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The functions performed by pyrotechnic systems and devices in the Apollo spacecraft during a lunar exploration mission and in aborts are presented. The devices and systems are described. ...The modular cartridge concept and the standard electroexplosive device used throughout the spacecraft are innovations and are discussed in detail. Some of the techniques used to attain the high levels of reliability, to assure crew safety, to control quality, and to eliminate human errors are briefly presented.

Thermal conductances are computed for relatively simple node geometries that are typical of analytical models of spacecraft. Heat-transfer rates computed with these conductances are compared to heat-transfer rates computed from exact, closed-form mathematical formulas.

Former maintainability concepts for weapon systems are reviewed briefly, pointing out their inadequacies for manned spacecraft. The reliability concepts for manned spacecraft which require that all systems function during a mission are examined. ...This paper discusses a concept of reliability, which includes the relationship of man to total system reliability, and the techniques and controls used to insure spacecraft mission success through reliability. Former maintainability concepts for weapon systems are reviewed briefly, pointing out their inadequacies for manned spacecraft. ...Examples of man's contribution to the reliability of aircraft and spacecraft systems are discussed. These concepts will permit achievement of mission success that approaches 100 percent, using hardware with a reliability of 80 percent.

The technological requirements and the development program required in producing a spacecraft have significant effects on the manufacturing operations of an aerospace corporation, particularly when there is no prospect of follow-on production. ...The technological requirements and the development program required in producing a spacecraft have significant effects on the manufacturing operations of an aerospace corporation, particularly when there is no prospect of follow-on production. The spacecraft’s internal and external environment considerations, weight controls, reliability, traceability, and limited production are reviewed with respect to their influence on manufacturing costs, schedules, operations, skill levels, and training requirements.

As assembly of the International Space Station (ISS) proceeds, predictive techniques are used to determine the best approach for handling a variety of cabin air quality challenges. These techniques use equipment offgassing data collected from each ISS module before flight to characterize the trace chemical contaminant load. Combined with crew metabolic loads, these data serve as input to a predictive model for assessing the capability of the onboard atmosphere revitalization systems to handle the overall trace contaminant load as station assembly progresses. The techniques for predicting in-flight air quality are summarized along with results from early ISS mission analyses. Results from ground-based analyses of in-flight air quality samples are compared to the predictions to demonstrate the technique’s relative conservatism.

The durability of ceramic is limited due to chemical reactions with the atmosphere and due to sublimation. Another aspect of the ceramic composites are their non-isotropic mechanical and thermal characteristics. Models for both the erosion and the heat transport properties have been established. These models were validated by comparison with experimental results. Applications to different design problems are shown.

This paper describes a Stirling Cycle Refrigerator that has been built and tested by Stirling Technology Company (STC) for the NASA Marshall Space Flight Center (MSFC). Its intended application is the space station food refrigerator freezer. The Stirling Cycle Refrigerator described herein has few moving parts, is nontoxic to both humans and the environment, is insensitive to gravity, and has a moderate efficiency. Its temperature setpoint is adjustable, making it adaptable to other space station applications including a -70 °C freezer and freeze drier, a -183 °C freezer, and a -196 °C snap freezer. Test results have been very promising, with a Coefficient of Performance (COP) of 1.1 at -26 °C (-15 °F) and a heat load of 130 watts. Reliability tests on individual components and the entire Stirling Cycle Refrigerator system show a 10-year life is possible. In addition, the benefits of using this technology for the space station refrigerator freezer will be described.

The development of this computerized system was sponsored by NASA specifically for the Acceptance Checkout Equipment for the Apollo Spacecraft (or ACE-S/C). This checkout equipment is being used to monitor Apollo Spacecraft performance at the Grumman facility at Bethpage, Long Island; at the NAA facility at Downey, California; at the Manned Spacecraft Center at Houston, Texas; and at the NASA Merritt Island complex at Cape Kennedy. ...This checkout equipment is being used to monitor Apollo Spacecraft performance at the Grumman facility at Bethpage, Long Island; at the NAA facility at Downey, California; at the Manned Spacecraft Center at Houston, Texas; and at the NASA Merritt Island complex at Cape Kennedy. Although the computerized system was designed for a specific hardware project, the surveillance and product improvement tools used are of such a generalized nature that they would be applicable in other hardware projects, whether intended for earth or space applications.

Thus a versatile usable air monitor is provided allowing for the first time the detection and monitoring of trace gas dynamics of a spacecraft atmosphere. The plan is to accommodate ANITA in a Destiny (US LAB) Express Rack on ISS.

Through the last decade ESA (European Space Agency) have developed a TGM (Trace Gas Monitoring) system for spacecraft air analysis from paper study to a fully operational breadboard [1–9]. The TGM system is a combination of FTIR spectrometry and specially developed analysis techniques.

This paper reports a development of a εH measurement system. The system has been evaluated by comparing the measurement data with the data, which were obtained by conventional reliable techniques in the laboratory. From the evaluation results it was confirmed that the measurement accuracies of the present systems is Δε = ±0.05. Now this system is being improved for higher measurement accuracy, and it will be commercialized in 2007.

Developmental efforts are seeking to improve upon the efficiency and reliability of typical packed beds of sorbent pellets by using structured sorbents and alternative bed configurations. The benefits include increased structural stability gained by eliminating clay bound zeolite pellets that tend to fluidize and erode, and better thermal control during sorption leading to increased process efficiency. Test results that demonstrate such improvements are described and presented.

This study involved a detailed investigation of the sensitivity of some of the major parameters on a typical 1975 near earth orbit spacecraft and mission. A mechanized analytical math model and a mission simulation model were utilized to evaluate the effects of: spacecraft system weight, volume and reliability; mission duration and resupply rate; and maintenance requirements on the total spacecraft requirements to achieve various probabilities of crew survival and mission success. ...A mechanized analytical math model and a mission simulation model were utilized to evaluate the effects of: spacecraft system weight, volume and reliability; mission duration and resupply rate; and maintenance requirements on the total spacecraft requirements to achieve various probabilities of crew survival and mission success. ...A mechanized analytical math model and a mission simulation model were utilized to evaluate the effects of: spacecraft system weight, volume and reliability; mission duration and resupply rate; and maintenance requirements on the total spacecraft requirements to achieve various probabilities of crew survival and mission success. Preliminary information developed in the NAS 2-3705 contract is presented.

Like other spacecraft subsystems, the thermal control system had to comply with the following requirements: (i) robust/reliable in harsh environments, (ii) minimal power consumption, (iii) compact/lightweight, and (iv) long life even without maintenance. ...For this reason, passive two-phase heat transport technologies such as heat pipes, Loop Heat Pipes, and Capillary Pumped Loops became popular among spacecraft engineers. Future thermal requirements may outgrow the capabilities of the existing devices. ...The US Naval Research Laboratory is leading a research and development effort to produce advanced technologies for the thermal management of the Navyapos;s next-generation spacecraft and satellites.

When viewed on a National scale, data are presented to show that simple spacecraft have achieved a high degree of reliability while the complex spacecraft record leaves considerable room for improvement. ...Attainment of successful mission performance for complex spacecraft will therefore require a concentrated effort on the part of Management to maintain a constant appraisal of Program Risk.

Most of the neutrons seen in the habitable environment of spacecraft in LEO are produced in local materials of the spacecraft structures by the impact of the LEO radiation environment. ...The diffuse component is generally of lower energy and nearly isotropically scattered as they diffuse through the spacecraft structures. Leakage at near boundaries marks the diffusion process and solutions are strongly dependent on forward and backward boundaries with minor contributions from lateral diffusion along spacecraft wall structures. ...Leakage at near boundaries marks the diffusion process and solutions are strongly dependent on forward and backward boundaries with minor contributions from lateral diffusion along spacecraft wall structures. The diffuse neutron equation is solved using multigroup methods with impressed forward and backward boundary conditions.

The successful Project Mercury flight test program placed great emphasis on the Mercury Capsule Reaction Control System on board the spacecraft. Design of the redundant, automatic and manual, subsystems is discussed, as well as the variety of operating modes which were available for astronaut selection. ...During the course of the orbital Mercury spacecraft flights, minor discrepancies occurred in the reaction control system operation. These discrepancies were in no way deleterious to the success of the mission; however, they revealed the need for minor redesign to enhance system reliability. ...The personal reaction of the astronauts to the performance and handling of the spacecraft attitude controls is discussed, along with system changes which were effected for each particular manned space flight.

A key element of spacecraft thermal balance testing is the reliable determination of the final temperature values of the temperature equilibrium. ...This paper concentrates on a mathematical theory for practical use in the extrapolation of equilibrium temperatures for spacecraft and units with essentially radiative couplings to their thermal environment.

Spacecraft hardware trade studies compare options primarily on mass while considering impacts to cost, risk, and schedule. ...To provide for even comparisons of spacecraft hardware, trades need to consider functionality, mission constraints, integer vs. real number of flight hardware units, and mass growth allowances by TRL.