David J. Weeks

Advanced automation approaches for space power systems

The short-term objective of the work described is to develop ground and knowledge-based systems integrated with actual electric power system breadboards and testbeds to demonstrate the viability of advanced automation approaches for spacecraft onboard and ground-support applications. Initially, such systems would be used primarily in advisory capacities. As confidence is gained in their operation, these systems would evolve to allow closed-loop control. The long-term objective is to develop such intelligent knowledge-based systems for actual onboard autonomous operation of the spacecraft electric power system. The approach taken has been to start with well-defined, limited electric power system applications as stand-alone systems. The next step has been to integrate such applications with actual breadboards that are representative of flight systems. The next activity is concerned with focusing on integrating these knowledge-based systems with conventional automation software and hardware. Current efforts emphasize adding robustness to the interactions among the knowledge-based systems as well as adding intermediate levels of autonomy for the power system management.<<ETX>>

Artificial intelligence approaches in space power systems automation at Marshall space flight center

Advancements in the field of artificial intelligence (AI) made during this decade have forever changed the way we look at automating spacecraft subsystems including the electrical power system. This paper will discuss various applications of AI to spacecraft electrical power systems. Such discussion will include an overview of various completed, on-going, and planned knowledge-based system activities. These applications include NICBES (Nickel-Cadmium Battery Expert System which is interfaced with the Hubble Space Telescope electrical power system test bed); the SSES (power system loads scheduler); the three cooperating AI systems in the Space Station Module Power Management and Distribution system test bed; and I-DARE, the intelligent data reduction expert. The progress, as well as the issues raised by, of each of these projects will be addressed.

Expert systems in space: Minimizing crew and ground support with knowledge-based systems at Marshall Space Flight Center

The author discusses briefly several expert system prototypes that have been developed. The describes three of these systems in detail, namely, the Fault Isolation Expert System (FIES II), the Hubble Space Telescope electrical power system diagnoser, the load priority list maintenance system (LPLMS), and an integrated electrical power system schedule/fault isolation. Future research and development efforts are examined.

Application Of Expert Systems In The Common Module Electrical Power System

Space Station will require a tremendous increase in autonomous power management capabilities over previous spacecraft. Americas first space station, Skylab, was operational from July 1973 until March 1974. The eight kilowatt electrical power bus required fifteen ground support personnel for monitoring, analysis, and control as well as extensive periods of onboard crew involvement. In contrast, the Initial Operational Configuration (IOC) Space Station has a requirement for 75 kilowatts of primary power distribution while the growth Space Station will require 300 kilowatts. It is anticipated that the Common Modules will each have the capability of managing up to 50 kilowatts of power; 25 kilowatts to be routed to adjoining Common Modules or attached payloads and 25 kilowatts for consumption within the Common Module. Minimization of crew involvement and ground support is a critical requirement for the complex Common Module electrical power system. The goal is to make this system as autonomous as is practical. Expert systems are envisioned to play a critical role in the electrical power system in both the IOC and growth versions of Space Station.

Space Station power system autonomy demonstration

The Office of Aeronautics and Space Technology has selected the Space Station Electrical Power System as one of the systems that will participate in the Systems Autonomy Demonstration Project(SADP) 1990 Power/Thermal Demonstration. The purpose of this demonstration is the autonomous operation of two major Space Station systems through the application of cooperating knowledge-based systems technology. Lewis Research Center(LeRC) and Marshall Space Flight Center(MSFC) will first jointly develop an autonomous power system using existing Space Station testbed facilities at each center. The subsequent 1990 power-thermal demonstrationwill then involve the cooperative operation of the LeRC/MSFC power system with the Johnson Space Center(JSC)s thermal control and DMS/OMS testbed facilities. The testbeds and expert systems at each of the NASA centers will be interconnected via communication links. The appropriate knowledge-based technology will be developed for each testbed and applied to problems requiring inter-system cooperation. Primary emphasis will be focused on failure detection and classification, system reconfiguration, planning and scheduling of electrical power resources and integration of knowledge-based and conventional control system software into the design and operation of Space Station testbeds.

Going for the long term: Increased automation in spacecraft power systems to lengthen the duration of voyages is being developed

A description is given of the AMPS (autonomously managed power system) program, which is developing a photovoltaic-based power system suitable for long-term space missions, particularly the US Space Station. The AMPS test facility is discussed, and the role of artificial intelligence is examined.