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NASA NTRS1992

Running SINDA '85/FLUINT interactive on the VAX

Computer software as engineering tools are typically run in three modes: Batch, Demand, and Interactive. The first two are the most popular in the SINDA world. The third one is not so popular, due probably to the users inaccessibility to the command procedure files for running SINDA '85, or lack of familiarity with the SINDA '85 execution processes (pre-processor, processor, compilation, linking, execution and all of the file assignment, creation, deletions and de-assignments). Interactive is the mode that makes thermal analysis with SINDA '85 a real-time design tool. This paper explains a command procedure sufficient (the minimum modifications required in an existing demand command procedure) to run SINDA '85 on the VAX in an interactive mode. To exercise the procedure a sample problem is presented exemplifying the mode, plus additional programming capabilities available in SINDA '85. Following the same guidelines the process can be extended to other SINDA '85 residence computer platforms.

Simmonds, Boris↗

NASA NTRS1992

Advanced Communications Technology Satellite high burst rate link evaluation terminal experiment control and monitor software maintenance manual, version 1.0

The Experiment Control and Monitor (EC&M) software was developed at NASA Lewis Research Center to support the Advanced Communications Technology Satellite (ACTS) High Burst Rate Link Evaluation Terminal (HBR-LET). The HBR-LET is an experimenter's terminal to communicate with the ACTS for various investigations by government agencies, universities, and industry. The EC&M software is one segment of the Control and Performance Monitoring (C&PM) software system of the HBR-LET. The EC&M software allows users to initialize, control, and monitor the instrumentation within the HBR-LET using a predefined sequence of commands. Besides instrument control, the C&PM software system is also responsible for computer communication between the HBR-LET and the ACTS NASA Ground Station and for uplink power control of the HBR-LET to demonstrate power augmentation during rain fade events. The EC&M Software User's Guide, Version 1.0 (NASA-CR-189160) outlines the commands required to install and operate the EC&M software. Input and output file descriptions, operator commands, and error recovery procedures are discussed in the document. The EC&M Software Maintenance Manual, Version 1.0 (NASA-CR-189161) is a programmer's guide that describes current implementation of the EC&M software from a technical perspective. An overview of the EC&M software, computer algorithms, format representation, and computer hardware configuration are included in the manual.

Reinhart, Richard C.↗

NASA NTRS1992

Advanced communications technology satellite high burst rate link evaluation terminal experiment control and monitor software user's guide, version 1.0

Reinhart, Richard C.↗

NASA NTRS1993

Advanced communications technology satellite high burst rate link evaluation terminal communication protocol software user's guide, version 1.0

The Communication Protocol Software was developed at the NASA Lewis Research Center to support the Advanced Communications Technology Satellite High Burst Rate Link Evaluation Terminal (ACTS HBR-LET). The HBR-LET is an experimenters terminal to communicate with the ACTS for various experiments by government, university, and industry agencies. The Communication Protocol Software is one segment of the Control and Performance Monitor (C&PM) Software system of the HBR-LET. The Communication Protocol Software allows users to control and configure the Intermediate Frequency Switch Matrix (IFSM) on board the ACTS to yield a desired path through the spacecraft payload. Besides IFSM control, the C&PM Software System is also responsible for instrument control during HBR-LET experiments, uplink power control of the HBR-LET to demonstrate power augmentation during signal fade events, and data display. The Communication Protocol Software User's Guide, Version 1.0 (NASA CR-189162) outlines the commands and procedures to install and operate the Communication Protocol Software. Configuration files used to control the IFSM, operator commands, and error recovery procedures are discussed. The Communication Protocol Software Maintenance Manual, Version 1.0 (NASA CR-189163, to be published) is a programmer's guide to the Communication Protocol Software. This manual details the current implementation of the software from a technical perspective. Included is an overview of the Communication Protocol Software, computer algorithms, format representations, and computer hardware configuration. The Communication Protocol Software Test Plan (NASA CR-189164, to be published) provides a step-by-step procedure to verify the operation of the software. Included in the Test Plan is command transmission, telemetry reception, error detection, and error recovery procedures.

Reinhart, Richard C.↗

NASA NTRS1993

LARCRIM user's guide, version 1.0

LARCRIM is a relational database management system (RDBMS) which performs the conventional duties of an RDBMS with the added feature that it can store attributes which consist of arrays or matrices. This makes it particularly valuable for scientific data management. It is accessible as a stand-alone system and through an application program interface. The stand-alone system may be executed in two modes: menu or command. The menu mode prompts the user for the input required to create, update, and/or query the database. The command mode requires the direct input of LARCRIM commands. Although LARCRIM is an update of an old database family, its performance on modern computers is quite satisfactory. LARCRIM is written in FORTRAN 77 and runs under the UNIX operating system. Versions have been released for the following computers: SUN (3 & 4), Convex, IRIS, Hewlett-Packard, CRAY 2 & Y-MP.

Davis, John S.↗

NASA NTRS1992

Interactive Scene Analysis Module - A sensor-database fusion system for telerobotic environments

Accomplishing a task with telerobotics typically involves a combination of operator control/supervision and a 'script' of preprogrammed commands. These commands usually assume that the location of various objects in the task space conform to some internal representation (database) of that task space. The ability to quickly and accurately verify the task environment against the internal database would improve the robustness of these preprogrammed commands. In addition, the on-line initialization and maintenance of a task space database is difficult for operators using Cartesian coordinates alone. This paper describes the Interactive Scene' Analysis Module (ISAM) developed to provide taskspace database initialization and verification utilizing 3-D graphic overlay modelling, video imaging, and laser radar based range imaging. Through the fusion of taskspace database information and image sensor data, a verifiable taskspace model is generated providing location and orientation data for objects in a task space. This paper also describes applications of the ISAM in the Intelligent Systems Research Laboratory (ISRL) at NASA Langley Research Center, and discusses its performance relative to representation accuracy and operator interface efficiency.

Cooper, Eric G.↗

NASA NTRS1993

How well does voice interaction work in space?

The methods and results of an evaluation of the Voice Navigator software package are discussed. The first phase or ground phase of the study consisted of creating, or training, computer voice files of specific commands. This consisted of repeating each of six commands eight times. The files were then tested for recognition accuracy by the software aboard the microgravity aircraft. During the second phase, both voice training and testing were performed in microgravity. Inflight training was done due to problems encountered in phase one which were believed to be caused by ambient noise levels. Both quantitative and qualitative data were collected. Only one of the commands was found to offer consistently high recognition rates across subjects during the second phase.

Morris, Randy B.↗

NASA NTRS1991

Control algorithm implementation for a redundant degree of freedom manipulator

This project's purpose is to develop and implement control algorithms for a kinematically redundant robotic manipulator. The manipulator is being developed concurrently by Odetics Inc., under internal research and development funding. This SBIR contract supports algorithm conception, development, and simulation, as well as software implementation and integration with the manipulator hardware. The Odetics Dexterous Manipulator is a lightweight, high strength, modular manipulator being developed for space and commercial applications. It has seven fully active degrees of freedom, is electrically powered, and is fully operational in 1 G. The manipulator consists of five self-contained modules. These modules join via simple quick-disconnect couplings and self-mating connectors which allow rapid assembly/disassembly for reconfiguration, transport, or servicing. Each joint incorporates a unique drive train design which provides zero backlash operation, is insensitive to wear, and is single fault tolerant to motor or servo amplifier failure. The sensing system is also designed to be single fault tolerant. Although the initial prototype is not space qualified, the design is well-suited to meeting space qualification requirements. The control algorithm design approach is to develop a hierarchical system with well defined access and interfaces at each level. The high level endpoint/configuration control algorithm transforms manipulator endpoint position/orientation commands to joint angle commands, providing task space motion. At the same time, the kinematic redundancy is resolved by controlling the configuration (pose) of the manipulator, using several different optimizing criteria. The center level of the hierarchy servos the joints to their commanded trajectories using both linear feedback and model-based nonlinear control techniques. The lowest control level uses sensed joint torque to close torque servo loops, with the goal of improving the manipulator dynamic behavior. The control algorithms are subjected to a dynamic simulation before implementation.

Cohan, Steve↗

NASA NTRS1992

Database activity in the Italian Astronet: DIRA 2

The development and utilization of informational archives and databases started, in the Italian Astronet Project, in the middle of 1983. In that year, a small group of astronomers and some more technical people met together in an Astronet working group, with a common, painful experience in managing astronomical catalogues and archives with computers. Nowadays, some years later, some software packages and the contents of both, a relative general database and several local databases represent the work and the effort of the group. The systems have been conceived and developed keeping in mind the original goal of the group: to allow the single atronomer to make a free use of original data. The main package (DIRA) was rewritten, after some years of use, to fully take advantage of the several suggestions of the astronomer that used it and gathered experiences in the astronomical catalog's management. A more technical goal was to install the whole system, born and developed in the vms environment, on unix and unix-like systems. This new version, DIRA2, has a new user interface, a query language with SQL style commands supporting numerical and character functions also and a set of commands to create new catalogues from existing data. The graphics commands are also more powerful with respect to the previous version. DIRA (and DIRA2 of course) philosophy and design are very simple and proved to be very appreciated by astronomers, namely, to normalize and homogenize, at minimum, astronomical catalogues, to collect satisfactory astronomical documentation on their contents and, finally, to allow an astronomical approach to the dialogue with the database. DIRA2 is currently used in most Italian astronomical institutes to retrieve data from a still growing database of about 140 well documented and controlled astronomical catalogues, for the identification of objects and the preparation of a 'medium size' survey, in astrometry and in the creation of new catalogues.

Benacchio, L.↗

NASA NTRS1992

AXAF user interfaces for heterogeneous analysis environments

The AXAF Science Center (ASC) will develop software to support all facets of data center activities and user research for the AXAF X-ray Observatory, scheduled for launch in 1999. The goal is to provide astronomers with the ability to utilize heterogeneous data analysis packages, that is, to allow astronomers to pick the best packages for doing their scientific analysis. For example, ASC software will be based on IRAF, but non-IRAF programs will be incorporated into the data system where appropriate. Additionally, it is desired to allow AXAF users to mix ASC software with their own local software. The need to support heterogeneous analysis environments is not special to the AXAF project, and therefore finding mechanisms for coordinating heterogeneous programs is an important problem for astronomical software today. The approach to solving this problem has been to develop two interfaces that allow the scientific user to run heterogeneous programs together. The first is an IRAF-compatible parameter interface that provides non-IRAF programs with IRAF's parameter handling capabilities. Included in the interface is an application programming interface to manipulate parameters from within programs, and also a set of host programs to manipulate parameters at the command line or from within scripts. The parameter interface has been implemented to support parameter storage formats other than IRAF parameter files, allowing one, for example, to access parameters that are stored in data bases. An X Windows graphical user interface called 'agcl' has been developed, layered on top of the IRAF-compatible parameter interface, that provides a standard graphical mechanism for interacting with IRAF and non-IRAF programs. Users can edit parameters and run programs for both non-IRAF programs and IRAF tasks. The agcl interface allows one to communicate with any command line environment in a transparent manner and without any changes to the original environment. For example, the authors routinely layer the GUI on top of IRAF, ksh, SMongo, and IDL. The agcl, based on the facilities of a system called Answer Garden, also has sophisticated support for examining documentation and help files, asking questions of experts, and developing a knowledge base of frequently required information. Thus, the GUI becomes a total environment for running programs, accessing information, examining documents, and finding human assistance. Because the agcl can communicate with any command-line environment, most projects can make use of it easily. New applications are continually being found for these interfaces. It is the authors' intention to evolve the GUI and its underlying parameter interface in response to these needs - from users as well as developers - throughout the astronomy community. This presentation describes the capabilities and technology of the above user interface mechanisms and tools. It also discusses the design philosophies guiding the work, as well as hopes for the future.

Mandel, Eric↗

NASA NTRS1992

XPI: The Xanadu Parameter Interface

XPI is a table driven parameter interface which greatly simplifies both command driven programs such as BROWSE and XIMAGE as well as stand alone single-task programs. It moves all of the syntax and semantic parsing of commands and parameters out of the users code into common code and externally defined tables. This allows the programmer to concentrate on writing the code unique to the application rather than reinventing the user interface and for external graphical interfaces to interface with no changes to the command driven program. XPI also includes a compatibility library which allows programs written using the IRAF host interface (Mandel and Roll) to use XPI in place of the IRAF host interface.

White, N.↗

NASA NTRS1993

Reliable transfer of data from ground to space

This paper describes the problems involved in uplink of data from control centers on the ground to spacecraft, and explores the solutions to those problems, past. present. and future. The evolution of this process, from simple commanding to transfer of large volumes of data and commands is traced. The need for reliable end-to-end protocols for commanding and file transfer is demonstrated, and the shortcomings of both existing telecommand protocols and commercial products to meet this need are discussed. Recent developments in commercial protocols that may be adaptable to the mentioned operations environment are surveyed, and current efforts to develop a suite of protocols for reliable transfer in this environment are presented.

Brosi, Fred↗

NASA NTRS1993

The EURECA telecommanding chain: Experience with packet telecommand and telemetry systems

The European Retrieval Carrier (EURECA) was launched on its first flight on the 31st July 1992 by the Space Shuttle Atlantis. EURECA is characterized by several new on-board features, most notable Packet Telemetry and a partial implementation of Packet Telecommanding using an early version of the Command Operation Procedure (COP-1) protocol. EURECA has also very low contact time with its Ground Station, with a consequent high number of out-of-visibility onboard operations. This paper concentrates on the implementation and operational experience with the COP-1 Protocol and the effect the short ground contact time has on the design of the Commanding System. Another interesting feature is that the COP-1 is implemented at the control center rather than at the ground station. The COP-1 protocol also successfully supported the mission during the launch where commands were sent via NASCOM and the Shuttle.

Mueller, C.↗

NASA NTRS1993

An intelligent planning and scheduling system for the HST servicing missions

A new, intelligent planning and scheduling system has been delivered to NASA-Goddard Space Flight Center (GSFC) to provide support for the up-coming Hubble Space Telescope (HST) Servicing Missions. This new system is the Servicing Mission Planning and Replanning Tool (SM/PART). SM/PART is written in C and runs on a UNlX-based workstation (IBM RS/6000) under Motif. SM/PART effectively automates the complex task of building or rebuilding integrated timelines and command plans which are required by HST Servicing Mission personnel at their consoles during the missions. SM/PART is able to quickly build or rebuild timelines based on information stored in a Knowledge Base (KB) by using an Artificial Intelligence (AI) tool called the Planning And Resource Reasoning (PARR) shell. After a timeline has been built in the batch mode, it can be displayed and edited in an interactive mode with help from the PARR shell. Finally a detailed command plan is generated. The capability to quickly build or rebuild timelines and command plans provides an additional safety factor for the HST, Shuttle and Crew.

Johnson, Jay↗

NASA NTRS1994

Development of a Power Electronics Unit for the Space Station Plasma Contactor

A hollow cathode plasma contactor has been baselined as a charge control device for the Space Station (SS) to prevent deleterious interactions of coated structural components with the ambient plasma. NASA LeRC Work Package 4 initiated the development of a plasma contactor system comprised of a Power Electronics Unit (PEU), an Expellant Management Unit (EMU), a command and data interface, and a Plasma Contactor Unit (PCU). A breadboard PEU was designed and fabricated. The breadboard PEU contains a cathode heater and discharge power supply, which were required to operate the PCU, a control and auxiliary power converter, an EMU interface, a command and telemetry interface, and a controller. The cathode heater and discharge supplies utilized a push-pull topology with a switching frequency of 20 kHz and pulse-width-modulated (PWM) control. A pulse ignition circuit derived from that used in arcjet power processors was incorporated in the discharge supply for discharge ignition. An 8088 based microcontroller was utilized in the breadboard model to provide a flexible platform for controller development with a simple command/data interface incorporating a direct connection to SS Mulitplexer/Demultiplexer (MDM) analog and digital I/O cards. Incorporating this in the flight model would eliminate the hardware and software overhead associated with a 1553 serial interface. The PEU autonomously operated the plasma contactor based on command inputs and was successfully integrated with a prototype plasma contactor unit demonstrating reliable ignition of the discharge and steady-state operation.

Hamley, John A.↗

NASA NTRS1994

Emergency medical services

When NASA was established in 1958, it was known that space flight would require efforts beyond those of NASA to ensure the health and safety of our astronauts. On 10 Aug. 1958, a Secretary of Defense memorandum was signed that assigned the first Department of Defense (DOD) Manager to provide support to NASA for Project Mercury. This established a chain of command through the Joint Chiefs of Staff to the Secretary of Defense. The current charter is dated 19 Mar. 1986 and assigns the DOD Manager responsibilities to the Commander and Chief, US Space Command. The DOD Managers charter has many support areas and among them are recovery of astronauts and medical support. Today these efforts support the Space Shuttle and Space Station Programs. Briefly, the program works with each organization tasking the other through a requirements document. Level of care, communications, and recovery requirements are established; NASA and the DOD provide the capability to meet them. NASA is also responsible for the specialized training and equipment needed to meet these requirements. A Shuttle launch a KSC requires an Emergency Medical Services (EMS) coordinator on console to facilitate communications, ensure proper coverage, and coordinate with area hospitals. A contingent of NASA medical personnel are assembled to provide triage and medical support capabilities. The DOD provides medical evacuation (MEDEVAC) helicopters with surgeons and pararescue specialists (PJ's) or emergency medical technicians (EMT's). Each helicopter is equipped with at least one doctor and one PJ/EMT per astronaut crew member. Transoceanic abort landing (TAL) sites and end of mission (EOM) sites have similar structures, with TAL sites utilizing fixed wingg aircraft for MEDEVAC. The DOD also supports contingency planning for the support and return of crew members from the Space Station Freedom. Much of this support has been directed at the recovery of crew members following the landing of an Assured Crew Return Vehicle.

Billica, Roger↗

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 NTRS1994

Autonomous mission planning and scheduling: Innovative, integrated, responsive

Autonomous mission scheduling, a new concept for NASA ground data systems, is a decentralized and distributed approach to scientific spacecraft planning, scheduling, and command management. Systems and services are provided that enable investigators to operate their own instruments. In autonomous mission scheduling, separate nodes exist for each instrument and one or more operations nodes exist for the spacecraft. Each node is responsible for its own operations which include planning, scheduling, and commanding; and for resolving conflicts with other nodes. One or more database servers accessible to all nodes enable each to share mission and science planning, scheduling, and commanding information. The architecture for autonomous mission scheduling is based upon a realistic mix of state-of-the-art and emerging technology and services, e.g., high performance individual workstations, high speed communications, client-server computing, and relational databases. The concept is particularly suited to the smaller, less complex missions of the future.

Sary, Charisse↗