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Michael R Callahan

Publications and source records attributed to Michael R Callahan.

10 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2026

Spacecraft Water Impurity Monitor, a System for Water Quality Analysis on Exploration Missions Beyond Low Earth Orbit

Exploration missions beyond low-earth-orbit (LEO) will require advanced instrumentation to monitor water quality. Traveling beyond LEO means the transfer of water samples to an Earth-based laboratory for detailed analysis is not feasible. Detailed analysis of water composition during exploration is still necessary, because having the capability to determine the specific organic chemical causing a change in total organic carbon (TOC) or the specific metal or ionic species causing a change in conductivity has the potential to inform the crew health and system management decisions. On a new vehicle such as a lunar or Mars surface habitat or a Mars transit vehicle, finding “new” impurities not seen on ISS should be expected. The key is to identify the impurity so the correct action can be taken. On ISS we can measure TOC, conductivity, and other physical properties but do not have the capability for detailed analysis using vehicle instrumentation. This is acceptable because ISS can send samples down to Earth for further analysis and obtain the detailed composition. The Spacecraft Water Impurity Monitor (SWIM) will provide detailed water quality analysis for missions in which sample down mass is not available. SWIM is a system comprising organic and inorganic analysis modules. For organic chemicals, a gas chromatograph mass spectrometer (GCMS) detects and identifies organic impurities. For inorganic species, a capillary electrophoresis capacitively coupled contactless conductivity detection (CE-C4D) system as well as ion specific electrodes detect and identify metal ions and other inorganic salts / acids. The SWIM technology demonstration project has completed a System Requirements Review (SRR) to finalize detection requirements and is currently working to refine vehicle interface requirements for a future technology demonstration. The project also has begun preliminary flight design activities for the core analyzers in the instrument suite.

Water Monitoring↗
NASA NTRSDate not supplied

Silver Foam: A Novel Approach for Long-Term Passive Dosing of Biocide in Spacecraft Potable Water Systems

A spacecraft water disinfection system suitable for extended length space exploration should prevent or control the growth of microbes, prevent or limit biofilm formation, and prevent microbiologically influenced corrosion. In addition, the system should have minimal maintenance requirements,should be chemically compatible with all materials in contact with the water, be safe for human consumption, and suitable to be shared across international spacecraft platforms and mission architectures. Silver ions are a proven broad-spectrum biocide under consideration as a potable water biocide for future exploration missions. The leading technology for actively dosing silver in future water systems is based on electrolytic production. Several challenges remain with this approach that have prompted additional investigations into alternative dosing techniques. Control-release technology is an attractive option for developing a high-reliability passive silver dosing device. This paper describes the development of a silver chloride (AgCl) nanoparticle (NP)/polyurethane (PU) composite foam for the controlled release of silver ions, and is intended to build upon the 2019 International Conference on Environmental Systems (ICES) paper number 272.This paper provides the technical background and results from the updated AgClNP/PU composite foam (AgFoam) synthesis and property testing. The ultimate goal of the project is to develop a stable and reliable passive dosing silver ion release device for use in future spacecraft potable water systems.

Tesia Dawn Irwin↗
NASA NTRSDate not supplied

Literature Review of Disinfection Techniques For Water Treatment

Water treatment is a developing concern, both terrestrially and in spacecraft, as exploration missions extend in time and distance. Current biofilm control is limited for long-term applications. To optimize biocides for present and future space exploration vehicles, a thorough understanding of common and traditional disinfectant techniques is required. This review is focused on the three fundamental disinfection techniques: chemical, physical, and biological. Mechanisms, advantages, disadvantages, and specific properties of each major technique, as well as their studied effect on established biofilms, are also considered. This paper provides a general background on disinfectants and some information on effects on biofilms that can be useful to develop innovative ideas for state-of-the-art disinfection techniques for water treatment in specific environments, such as those currently posing mission risks as well as for future spacecraft water system development.

Nilab Azim↗
NASA NTRSDate not supplied

A Preliminary Modeling Study of Biofilm Accumulation in the Water Recovery System

Bacterial biofilms are ubiquitous in wastewater systems on earth and in spacecraft, such as in the International Space Station (ISS) wastewater processing assembly (WPA), where they cause problems in the tank, solenoid valves, and pipelines. Downstream filter applications, tank cycling, and regular biocide water flushing have been used to control biofilm accumulation on board the ISS. Biofilm control is expected to be a challenge for long-term missions with a dormancy period of up to a year, as stagnant water systems are highly susceptible to biofilm growth. Flushing of the system with biocidal water has been proposed to avoid biomass problems for long-term missions. To validate the proposed flush method, a mathematical model, based on the metabolism maintenance rate of bacteria, is being developed to understand the current biofilm accumulation rate in the ISS WPA system and to calculate the biomass production rate under dormancy-like conditions. This method of quantification of biofilm can be applied as a function of nutrient inputs to guide the selection and optimization of biofilm mitigation approaches. The method can also be helpful in understanding, defining, quantifying, visualizing, and simulating the state of the water processing system during operation and after dormancy.

Angie M Diaz↗
NASA NTRSDate not supplied

A Review of Baseline Assumptions and Ersatz Waste Streams for Partial Gravity Habitats and Orbiting Microgravity Habitats

Highly efficient water management and recovery systems will be required to support human missions beyond the low Earth orbit of the International Space Station (ISS).A review of baseline assumptions for the human activities and associated water cycle in surface, partial gravity habitats and orbiting, microgravity habitats is conducted. The paper reviews and updates ersatz formulations and water flow rates for the main liquid water waste streams of urine, humidity condensate, hygiene, and laundry. A framework is provided to coordinate development of water recovery systems for 30-day crew occupancies under partial gravity with longer term, continuous occupancy in orbiting microgravity habitats and the Mars transit habitat.

Water Ersatz Habitat↗
NASA NTRSDate not supplied

Silver Foam: A Novel Approach for Long-Term Passive-Dosing of Biocide in Spacecraft Potable Water Systems – Update 2022

A spacecraft water disinfection system suitable for extended length space exploration should meet a list of requirements. It should prevent or control the growth of microbes, prevent or limit biofilm formation, and prevent microbiologically influenced corrosion. In addition, the system should have minimal maintenance requirements, be chemically compatible with all materials in contact with the water, be safe for human consumption, and be suitable to be shared across international spacecraft platforms and mission architectures. Silver ions are a proven broad-spectrum potable water biocide under investigation for future exploration missions. The competing technology for dosing silver ions in future water systems is based on actively dosing the ions via electrolytic production. Several challenges with this approach have prompted additional investigations into alternative dosing techniques. Control-release technology is an attractive option for developing a high-reliability passive silver dosing device. This paper describes the continued development of a nanoparticle/polyurethane (NP/PU) composite foam for the controlled release of silver ions and is intended to build upon previously published work. This paper provides the technical background and performance results (wash testing and ongoing long-term silver ion release testing) from the silver chloride (AgCl) NP/PU composite foams. The goal of the project is to develop a stable and reliable passive-dosing silver ion release device for use in future spacecraft potable water systems.

Tesia D Irwin↗
NASA NTRSDate not supplied

Baseline Assumptions and Ersatz Waste Streams for Partial Gravity Habitats with Mobile Female and Male Crew

Effective and reliable water management and recovery systems will be required to support human missions beyond the low Earth orbit (LEO) of the International Space Station (ISS). Lunar and Mars surface missions will introduce new challenges to managing water and associated waste streams from mobile crew members who are transiting between up to six living shelters in extreme environmental conditions under a range of gravity conditions. A review of baseline assumptions for the human activities and associated air and water cycles in and between transit vehicle, orbiting station, lander-ascent vehicle, surface habitat, pressurized rover, and suits is conducted. The paper updates ersatz formulations and water flow rates for the main liquid water waste streams of urine, humidity condensate, hygiene, and laundry. Emphasis is placed on the metabolic emissions partitioning between the six vehicles during a design reference mission scenario. Ersatz to represent menses are reviewed.

Dean L Muirhead↗
NASA NTRSDate not supplied

Silver Foam: A Novel Approach for Long-Term Passive Dosing of Biocide in Spacecraft Potable Water Systems – Update 2024

A spacecraft water disinfection system, suitable for extended length space exploration, should prevent or control the growth of microbes, prevent or limit biofilm formation, and prevent microbiologically influenced corrosion. In addition, the system should have minimal maintenance requirements, be chemically compatible with all materials in contact with the water, be safe for human consumption, and be suitable to be shared across international spacecraft platforms and mission architectures. Silver ions are a proven broad-spectrum potable water biocide under investigation for future exploration missions. The competing technology for dosing silver ions in future water systems is based on actively dosing the ions via electrolytic production. Several challenges with this approach have prompted additional investigations into alternative dosing techniques. Control-release technology is an attractive option for developing a high-reliability passive silver dosing device. This paper describes the continued development of a nanoparticle/polyurethane (NP/PU) composite foam for the controlled release of silver ions and is intended to build upon the 2023 International Conference on Environmental Systems (ICES) paper number 251. This paper provides the technical background and performance results for the product variability testing and microbial check valve (MCV) testing of the silver chloride (AgCl) NP/PU composite foams, referred to as AgFoams. The ultimate goal of the project is to develop a stable and reliable passive dosing silver ion release device for use in future spacecraft potable water systems.

Tesia D Irwin↗
NASA NTRSDate not supplied

TOC Calibration Method for Exploration Application

Total organic carbon (TOC) is the amount of carbon associated with organic compounds in solution and is often used as a non-specific indicator for water quality or cleanness. Currently, the Total Organic Carbon Analyzer (TOCA) is being used onboard the International Space Station (ISS) for water recovery system process control. An exploration-class TOCA is now being developed to close the technology gaps between the State-of-the-Art ISS TOCA and the emerging requirements of future exploration missions. One of the technical gaps for an exploration TOC analyzer is the development of suitable methods for on-orbit calibration. While the ISS TOCA uses pre-packaged ground-supplied TOC calibration standards, there is limited stability data. Other options include preparing calibration standards in space, which can be challenging due to the lack of low TOC reagent water. This paper explores the practice of the standard addition method and passive dosing approaches as potential solutions to overcome this problem.

Wenyan Li↗