ALBERT

Description: Space construction poses new challenges not yet met in the space program to date. New materials: High strength to weight ratio metal matrix composites and other kinds of composites have been developed. They have not been fully characterized as regards rolling, drilling, cutting, forming, joining, etc. New joining methods: Many types of joining methods are proposed for use in space construction. It is important to understand the key discriminators in choosing one method over another. Once the discriminators are known, one can rank the various methods of joining or connecting things in space. New constructors: Astronauts frequently mention that EVA effort is very exhausting because of the suit inflexibility. For these reasons, as well as the inherent risk, hazards due to radiation, and other concerns mentioned in the literature, it is likely that robot workers of various sorts will play a key role. Now one must consider the question of qualifying space joining methods that will be applied by robots as well as those being applied by humans. New NDE methods/space qualification of detectors: For every joining method that is used here on earth, there are various non-destructive inspection techniques, such as ultrasonic inspection and x-ray inspection. It will be necessary to develop inspection techniques for all joining methods that will be approved for use in space. The detector must also be space qualified. Development testing: As a new concept for space habitat goes through its conceptual phases, various development tests are anticipated for the first time. Some elements cannot be adequately tested except in space itself. Flight check-out: Assuming that one is assembling the Mars spacecraft in earth orbit and that all of the preceding questions have been resolved, the day finally arrives when the fully assembled vehicle is ready for occupancy and journeying to Mars. It will be necessary to conduct a final flight readiness review, countdown procedure, and certification before the vehicle is permitted to depart for Mars with humans on board. When an error is found on earth, one can disassemble, go to a storeroom, pull a spare, or perform other readily available services to correct the anomaly. What should be done to correct errors and how it should be done in space needs to be addressed.

Description: During 1989-1990 the Center for Space Construction developed the Launch-On-Time (L-O-T) Model to help asses and improve the likelihood of successfully supporting space construction requiring multi-logistic delivery flights. The model chose a reference by which the L-O-T probability and improvements to L-O-T probability can be judged. The measure of improvement was chosen as the percent reduction in E(S(sub N)), the total expected amount of unscheduled 'hold' time. We have also previously developed an approach to determining the reduction in E(S(sub N)) by reducing some of the causes of unscheduled holds and increasing the speed at which the problems causing the holds may be 'fixed.' We provided a mathematical (binary linear programming) model for measuring the percent reduction in E(S(sub N)) given such improvements. In this presentation we shall exercise the model which was developed and draw some conclusions about the following: methods used, data available and needed, and make suggestions for areas of improvement in 'real world' application of the model.

Description: Designing software systems, like all design activities, is a knowledge-intensive task. Several studies have found that the predominant cause of failures among system designers is lack of knowledge: knowledge about the application domain, knowledge about design schemes, knowledge about design processes, etc. The goal of domain-specific software design systems is to explicitly represent knowledge relevant to a class of applications and use it to partially or completely automate various aspects of the designing systems within that domain. The hope is that this would reduce the intellectual burden on the human designers and lead to more efficient software development. In this paper, we present a domain-specific system built on top of KASE, a knowledge-assisted software engineering environment being developed at the Stanford Knowledge Systems Laboratory. We introduce the main ideas underlying the construction of domain specific systems within KASE, illustrate the application of the idea in the synthesis of a system for tracking aircraft from radar signals, and discuss some of the issues in constructing domain-specific systems.

Description: This report summarizes a study of the state-of-the-art in knowledge-based systems technology in Japan, organized by the Japanese Technology Evaluation Center (JTEC) under the sponsorship of the National Science Foundation and the Advanced Research Projects Agency. The panel visited 19 Japanese sites in March 1992. Based on these site visits plus other interactions with Japanese organizations, both before and after the site visits, the panel prepared a draft final report. JTEC sent the draft to the host organizations for their review. The final report was published in May 1993.

Description: Researchers are entering the second decade of research in the Blackboard problem solving framework with focus in the following areas: (1) extensions to the basic concepts implemented in AGE-1 to address, for example, reasoning with uncertain data; (2) a new architecture and development environment, BB1, that implements methods for explicity controlling the reasoning; and (3) the design of and experimentation with multiprocessor architectures using the Blackboard as an organizing framework. A summary of these efforts is presented.

Description: Abstraction fosters reuse by providing a class of artifacts that can be instantiated or customized to produce a set of artifacts meeting different specific requirements. It is proposed that significant leverage can be obtained by abstracting software system designs and the design process. The result of such an abstraction is a generic architecture and a set of knowledge-based, customization tools that can be used to instantiate the generic architecture. An approach for designing software systems based on the above idea are described. The approach is illustrated through an implemented example, and the advantages and limitations of the approach are discussed.

Description: The chemical composition of the primary cosmic rays between 10 to the 15th power eV and 10 to the 18th power eV were determined by a Large Area Cosmic Muon Detector located at Ohya stone mine. The experimental aims of Ohya project are; (1) search for the ultra high-energy gamma-rays; (2) search for the GUT monopole created by Big Bang; and (3) search for the muon bundle. A large number of muon chambers were installed at the shallow underground near Nikko (approx. 100 Km north of Tokyo, situated at Ohya-town, Utsunomiya-city). At the surface of the mine, very fast 100 channel scintillation counters were equipped in order to measure the direction of air showers. These air shower arrays were operated at the same time, together with the underground muon chamber.

Description: This paper summarizes the current state of the art in interplanetary supply chain modeling and discusses SpaceNet as one particular method and tool to address space logistics modeling and simulation challenges. Fundamental upgrades to the interplanetary supply chain framework such as process groups, nested elements, and cargo sharing, enabled SpaceNet to model an integrated set of missions as a campaign. The capabilities and uses of SpaceNet are demonstrated by a step-by-step modeling and simulation of a lunar campaign.