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This specification covers an aircraft-quality, low-alloy steel in the form of bars, forgings, mechanical tubing, and forging stock.

This SAE Standard for Reliability Centered Maintenance (RCM) is intended for use by any organization that has or makes use of physical assets or systems that it wishes to manage responsibly.

This specification covers crimp style aluminum lug terminals and conductor splices for aluminum aircraft wire. Lug terminals and conductor splices are hereafter called “terminals”.

This specification covers deicing and anti-icing materials in the form of a fluid.

Since 1985 in a step by step approach an advanced air revitalisation system has been developed for a crewed spacecraft. The metabolically produced carbon dioxide is concentrated through a solid amine water steam desorp-tion system and reduced to water and methane in a so-called Sabatier reactor. The water is currently fed into a fixed alkaline electrolyser to reclaim the oxygen for the crew. However, also water from other sources may be used. The hydrogen is recycled into the Sabatier reactor. The present system handles methane as a waste product closing so far the oxygen loop only. The system has been already successfully demonstrated in a laboratory scale configuration for a crew of three persons in 1996/1997. This paper discusses the results of the current development phase in which the system is reconfigured to fit into an International Space Station payload rack (ISPR). For this purpose the complete system design has been reviewed and upgraded where necessary.

BioBLAST® is a multimedia curriculum supplement for high school biology classes that incorporates NASA’s Advanced Life Support (ALS) research methods and data. The curriculum culminates with students designing and testing their own ALS system using the BaBS (Build a BLSS System) simulator, an integrated modeling system developed at the Classroom of the Future. BaBS integrates data from a number of research projects currently underway at NASA centers. In designing BaBS, the goal was to develop a teaching tool that balanced complexity and ease of use, while maintaining scientific accuracy.

Conventional ratcheting tools do not work efficiently in confined spaces and they have other limitations when used in space during extravehicular activity (EVA). The National Aeronautics and Space Administration’s (NASA) Goddard Space Flight Center has developed a three-dimensional (3-D) sprag/roller technology that has many benefits over the ratchet mechanism. The Space Systems Laboratory at the University of Maryland is using this technology in the development of EVA tools. The research discussed here describes the testing of an EVA roller wrench aboard NASA’s Reduced-Gravity Flying Laboratory (the KC-135), evaluation by astronauts in NASA/Johnson Space Center’s Neutral Buoyancy Laboratory, and the flight of a 3-D roller mechanism on Space Shuttle Mission STS-95.

The process of developing a Payload Attach System (PAS) which will support a wide range of experimental and commercial payloads on the International Space Station (ISS) has experienced an interesting evolution during its design, development, test and evaluation (DDT&E) phase. This evolution has been caused in large measure by requirements intended to insure compatibility of the PAS with the extravehicular activity (EVA) crewmember during nominal and contingency operations in and around the PAS sites. As the design of the ISS transitioned from its Freedom predecessor, the effort to keep costs down by preserving as much of the original Freedom design as possible led to design decisions that challenged engineering thinking.

Micrometeoroid and orbital debris (MMOD) penetration hazards have been a concern for the large number of EVA’s (Extravehicular Activities) expected during the assembly and operation of the International Space Station (ISS). Earlier studies have shown large uncertainties in estimated spacesuit penetration risks. This paper reports the results of recent tests and analyses that have significantly expanded the Shuttle EMU (Extravehicular Mobility Unit) hypervelocity penetration database and clarified our understanding of the associated risks. The results of testing have been used to develop improved estimates of the cumulative risk of penetration during EVA's through the first ten years after the beginning of ISS construction. These analyses have shown that the risks of MMOD penetration during EVA will be somewhat less than the risk of a critical penetration of the ISS itself over the same ten-year period.

Membranes are highly desirable for separating gases in life-support applications. They are small, light, efficient, selective and require little operational or physical maintenance. Facilitated transport membranes have particularly high flux and selectivity. We created enzyme-based facilitated transport membranes using isozymes and mutants as immobilized arrays alone and in conjunction with polymeric membranes. The enzyme operates efficiently at the low CO2 concentrations encountered in respiratory gases and can bring CO2 to near ambient levels. CO2 flux is greatly enhanced and selectivities for CO2 over O2 of 200:1 or greater are possible. The enzymes are robust and stable for long periods under a variety of storage and use conditions.

Based on the high volume of Extravehicular Activity (EVA) needed for assembly and operation of the International Space Station (1792 hrs through GFY2005), a large number of new crewmembers will be trained in the use of the Extravehicular Mobility Unit (EMU). In addition, the crewmembers will require on-orbit refresher training in the use of an EMU given their extended duration on-orbit of 90-180 days. Currently, there is a single hardware based training unit at Johnson Spaceflight Center (JSC) (the MALF II Simulator). This paper reports on the development of a software based training simulator (EMU Malfunction Training Simulator [EMTS]) which will run on any PC under Microsoft Windows and will be used to supplement MALF II.

A cooperative program undertaken by Zvezda and Hamilton Standard to address the required walking mobility for future planetary missions has focussed on space suit foot and ankle mobility. It has included the evaluation of the performance of a boot sole metatarsal (toe) joint and two different ankle joint configurations. A field test with a highly mobile space suit prototype by NASA provides data that complement the results of the above study. Experience in traversing a variety of terrain similar to that expected on Mars provides confirmation of the value of pressure suit ankle and boot sole mobility in the field. Taken together, these studies provide useful data for the design of future planetary exploration spacesuits. Laboratory and field test results are presented and some of their implications for planetary space suit designs are discussed.

When discussing how to design and control a Closed Ecology Life Support System (CELSS), element-level calculations should be performed on materials circulating in the system. Performing these calculations through computer simulation allows great advantages, especially when analyzing a CELSS for applications having various forms at experimental facilities. In the present study, models for analyzing the balance and circulation of CELSS materials are developed, and material balance analysis software for CELSS (MBASC) and material circulation analysis software for CELSS (MCASC) are created using these models. The present paper proposes a new method for integrating an entire CELSS and controlling material circulation through the analysis of CELSS material circulation using the proposed software.

Firefighters want to go to work, do their job well, and go home alive and uninjured. For their most important job, saving lives, firefighters want protective equipment that will allow more extended and effective time at fire scenes in order to perform victim search and rescue. A team, including engineers at NASA JSC and firefighters from Houston, has developed a list of problem areas for which NASA technology and know-how can recommend improvements for firefighter suits and gear. Prototypes for solutions have been developed and are being evaluated. This effort will spin back to NASA as improvements for lunar and planetary suits.

The ALS community faces unique challenges for the interactive modeling of a closed life support system. A top-level model is being developed as part of the System Studies and Modeling team of NJ-NSCORT. This top-level model has been broken down into several groups one of which is the ‘Human Requirements’ or ‘Human Factor’apos in an ALSS. This model examines the physical needs of crew members with respect to the effects of varying mission lengths, habitats and specific human characteristics. The model can be investigated independent of and interactive with the top-level model to examine the human factor using an object oriented approach. Through the object oriented programming language, Java, this model is meant to be accessible to the ALS community to aid in system analysis. This paper will explain the structure and examine the utility of the model with known requirements of humans in space.

Experience with the Space Shuttle Extravehicular Mobility Unit (EMU) and A7LB spacesuits has shown the need to investigate new spacesuit technologies for future missions requiring highly mobile, light weight and lower cost Extravehicular Activity spacesuit alternatives. An experimental spacesuit designated the I-Suit was developed to show the feasibility of attaining all three major design goals. The I-Suit is a highly mobile, multi-bearing, all soft fabric, prototype full pressure suit designed to operate effectively in zero gravity as well as in planetary applications. The I-Suit was designed with several fixed design requirements and a long list of goals. Once the prototype suit was fabricated, laboratory environment testing was performed in order to compare the I-Suit to the Shuttle EMU spacesuit and the Apollo A7LB spacesuit.

Computer modeling of top-level advanced life support systems (ALSS) has been initiated with completion of a prototype model of the biomass production component (BPC). Object oriented analysis and design were utilized to develop a flexible programming structure capable of expansion and incorporation with other components of the ALSS model. The biomass production model (BPM) has a world wide web (WWW) -accessible user interface which facilitates data viewing, modification, and input. Users utilize default values in the existing database or enter data specific to a scenario under consideration. The BPM simulates production of multiple crops within controlled environments, tracking automation, labor, production of edible and inedible biomass, and resource needs. At the conclusion of a simulation run, graphs showing the history of key variable values are available for the user to view on the monitor. This paper focuses on design and implementation the BPM.

Advanced space suit mobility studies were successfully conducted during the period of May 2-17, 1998, under representative Lunar and Mars-like terrain conditions at remote field site locations in the Flagstaff, Arizona, area. The sites visited included Cinder Lake, a volcanic ash area that was an actual Apollo-era test site with simulated craters developed by the United States Geological Survey (USGS); SP Mountain, an area that contained a young lava field with extensive rock rubble; Grand Falls, a canyon area that contained a variety of rock outcroppings, volcanic ash, and rock rubble; and Meteor Crater, a young impact crater area that contained various slopes with loose rock rubble. The test activities were supported by a team of JSC personnel utilizing the MK III advanced space suit technology demonstrator suit and a NASA modified commercial liquid air backpack system. The suit test subject was Dr. Dean Eppler, a trained field geologist.