios; Kotsia, Anna P; Brilakis, Emmanouil S

    2015-09-01

    Subintimal dissection and reentry techniques are widely used in chronic total occlusion (CTO) interventions; however, inability to reenter into the distal true lumen is a common cause of failure. In some patients, subintimal hematoma may develop, compressing the lumen and hindering reentry. We describe 3 CTO cases in which the distal vessel could not be visualized after subintimal crossing, in spite of attempts to decompress the subintimal hematoma. Bidirectional "blind" puncture was performed with the Stingray wire through both ports of the Stingray balloon, followed by exchange of the Stingray wire for a Pilot 200 guidewire (the "double-blind stick-and-swap" technique) achieving distal true lumen reentry. PMID:26332885

  10. Profitable capitation requires accurate costing.

    PubMed

    West, D A; Hicks, L L; Balas, E A; West, T D

    1996-01-01

    In the name of costing accuracy, nurses are asked to track inventory use on per treatment basis when more significant costs, such as general overhead and nursing salaries, are usually allocated to patients or treatments on an average cost basis. Accurate treatment costing and financial viability require analysis of all resources actually consumed in treatment delivery, including nursing services and inventory. More precise costing information enables more profitable decisions as is demonstrated by comparing the ratio-of-cost-to-treatment method (aggregate costing) with alternative activity-based costing methods (ABC). Nurses must participate in this costing process to assure that capitation bids are based upon accurate costs rather than simple averages. PMID:8788799

  11. 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

  12. Accurate documentation and wound measurement.

    PubMed

    Hampton, Sylvie

    This article, part 4 in a series on wound management, addresses the sometimes routine yet crucial task of documentation. Clear and accurate records of a wound enable its progress to be determined so the appropriate treatment can be applied. Thorough records mean any practitioner picking up a patient's notes will know when the wound was last checked, how it looked and what dressing and/or treatment was applied, ensuring continuity of care. Documenting every assessment also has legal implications, demonstrating due consideration and care of the patient and the rationale for any treatment carried out. Part 5 in the series discusses wound dressing characteristics and selection.

  13. Cast Glance Near Infrared Imaging Observations of the Space Shuttle During Hypersonic Re-Entry

    NASA Technical Reports Server (NTRS)

    Tack, Steve; Tomek, Deborah M.; Horvath, Thomas J.; Verstynen, Harry A.; Shea, Edward J.

    2010-01-01

    High resolution calibrated infrared imagery of the Space Shuttle was obtained during hypervelocity atmospheric entries of the STS-119, STS-125 and STS128 missions and has provided information on the distribution of surface temperature and the state of the airflow over the windward surface of the Orbiter during descent. This data collect was initiated by NASA s Hypersonic Thermodynamic Infrared Measurements (HYTHIRM) team and incorporated the use of air- and land-based optical assets to image the Shuttle during atmospheric re-entry. The HYTHIRM objective is to develop and implement a set of mission planning tools designed to establish confidence in the ability of an existing optical asset to reliably acquire, track and return global quantitative surface temperatures of the Shuttle during entry. On Space Shuttle Discovery s STS-119 mission, NASA flew a specially modified thermal protection system tile and instrumentation package to monitor heating effects from boundary layer transition during re-entry. On STS-119, the windward airflow on the port wing was deliberately disrupted by a four-inch wide and quarter-inch tall protuberance built into the modified tile. In coordination with this flight experiment, a US Navy NP-3D Orion aircraft was flown 28 nautical miles below Discovery and remotely monitored surface temperature of the Orbiter at Mach 8.4 using a long-range infrared optical package referred to as Cast Glance. Approximately two months later, the same Navy Cast Glance aircraft successfully monitored the surface temperatures of the Orbiter Atlantis traveling at approximately Mach 14.3 during its return from the successful Hubble repair mission. In contrast to Discovery, Atlantis was not part of the Boundary Layer Transition (BLT) flight experiment, thus the vehicle was not configured with a protuberance on the port wing. In September 2009, Cast Glance was again successful in capturing infrared imagery and monitoring the surface temperatures on Discovery s next

  14. High-power laser-experiments on shear-flow instabilities in a re-entry sheath

    NASA Astrophysics Data System (ADS)

    Niemann, C.; Ashour-Abdalla, M.; Clark, S. E.; Niehoff, D.; Schaeffer, D.; Constantin, C.; Schriver, D.; El-Alaoui, M.

    2013-12-01

    Microscopic plasma fluctuations in the reentry sheath surrounding hypersonic aircraft can be detrimental to radio-communication but can only be limitedly studied in-situ. Here we present new measurements of plasma-fluctuations in the lower-hybrid range, created in a laser-produced plasma plume that closely resembles a reentry sheath (10E11-10E13 cm-3, 1-20 eV). Shear-flow instabilities form in the diamagnetic current layer of the laser-produced plasma (20 J) exploding at hypersonic speed (M>10) into a preformed magnetic field (400 G). Electric- and magnetic-field gradients are characterized with magnetic flux probes over large temporal and spatial (20 cm) scales. The frequency spectrum of plasma pulsations is investigated with biased Langmuir probes, while the plasma parameters are measured via optical Thomson scattering. The data is used to benchmark simulations performed with a 2D PIC code.

  15. 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.

  16. 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

  17. Cell cycle reentry from the late S phase: implications from stem cell formation in the moss Physcomitrella patens.

    PubMed

    Ishikawa, Masaki; Hasebe, Mitsuyasu

    2015-05-01

    Differentiated cells are in a non-dividing, quiescent state, but some differentiated cells can reenter the cell cycle in response to appropriate stimuli. Quiescent cells are generally arrested at the G0/G1 phase, reenter the cell cycle, and progress to the S phase to replicate their genomic DNA. On the other hand, some types of cells are arrested at the different phase and reenter the cell cycle from there. In the moss Physcomitrella patens, the differentiated leaf cells of gametophores formed in the haploid generation contain approximately 2C DNA content, and DNA synthesis is necessary for reentry into the cell cycle, which is suggested to be arrested at late S phase. Here we review various cell-division reactivation processes in which cells reenter the cell cycle from the late S phase, and discuss possible mechanisms of such unusual cell cycle reentries with special emphasis on Physcomitrella.

  18. SPLASH: Accurate OH maser positions

    NASA Astrophysics Data System (ADS)

    Walsh, Andrew; Gomez, Jose F.; Jones, Paul; Cunningham, Maria; Green, James; Dawson, Joanne; Ellingsen, Simon; Breen, Shari; Imai, Hiroshi; Lowe, Vicki; Jones, Courtney

    2013-10-01

    The hydroxyl (OH) 18 cm lines are powerful and versatile probes of diffuse molecular gas, that may trace a largely unstudied component of the Galactic ISM. SPLASH (the Southern Parkes Large Area Survey in Hydroxyl) is a large, unbiased and fully-sampled survey of OH emission, absorption and masers in the Galactic Plane that will achieve sensitivities an order of magnitude better than previous work. In this proposal, we request ATCA time to follow up OH maser candidates. This will give us accurate (~10") positions of the masers, which can be compared to other maser positions from HOPS, MMB and MALT-45 and will provide full polarisation measurements towards a sample of OH masers that have not been observed in MAGMO.

  19. 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.

  20. Low-Speed Static Stability and Control Characteristics of a Model of a Right Triangular Pyramid Reentry Configuration

    NASA Technical Reports Server (NTRS)

    Paulson, John W.

    1959-01-01

    An investigation of the low-speed static stability and control characteristics of a model of a right triangular pyramid reentry configuration has been made in the Langley free-flight tunnel. The investigation showed that the model had generally satisfactory longitudinal and lateral static stability characteristics. The maximum lift-drag ratio was increased from about 3 to 5 by boattailing the base of the model.