Impact of Water Recovery from Wastes on the Lunar Surface Mission Water Balance

Future extended lunar surface missions will require extensive recovery of resources to reduce mission costs and enable self-sufficiency. Water is of particular importance due to its potential use for human consumption and hygiene, general cleaning, clothes washing, radiation shielding, cooling for extravehicular activity suits, and oxygen and hydrogen production. Various water sources are inherently present or are generated in lunar surface missions, and subject to recovery. They include: initial water stores, water contained in food, human and other solid wastes, wastewaters and associated brines, ISRU water, and scavenging from residual propellant in landers. This paper presents the results of an analysis of the contribution of water recovery from life support wastes on the overall water balance for lunar surface missions. Water in human wastes, metabolic activity and survival needs are well characterized and dependable figures are available. A detailed life support waste model was developed that summarizes the composition of life support wastes and their water content. Waste processing technologies were reviewed for their potential to recover that water. The recoverable water in waste is a significant contribution to the overall water balance. The value of this contribution is discussed in the context of the other major sources and loses of water. Combined with other analyses these results provide guidance for research and technology development and down-selection

Heat Melt Compactor Development Progress

The status of the Heat Melt Compactor (HMC) development project is reported. HMC Generation 2 (Gen 2) has been assembled and initial testing has begun. A baseline mission use case for trash volume reduction, water recovery, trash sterilization, and the venting of effluent gases and water vapor to space has been conceptualized. A test campaign to reduce technical risks is underway. This risk reduction testing examines the many varied operating scenarios and conditions needed for processing trash during a space mission. The test results along with performance characterization of HMC Gen 2 will be used to prescribe requirements and specifications for a future ISS flight Technology Demonstration. We report on the current status, technical risks, and test results in the context of an ISS vent-to-space Technology Demonstration

Enhanced Lighting Techniques and Augmented Reality to Improve Human Task Performance

One of the most versatile tools designed for use on the International Space Station (ISS) is the Special Purpose Dexterous Manipulator (SPDM) robot. Operators for this system are trained at NASA Johnson Space Center (JSC) using a robotic simulator, the Dexterous Manipulator Trainer (DMT), which performs most SPDM functions under normal static Earth gravitational forces. The SPDM is controlled from a standard Robotic Workstation. A key feature of the SPDM and DMT is the Force/Moment Accommodation (FMA) system, which limits the contact forces and moments acting on the robot components, on its payload, an Orbital Replaceable Unit (ORU), and on the receptacle for the ORU. The FMA system helps to automatically alleviate any binding of the ORU as it is inserted or withdrawn from a receptacle, but it is limited in its correction capability. A successful ORU insertion generally requires that the reference axes of the ORU and receptacle be aligned to within approximately 0.25 inch and 0.5 degree of nominal values. The only guides available for the operator to achieve these alignment tolerances are views from any available video cameras. No special registration markings are provided on the ORU or receptacle, so the operator must use their intrinsic features in the video display to perform the pre-insertion alignment task. Since optimum camera views may not be available, and dynamic orbital lighting conditions may limit viewing periods, long times are anticipated for performing some ORU insertion or extraction operations. This study explored the feasibility of using augmented reality (AR) to assist with SPDM operations. Geometric graphical symbols were overlaid on the end effector (EE) camera view to afford cues to assist the operator in attaining adequate pre-insertion ORU alignment

Neuroimaging of structural pathology and connectomics in traumatic brain injury: Toward personalized outcome prediction.

Recent contributions to the body of knowledge on traumatic brain injury (TBI) favor the view that multimodal neuroimaging using structural and functional magnetic resonance imaging (MRI and fMRI, respectively) as well as diffusion tensor imaging (DTI) has excellent potential to identify novel biomarkers and predictors of TBI outcome. This is particularly the case when such methods are appropriately combined with volumetric/morphometric analysis of brain structures and with the exploration of TBI-related changes in brain network properties at the level of the connectome. In this context, our present review summarizes recent developments on the roles of these two techniques in the search for novel structural neuroimaging biomarkers that have TBI outcome prognostication value. The themes being explored cover notable trends in this area of research, including (1) the role of advanced MRI processing methods in the analysis of structural pathology, (2) the use of brain connectomics and network analysis to identify outcome biomarkers, and (3) the application of multivariate statistics to predict outcome using neuroimaging metrics. The goal of the review is to draw the community's attention to these recent advances on TBI outcome prediction methods and to encourage the development of new methodologies whereby structural neuroimaging can be used to identify biomarkers of TBI outcome

Characterization of Heat Melt Compactor (HMC) Product Water

The Heat Melt Compactor (HMC) is designed to sterilize and process wastes produced during space missions. Benefits of the HMC include reduction of biohazards to the crew, reduction in volume of wastes that would otherwise require storage, production of radiation shielding tiles, and recovery of water and other resources. Water reuse is critical onboard spacecrafts; it reduces the need for resupply missions and saves valuable storage space. The main sources of water in HMC batches are food, beverages, shampoo, disinfecting wipes, toothpaste, and diapers. Water reclaimed by the HMC was analyzed for concentrations of Na+, NH4+, K+, Mg2+, Ca2+, Cl-, NO2-, Br-, NO3-, PO43-, SO42-, total organic carbon (TOC), total inorganic carbon (TIC), % total solids, and pH. The data are discussed in relation to the current water input characteristics established for the International Space Station Water Processor Assembly system. Batches with higher than average amounts of food produced HMC product water with higher sulfate content, and batches with higher proportions of disinfectant wipes and food yielded HMC product water with higher ammonium concentration. We also compared theoretical chemical composition of HMC product water based on food labels and literature values to experimental results

Synaptically activated burst-generating conductances may underlie a group-pacemaker mechanism for respiratory rhythm generation in mammals

Breathing, chewing, and walking are critical life-sustaining behaviors in mammals that consist essentially of simple rhythmic movements. Breathing movements in particular involve the diaphragm, thorax, and airways but emanate from a network in the lower brain stem. This network can be studied in reduced preparations in vitro and using simplified mathematical models that make testable predictions. An iterative approach that employs both in vitro and in silico models argues against canonical mechanisms for respiratory rhythm in neonatal rodents that involve reciprocal inhibition and pacemaker properties. We present an alternative model in which emergent network properties play a rhythmogenic role. Specifically, we show evidence that synaptically activated burst-generating conductances-which are only available in the context of network activity-engender robust periodic bursts in respiratory neurons. Because the cellular burst-generating mechanism is linked to network synaptic drive we dub this type of system a group pacemaker. © 2010 Elsevier B.V

History, College of Medicine: 1959-1968. Chapter 2: College Administration

Prepared for the Centennial of The Ohio State University

Sodium and Calcium Current-Mediated Pacemaker Neurons and Respiratory Rhythm Generation

The breathing motor pattern in mammals originates in brainstem networks. Whether pacemaker neurons play an obligatory role remains a key unanswered question. We performed whole-cell recordings in the pre-Botzinger complex in slice preparations from neonatal rodents and tested for pacemaker activity. We observed persistent Na+ current (INaP)-mediated bursting in ∼5% of inspiratory neurons in postnatal day 0 (P0)-P5 and in P8-P10 slices. INaP-mediated bursting was voltage dependent and blocked by 20 μm riluzole (RIL). We found Ca2+ current (ICa)-dependent bursting in 7.5% of inspiratory neurons in P8-P10 slices, but in P0-P5 slices these cells were exceedingly rare (0.6%). This bursting was voltage independent and blocked by 100 μm Cd2+ or flufenamic acid (FFA) (10-200 μm), which suggests that a Ca2+-activated inward cationic current (ICAN) underlies burst generation. These data substantiate our observation that P0-P5 slices exposed to RIL contain few (if any) pacemaker neurons, yet maintain respiratory rhythm. We also show that 20 nm TTX or coapplication of 20 μm RIL + FFA (100-200 μm) stops the respiratory rhythm, but that adding 2 μm substance P restarts it. We conclude that INaP and ICAN enhance neuronal excitability and promote rhythmogenesis, even if their magnitude is insufficient to support bursting-pacemaker activity in individual neurons. When INaP and ICAN are removed pharmacologically, the rhythm can be maintained by boosting neural excitability, which is inconsistent with a pacemaker-essential mechanism of respiratory rhythmogenesis by the pre-Botzinger complex

Magellan/M2FS and MMT/Hectochelle Spectroscopy of Dwarf Galaxies and Faint Star Clusters within the Galactic Halo

We present spectroscopic data for 16369 stellar targets within and/or toward 38 dwarf spheroidal galaxies and faint star clusters within the Milky Way halo environment. All spectra come from observations with the multi-object, fiber-fed echelle spectrographs M2FS at the Magellan/Clay telescope or Hectochelle at the MMT, reaching a typical limiting magnitude G < 21. Data products include processed spectra from all observations and catalogs listing estimates -- derived from template model fitting -- of line-of-sight velocity (median uncertainty 1.1 km/s) effective temperature (234 K), (base10 logarithm of) surface gravity (0.52 dex in cgs units), [Fe/H] (0.38 dex) and [Mg/Fe] (0.24 dex) abundance ratios. The sample contains multi-epoch measurements for 3720 sources, with up to 15 epochs per source, enabling studies of intrinsic spectroscopic variability. The sample contains 6078 likely red giant stars (based on surface gravity), and 4494 likely members (based on line-of-sight velocity and Gaia-measured proper motion) of the target systems. The number of member stars per individual target system ranges from a few, for the faintest systems, to ~ 850 for the most luminous. For most systems, our new samples extend over wider fields than have previously been observed; of the likely members in our samples, 823 lie beyond twice the projected halflight radius of their host system, and 42 lie beyond 5 Rhalf.Comment: Published September 2023 in The Astrophysical Journal Supplement Series, processed spectra and catalogs publicly available at the Zenodo database doi:10.5281/zenodo.783792

Spectroscopic Confirmation of the Sixth Globular Cluster in the Fornax Dwarf Spheroidal Galaxy

The Fornax dwarf spheroidal galaxy has an anomalous number of globular clusters, five, for its stellar mass. There is a longstanding debate about a potential sixth globular cluster (Fornax~6) that has recently been `rediscovered' in DECam imaging. We present new Magellan/M2FS spectroscopy of the Fornax~6 cluster and Fornax dSph. Combined with literature data we identify $\sim15-17$ members of the Fornax~6 cluster that this overdensity is indeed a star cluster and associated with the Fornax dSph. The cluster is significantly more metal-rich (mean metallicity of $\overline{\rm [Fe/H]}=-0.71\pm0.05$) than the other five Fornax globular clusters ($-2.5<[Fe/H]<-1.4$) and more metal-rich than the bulk of Fornax. We measure a velocity dispersion of $5.6_{-1.6}^{+2.0}\,{\rm km \, s^{-1}}$ corresponding to anomalously high mass-to-light of 15$<$M/L$<$258 at 90\% confidence when calculated assuming equilibrium. Two stars inflate this dispersion and may be either Fornax field stars or as yet unresolved binary stars. Alternatively the Fornax~6 cluster may be undergoing tidal disruption. Based on its metal-rich nature, the Fornax 6 cluster is likely younger than the other Fornax clusters, with an estimated age of $\sim2$ Gyr when compared to stellar isochrones. The chemodynamics and star formation history of Fornax shows imprints of major events such as infall into the Milky Way, multiple pericenter passages, star formation bursts, and/or potential mergers or interactions. Any of these events may have triggered the formation of the Fornax~6 cluster.Comment: 17 pages, 9 figures. Accepted to ApJ. Data catalogs included. Comments welcom