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These neutrons are produced from several sources: from the terrestrial albedo and as secondary particles produced by the interaction of cosmic rays, solar protons and trapped protons with the material of the spacecraft. Recently, neutrons have also been observed originating in solar flares, at the solar surface. ...Theoretical estimates and experimental measurements of the neutron fluxes inside manned spacecraft in near-Earth orbit are reviewed and discussed. The anticipated neutron fluxes and their resulting dose-equivalents, as a function of shielding depth for exploration class missions, are presented and discussed.

Vacuum and radiation conditions in space are discussed, as these appear to cause the major limitations on lubrication for spacecraft equipment. While many lubricants suffer a drastic loss in lifetime as a result of these environments, experimental studies have demonstrated that certain oils and greases can lubricate lightly loaded ball bearings without replenishment for periods of two years and more under the following conditions of operation: speeds of 8000 rpm, temperatures of 160 to 200 F, and vacuum of 10−8 torr.

Research in microgravity (low-gravity) combustion promises innovations and improvements in fire prevention and response for human-crew spacecraft. Findings indicate that material flammability and fire spread in microgravity are significantly affected by atmospheric flow rate, oxygen concentration, and diluent composition. ...Research on smoke-particle changes in microgravity promises future improvements and increased sensitivity of smoke detectors in spacecraft. Research on fire suppression by extinguishing agents and venting can yield new information on effective control of the rare, but serious fire events in spacecraft. ...Research on fire suppression by extinguishing agents and venting can yield new information on effective control of the rare, but serious fire events in spacecraft.

In recent years, with the advent of large spacecraft, thermal balance testing techniques using infrared lamp sources have become increasingly attractive. ...In addition to cost savings, the IR technique is more versatile in terms of spacecraft orientation and supplied flux conditions. Because of the differences between solar illumination and IR simulation the IR lamp flux characteristics must be accurately determined. ...The radiation absorbed by spacecraft surfaces under test conditions can be obtained from a computer code incorporating lamp arrays, specular baffles and surface property variations with lamp power level and radiation angle of incidence.

Followed by brief discussions of the primary natural particle radiation sources and the operational sensitivities imposed by them on crew and spacecraft, the analytical system and methods are described. The use of this automated analytical tool called Brem (Boeing radiation exposure model), is then addressed regarding spacecraft design and the optimization of radiation shielding. ...The use of this automated analytical tool called Brem (Boeing radiation exposure model), is then addressed regarding spacecraft design and the optimization of radiation shielding.

(ADA) is developing a handheld fine water mist fire extinguisher for use on manned spacecraft and in future planetary habitats. This design employs only water and nitrogen as suppression agents to allow local refill and reuse. ...Continued development will result in prototype hardware suitable for use on future manned spacecraft.

Experience with free-flying space payloads in the current era of reduced budgets has led to a continuing need for an easier-to-use and more cost-effective capability for spacecraft thermal analyses. Preliminary thermal design of the MSX spacecraft has been developed using an 80386-based MS-DOS microcomputer. ...These programs provide both an interactive geometry editor and a graphical representation of the current spacecraft geometry. The output of VIEWI is converted to a SSPTA2 geometry input file. SSPTA, a software package that simplifies the procedures for conducting sophisticated thermal analyses of orbiting payloads, consists of CONSHAD, a view factor calculation program, SCRIPTF, a radiation conductance calculation program, ORBITAL, a satellite orbital heat flux program, and ABSORB, a program to calculate absorbed power.

To provide spacecraft thermal design engineers with the data needed to define the earth albedo and emission, we have analyzed data from the Earth Radiation Balance Experiment (ERBE) over a period of 36 months, covering orbital inclinations of 57 and 99 degrees.

Heat dissipated in conduction cooled spacecraft components must be transported across the component base plate/spacecraft mounting plate interface preparatory to final radiation to the space sink.

The Spacecraft Radiative Thermal Model Exchange System is a technology developed for the bi-directional exchange of spacecraft radiative thermal models via the TMG thermal software package. ...The Spacecraft Radiative Thermal Model Exchange System is a technology developed for the bi-directional exchange of spacecraft radiative thermal models via the TMG thermal software package. It provides a means for quickly and accurately transferring models between TMG and theree of the major thermal radiation codes used in the spacecraft industry, particularly the ESARAD and Thermica packages, which are widely used by contractors to the European Space Agency, and the TSS code which is prevalent in the United States space industry. ...It provides a means for quickly and accurately transferring models between TMG and theree of the major thermal radiation codes used in the spacecraft industry, particularly the ESARAD and Thermica packages, which are widely used by contractors to the European Space Agency, and the TSS code which is prevalent in the United States space industry.

The thermal design of a spacecraft is a time consuming and tedious process. As more graphical tools are becoming available, this process is becoming more efficient, and changes to the thermal design are more quickly implemented. ...This paper discusses the THERMICA-SINDA/G software system, where the entire spacecraft thermal design process in integrated in one interactive graphical environment.

This paper presents application of multi-objective optimization to the design of spacecraft power subsystem. The selection of optimum design can be achieved by having a comparative trade study among different alternatives available. ...The paper provides a methodology to optimize the SEPS (Spacecraft Electrical Power Subsystem) design process taking into account both the technology trades and initial sizing in a constrained environment. ...Then it presents spacecraft power system sizing, which is derived by the mission requirements and design constraints imposed by technology available.

The most, often utilized method of thermal design verification for past and current types of spacecraft has been by Solar Thermal Vacuum (STV) tests at system level. This approach, however, will require fundamental modifications for future large and complex spacecraft, three types of which are defined; a large communication satellite, a modular earth observation satellite and a large infrared telescope, all exceeding the capabilities of existing STV test facilities. ...This approach, however, will require fundamental modifications for future large and complex spacecraft, three types of which are defined; a large communication satellite, a modular earth observation satellite and a large infrared telescope, all exceeding the capabilities of existing STV test facilities. ...Alternative test methods - STV testing in parts, infrared radiation tests, thermal canister method, skin heater application - are also discussed with regard to their advantages and disadvantages of applying them to the large types of spacecraft. The thermal design considerations to be regarded and the critical parameters to be verified by test are highlighted, in order to enable the alternative verification test concept at an acceptable level of confidence.

This paper describes a new microcomputer-based program that evaluates the radiation shielding of spacecraft or Space Station modules. This program runs on a computer-aided design (CAD) system that constructs and manipulates models of spacecraft. ...This program runs on a computer-aided design (CAD) system that constructs and manipulates models of spacecraft. It uses the graphical and geometrical functions of the CAD system to analyse the radiation shielding provided by spacecraft models. ...It uses the graphical and geometrical functions of the CAD system to analyse the radiation shielding provided by spacecraft models. The program has the following new features: It uses solid angles of equal size that are distributed uniformly over a sphere surrounding the point of interest; It computes the geometrical intersection of each solid angle with a specified layer of a spacecraft model; It computes the volume, centroid and average thickness of each intersection, along with the variance of its volume and the standard error of its centroid position; It writes computer files of both the solid model and its volume, centroid and average thickness for each intersection for a given dose point and shielding layer.

The thermal behaviour of spacecraft especially of manned ones is governed by various thermophysical effects. Heat transfer by radiation, conduction and convection influence the overall behaviour of the spacecraft. ...Heat transfer by radiation, conduction and convection influence the overall behaviour of the spacecraft. Energy production, distribution and consumption have also strong impacts on the temperature field prevailing in the spaceplane. ...Moreover, chemical reactions, metabolic rates of the crew and external heat loads determine the thermal behaviour of the spacecraft. For design and optimisation of the system and its subsystems a mathematical model is required which describes these effects.

Research was initiated due to increased concern over trace contaminant gas build-up in an enclosed atmosphere of a spacecraft for long duration space flights. A gas mixture simulating conditions on long duration space missions must be created in order to test trace contaminant control hardware. ...This contaminant model gas mixture can be used to test trace contaminant control hardware for an enclosed spacecraft environment.

A fire in spacecraft or habitat supporting NASA's Exploration mission could jeopardize the system, mission, and/or crew.

The system consists of integrated applications to perform: surface and solid modeling, radiation coupling, orbital analysis, characterization of the thermal radiation heating environment for a spacecraft in orbit or on a planet surface, conduction network generation, two-phase flow modeling and analysis, temperature predictions, and general purpose post-processing. ...While TSS is tailored for spacecraft thermal analysis, it may be used for any general purpose thermal analysis as well. The TSS user interface allows simultaneous menu and command line input.

Fire detection, post fire atmospheric monitoring, fire extinguishing, and post fire atmospheric cleaning are vital components of a spacecraft fire response system, Preliminary efforts focused on the technology evaluation of fire detection, post fire atmospheric monitoring and post fire cleanup systems under realistic conditions are described in this paper. ...The fuel used to generate the smoke is a mixture of polymers in representative quantities of materials involved in a circuit board fire — this was labeled as a typical spacecraft fire as suggested by Sribnik, et al.1 Two fire conditions were examined, termed a no flame and flame.

CERES has been selected as a payload on the Earth Observing System (EOS-AM-1) spacecraft which is the principle component of NASA's Mission to Planet Earth. Several broadband scanning radiometers will measure emitted and reflected energy from the surface of the Earth and the atmosphere to provide a long-term consistent database of the Earth's radiation balance and ultimately the effect of clouds on the Earth's climate.