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Technical Paper

Atmospheric Monitoring Strategy for Ground Testing of Closed Ecological Life Support Systems

This paper reviews the evolution and current state of atmospheric monitoring on the International Space Station to provide context from which we can imagine a more advanced and integrated system. The unique environmental hazards of human space flight are identified and categorized into groups, taking into consideration the time required for the hazard to become a threat to human health or performance. The key functions of a comprehensive monitoring strategy for a closed ecological life support system are derived from past experience and a survey of currently available technologies for monitoring air quality. Finally, a system architecture is developed incorporating the lessons learned from ISS and other analogous closed life support systems. The paper concludes by presenting recommendations on how to proceed with requirements definition and conceptual design of an air monitoring system for exploration missions.
Technical Paper

Biosafe Dress Rehearsal for Mars Sample Containment Using In-Space Sterilization

Total sample containment is an absolute requirement for Mars sample return missions, derived from the requirement to protect against uncontrolled introduction of potentially hazardous foreign material into the earth's biosphere. These constraints of planetary protection comprise one of the major remaining hurdles to low cost implementation of sample return missions. It is suggested here that to spread the costs of the program, the first mission should consider sterilizing the samples and canister surfaces while still in space during the return to Earth.
Technical Paper

Carbon Dioxide Removal Assembly Software Product Improvements

The Carbon Dioxide Removal Assembly (CDRA) on board the International Space Station (ISS) has experienced periodic check valve and selector valve failures as a result of a gradual build-up of contamination from particles that have breeched the adsorbent bed seals. The current software that controls CDRA has limitations that make troubleshooting the unit difficult in these situations, in large part due to the fact that valve position telemetry is only available during certain times. There are also situations where it is required to perform operations manually that would benefit from added code logic and commands to facilitate these operations. The software has been reviewed for possible upgrades and changes that will allow engineers to better troubleshoot the unit in the event of various failures and also allow for better operability in degraded states.
Technical Paper

Evaluation of Commercial Off-the-Shelf Ammonia Sorbents and Carbon Monoxide Oxidation Catalysts

Designers of future space vehicles envision simplifying the Atmosphere Revitalization (AR) system by combining the functions of trace contaminant (TC) control and carbon dioxide removal into one swing-bed system. Flow rates and bed sizes of the TC and CO2 systems have historically been very different. There is uncertainty about the ability of trace contaminant sorbents to adsorb adequately in a high-flow or short bed length configurations, and to desorb adequately during short vacuum exposures. This paper describes preliminary results of a comparative experimental investigation into adsorbents for trace contaminant control. Ammonia sorbents and low temperature catalysts for CO oxidation are the foci. The data will be useful to designers of AR systems for Constellation. Plans for extended and repeated vacuum exposure of ammonia sorbents are also presented.
Technical Paper

Guidance for Trade Studies of Flight-Equivalent Hardware

Spacecraft hardware trade studies compare options primarily on mass while considering impacts to cost, risk, and schedule. Historically, other factors have been considered in these studies, such as reliability, technology readiness level (TRL), volume and crew time. In most cases, past trades compared two or more technologies across functional and TRL boundaries, which is an uneven comparison of the technologies. For example, low TRL technologies with low mass were traded directly against flight-proven hardware without consideration for requirements and the derived architecture. 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.
Technical Paper

Life Sciences Research in the Centrifuge Accommodation Module of the International Space Station

The Centrifuge Accommodation Module (CAM) will be the home of the fundamental biology research facilities on the International Space Station (ISS). These facilities are being built by the Biological Research Project (BRP), whose goal is to oversee development of a wide variety of habitats and host systems to support life sciences research on the ISS. The habitats and host systems are designed to provide life support for a variety of specimens including cells, bacteria, yeast, plants, fish, rodents, eggs (e.g., quail), and insects. Each habitat contains specimen chambers that allow for easy manipulation of specimens and alteration of sample numbers. All habitats are capable of sustaining life support for 90 days and have automated as well as full telescience capabilities for sending habitat parameters data to investigator homesite laboratories.
Technical Paper

Online Project Information System (OPIS) Description, Annual Reporting Outcomes, and Resulting Improvements

The On-line Project Information System (OPIS) is the Exploration Life Support (ELS) mechanism for task data sharing and annual reporting. Fiscal year 2008 (FY08) was the first year in which ELS Principal Investigators (PI's) were required to complete an OPIS annual report. The reporting process consists of downloading a template that is customized to the task deliverable type(s), completing the report, and uploading the document to OPIS for review and approval. In addition to providing a general status and overview of OPIS features, this paper describes the user critiques and resulting system modifications of the first year of OPIS reporting efforts. Specifically, this paper discusses process communication and logistics issues, user interface ambiguity, report completion challenges, and the resultant or pending system improvements designed to circumvent such issues for the fiscal year 2009 reporting effort.
Technical Paper

Predicting Fatigue for Isolated Joints While Wearing an Extra-vehicular Mobility Unit (EMU)

To work outside a space craft, humans must wear a protective suit. The required suit pressurization creates additional resistance for the wearer while performing work. How much does the suit effect work and fatigue? To answer these questions, dynamic torque was collected for the shoulder, elbow and wrist for six subjects in an Extra-vehicular Mobility Unit (EMU). In order to quantify fatigue, the subjects were to exert maximum voluntary torque for five minutes or until their maximum fell below 50% of their initial maximum for three consecutive repetitions. Using the collected torque and time data, logarithmic based functions were derived to estimate torque decay to within an absolute error of 20%. These results will be used in the development of a generalized tool for prediction of maximum available torque over time for humans using the current EMU.
Technical Paper

Testing of the Prototype Plant Research Unit Subsystems

The Plant Research Unit (PRU) is currently under development by the Space Station Biological Research Project (SSBRP) team at NASA Ames Research Center (ARC) with a scheduled launch in 2001. The goal of the project is to provide a controlled environment that can support seed-to-seed and other plant experiments for up to 90 days. This paper describes testing conducted on the major PRU prototype subsystems. Preliminary test results indicate that the prototype subsystem hardware can meet most of the SSBRP science requirements within the Space Station mass, volume, power and heat rejection constraints.
Journal Article

The Orion Air Monitor; an Optimized Analyzer for Environmental Control and Life Support

This paper describes the requirements for and design implementation of an air monitor for the Orion Crew Exploration Vehicle (CEV). The air monitor is specified to monitor oxygen, nitrogen, water vapor, and carbon dioxide, and participates with the Environmental Control Life Support System (ECLSS) pressure control system and Atmosphere Revitalization System (ARS) to help maintain a breathable and safe environment. The sensing requirements are similar to those delivered by the International Space Station (ISS) air monitor, the Major Constituent Analyzer or MCA (1, 2 and 3), and the predecessors to that instrument, the Skylab Mass Spectrometer (4, 5), although with a shift in emphasis from extended operations to minimized weight. The Orion emphasis on weight and power, and relatively simpler requirements on operating life, allow optimization of the instrument toward the mass of a sensor assembly.
Technical Paper

Virtual Human Modeling for Manufacturing and Maintenance

Deneb's Interactive Graphic Robot Instruction Progam (IGRIP) and Envision software packages with the Ergonomic analysis option enabled were used for manufacturing process analysis and maintainability / human factors design evaluation in the Lockheed Martin Tactical Aircraft Systems - Fort Worth facility. The initial objective of both the manufacturing and maintainability engineering community was to validate the use of ergonomic modeling and simulation tools in an effort to gain acceptance of this new technology. Each discipline selected an existing operation to baseline the validation. Manufacturing selected the F-16 vertical fin as it is assembled from detail parts into a complete assembly, ready to be mated to the aircraft. Maintainability selected the removal of the Expanded Data Entry Electronics Unit (EXDEEU) located behind the ejection seat of the F-16 aircraft.