Flight design system requirements evaluation program
Flight planning requirements were analyzed and a computer system architecture was defined. An evaluation method of the proposed flight design system is also included.
Folk, R. A.↗
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Vehicle systems and payload requirements evaluation
Techniques developed for identifying launch vehicle system requirements for NASA automated space missions are discussed. Emphasis is placed on development of computer programs and investigation of astrionics for OSS missions and Scout. The Earth Orbit Mission Program - 1 which performs linear error analysis of launch vehicle dispersions for both vehicle and navigation system factors is described along with the Interactive Graphic Orbit Selection program which allows the user to select orbits which satisfy mission requirements and to evaluate the necessary injection accuracy.
Rea, F. G.↗
Quantitative nondestructive evaluation: Requirements for tomorrow's reliability
Quantitative Nondestructive Evaluation (QNDE) is the technology of measurement, analysis, and prediction of the state of material/structural systems for safety, reliability, and mission assurance. QNDE has impact on everyday life from the cars we drive, the planes we fly, the buildings we work or live in, literally to the infrastructure of our world. Here, researchers highlight some of the new sciences and technologies that are part of a safer, cost effective tomorrow. Specific technologies that are discussed are thermal QNDE of aircraft structural integrity, ultrasonic QNDE for materials characterization, and technology spinoffs from aerospace to the medical sector. In each case, examples are given of how new requirements result in enabling measurement technologies, which in turn change the boundaries of design/practice.
Heyman, Joseph S.↗
SLS Block-1B USA Separation Analysis and Requirements Evaluation Using the CLVTOPS Toolchain
Ensuring that rocket stage separation events provide positive clearance is critical to avoid loss of mission or crew. NASA's Marshall Space Flight Center (MSFC) has developed a cutting-edge toolchain to address this type of problem and it was used to set abstracted impulse requirements on, and to analyze the results of, the in-space separation event of the Universal Stage Adapter (USA) and the Exploration Upper Stage (EUS) of NASA's Space Launch System (SLS) Block-1B configuration. The toolchain is used as a hardware simulation to confirm positive body-to-body clearance during the separation event. It is also used to create a requirements-space simulation, which helps inform requirements as the hardware design matures.
Zach Muscha↗
Radiation Hardness Assurance (RHA): Challenges and New Considerations
Radiation Hardness Assurance (RHA) challenges associated with the use of commercial-off-the-shelf (COTS) components and emerging technologies are cause for risk acceptance in space flight missions. The RHA flow includes environment definition, hazard evaluation, requirements definition, evaluation of design, and design trades to accommodate the risk a project or program takes. The varied missions profiles and environments don't necessarily benefit from the same risk reduction efforts or cost reduction attempts. The level of effort within the RHA flow can be tailored to minimize risk based on the environment or design criticality.
Space Technology↗
The case for applying an early-lifecycle technology evaluation methodology to comparative evaluation of requirements engineering research
The premise of this paper is taht there is a useful analogy between evaluation of proposed problem solutions and evaluation of requirements engineering research itself. Both of these application areas face the challenges of evaluation early in the lifecycle, of the need to consider a wide variety of factors, and of the need to combine inputs from multiple stakeholders in making thse evaluation and subsequent decisions.
technology transfer↗
Apollo Applications Program /AAP/ payload integration. Determination of simulator requirements and evaluation of an alternate test program for AAP 1/2/3/4
Simulator requirements and flight program evaluation of Apollo applications program payload integration
Best, J.↗
Flight program language requirements. Volume 2: Requirements and evaluations
The efforts and results are summarized for a study to establish requirements for a flight programming language for future onboard computer applications. Several different languages were available as potential candidates for future NASA flight programming efforts. The study centered around an evaluation of the four most pertinent existing aerospace languages. Evaluation criteria were established, and selected kernels from the current Saturn 5 and Skylab flight programs were used as benchmark problems for sample coding. An independent review of the language specifications incorporated anticipated future programming requirements into the evaluation. A set of detailed language requirements was synthesized from these activities. The details of program language requirements and of the language evaluations are described.
Source record↗
Space solar power. Description of concept, results of preliminary studies, requirements for evaluation
The nation is actively pursuing alternate sources of energy because of the problems or concerns related to obtaining required energy for the future from oil, gas, nuclear, and coal sources. Solar energy is an obvious candidate for consideration. Its use in the past has been limited by the relative cost of collecting and converting solar energy into electrical power. The increasing costs of other energy sources will make solar energy more attractive. During recent years a new concept for the collection of solar energy has been developed. This concept involves the location of solar power stations in space. The concept, results of preliminary studies, and requirements for space evaluation of such a project are discussed.
Source record↗
A Methodology for Writing High Quality Requirements Specification and Evaluating Existing Ones
Requirements development and management have always been critical in the implementation of software systems; engineers are unable to build what analysts can't define. It is generally accepted that the earlier in the life cycle potential risks are identified the easier it is to eliminate or manage the conditions that introduce that risk. Problems that are not found until testing are approximately 14 times more costly to fix than if the problem was found in the requirement phase. The requirements specification, as the first tangible representation of the capability to be produced, establishes the basis for all of the project's engineering management and assurance functions. If the quality of the requirements specification is poor it can give rise to risks in all areas of the project. Recently, automated tools have become available to support requirements management. The use of these tools not only provides support in the definition and tracing of requirements, but it also opens the door to effective use of metrics in characterizing and assessing the quality of the requirement specifications.
Rosenberg, Linda↗
Large Area Crop Inventory, Experiment (LACIE). Level 3 baseline, Information Evaluation (IE) requirements, volume 7
There are no author-identified significant results in this report.
Source record↗
System Analysis and Generative Design for Icenode, a Buoyant Vehicle for Measuring Melt Rate Under Ice Shelves
Antarctic ice shelves buttress the Antarctic Ice Sheet from sliding into the ocean, and their collapse could trigger a meter or more of global sea level rise by the end of the century. Current state-of-the-art predictions for ice shelf behavior in a warming climate have large uncertainty, significantly hindered by a lack of in situ melt rate observations under ice shelves, especially near grounding zones. IceNode is a novel robotic vehicle under development at the NASA Jet Propulsion Laboratory to acquire such measurements, but presents a complex design problem owing to the large design space and conflicting performance requirements. Evaluating a preliminary design requires several types of tedious analysis which prevents rapid iteration and exploration of the design space. We present the implementation of a custom system analysis framework which was used to automate analysis such as resource budgeting, mission simulation, mass and buoyancy balancing, and static landing stability analysis of a given design configuration. Using this framework, we selected parameters which had the largest effects on design success and conducted a generative design study in which we programmatically varied a handful of parameters to generate 1540 different design candidates and test them across 160 different environmental scenarios. The custom built system analysis tool enabled rapid development of critical analysis and automated exploration of a large design space to guide preliminary design of the IceNode vehicle.
Gebara, Christine↗
Radiation Hardness Assurance (RHA): Challenges and New Considerations
Use of commercial-off-the-shelf (COTS) components and emerging technologies often require space flight missions to accept elevated risk. The Radiation Hardness Assurance (RHA) flow includes environment definition, hazard evaluation, requirements definition, evaluation of design, and design trades to accommodate and mitigate the risk a project or program takes. Depending on the mission profile and environment, different missions may not necessarily benefit from the same risk reduction efforts or cost reduction attempts. While this poses challenges for the radiation engineer, it also presents opportunities to tailor the RHA flow to minimize risk based on the environment or design criticality while remaining within budget. This presentation will focus on an approach to RHA amidst the present challenges, using the same RHA flow as in the past, with examples from recent radiation test results. The current challenges and the types of risk will be identified. How these risks drive requirements development and realization will be explained with examples of device results and data for single event effects (SEE) and in one case total ionizing dose (TID).
Radiation Hardness Assurance (RHA); Risk Managemen↗
DSN Array Simulator
The DSN Array Simulator (wherein 'DSN' signifies NASA's Deep Space Network) is an updated version of software previously denoted the DSN Receive Array Technology Assessment Simulation. This software (see figure) is used for computational modeling of a proposed DSN facility comprising user-defined arrays of antennas and transmitting and receiving equipment for microwave communication with spacecraft on interplanetary missions. The simulation includes variations in spacecraft tracked and communication demand changes for up to several decades of future operation. Such modeling is performed to estimate facility performance, evaluate requirements that govern facility design, and evaluate proposed improvements in hardware and/or software. The updated version of this software affords enhanced capability for characterizing facility performance against user-defined mission sets. The software includes a Monte Carlo simulation component that enables rapid generation of key mission-set metrics (e.g., numbers of links, data rates, and date volumes), and statistical distributions thereof as functions of time. The updated version also offers expanded capability for mixed-asset network modeling--for example, for running scenarios that involve user-definable mixtures of antennas having different diameters (in contradistinction to a fixed number of antennas having the same fixed diameter). The improved version also affords greater simulation fidelity, sufficient for validation by comparison with actual DSN operations and analytically predictable performance metrics.
Tikidjian, Raffi↗
DSN Simulator
The DSN Simulator (wherein DSN signifies NASA's Deep Space Network) is an updated version of the software described in DSN Array Simulator (NPO-44506), Software Tech Briefs (Special supplement to NASA Tech Briefs), Vol. 32, No. 9 (September 2008), page 26. To recapitulate: This software is used for computational modeling of proposed DSN facilities comprising arrays of antennas and transmitting and receiving equipment for microwave communication with spacecraft on interplanetary missions. Such modeling is performed to estimate facility performance, evaluate requirements that govern facility design, and evaluate proposed improvements in hardware and/or software. The software includes a Monte Carlo simulation component that enables rapid generation of key mission-set metrics (e.g., numbers of links, data rates, and data volumes), and statistical distributions thereof as functions of time. The prior version of the software could model only one DSN facility at a time and included hard-coded, unconfigurable metrics. The present updated version is capable of modeling the entire DSN and provides for configurable metrics, making it possible to perform loading analyses for alternative future DSN architectures and mission-set scenarios. The present version also features an improved user interface and interfaces for exchange of data with other DSN software and with a DSN mission model database.
Fijany, Amir↗
Orbital Spacecraft Consumables Resupply System (OSCRS): Monopropellant application to space station and OMV automatic refueling impacts of an ELV launch, volume 4
The use of orbital spacecraft consumables resupply system (OSCRS) at the Space Station is investigated, its use with the orbital maneuvering vehicle, and launch of the OSCRS on an expendable launch vehicles. A system requirements evaluation was performed initially to identify any unique requirements that would impact the design of OSCRS when used at the Space Station. Space Station documents were reviewed to establish requirements and to identify interfaces between the OSCRS, Shuttle, and Space Station, especially the Servicing Facility. The interfaces between OSCRS and the Shuttle consists of an avionics interface for command and control and a structural interface for launch support and for grappling with the Shuttle Remote Manipulator System. For use of the OSCRS at the Space Station, three configurations were evaluated using the results of the interface definition to increase the efficiency of OSCRS and to decrease the launch weight by Station-basing specific OSCRS subsystems. A modular OSCRS was developed in which the major subsystems were Station-based where possible. The configuration of an OSCRS was defined for transport of water to the Space Station.
Source record↗
Requirements for CFD validation experiments
A list of requirements for computational fluid dynamics verification is analyzed and evaluated. Requirements include: clearly defined physics and modeling, sensitivity studies, range, validation to real conditions, duplication of key experiments and computations, and combining experiments and computations. All results are presented in viewgraph format.
Bogdonoff, S. M.↗
A Methodology for Writing High Quality Requirement Specifications and for Evaluating Existing Ones
Requirements development and management have always been critical in the implementation of software systems-engineers are unable to build what analysts can not define. It is generally accepted that the earlier in the life cycle potential risks are identified the easier it is to eliminate or manage the conditions that introduce that risk. Problems that are not found until testing are approximately 14 times more costly to fix than if the problem was found in the requirement phase. The requirements specification, as the first tangible representation of the capability to be produced, establishes the basis for all of the project's engineering management and assurance functions. If the quality of the requirements specification is poor it can give rise to risks in all areas of the project. Recently, automated tools have become available to support requirements management. The use of these tools not only provides support in the definition and tracing of requirements, but it also opens the door to effective use of metrics in characterizing and assessing the quality of the requirement specifications.
Rosenberg, Linda↗