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

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NASA NTRS2009

From Verified Models to Verifiable Code

Declarative specifications of digital systems often contain parts that can be automatically translated into executable code. Automated code generation may reduce or eliminate the kinds of errors typically introduced through manual code writing. For this approach to be effective, the generated code should be reasonably efficient and, more importantly, verifiable. This paper presents a prototype code generator for the Prototype Verification System (PVS) that translates a subset of PVS functional specifications into an intermediate language and subsequently to multiple target programming languages. Several case studies are presented to illustrate the tool's functionality. The generated code can be analyzed by software verification tools such as verification condition generators, static analyzers, and software model-checkers to increase the confidence that the generated code is correct.

Lensink, Leonard↗
DOE OSTI2024

MOOSE-Based Fast Reactor Core Bowing Capabilities: Coupled Structural Mechanics – Thermal Fluids Demonstration and Related Verification Efforts

Under the U.S. Department of Energy Office of Nuclear Energy’s Advanced Modeling and Simulation (NEAMS) Program, an integrated multiphysics approach is being developed to model the core bowing phenomena important to liquid metal-cooled fast reactors. Core bowing is an important passive safety mechanism in liquid metal-cooled fast reactors and involves multiphysics effects including radiation transport, fluid flow, heat transfer, and mechanical response to temperature and flux gradients. Verification and assessment efforts continued on the Multiphysics Object Oriented Simulation Environment (MOOSE) capabilities relevant for modeling thermo-mechanical core bowing behavior. IAEA Verification Problem 4, which was started in FY23, was further examined with MOOSE capabilities to rectify discrepancies observed in previous years when compared to IAEA benchmark participant data. Meshing and postprocessing capabilities in MOOSE were also advanced by other teams and utilized this year. A thermal fluids-structural mechanical coupling demonstration has performed on 7-assemblyand 19-assembly fast reactor assembly configurations using MOOSE. Subchannel capabilities are used to calculate coolant temperature, and heat conduction capabilities calculate duct wall temperature as well as heat transfer through the inter-assembly gap. Structural mechanical capabilities then deform the mesh, accounting for contact between assemblies, according to the temperature gradients calculated by the thermal solvers. Power distributions are imposed rather than calculated to demonstrate different deformations.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
NASA NTRS1992

Manipulator design and development for the Ranger satellite servicing vehicle

The Ranger program is a planned series of low cost telerobotics flight experiments, based on the use of Pegasus launch vehicles. As the first step towards this goal, the Space Systems Lab was developing a neutral buoyancy version of Ranger for use in design verification and operations testing. The design approach and results of the Ranger manipulator development program is related. Ranger is designed to incorporate four appendages: a pair of dexterous, seven degree of freedom manipulators for general manipulation; a six DOF grappling arm for securing the vehicle to the local work site; and a five DOF positioning manipulator for the stereo camera pair that provide feedback to the remote operator. Each of these manipulators incorporate unique approaches to satisfying design requirements. The numerical and operational requirements are given for Ranger manipulators, and the evolution is discussed of the differing design approaches based on similarities and differences in the requirements. Testing results for individual joints and manipulator assemblies are presented, followed by initial results of operational testing on satellite servicing tasks with the integrated Ranger neutral buoyancy vehicle.

Howard, Russell D.↗
NASA NTRS1987

Verification of FANTASTIC integrated code

FANTASTIC is an acronym for Failure Analysis Nonlinear Thermal and Structural Integrated Code. This program was developed by Failure Analysis Associates, Palo Alto, Calif., for MSFC to improve the accuracy of solid rocket motor nozzle analysis. FANTASTIC has three modules: FACT - thermochemical analysis; FAHT - heat transfer analysis; and FAST - structural analysis. All modules have keywords for data input. Work is in progress for the verification of the FAHT module, which is done by using data for various problems with known solutions as inputs to the FAHT module. The information obtained is used to identify problem areas of the code and passed on to the developer for debugging purposes. Failure Analysis Associates have revised the first version of the FANTASTIC code and a new improved version has been released to the Thermal Systems Branch.

Chauhan, Rajinder Singh↗
NASA NTRS1993

Verification of thermal analysis codes for modeling solid rocket nozzles

One of the objectives of the Solid Propulsion Integrity Program (SPIP) at Marshall Space Flight Center (MSFC) is development of thermal analysis codes capable of accurately predicting the temperature field, pore pressure field and the surface recession experienced by decomposing polymers which are used as thermal barriers in solid rocket nozzles. The objective of this study is to provide means for verifications of thermal analysis codes developed for modeling of flow and heat transfer in solid rocket nozzles. In order to meet the stated objective, a test facility was designed and constructed for measurement of the transient temperature field in a sample composite subjected to a constant heat flux boundary condition. The heating was provided via a steel thin-foil with a thickness of 0.025 mm. The designed electrical circuit can provide a heating rate of 1800 W. The heater was sandwiched between two identical samples, and thus ensure equal power distribution between them. The samples were fitted with Type K thermocouples, and the exact location of the thermocouples were determined via X-rays. The experiments were modeled via a one-dimensional code (UT1D) as a conduction and phase change heat transfer process. Since the pyrolysis gas flow was in the direction normal to the heat flow, the numerical model could not account for the convection cooling effect of the pyrolysis gas flow. Therefore, the predicted values in the decomposition zone are considered to be an upper estimate of the temperature. From the analysis of the experimental and the numerical results the following are concluded: (1) The virgin and char specific heat data for FM 5055 as reported by SoRI can not be used to obtain any reasonable agreement between the measured temperatures and the predictions. However, use of virgin and char specific heat data given in Acurex report produced good agreement for most of the measured temperatures. (2) Constant heat flux heating process can produce a much higher heating rate than the radiative heating process. The results show that heating rates of 125 C/s (225 F/s) can be achieved. (3) The electrical resistance of the FM 5055 samples were about 150 Omega in the virgin state, and decreased to about 35 Omega when charred. A reliable scheme must be developed to electrically insulate the composite from the heater foil in order to prevent any current leakage into the sample which can result in volumetric heating of the char zone of the composite.

Keyhani, M.↗
NASA NTRS1986

Design and Verification Guidelines for Vibroacoustic and Transient Environments

Design and verification guidelines for vibroacoustic and transient environments contain many basic methods that are common throughout the aerospace industry. However, there are some significant differences in methodology between NASA/MSFC and others - both government agencies and contractors. The purpose of this document is to provide the general guidelines used by the Component Analysis Branch, ED23, at MSFC, for the application of the vibroacoustic and transient technology to all launch vehicle and payload components and payload components and experiments managed by NASA/MSFC. This document is intended as a tool to be utilized by the MSFC program management and their contractors as a guide for the design and verification of flight hardware.

Source record↗
NASA NTRSDate not supplied

Fusion of Test and Analysis: Artemis I Booster to Mobile Launcher Interface Validation

NASA is in the midst of bold and exciting next steps in human exploration and spaceflight. The designs of the new Space Launch System (SLS), the Orion spacecraft and the Exploration Ground Systems (EGS) for vehicle processing and launch are essentially complete and there has been significant progress in manufacturing and assembly of specific hardware for the Artemis I and Artemis II missions. Equally as important, the program level and integrated system level testing and analyses are also well underway to support integrated verification, validation, and Certificate of Flight Readiness (CoFR) for Artemis I. Testing and analysis are key to addressing technical challenges faced by the Artemis missions. Building block approaches are required that provide the right balance between component, element, and/or system level testing that satisfies verification and validation objectives where uncertainties are quantified and minimized. Artemis I is a system of systems that requires a fusion of test and analysis that adeptly characterizes critical interfaces between major program elements. An example of this fusion involves characterizing the interface between the SLS booster and the Mobile Launcher (ML) Vertical Support Post (VSP) interfaces. Proper characterization of this interface represents a number of challenges beginning with the fact that it is a mating of ground support structure in the form of a civil structure to flight hardware. Both sides of the interface are built to different construction standards, but are governed by interface requirements to ensure compatibility when mated. From past program experience, the flexibility at the booster to ML interface is critical in developing accurate prelaunch stacking and cryogenic preloads, squat loads, and pad separation release of preloads and squat loads. This same premise holds for Artemis I. To characterize the asymmetric characteristics at this interface, careful consideration of static forces due to gravity loading with the commensurate effects due to leveling during booster stacking (i.e., spacing and shimming) and nonlinear geometric forces are necessary for inclusion in pre-test assessments. This paper will look at these issues for the upcoming Booster Pull Test in which two boosters will be installed on the ML and one of these boosters will undergo static lateral loading followed afterwards with dynamic excitation into resonance and free-decay. This paper evaluates the booster to ML interface characteristics by characterizing the interface flexibility between the booster aft skirt and the ML VSP interfaces. Furthermore, this paper methodically evaluates the effect of the following on the test outcome: gravitational effects on the booster and ML, the effects of VSP leveling, spacing, and shimming under gravitational loading during booster stacking, the effect of geometric nonlinear follower force due to cg offset as booster is laterally displaced, and the system coupling between the booster under test, ML, and the second booster. Simulated results for a static load pull and dynamic excitation provide insight into the differences in measurement responses when boundary conditions and geometric conditions are included and not included.

Joel W Sills Jr.↗
DOE OSTI2026

Quantifying Operational Drivers of Multimodal Biometric Verification in Aerial Surveillance

Multimodal biometric verification is increasingly applied across operational contexts ranging from close-range security cameras and building-mounted surveillance to long-range ground sensors and unmanned aerial system (UAS) imagery. Variations in acquisition conditions—such as image resolution, viewing geometry, and motion artifacts—pose significant challenges for cross-domain algorithmic generalization. This study evaluates two independent multimodal biometric verification systems developed under the Intelligence Advanced Research Projects Activity (IARPA) Biometric Recognition and Identification at Altitude and Range (BRIAR) program, comparing performance on close-range and aerial datasets. Close-range video served as a baseline to quantify the decline in verification performance on aerial footage. The dataset included six UAS platforms, spanning small quadcopters at 10m altitude to medium-sized fixed-wing aircraft at 360m. Mixed-effects logistic regression identified image resolution (head and body pixel counts), head height, sensor characteristics, and algorithm selection as primary determinants of verification success, whereas demographic attributes and mission gait were not significant predictors. Activity type and collection site influenced performance in close-range data but had negligible impact on UAS imagery. These results clarify modality-specific strengths and limitations and highlight opportunities to enhance cross-domain biometric verification.

Peluso, Alina [ORNL] (ORCID:0000000328950406)↗
NASA NTRSDate not supplied

Multidisciplinary Dynamic Testing Challenges in Validating the NASA Artemis Architecture

NASA is in the midst of bold and exciting next steps in human exploration and spaceflight. The designs of the new Space Launch System (SLS), the Orion spacecraft and the Exploration Ground Systems (EGS) for vehicle processing and launch are essentially complete and there has been significant progress in manufacturing and assembly of specific hardware for the Artemis I and Artemis II missions. Equally as important, the program level and integrated system level testing and analyses are also well underway to support integrated verification, validation, and certificate of flight readiness (CoFR) for the first Artemis mission. Testing and analysis are key to addressing technical challenges that the Artemis missions offer. Building block approaches are required that provide the right balance between component, system, and/or element level testing that satisfies verification and validation objectives and where, uncertainties are quantified and minimized. Artemis I is a system of systems that requires a fusion of test and analysis that adeptly characterizes critical interfaces between major program elements. NASA is implementing new in-situ testing that fuse traditional aerospace structures with civil structures, such as the Integrated Modal Test for the Artemis I vehicle where the Mobile Launcher and Crawler Transporter serve as a support structure whose dynamics couple with that of the Artemis I vehicle. This new paradigm requires a closer inspection of structural behavior of the Crawler Transporter and the Mobile Launcher as they now serve multiple purposes. This requires a paradigm shift to look beyond experimental modal techniques and incorporates operational modal analysis techniques to validate dynamic models from data collected during rollout to the launch pad. A further complicating factor is the Crawler Transporter generated ground forces have numerous harmonics making extracting dynamic responses of the Artemis I, Mobile Launcher, and Crawler Transporter coupled system challenging. This discussion explores all these challenges with and attempts to understand how we best build confidence in systems and system-of-systems performance capabilities and margins and understand uncertainties.

Joel W Sills↗
NASA NTRS1978

Shuttle Entry Air Data System

The SEADS system (Shuttle Entry Air Data System) is being developed to provide research quality hypersonic (M greater than 3.5) air data. SEADS will accomplish this through the instrumentation of the orbiter's baseline nose cap. The SEADS development program consists of (1) the design and testing program required to define a reinforced carbon-carbon (RCC) nose cap penetration concept which will not degrade nose cap performance, (2) the definition of analytical techniques and design criteria for array definition and flight data analysis, (3) the verification of these analytical techniques and array criteria through a comprehensive wind-tunnel test program, (4) the demonstration of the system concept through detailed testing, and (5) the analyses and tests required to flight-certify the SEADS system.

Siemers, P. M., III↗
NASA NTRS1987

Space station structures and dynamics test program

The design, construction, and operation of a low-Earth orbit space station poses challenges for development and implementation of technology. One specific challenge is the development of a dynamics test program for defining the space station design requirements, and identifying and characterizing phenomena affecting the space station's design and development. The test proposal, as outlined, is a comprehensive structural dynamics program to be launched in support of the space station (SS). Development of a parametric data base and verification of the mathematical models and analytical analysis tools necessary for engineering support of the station's design, construction, and operation provide the impetus for the dynamics test program. The four test phases planned are discussed: testing of SS applicable structural concepts; testing of SS prototypes; testing of actual SS structural hardware; and on-orbit testing of SS construction.

Bugg, Frank M.↗
NASA NTRS1972

Apollo experience report: Thermal protection from engine-plume environments

Portions of the combined Apollo spacecraft (the command and service module and the lunar module) are subjected to the impingement of hot exhaust gases from the various propulsion systems of the modules. The configurations of the vehicles and the sources of impinging engine plumes are described. A typical Apollo mission is outlined. Protection and design-verification methods are discussed. Finally, recommendations are made for future spacecraft programs.

Taylor, J. T.↗
NASA NTRS1972

Umbilical Connect Techniques Improvement-Technology Study

The objective of this study was to develop concepts, specifications, designs, techniques, and procedures capable of significantly reducing the time required to connect and verify umbilicals for ground services to the space shuttle. The desired goal was to reduce the current time requirement of several shifts for the Saturn 5/Apollo to an elapsed time of less than one hour to connect and verify all of the space shuttle ground service umbilicals. The study was conducted in four phases: (1) literature and hardware examination, (2) concept development, (3) concept evaluation and tradeoff analysis, and (4) selected concept design. The final product of this study was a detail design of a rise-off disconnect panel prototype test specimen for a LO2/LH2 booster (or an external oxygen/hydrogen tank for an orbiter), a detail design of a swing-arm mounted preflight umbilical carrier prototype test specimen, and a part 1 specification for the umbilical connect and verification design for the vehicles as defined in the space shuttle program.

Valkema, Donald C.↗
NASA NTRS1975

Summary report on the Viking 1975 DSN telecommunications compatibility test program

The system design tests and test results that provided the basis for establishment of telecommunications design between the DSN and Viking 1975 were described. The Viking 1975/DSN Telecommunications Compatibility Test Program Consisted of three phases: subsystem design, system design, and system verification tests which were performed at JPL and at the Air Force Eastern Test Range and Kennedy Space Center complexes. Subsystem design tests were performed with the Viking Orbiter (VO) and the Viking Lander (VL) during 1973. System design compatibility tests were performed with the Viking Proof Test Orbiter, Viking Spacecraft Test Lander, and a multiple Viking spacecraft configuration during the summer of 1974. System verification tests were performed with the Viking Orbiter, Viking Lander and Viking spacecraft during the spring and summer of 1975.

A. I. Bryan↗
NASA NTRS1977

Voyager flight project: DSN Telecommunications Compatibility Test Program

The Voyager Flight Project - DSN Telecommunications Compatibility Test Program consisted of three phases: Subsystem Design, System Design, and System Verification Tests. Subsystem Design Tests were performed during mid 1976. System Design Tests were performed during late 1976 and early 1977. System Verification Tests were performed during the spring and summer of 1977. This article describes the System Design Tests and test results that provided the basis for establishment of telecommunications design between the DSN and the Voyager Flight Project.

Bryan, A. I.↗
NASA NTRS1979

To the first Shuttle launch

The major Shuttle-related testing currently in progress includes: static testing of all major elements, full scale ground vibration testing, main propulsion system testing, software verification and validation, qualification testing of many components and subsystems, and SSME verification testing. This paper reviews the current status of the Shuttle program and gives attention to the transition to operations, near-term traffic plans, user-charge policies, and payload integration. It is concluded that the transition from individual space-research projects to a fully integrated Space Transportation System, providing low-cost routine access to space for many users, involves a complete rethinking of the role NASA and the user will play.

Yardley, J. F.↗
NASA NTRS1980

Study of solution procedures for nonlinear structural equations

A method for the redution of the cost of solution of large nonlinear structural equations was developed. Verification was made using the MARC-STRUC structure finite element program with test cases involving single and multiple degrees of freedom for static geometric nonlinearities. The method developed was designed to exist within the envelope of accuracy and convergence characteristic of the particular finite element methodology used.

Young, C. T., II↗