NASA's advanced multimission operations system

In order to solve the problem of the complexity of software system and the efficiency of large-scale collaboration, software architecture design methods have gradually developed. In the process of software architecture evolution, users and concurrency are increasing day by day, and software technology is constantly evolving and improving accordingly. Although there are many researches and technical discussions on software architecture methodology, there are few papers that fully discuss the development of technology in terms of the evolution of the architecture. This paper takes the evolution of software architecture as the research object, discusses problems, solutions and related technologies involved in the evolution of software architecture, and comprehensively explains how the system gradually evolves from a single architecture to a complex high-concurrency architecture. KeywordsArchitecture designArchitecture evolutionHigh concurrency

The Advanced Multi-Mission Operations System (AMMOS) provides a common Mission Operation System (MOS) infrastructure to NASA deep space missions. The evolution of AMMOS has been driven by two factors: increasingly challenging requirements from space missions, and the emergence of new IT technology. The work described in this paper focuses on three key tasks related to IT technology requirements: first, to eliminate duplicate functionality; second, to promote the use of loosely coupled application programming interfaces, text based file interfaces, web-based frameworks and integrated Graphical User Interfaces (GUI) to connect users, data, and core functionality; and third, to build, develop, and deploy AMMOS services that are reusable, agile, adaptive to project MOS configurations, and responsive to industrially endorsed information technology standards.

The NASA Engineering and Safety Center (NESC) was established in 2003 (after the Columbia accident) to provide an independent technical resource for the resolution of challenging technical problems (through the use of studies, analysis, tests, etc.) for NASA programs and projects. Since its inception, NESC has completed nearly 1000 technical assessments for NASA’s Human Exploration and Operation Mission Directorate (HEOMD), Science Mission Directorate (SMD), Space Technology Mission Directorate (STMD), and Aeronautics Research Mission Directorate (ARMD). Of the SMD related assessments, several were for the resolution of technical problems, analysis, or studies related to NASA’s astrophysics missions in various phases of the project from design to operation. Some of the recent examples of NESC technical support for NASA astrophysics missions have been for: Hubble Space Telescope (HST), Chandra X-ray Observatory (CXO), Fermi Gamma-ray Space Telescope, Kepler Space Telescope, Transiting Exoplanet Survey Satellite (TESS), James Webb Space Telescope (JWST), and Laser Interferometer Space Antenna (LISA). In this paper, we outline some of the technical challenges faced by these astrophysics missions and describe how NESC contributed to their resolution. The case studies cover a wide range of disciplines involving space telescopes, detectors, lasers, and attitude control systems. These efforts include innovative solutions for extending the life of the missions, technical resolution of challenging problems, strategies for risk mitigation, and failure investigations combined with lessons learned reports to advance discipline knowledge, enhance NASA capabilities, and avoid future problems.

Architecture-centric software evolution enables change in a system’s structure and behaviour while maintaining a global view of the software to address evolution-centric trade-offs. The existing solutions for architectural maintenance and evolution fall short of exploiting generic and reusable expertise to address recurring evolution problems. We present a pattern language as a collection of interconnected change patterns that enable reuse-driven and consistent evolution of component-based software architectures. Pattern interconnections represent possible relationships among patterns (such as variants or related patterns) in the language. In general, we introduce architecture change mining (pattern language development) as a complementary and integrated phase to facilitate reuse-driven architecture change execution (pattern language application). We evaluate the language applicability to support pattern-driven reuse in architecture evolution of a payment system case study. We also analyse the precision and recall factor as a measure of selecting the most appropriate pattern(s) from the language collection. The pattern language itself continuously evolves with an incremental discovery of new patterns from change logs over time

Before beginning this discussion, I would like to make a few remarks concerning the Jet Propulsion Laboratory (JPL). The Jet Propulsion Laboratory is responsible to the National Aeronautics and Space Administration (NASA) for unmanned missions in deep space. A worldwide tracking network encompasses Goldstone, California; Madrid, Spain; Johannesburg, South Africa; and Woomera and Tidbinbilla, Australia. In addition to the deep space missions, there are a great number of scientifically oriented projects throughout JPL. The Laboratory has approximately 4,100 employees, as well as some support contractor personnel.

Welcome you to the Fifth Edition of the track Software Architecture: Theory, Technology, and Applications (SA-TTA 2017) as part of the 32th ACM/SIGAPP Symposium on Applied Computing (SAC).

RISK MANAGEMENT IN THE PROGRAM/PROJECT ENVIRONMENT: The Risk Management process is assuming greater influence in the process of Project and Program Management. The requirements of NPG 7120.5A [NPG, 1998] have created inroads for the results of identifying risk to influence project decisions. Program needs and the interdependencies of risks among projects are receiving increasing attention on major JPL projects. Creating Risk Management plans and requiring risk reporting are beginning to make project personnel aware of the benefit of identifying and mitigating potential future adverse consequences and understanding the trade-offs involved in spending reserves for prevention as opposed to recovery from problems. Risk-based decision-making in the planning phase is allowing risks balancing to be considered, and hard decisions in the cost-capped environment require even reduction in expected mission return in order to provide adequate performance assurance. RISK ASSESSMENT TOOLS USED IN DESIGN AND ASSURANCE: The paper will describe the use of Risk-revealing checklists and compilations of engineering guidance principles as enabling tools for comprehensive risk identification. Also, effective risk assessment methods (such as Failure Modes Effects Analyses (FMEAs), and Probabilistic Risk Analyses (PRAs) will be discussed. Tracking tools appropriate to maintaining cognizance of risk will be covered. INTEGRATING RISK AND MANAGING PROJECT RESOURCES: JPL is in the process of identifying a standardized Risk Management methodology, which is based on the two pioneering methodologies developed on the Space Infrared Telescope Facility (SIRTF) and Mars Global Surveyor (MGS) projects. Criteria for assessing risk will be “normalized” with tailoring allowed. Database tools are available now to support this approach for flight projects. The Risk Management team at JPL has developed such a tool, which is in use on many of our projects. An advanced version of the JPL tool has been demonstrated which will provide options for quantitative analysis and resource management trade-offs. Implementation of risk tracking metrics in cost and schedule management systems, and design tools, will allow change to be quickly detected. Also, experience on the MGS project suggests that project management can make effective use of risk impact assessments based on cost, and can therefore gain insight into the effective use of project reserves. Utilizing common risk metrics between the risk management process and design metrics, Problem/ Failure Reports (PFRs), earned value reporting, and other management areas will provide more confidence in the impact of project decisions. INDEPENDENT ASSESSMENTS AND THE SYSTEMS MANAGEMENT OFFICE (SMO): The requirement to balance faithful service to the project customer while at the same time provide an objective assessment of the health of the project to the JPL administration and to the agency will be facilitated through the SMO function. Risk Assessments using criteria common to those that the project uses but identification and assessment by independent “eyes” will allow added possibility for early detection and correction of problems. This will enhance the Risk Management effectiveness on the project, and undoubtedly increase the likelihood of mission success.

The software industry increasingly needs to consider architecture evolution in the context of industrial ecosystem platforms. These environments feature a large number third-party offerings with a high variety and complexity of design and technology options. The software architects working on platform migration and in-platform evolution scenarios in such environments require support to find and utilize optimal offerings, ensure design compatibility with various technical and non-technical constraints, and optimize architectures. Based on a multi-case study of three industrial cases, we have derived an architecture knowledge model that provides a basis for supporting software architects in platform migration and in-platform evolution scenarios.

Modern computing and network environments demand ahigh degree of adaptability from applications. At run time, an application may have to face many changes: in configuration, in protocols used, in terms of the available resources, etc. Many such changes can only be adequately addressed through dynamic evolution of the software architecture of the application. In this paper, we propose a novel approach to dynamically evolve a software architecture based on run-time aspect oriented programming. In our framework, a system designer/administrator can control the architecture of an application by dynamically inserting and removing code extensions. It is even possible to replace a significant part of the underlying middleware infrastructure without stopping the application. The novelty of this work is that it allows for a much more flexible development strategy as it delegates issues like middleware choice and adherence to an architectural specification to a framework enhanced by dynamic code extensions.

Future-generation space missions across the solar system to the planets, moons, asteroids, and comets may someday incorporate supercomputers both to expand the range of missions being conducted and to significantly reduce their cost. By performing science computation directly on the spacecraft itself, the amount of data required to be downlinked may be reduced by many orders of magnitude, thus greatly reducing the mass of the resources needed for communication while increasing the quality and quantity of the science achieved. By performing the mission planning in real time directly on the spacecraft, complex and highly responsive missions can be conducted out of range of direct human intervention, and the cost of mission management can be reduced. Through highly replicated computing structures, continued operation can be maintained in the presence of faults by means of graceful degradation. Two classes of systems, reflecting very different strategies of computer system architecture, are actively being pursued by the NASA Jet Propulsion Laboratory (JPL) to take advantage of the opportunity of embedded high performance computing on spacecraft for deep-space missions. Commodity off-the-shelf (COTS) clusters may permit the direct application of commercial computing hardware in loosely coupled ensembles to benefit from the enormous investment of industry in mass-market components. New processor-in-memory (PIM) architectures combine multiple nodes on a single chip of processor-memory pairs exposing the full memory bandwidth. This paper examines the driving issues motivating the use of supercomputing for future deep-space missions and describes two active research projects at NASA JPL that are pursuing both the COTS and PIM strategies for next-generation spaceborne computing.

Cocaine consumption in the United States: Estimating past trends and future scenarios

Formal methods have exhibited as a promising technique that provides verifiable specifications for highly reliable software. However from the practical robotics perspective, formal methods remain unaccustomed among real-world robotic control software projects. The underlying reason is the unreasonable fear in working with purely theoretical foundations of formal methods and as a consequence many of their remarkable abilities are often ignored.

Change is an intrinsic property of software.A software system, during its lifetime, may require several updates, improvements, or new features.If these change requirements are not addressed, the risk of becoming a useless system increases.In fact, this is a challenging issue of safety-and mission-critical software systems, which cannot be stopped to perform maintenance or evolution operations due to their continuous operation.To reduce the aging of these critical systems, they must be provided with mechanisms enabling their dynamic evolution, i.e. the support of changes on their structure and behaviour while they remain in operation.This thesis is concerned with the design of a framework to build architecturebased, dynamically evolvable, software systems.The fact that this framework is a software architecture based approach provides the following advantages: (i) it offers a high-level of abstraction for describing dynamic changes; (ii) it allows varying the level of system description; and (iii) it advantages from the existing support for system modelling, code-generation, and formal analysis provided by architecture description languages.The framework presented in this thesis, called Dynamic PRISMA, is characterized by the combination of two levels of dynamism: Dynamic Reconfiguration, which addresses changes at the configuration level (i.e. the architectural configuration), and Dynamic Type Evolution, which addresses changes at the type-level (i.e. the specification of architectural types and instances).This combination is one of the major contributions of this thesis: thus a system is not only able to reconfigure at runtime the building blocks it is composed of (i.e.architectural types), but also to redefine these building blocks (or introduce new ones) at runtime.Another contribution of the thesis is the identification of the concerns related to dynamic evolution and their integration in the framework through aspects.This improves the separation of concerns and allows us to change reconfiguration specifications, evolution mechanisms, or the business logic independently of each other.A third contribution of this thesis is how this dynamism is supported: reconfiguration through autonomic capabilities, which provides proactivity according to either internal or external stimuli; and type evolution through asynchronous reflection, which enables the modification of a type specification and the transformation of their instances at different rates (i.e. when they are ready for evolution).Specifically, the asynchronous evolution vi semantics is precisely described by means of graph transformations.This formalism has been chosen because it naturally models both the system architecture and its asynchronous evolution.The work presented in this thesis is illustrated through a case study from the robotics domain; an area which could potentially benefit from the results of this thesis.

Managing evolution of complex software architecture is a continuous challenge in industry. Systems such as mobile handsets undergo a continuous increase in complexity, while the fast market evolution imposes quick integration of new features. Being able to easily manage software architecture evolution is the basis for shorter time-to-market and faster product release. The term “viewpoint” has become familiar with the publication of the IEEE standard 1471–2000 on recommended practices for architectural modelling. Based on the classical 4+1 view model, we have elaborated our own set of viewpoints in order to support our domain-specific architectural modelling needs. We hereby justify the introduction of the architectonic viewpoint, which models the evolutionary aspects of software architecture. The term, as well as the rationale behind it, is inspired from architecture as in buildings. We describe the viewpoint and the way it links to the others we use. Additionally, we briefly elaborate on the other viewpoints that we use for architectural modelling of mobile telephone software architecture. We provide basis for discussion and further research into the matter.

The app reviews are useful for app developers because they contain valuable information, e.g. bug, feature request, user experience, and rating. This information can be used to better understand user needs and application defects during software maintenance and evolution phase. The increasing number of reviews causes problems in the analysis process for developers. Reviews in textual form are difficult to understand, this is due to the difficulty of considering semantic between sentences. Moreover, manual checking is time-consuming, requires a lot of effort, and costly for manual analysis. Previous research shows that the collection of the review contains non-informative reviews because they do not have valuable information. Non-informative reviews considered as noise and should be eliminated especially for classification process. Moreover, semantic problems between sentences are not considered for the reviews classification. The purpose of this research is to classify user reviews into three classes, i.e. bug, feature request, and non-informative reviews automatically. User reviews are converted into vectors using word embedding to handle the semantic problem. The vectors are used as input into the first classifier that classifies informative and non-informative reviews. The results from the first classifier, that is informative reviews, then reclassified using the second classifier to determine its category, e.g. bug report or feature request. The experiment using 306,849 sentences of reviews crawled from Google Play and F-Droid. The experiment result shows that the proposed model is able to classify mobile application review by produces best accuracy of 0.79, precision of 0.77, recall of 0.87, and F-Measure of 0.81.