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Louvers are used for overpressure safety venting in rooms or chambers where explosion hazards exist. The louvers have individually hinged closures that are held in locked position by commercially available magnets that quickly release them in an overpressure condition.
This presentation concentrates on knowledge acquisition and its application to the development of an expert module and a user interface for an Intelligent Tutoring System (ITS). The Systems Test and Operations Language (STOL) ITS is being developed to assist NASA control center personnel in learning a command and control language as it is used in mission operations rooms. The objective of the tutor is to impart knowledge and skills that will permit the trainee to solve command and control problems in the same way that the STOL expert solves those problems. The STOL ITS will achieve this object by representing the solution space in such a way that the trainee can visualize the intermediate steps, and by having the expert module production rules parallel the STOL expert's knowledge structures.
A thermal monitoring and control concept is described for a volatile condensable materials (VCM) test apparatus where electric resistance heaters are employed. The technique is computer based, but requires only proportioning ON/OFF relay control signals supplied through a programmable scanner and simple quadrac power controllers. System uniqueness is derived from automatic temperature measurements and the averaging of these measurements in discrete overlapping temperature zones. Overall control tolerance proves to be better than + or - 0.5 C from room ambient temperature to 150 C. Using precisely calibrated thermocouples, the method provides excellent temperature control of a small copper VCM heating plate at 125 + or - 0.2 C over a 24 hr test period. For purposes of unattended operation, the programmable computer/controller provides a continual data printout of system operation. Real time operator command is also provided for, as is automatic shutdown of the system and operator alarm in the event of malfunction.
Stress-controlled isothermal fatigue experiments were performed at room temperature (RT) and 548 C (in argon) on (0)8 SCS6/Ti 15-3 metal matrix composites (MMC's) with 15 and 41 volume percent SCS6 (SiC) fibers. The primary objectives were to evaluate the mechanical responses, and to obtain a clear understanding of the damage mechanisms leading to failure of the MMC's. The mechanical data indicated that strain ranges attained fairly constant values in the stress-controlled experiments at both RT and 538 C, and remained so for more than 85 percent of life. The fatigue data for MMC's with different volume fraction fibers showed that MMC life was controlled by the imposed strain range rather than the stress range. At RT, and at low and intermediate strain ranges, the dominant fatigue mechanism was matrix fatigue, and this was confirmed metallurgically from fractographic evidence as well as from observations of channel type dislocation structures in the matrix of fatigued MMC specimens. Reaction-zone cracks acted as important crack initiating sites at RT, with their role being to facilitate slip band formation and consequent matrix crack initiation through classical fatigue mechanisms. MMC life agreed with matrix life at the lower strain ranges, but was smaller than matrix life at higher strain ranges. Unlike the case of monotonic deformation, debonding damage was another major damage mechanism during fatigue at RT, and it increased for higher strain ranges. At high strain ranges at RT, fractography and metallography showed an absence of matrix cracks, but long lengths of debonds in the outer layers of the SCS6 fibers. Such debonding and consequent rubbing during fatigue is believed to have caused fiber damage and their failure at high strain ranges. Thus, whereas life was matrix dominated at low and intermediate strain ranges, it was fiber dominated at high strain ranges. At 538 C, the mean stain constantly increased (ratchetting) with the number of cycles. At high strain ranges, such ratchetting led to overload failure of the fibers, and debonding of the type at RT was very small. At intermediate strain ranges, fractography showed large areas of matrix cracks. However, in spite of this matrix dominated mechanism, the MMC life at elevated temperatures was significantly less than the matrix fatigue life at all strain ranges. The reason for this difference is still unclear, although metallographic and fractographic evidences suggest that internal crack initiation sites at Mo-ribbons and reaction-zone cracks may have played a critical role, with the former tending to dominate.
Clean room bacteriology - ambient air and bench top microbial contamination levels, and degree of environmental control in production areas
Room temperature alignment and evaluation techniques for the Infrared Astronomical Satellite (IRAS) telescope, which has a primary mirror figured to correct for surface distortions and the 2 K operating temperature are discussed. Interferometric cryogenic testing of the 0.6 m, f/1.5 lightweighted beryllium primary mirror at its intended operating temperature reveals surface distortions that can be modeled with Zernike polynomials. With this model, it becomes possible to derive the 'inverse' of the cryowavefront error (ideal cryo mirror) and to figure the cryo correction into the primary mirror using Perkin-Elmer's Computer Controlled Polisher. It is recognized that during room temperature assembly of the system, misalignment of the secondary mirror can introduce additional unwanted aberrations that may cancel or distort the wavefront errors purposely introduced by the cryo figuring. To avoid this possible degradation and to ensure optimum telescope performance, the system Zernike polynomial coefficients and wavefront maps generated from the in-process alignment interferograms are monitored and compared to Zernike coefficients and wavefront maps for the cryo corrected primary mirror.
This internship provides the opportunity to support the creation and use of Firing Room Displays and Firing Room Applications that use an abstraction layer called the Application Control Language (ACL). Required training included video watching, reading assignments, face-to-face instruction and job shadowing other Firing Room software developers as they completed their daily duties. During the training period various computer and access rights needed for creating the applications were obtained. The specific ground subsystems supported are the Cryogenics Subsystems, Liquid Hydrogen (LH2) and Liquid Oxygen (LO2). The cryogenics team is given the task of finding the best way to handle these very volatile liquids that are used to fuel the Space Launch System (SLS) and the Orion flight vehicles safely.
Space-compatible cryogenic valves are now required to operate between room and liquid helium temperatures. A remotely controllable cryogenic valve is described, which is made of bellows-type stainless steel and is operated by a miniature dc motor with integral gearset (485:1) at a nominal voltage of 28 Vdc. The power transmission provides a further reduction of 7.2:1 to give an overall gear ratio of nearly 3500:1, assuring reliability of operation at low temperatures. Valve performance (leak rate) data are presented at LN2, LHe, and SfHe temperatures at delivered torques of 18, 27, 31, and 35 N-m. At a closing torque of 31 N-m, a leak rate of 0.028 scc/sec was achieved at 2 K, while at a torque of 18 N-m the leak rate at 300 K was less than 3 x 10 to the -9th scc/sec.
Detector for trace chemicals senses as few as 10 to the 12th power molecules of given material on surface. Contains no moving parts, amenable to large-scale integration, and operates at room temperature. Potential applications in industrial process control and in environmental analysis. Characteristic signals indicate presence of certain chemicals.
This paper describes how simple client-server connection status monitoring can be implemented using Ajax (Asynchronous JavaScript and XML), JSF (Java Server Faces) and ICEfaces technologies. This functionality is required for NASA LCS (Launch Control System) displays used in the firing room for the Constellation project. Two separate implementations based on two distinct approaches are detailed and analyzed.
A facility has been constructed at NASA Langley Research Center to simulate the soundscape inside residential houses that are exposed to environmental noise from aircraft. This controllable indoor listening environment, the Interior Effects Room, enables systematic study of parameters that affect psychoacoustic response. The single-room facility, built using typical residential construction methods and materials, is surrounded on adjacent sides by two arrays of loudspeakers in close proximity to the exterior walls. The arrays, containing 52 subwoofers and 52 mid-range speakers, have a usable bandwidth of 3 Hz to 5 kHz and sufficient output to allow study of sonic boom noise. In addition to these exterior arrays, satellite speakers placed inside the room are used to augment the transmitted sound with rattle and other audible contact ]induced noise that can result from low frequency excitation of a residential house. The layout of the facility, operational characteristics, acoustic characteristics and equalization approaches are summarized.
For new flight controllers, the two main learning tools are simulations and real time console performance training. These benefit the new flight controllers in different ways and could possibly be improved. Simulations: a) Allow for mistakes without serious consequences. b) Lets new flight controllers learn the working style of other new flight controllers. c) Lets new flight controllers eventually begin to feel like they have mastered the sim world, so therefore they must be competent in the real time world too. Real time: a) Shows new flight controllers some of the unique problems that develop and have to be accounted for when dealing with certain payloads or systems. b) Lets new flight controllers experience handovers - gathering information from the previous shift on what the room needs to be aware of and what still needs to be done. c) Gives new flight controllers confidence that they can succeed in the position they are training for when they can solve real anomalies. How Sims could be improved and more like real-time ops for the ISS Operations Controller position: a) Operations Change Requests to review. b) Fewer anomalies (but still more than real time for practice). c) Payload Planning Manager Handover sheet for the E-1 and E-3 reviews. d) Flight note in system with at least one comment to verify for the E-1 and E-3 reviews How the real time console performance training could be improved for the ISS Operations Controller position: a) Schedule the new flight controller to be on console for four days but with a different certified person each day. This will force them to be the source of knowledge about every OCR in progress, everything that has happened in those few days, and every activity on the timeline. Constellation program flight controllers will have to learn entirely from simulations, thereby losing some of the elements that they will need to have experience with for real time ops. It may help them to practice real time console performance training in the International Space Station or Space Shuttle to gather some general anomaly resolution and day-to-day task management skills.
The Master Console internship during the spring of 2013 involved the development of firing room displays at the John F. Kennedy Space Center (KSC). This position was with the Master Console Product Group (MCPG) on the Launch Control System (LCS) project. This project is responsible for the System Monitoring and Control (SMC) and Record and Retrieval (R&R) of launch operations data. The Master Console is responsible for: loading the correct software into each of the remaining consoles in the firing room, connecting the proper data paths to and from the launch vehicle and all ground support equipment, and initializing the entire firing room system to begin processing. During my internship, I developed a system health and status display for use by Master Console Operators (MCO) to monitor and verify the integrity of the servers, gateways, network switches, and firewalls used in the firing room.
For the past 9 years, the AI group at NASA's Kennedy Space Center (KSC) has been developing a real-time model-based reasoning (MBR) system that can diagnose faults and provide control advisories. The system resulting from this effort is called KATE (Knowledge-based Autonomous Test Engineer). This article describes the transition of KATE from the applied research lab to the firing room (the firing room is the main control and monitoring center for all Shuttle ground support and launch processing). Because the problems that were countered along the way are not unique, we decided to share some of our experiences. This article also includes a brief overview of the latest application of KATE.
The Master Console oversees the function of Computer Systems in Firing room 1 (FR1). Master Console Operators, MCOs' for short, are our customer. I was integrated into the System Monitoring and Control (SMC) software team that is under the guidance of David Slaiman, who is the product group lead. I have been brought up to speed with System Monitoring and Control. The initial time spent reading SMC software design description and understanding how it works. The current Firing Room 1 Console Display is a floor layout giving the MCO two essential pieces of information which are Health and Status. When an issue arises, the MCO has to look on the display to find which console is affected and then the MCO must use the Reference designator from the display to manually search for the Portal Workstation (PWS) installed in the console using the hardware map; which is a long process to lookup a PWS if an issue is present. My project is to make the FR1 Console Display easier for the MCO's to pinpoint PWS's without having to lookup additional resources in the process. My project also includes updating Firing Room 1 Console Display to include the F1R Non-Redundant Set. The display does not have good use of space and functionality. PWS numbers were not present in the previous design and are the critical component in efficient understanding and administration of the consoles. Part of the process includes getting feedback from the customer, instead of just emailing them with a question, we made a proposal with changes so they could respond and give us their input; which proved to be an effective method for engaging them. In order to do this I had to use the Display Editor (DE) tool developed by NASA, Paint.Net and Visio. The process I have been using has been Visio to alter the floor layout of Firing Room and take advantage of the white areas, and then I take the altered floor plan into Paint.Net. Once in Paint.Net I put the new floor plan as a background to the standard console display. Paint.Net also serves as a tool to create the new service state bars for the new background; finally I used the DE to assemble everything and setup the right CUI's for each PWS.
The reafference model has frequently been used to explain spatial constancy during eye and head movements. We have found that its basic concepts also form part of the information processing necessary for the control and recalibration of reaching movements. Reaching was studied in a novel force environment--a rotating room that creates centripetal forces of the type that could someday substitute for gravity in space flight, and Coriolis forces which are side effects of rotation. We found that inertial, noncontacting Coriolis forces deviate the path and endpoint of reaching movements, a finding that shows the inadequacy of equilibrium position models of movement control. Repeated movements in the rotating room quickly lead to normal movement patterns and to a failure to perceive the perturbing forces. The first movements made after rotation stops, without Coriolis forces present, show mirror-image deviations and evoke perception of a perturbing force even though none is present. These patterns of sensorimotor control and adaptation can largely be explained on the basis of comparisons of efference copy, reafferent muscle spindle, and cutaneous mechanoreceptor signals. We also describe experiments on human locomotion using an apparatus similar to that which Mittelstaedt used to study the optomotor response of the Eristalis fly. These results show that the reafference principle relates as well to the perception of the forces acting on and exerted by the body during voluntary locomotion.
Two studies were performed to determine whether a subject's response to naturalistic optical flow specifying egomotion would be affected by a concurrent attention task. In the first study subjects stood in a moving room in which various areas of the optical flow generated by room movement were visible. Subjects responded to room motion with strong compensatory sway when the entire room was visible. When the side walls of the room were completely obscured by stationary screens, leaving only the front wall visible, sway was significantly reduced, though it remained greater than in an eyes-closed control. In Exp. 2 subjects were presented with either the full room (large sway response) or the room with only the front wall visible (moderate response), each in combination with either a hard or easy verbal addition task. Preliminary results show that swaying in the fully visible room and in the room with only the front wall visible increased when combined with either the hard or easy tasks. These preliminary results suggest that at the least the pick-up of optical flow specifying egomotion is not affected by concurrent attentional activity.
Contamination problems in space program, discussing clean room equipment, maintenance, cleaning problems, etc