SEARCH · Search NASA

Results for “reentry breakup analysis”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records

All sources NASA NTRS DOE OSTI

NASA NTRS2007

Inadvertent Earth Reentry Breakup Analysis for the New Horizons Mission

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.

Ling, Lisa M.↗

NASA NTRS2005

A methodology of MSL breakup analysis for Earth accidental reentry and its application to breakup analysis for Mars off-nominal entry

Vehicle breakup analysis has been performed for missions that may carry nuclear fuel for heating or power purposes to assess nuclear safety in case of launch failure leading to atmospheric reentry. Also, failure scenarios exist which could lead to breakup during Entry / Descent / Landing (EDL) at Mars due to off-nominal entries, with implications for planetary protection requirements. Since the Mars Science Laboratory (MSL) spacecraft may include a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), an analysis of breakup in case of launch failure is required. Also, breakup during Mars EDL due to off-nominal entries could release the RTG heat source that has implications for planetary protection requirements. This paper presents a methodology of MSL breakup analysis for launch failure with application to Mars off-nominal entry.

nuclear safety↗

NASA NTRSDate not supplied

OSIRIS-REx Off-Nominal Re-entry Breakup Analysis

The Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) is a NASA asteroid sampling mission that launched on September 8, 2016. Its objectives are to study the asteroid Bennu for up to 505 days and obtain at least 60 grams of pristine regolith. The sample return to Earth is planned for September 2023. For contingency planning and risk assessment of a potential off-nominal Earth-return trajectory, a re-entry breakup analysis was performed to determine the response of the spacecraft to the environment and predict the breakup sequence and timeline, debris survival, and debris impact conditions. The failure scenario assumed a failure to separate between the bus and the sample return capsule (SRC), resulting in the combined bus+SRC configuration for the re-entry vehicle. Furthermore, consistent overburns or underburns were considered to produce three sets of initial conditions for the analysis consisting of nominal, steep, and shallow entry flight path angles. The results were compared to the breakup analysis performed for a similar vehicle, the Stardust spacecraft, which returned samples from the comet Wild 2 in 2006. This paper describes the OSIRIS-REx spacecraft and presents the results of the re-entry breakup analysis.

reentry breakup analysis↗

NASA NTRS2010

Comparison of ORSAT and SCARAB Reentry Analysis Tools for a Generic Satellite Test Case

Reentry analysis is essential to understanding the consequences of the full life cycle of a spacecraft. 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 Reentry 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 significant, 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.

Kelley, Robert L.↗

NASA NTRS1992

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

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.

Snyder, Michael W.↗

NASA NTRS2014

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

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

Ling, Lisa↗

NASA NTRS1987

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

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

Stamatelatos, M. G.↗

NASA NTRS2014

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

For the purpose of performing safety analysis and risk assessment for a potential off-nominal atmospheric reentry resulting in vehicle breakup, a synthesis of trajectory propagation coupled with thermal analysis and the evaluation of node failure is required to predict the sequence of events, the timeline, and the progressive demise of spacecraft components. To provide this capability, the Simulation for Prediction of Entry Article Demise (SPEAD) analysis tool was developed. The software and methodology have been validated against actual flights, telemetry data, and validated software, and safety/risk analyses were performed for various programs using SPEAD. This report discusses the capabilities, modeling, validation, and application of the SPEAD analysis tool.

Ling, Lisa↗

NASA NTRS2003

Application of the V-Gamma map to vehicle breakup analysis

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

vehicle breakup analysis↗

NASA NTRS1979

Monte Carlo analysis of satellite debris footprint dispersion

A comprehensive study is performed to investigate satellite debris impact point dispersion using a combination of Monte Carlo statistical analysis and parametric methods. The Monte Carlo technique accounts for nonlinearities in the entry point dispersion, which is represented by a covariance matrix of position and velocity errors. Because downrange distance of impact is a monotonic function of debris ballistic coefficient, a parametric method is useful for determining dispersion boundaries. The scheme is applied in the present analysis to estimate the Skylab footprint dispersions for a controlled reentry. A significant increase in the footprint dispersion is noticed for satellite breakup above a 200,000-ft altitude. A general discussion of the method used for analysis is presented together with some typical results obtained for the Skylab deboost mission, which was designed before NASA abandoned plans for a Skylab controlled reentry.

Rao, P. P.↗

NASA NTRS2009

Orbital Debris Quarterly News, Volume 13, No. 3

Inside - Congressional Hearing Held on Orbital Debris and Space Traffic - United Nations' COPUOS Receives Update on Iridium-Cosmos Collision - MMOD Inspection of the HST WFPC2 Radiator - Reentry Survivability Analysis of GPM Spacecraft - Update on Recent Major Breakup Fragments - Upcoming Meetings - Space Missions and Orbital Box Score

J.-C. Liou↗

NASA NTRS2024

The NASA Orbital Debris Program Office - In Service of Space Safety

Since the NASA Orbital Debris Program Office’s (ODPO) founding in 1979 at the Johnson Space Center in Houston, Texas, it has been at the forefront of orbital debris research, modeling, and policy development. The ODPO has worked in collaboration with NASA and other U.S. government missions since the 1980s to mitigate the growth of the orbital debris environment and protect the population of the Earth. Two main products from the ODPO, the Orbital Debris Engineering Model (ORDEM) and the Debris Assessment Software (DAS), are frequently among the top three most-downloaded software packages from the NASA Software Catalog. These products are provided free of charge to the public in furtherance of the goal to ensure that new space missions, in compliance with NASA’s orbital debris mitigation requirements, are developed, operated, and disposed of responsibly. In addition to these external-facing software tools, the ODPO maintains high-fidelity internal tools for reentry simulation (the Object Reentry Survival Analysis Tool, ORSAT), short-term risk assessment for robotic and human spaceflight missions (the Satellite Breakup Risk Assessment Module, SBRAM), among others. Using data from the ORDEM model, as well as using the Meteoroid Environment Model (MEM) developed by the Meteoroid Environment Office (MEO) at NASA’s Marshall Space Flight Center, the Hypervelocity Impact Technology (HVIT) team uses the BUMPER code to assess penetration risk to space vehicles in Earth orbit and beyond. This paper will discuss the services that the ODPO and HVIT provide, from mission concept development through end-of-mission, for NASA-related and commercial missions.

Chris Ostrom↗

NASA NTRS2019

Operational and Technical Updates to the Object Reentry Survival Analysis Tool

The Object Reentry Survival Analysis Tool (ORSAT) has been used in the NASA Orbital Debris Program Office for over 25 years to estimate risk due to uncontrolled reentry of spacecraft and rocket bodies. Development over the last 3 years has included: a major change to the treatment of carbon fiber- and glass fiber-reinforced plastics (CFRP and GFRP, respectively); an updated atmospheric model; a new model for computing casualty area around an impacting debris object; and a newly-implemented scheme to determine the breakup altitude of a reentry object. Software also was written to automatically perform parameter sweeps in ORSAT to allow for uncertainty quantification and sensitivity analysis for components with borderline demisability. These updates have improved the speed and fidelity of the reentry analysis performed using ORSAT, and have allowed for improved engineering understanding by estimating the uncertainty for each component’s survivability. A statistical model for initial conditions captures the latitude bias in population density, a large improvement over the previous inclination-based latitude-averaged models. A sample spacecraft has been analyzed with standard techniques using ORSAT 6.2.1 and again using all the updated models; we will demonstrate the variation in the total debris casualty area and overall expectation of casualty.

Ostrom, C.↗

NASA NTRS1988

Controlled reentry of the Gamma Ray Observatory (GRO)

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.

Brown, Evette R.↗

NASA NTRS2019

Development and Analysis of the Automated Object Reentry Survival Analysis Tool Parametric Study Wrapper

The NASA Orbital Debris Program Office (ODPO) studies all aspects of spacecraft end-of-life and orbital debris measurement, modeling, and mitigation. The reentry safety group within the ODPO uses the Object Reentry Survival Analysis Tool (ORSAT) to calculate the casualty risk due to reentry of spacecraft and other types of orbital debris. ORSAT models spacecraft as a collection of fragments that break apart from the parent object at a pre-defined “breakup altitude.” It then calculates the trajectory and aero-heating of these fragments to determine which fragments are completely destroyed and which survive to the ground and pose a risk to human population. Because of the historically high computational cost of these calculations, many simplifying assumptions have been made in the traditional calculation and analysis process used by the ODPO, some of which have been shown by recent research by the ODPO and others to be incorrect. Improvements to the ORSAT code and advancements in computer technology have vastly decreased the program’s processing time, and have allowed the ODPO to develop a capability for large-scale parametric studies and Monte Carlo reentry simulations that can aid in both the initial spacecraft design and provide more detailed and accurate risk analysis to spacecraft operators.

Smith, Andrew N.↗

NASA NTRS2009

Crystallographic Oxide Phase Identification of Char Deposits Obtained from Space Shuttle Columbia Window Debris

Analyzing the remains of Space Shuttle Columbia has proven technically beneficial years after the vehicle breakup. This investigation focused on charred deposits on fragments of Columbia overhead windowpanes. Results were unexpected relative to the engineering understanding of material performance in a reentry environment. The TEM analysis demonstrated that the oxides of aluminum and titanium mixed with silicon oxides to preserve a history of thermal conditions to which portions of the vehicle were exposed. The presence of Ti during the beginning of the deposition process, along with the thermodynamic phase precipitation upon cool down, indicate that temperatures well above the Ti melt point were experienced. The stratified observations implied that additional exothermic reaction, expectedly metal combustion of a Ti structure, had to be present for oxide formation. Results are significant for aerospace vehicles where thermal protection system (TPS) breaches cause substructures to be in direct path with the reentry plasma. 1

Olivas, J. D.↗

NASA NTRSDate not supplied

Recent Updates to the Object Reentry Survival Analysis Tool (ORSAT) Version 7.1

The Object Reentry Survival Analysis Tool (ORSAT) code is maintained and used by the NASA Orbital Debris Program Office (ODPO) and has been under continuous development and improvement since the mid-1990s. ORSAT is an object-oriented reentry simulation tool; it models a satellite as a collection of discrete components that follow independent trajectories upon the breakup of the parent object. Version 7.1 of the tool incorporates five years of new thermal and aerodynamic model development, multi-processor parametric study capability, codebase upgrades, and numerous bug-fixes. The thermal demise model was completely rewritten using a forward-time/central-space numerical stencil and incorporating a new pyrolysis model for fiber-reinforced plastic (FRP) materials. New aerodynamic and aeroheating models for hollow cylinders and hollow square prisms were developed using a combination of flow simulations in the direct simulation Monte Carlo (DSMC) Analysis Code (DAC) and Data Parallel Line Relaxation (DPLR) code and free-flight tests in the University of Texas at San Antonio’s Hypersonic Wind Tunnel. The latest version also incorporates a mechanical, strength-based demise model for FRP materials. Minor improvements include an update to the Fortran 2018 codebase; improved integration and speed with the Python-based, multi-core, parametric study tool, AutoORSAT; and fixes for many minor bugs. This new version of ORSAT will enable more accurate reentry risk assessments for modern satellites. This paper presents an overview of these changes and a summary of the verification and validation performed on the final code.

Benton R. Greene↗

NASA NTRSDate not supplied

Recent Updates to the Object Reentry Survival Analysis Tool (ORSAT) Version 7.1

Benton R. Greene↗