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NASA NTRS2023

The Digital Astronaut Simulation

The Digital Astronaut Simulation provides a human biomechanics modeling, simulation, and analysis capability that is enabling spaceflight hardware design to incorporate the human dynamic input early in development cycles as well as characterize performance after prototypes are built. The enhanced toolset includes a modified multibody model, updated motion capture marker sets, and refined methods for scaling and inverse kinematics. These provide increased accuracy for applications in exercise and extravehicular tasks in reduced gravity, especially where upper extremity motion is involved. A core capability highlighted is the calculation of ground reaction forces, moments, and center of pressure based on motion capture. Verification and validation efforts include comparison with force platform measurements.

Human Spaceflight↗

NASA NTRS2024

Current Status of Martian Moons eXploration (MMX) Contamination Control and Curation Activity

Martian Moons eXploration (MMX) is a sample return mission from the Martian moon Phobos. The MMX spacecraft is scheduled to launch in 2026 and return to Earth in 2031. The main science goals of MMX are “to reveal the origin of the Martian moons and make progress in the understanding of planetary system formation and material transport in the solar system, and to observe processes that impact the circumplanetary and surface environments of Mars”. MMX has two sampling systems: coring (C)-sampler and pneumatic (P)-sampler and plans to bring back >10 g of Phobos sample. The retuned sample in the sample capsule will be transferred to the curation facility in ISAS/JAXA for sample curation and subsequent sample analysis. Contamination control of the sample return mission requires special care to prevent terrestrial contamination to the spacecraft, which would ruin the scientific value of the returned sample. Retaining the pristineness of the retuned sample is an important task of the MMX Curation and Sampler Science teams. The basis of the contamination control is (1) to minimize and understand the nature and amount of contaminants, (2) to perform contamination assessment and evaluate the effect of contaminants in the spacecraft on the retuned sample, (3) to employ a contamination knowledge (CK) material coupon in the spacecraft to identify the contaminants in the returned samples. In the MMX contamination control plan, the allowable contamination level for each contaminant is carefully defined. They are mostly set to be 1/1000 of the expected amount of each material in the returned sample and are divided into two main categories: organic and inorganic. The allowable atmospheric leakage rate to the sample container is also defined. The allowable contamination level of the organic materials is based on the composition of carbonaceous chondrites. The target contaminants are amino acids, aliphatic and aromatic hydrocarbons, carboxylic acids, etc. In case of the inorganic materials, the target contaminants are important elements to permit distinguishing the origin of the Martian moon by nucleosynthetic isotope anomalies (Cr, Ti, and Mo) and to reveal the evolution of the Martian moon by chronology (Hf, W, U, Pb, Rb, Sr, Sm, and Nd). The key instrument of contamination control in the sample return mission is the sampler system. The C-sampler has been developed by JAXA and the P-sampler was provided by Honeybee/NASA. In MMX, materials used in the two samplers (C- and P- sampler) were carefully selected to avoid potential contamination from the design stage of the system. The individual parts of the C-sampler FM (Flight Model) were thoroughly cleaned at the curation facility in ISAS/JAXA by the full-course cleaning procedure, which is an ultrasonic cleaning with organic solvents and ultrapure water in several steps. The equivalent level of cleaning was also carried out on the P-Samper FM as well by Honeybee Robotics in the USA. Now, MMX is in the critical phase for contamination control called ATLO: Assembly, Test, and Launch Operations. During the ATLO phase, sampler FM is constantly purged with nitrogen gas and maintained at positive pressure to prevent environmental contamination. The surrounding environments of the sampler FM are also simultaneously monitored using the CK Monitoring Coupon Set, which consists of several witness materials such as a glass petri dish, sapphire glass disk, and carbon adhesive tape (Figure 1). The detailed environmental assessment of each clean room used for the assembly and test of the sampler FM has also been conducted. This assessment includes microbial analysis, which was performed for OSIRIS-REx. Regarding the sample recovery and sample curation, we have started the designing of Sample Container Disassembling Instrument for the sample recovery from the sample container and the MMX curation chamber for sample curation. The curation protocol for the Phobos returned sample has also been discussed by the MMX Sample Analysis Working Team (SAWT). The MMX curation protocol consists of three phases: (1) quick analysis, (2) pre-basic characterization, and (3) basic characterization. (1) is extraction of the sample gas from the sample container and analysis by mass spectrometry, (2) is observation in bulk level, and (3) is observation in grain level and allocation of the sample aliquots. In parallel with the curation protocol, the returned sample undergoes preliminary examination for scientific investigations to achieve science goals. In addition, the CK witness plates made of sapphire glass are on board the sampler system. The CK witness plates will be recovered from the sampler system and analyzed by SAWT for the assessment of in-flight contamination.

Haruna Sugahara↗

NASA NTRS1978

Analysis and in-simulator evaluation of display and control concepts for a terminal configured vehicle in final approach in a windshear environment

Display Control configurations for the Terminal configured Vehicle in approach to landing situations were analyzed. A pilot/vehicle model was used to compare with a real time simulation study. Model results are presented and extended for the approach task during wind shear and random turbulence environments. In general, model results of performance trends matched those obtained experimentally.

Levison, W. H.↗

NASA NTRS1982

LSS reference platform control

The long range objective of this task is to develop basic technology in the design, mechanization, and analysis of control systems for large flexible space structures. The focus of the FY'81 platform control effort was on the pointing control problems associated with multiple independently controlled experiment packages operating simultaneously on a single platform. Particular emphasis was placed on obtaining a quantitative comparison of controller performance with and without base motion compensation.

Edmunds, R. S.↗

NASA NTRS1987

On 3-D inelastic analysis methods for hot section components. Volume 1: Special finite element models

This Annual Status Report presents the results of work performed during the third year of the 3-D Inelastic Analysis Methods for Hot Section Components program (NASA Contract NAS3-23697). The objective of the program is to produce a series of new computer codes that permit more accurate and efficient three-dimensional analysis of selected hot section components, i.e., combustor liners, turbine blades, and turbine vanes. The computer codes embody a progression of mathematical models and are streamlined to take advantage of geometrical features, loading conditions, and forms of material response that distinguish each group of selected components. This report is presented in two volumes. Volume 1 describes effort performed under Task 4B, Special Finite Element Special Function Models, while Volume 2 concentrates on Task 4C, Advanced Special Functions Models.

Nakazawa, S.↗

NASA NTRS1993

FNAS/summer faculty fellowship research continuation program. Task 6: Integrated model development for liquid fueled rocket propulsion systems. Task 9: Aspects of model-based rocket engine condition monitoring and control

The objective of Phase I of this research effort was to develop an advanced mathematical-empirical model of SSME steady-state performance. Task 6 of Phase I is to develop component specific modification strategy for baseline case influence coefficient matrices. This report describes the background of SSME performance characteristics and provides a description of the control variable basis of three different gains models. The procedure used to establish influence coefficients for each of these three models is also described. Gains model analysis results are compared to Rocketdyne's power balance model (PBM).

Santi, L. Michael↗

NASA NTRS1994

Magellan Project: Evolving enhanced operations efficiency to maximize science value

Magellan has been one of NASA's most successful spacecraft, returning more science data than all planetary spacecraft combined. The Magellan Spacecraft Team (SCT) has maximized the science return with innovative operational techniques to overcome anomalies and to perform activities for which the spacecraft was not designed. Commanding the spacecraft was originally time consuming because the standard development process was envisioned as manual tasks. The Program understood that reducing mission operations costs were essential for an extended mission. Management created an environment which encouraged automation of routine tasks, allowing staff reduction while maximizing the science data returned. Data analysis and trending, command preparation, and command reviews are some of the tasks that were automated. The SCT has accommodated personnel reductions by improving operations efficiency while returning the maximum science data possible.

Cheuvront, Allan R.↗

NASA NTRS1999

Goddard High Resolution Spectrograph SV/GTO Project

Contract number NAS5-30433, known at Ball Aerospace as the GHRS SV/GTO project, supported our participation in the post-launch activities of the Goddard High Resolution Spectrograph aboard the Hubble Space Telescope. The period of performance was December 1988 through December 1998. The contract supported the involvement of Dr Dennis Ebbets in the work of the GHRS Investigation Definition Team, and several of the Ball people in the documentation and publication of results. Three main categories of tasks were covered by this contract; in-orbit calibration of the GHRS, guaranteed time observations, and education and public outreach. The nature and accomplishments of these tasks are described in the report. This summary makes many references to publications in the scientific and technical literature. Appendix A is extracted from a complete bibliography, and lists those papers that are directly related to work performed under this GHRS contract. The tasks related to the in-orbit calibration of the GHRS were by far the largest responsibility during the first six years of the project. During this period Dr. Ebbets was responsible for the definition of calibration requirements, design of experiments, preparation of observing proposals, tracking their implementation and execution, and coordinating the analysis and publication of the results. Prior to the launch of HST in 1990 the observing proposals were developed in cooperation with the scientists on the GHRS DDT, engineers at Ball Aerospace, the operations staff at the STScI, and project coordinators at GSFC.

Ebbets, Dennis↗

NASA NTRS2010

Using Multi-Core Systems for Rover Autonomy

Task Objectives are: (1) Develop and demonstrate key capabilities for rover long-range science operations using multi-core computing, (a) Adapt three rover technologies to execute on SOA multi-core processor (b) Illustrate performance improvements achieved (c) Demonstrate adapted capabilities with rover hardware, (2) Targeting three high-level autonomy technologies (a) Two for onboard data analysis (b) One for onboard command sequencing/planning, (3) Technologies identified as enabling for future missions, (4)Benefits will be measured along several metrics: (a) Execution time / Power requirements (b) Number of data products processed per unit time (c) Solution quality

multi-core↗

NASA NTRS1990

Robotic lunar surface operations: Engineering analysis for the design, emplacement, checkout and performance of robotic lunar surface systems

The assembly, emplacement, checkout, operation, and maintenance of equipment on planetary surfaces are all part of expanding human presence out into the solar system. A single point design, a reference scenario, is presented for lunar base operations. An initial base, barely more than an output, which starts from nothing but then quickly grows to sustain people and produce rocket propellant. The study blended three efforts: conceptual design of all required surface systems; assessments of contemporary developments in robotics; and quantitative analyses of machine and human tasks, delivery and work schedules, and equipment reliability. What emerged was a new, integrated understanding of hot to make a lunar base happen. The overall goal of the concept developed was to maximize return, while minimizing cost and risk. The base concept uses solar power. Its primary industry is the production of liquid oxygen for propellant, which it extracts from native lunar regolith. Production supports four lander flights per year, and shuts down during the lunar nighttime while maintenance is performed.

Woodcock, Gordon R.↗

NASA NTRS2001

Empirical Analysis of EEG and ERPs for Psychophysiological Adaptive Task Allocation

The present study was designed to test the efficacy of using Electroencephalogram (EEG) and Event-Related Potentials (ERPs) for making task allocation decisions. Thirty-six participants were randomly assigned to an experimental, yoked, or control group condition. Under the experimental condition, a tracking task was switched between task modes based upon the participant's EEG. The results showed that the use of adaptive aiding improved performance and lowered subjective workload under negative feedback as predicted. Additionally, participants in the adaptive group had significantly lower RMSE and NASA-TLX ratings than participants in either the yoked or control group conditions. Furthermore, the amplitudes of the N1 and P3 ERP components were significantly larger under the experimental group condition than under either the yoked or control group conditions. These results are discussed in terms of the implications for adaptive automation design.

Prinzel, Lawrence J., III↗

NASA NTRS1985

System analysis study of space platform and station accommodations for life sciences research facilities. Volume 2: Study results. Appendix E: Work breakdown structure and dictionary

A work breakdown structure for the Space Station Life Sciences Research Facility (LSRF) is presented up to level 5. The purpose is to provide the framework for task planning and control and to serve as a basis for budgeting, task assignment, cost collection and report, and contractual performance measurement and tracking of the Full Scale Development Phase tasks.

Wiley, Lowell F.↗

NASA NTRS1987

Fault-free performance validation of fault-tolerant multiprocessors

A validation methodology for testing the performance of fault-tolerant computer systems was developed and applied to the Fault-Tolerant Multiprocessor (FTMP) at NASA-Langley's AIRLAB facility. This methodology was claimed to be general enough to apply to any ultrareliable computer system. The goal of this research was to extend the validation methodology and to demonstrate the robustness of the validation methodology by its more extensive application to NASA's Fault-Tolerant Multiprocessor System (FTMP) and to the Software Implemented Fault-Tolerance (SIFT) Computer System. Furthermore, the performance of these two multiprocessors was compared by conducting similar experiments. An analysis of the results shows high level language instruction execution times for both SIFT and FTMP were consistent and predictable, with SIFT having greater throughput. At the operating system level, FTMP consumes 60% of the throughput for its real-time dispatcher and 5% on fault-handling tasks. In contrast, SIFT consumes 16% of its throughput for the dispatcher, but consumes 66% in fault-handling software overhead.

Czeck, Edward W.↗

NASA NTRS1987

Improved silicon nitride for advanced heat engines

The technology base required to fabricate silicon nitride components with the strength, reliability, and reproducibility necessary for actual heat engine applications is presented. Task 2 was set up to develop test bars with high Weibull slope and greater high temperature strength, and to conduct an initial net shape component fabrication evaluation. Screening experiments were performed in Task 7 on advanced materials and processing for input to Task 2. The technical efforts performed in the second year of a 5-yr program are covered. The first iteration of Task 2 was completed as planned. Two half-replicated, fractional factorial (2 sup 5), statistically designed matrix experiments were conducted. These experiments have identified Denka 9FW Si3N4 as an alternate raw material to GTE SN502 Si3N4 for subsequent process evaluation. A detailed statistical analysis was conducted to correlate processing conditions with as-processed test bar properties. One processing condition produced a material with a 97 ksi average room temperature MOR (100 percent of goal) with 13.2 Weibull slope (83 percent of goal); another condition produced 86 ksi (6 percent over baseline) room temperature strength with a Weibull slope of 20 (125 percent of goal).

Yeh, Hun C.↗

NASA NTRS2009

Application of Reduced Order Transonic Aerodynamic Influence Coefficient Matrix for Design Optimization

Supporting the Aeronautics Research Mission Directorate guidelines, the National Aeronautics and Space Administration [NASA] Dryden Flight Research Center is developing a multidisciplinary design, analysis, and optimization [MDAO] tool. This tool will leverage existing tools and practices, and allow the easy integration and adoption of new state-of-the-art software. Today s modern aircraft designs in transonic speed are a challenging task due to the computation time required for the unsteady aeroelastic analysis using a Computational Fluid Dynamics [CFD] code. Design approaches in this speed regime are mainly based on the manual trial and error. Because of the time required for unsteady CFD computations in time-domain, this will considerably slow down the whole design process. These analyses are usually performed repeatedly to optimize the final design. As a result, there is considerable motivation to be able to perform aeroelastic calculations more quickly and inexpensively. This paper will describe the development of unsteady transonic aeroelastic design methodology for design optimization using reduced modeling method and unsteady aerodynamic approximation. The method requires the unsteady transonic aerodynamics be represented in the frequency or Laplace domain. Dynamically linear assumption is used for creating Aerodynamic Influence Coefficient [AIC] matrices in transonic speed regime. Unsteady CFD computations are needed for the important columns of an AIC matrix which corresponded to the primary modes for the flutter. Order reduction techniques, such as Guyan reduction and improved reduction system, are used to reduce the size of problem transonic flutter can be found by the classic methods, such as Rational function approximation, p-k, p, root-locus etc. Such a methodology could be incorporated into MDAO tool for design optimization at a reasonable computational cost. The proposed technique is verified using the Aerostructures Test Wing 2 actually designed, built, and tested at NASA Dryden Flight Research Center. The results from the full order model and the approximate reduced order model are analyzed and compared.

Pak, Chan-gi↗

NASA NTRS2016

Space to Space Advanced EMU Radio

The main task for this project was the development of a prototype for the Space to Space Advanced EMU Radio (SSAER). The SSAER is an updated version of the Space to Space EMU Radio (SSER), which is the current radio used by EMUs (Extravehicular Mobility Unit) for communication between suits and with the ISS. The SSER was developed in 1999, and it was desired to update the design used in the system. Importantly, besides replacing out-of-production parts it was necessary to decrease the size of the radio due to increased volume constraints with the updated Portable Life Support System (PLSS) 2.5, which will be attached on future space suits. In particular, it was desired to fabricate a PCB for the front-end of the prototype SSAER system. Once this board was manufactured and all parts assembled, it could then be tested for quality of operation as well as compliancy with the SSER required specifications. Upon arrival, a small outline of the target system was provided, and it was my responsibility to take that outline to a finished, testable board. This board would include several stages, including frequency mixing, amplification, modulation, demodulation, and handled both the transmit and receive lines of the radio. I developed a new design based on the old SSER system and the outline provided to me, and found parts to fit the tasks in my design. It was also important to consider the specifications of the SSER, which included the system noise figure, gain, and power consumption. Further, all parts needed to be impedance matched, and spurious signals needed to be avoided. In order to fulfill these two requirements, it was necessary to perform some calculations using a Smith Chart and excel analysis. Once all parts were selected, I drew the schematics for the system in Altium Designer. This included developing schematic symbols, as well as layout. Once the schematic was finished, it was then necessary to lay the parts out onto a PCB using Altium. Similar to the schematic design, in order to accomplish this it was necessary to develop component land patterns and add component 3D models. All of this was achieved, and the PCB is currently in review. After it is finished being reviewed, this board will be sent out for manufacture. All electronic components used in the PCB have been acquired, and once the board arrives they will be soldered onto the board using a machine in building 44. Finally, the board will be tested for performance on-site. This will likely be accomplished by the end of the internship.

Maicke, Andrew↗

NASA NTRS1993

Ultra-high resolution water window x ray microscope optics design and analysis

This project has been focused on the design and analysis of an ultra-high resolution water window soft-x-ray microscope. These activities have been accomplished by completing two tasks contained in the statement of work of this contract. The new results from this work confirm: (1) that in order to achieve resolutions greater than three times the wavelength of the incident radiation, it will be necessary to use spherical mirror surfaces and to use graded multilayer coatings on the secondary in order to accommodate the large variations of the angle of incidence over the secondary when operating the microscope at numerical apertures of 0.35 or greater; (2) that surface contour errors will have a significant effect on the optical performance of the microscope and must be controlled to a peak-to-valley variation of 50-100 A and a frequency of 8 periods over the surface of a mirror; and (3) that tolerance analysis of the spherical Schwarzschild microscope has been shown that the water window operations will require 2-3 times tighter tolerances to achieve a similar performance of operations with 130 A radiation. These results have been included in a manuscript included in the appendix.

Shealy, David L.↗

NASA NTRS2000

A Tool for Automatic Data Distribution for CFD Applications on Structured Grids

Development of HPF versions of NPB and ARC3D has shown that HPF provides an efficient, concise way to express parallelism and to organize data traffic. The use of HPF, as noted in the papers, requires an intimate knowledge of the applications and a detailed analysis of data affinity, data movement, and data granularity. To simplify and accelerate the task of developing HPF versions of existing CFD applications we have designed and implemented ADAPT (Automatic Data Alignment and Placement Tool). ADAPT analyzes a CFD application working on a single structured grid and generates HPF TEMPLATE, (RE)DISTRIBUTION, ALIGNMENT, and INDEPENDENT directives. The directives can be generated on the nest level, subroutine level, application level, or on the application interface level. ADAPT annotates an existing CFD FORTRAN application, performing computations on single or multiple grids. On each grid the application is considered as a sequence of operators, each applied to a set of variables defined in a particular grid domain. ADAPT automatically detects implicit operators (i.e., having data dependences) and explicit operators (without data dependences). For parallelization of an explicit operator ADAPT creates a template for the operator domain, aligns arrays used in the operator with the template, distributes the template, and declares the loops over the distributed dimensions as INDEPENDENT. For parallelization of an implicit operator, the distribution of the operator's domain should be consistent with the operator's dependences. Any dependence between sections distributed on different processors would preclude parallelization if the compiler does not have an ability to pipeline computations. If a data distribution is "orthogonal" to the dependences of an implicit operator, then the loop which implements the operator can be declared as INDEPENDENT. ADAPT starts with an analysis of array index expressions of the loop nests. For each pair of arrays referenced in an assignment statement, it generates an arc in the alignment graph and annotates it with an affinity relation. The template, alignment, and distribution directives for a particular loop nest are then derived from a transitive closure of the affinity relation. A compromise of data distributions in different nests and subroutines is achieved by merging annotated alignment graphs for adjacent nests/stibroutine calls in the nest/call graph of the application in the process called distribution lifting. ADAPT has been implemented as a C++ program running in conjunction with a parallelization tool called CAPTools. ADAPT uses the parse tree, interprocedural analysis and application database generated by CAPTools. It also uses the Directed Graph class, initially implemented in p2d2 (parallel debugger oi distributed programs), and some other classes supporting symbolic computations. ADAPT uses data distribution techniques described. ADAPT was tested with ARC3D and the FT benchmark and has demonstrated a code performance within a factor of 1.5 of handwritten versions.

Frumkin, Michael↗