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The Effect of Hydration Status on Neuromuscular Performance Before and After Intermittent Exercise in the Heat
No full textMaintaining optimal fluid balance is essential for athletic performance and recovery, especially during exercise in the heat. However, the effect of dehydration on neuromuscular performance with intermittent exercise remains unknown. PURPOSE: To examine the effect of hydration status on neuromuscular performance before and after intermittent exercise in the heat. METHODS: Eleven male soccer players (mean standard deviation; age, 20 ± 2 years; height, 179.0 ± 7.9 cm; body mass, 74.9 ± 10.3 kg; body fat; 17.1 ± 3.8%; maximal oxygen consumption [VO2max], 62.4 ± 11.5 mL·kg-1·min-1) completed a VO2max test to qualify for the study. Following this, they performed a familiarization trial, which included ultrasound (cross-sectional area [CSA], muscle thickness [MT], muscle quality [EI]), landing error scoring system (LESS), single-leg hop (SLH), and isometric knee extensions (peak torque [PT], peak rate of torque development [PRTD], rate of torque development [RTD] 30, 50, 100, 200). Then, participants completed the familiarization trial with a 45-minute intermittent exercise in the heat (33ºC, 30% relative humidity). Experimental trials included the same protocol of pre- and post-neuromuscular testing, and a soccer simulated intermittent exercise (two bouts of 45-minutes with a 15-minute break in between) that consisted of sprinting, jogging, walking, and standing. The exercise intensity was individualized based on the participant’s VO2max. During the exercise, heart rate (HR) and core temperature (Tc) were measured. Two experimental (euhydrated [EUH] or dehydrated [DEH]) trials were randomly assigned; DEH, participants completed a 24-hour fluid restriction prior to the trial and 300 mL of water was provided during the break; EUH, participants started the exercise in a euhydrated state and were prescribed fluid to maintain it. Before and after exercise, urine specific gravity (USG), urine osmolality (UOSM), body mass loss (BML), and lean body mass (LBM), were measured. RESULTS: CSA and LBM were smaller in DEH pre (13.3 2.4 mm2, 57.4 6.6 kg) compared to EUH pre (14.0 2.6 mm2, 59.1 6.7 kg, p 0.05). Additionally, HR, Tc, USG, UOSM, and BML, were all significantly higher in the DEH trial compared to the EUH trial (p < 0.05). CONCLUSION: Dehydration can negatively impact neuromuscular performance and injury risk along with thermoregulatory and cardiovascular strain during exercise in the heat
Performances of Flame Retardants in Microgravity: Insights from Opposed Flame Spread over Electrical Wires
No full textYutao Li, University College London, United KingdomAugustin Guibaud, NYU Tandon School of Engineering, United StatesJohan Sarazin, Université de Lille, FranceSerge Bourbigot, Université de Lille, FranceJean-Marie Citerne, Sorbonne Université, FranceGuillaume Legros, Sorbonne Université, FranceICES509: Fire Safety in Spacecraft and Enclosed HabitatsThe 54th International Conference on Environmental Systems was held in Prague, Czechia, on 13 July 2025 through 17 July 2025.Fire safety is a critical consideration for space
exploration. Flame retardants are a straightforward
solution to improve the fire resistance of flammable
material critical to the success of space missions, but
their performances in microgravity conditions can differ
from ground-based evaluations due to altered heat and mass
transfer. Understanding the behavior of flame retardants in
microgravity is essential for designing effective fire
safety strategies for spacecraft. This study examines the
opposed-flow extinction limits of flames spreading over
low-density polyethylene (LDPE) samples. The parabolic
flight experiments consider both monophasic cylindrical
samples and electrical wires featuring a Nickel-Chrome
core. The samples are loaded with three flame retardant
systems, i.e. Ammonium Polyphosphate/Pentaerythritol (AP),
Red Phosphorus (RP), and the commercial Intumescent Adeka
(AD). and RP works by combining gas-phase free radical
inhibition and solid-phase charring, while AP and AD rely
on intumescence and expand upon heating to form a thermal
barrier that slows down pyrolysis. Experimental results
reveal that the presence of AP and RP in a sample
significantly increases the extinction limits, while
AD-loaded samples show no notable improvement compared to
pure LPDE samples. The presence of a metal core markedly
enhanced the performance of AP, highlighting the need to
consider the use of fire retardant as part of a complex
assembly. These findings illustrate the varied performance
of flame retardants in microgravity and highlight the
importance of selecting materials based on their mechanisms
and compatibility with specific applications. This research
contributes to the development of fire-safe materials
tailored for the unique challenges of space exploration
Methods for Modeling Lunar Dust in Thermal Desktop Based on Lunar Dust Level Sensor and Effects on Surfaces Test Data
No full textJessie R. Beddoe, Barrios Technology/Amentum/NASA Johnson Space Center (JSC), United StatesLisa R. Erickson, NASA Johnson Space Center (JSC), United StatesCheyn L. Worn, NASA Johnson Space Center (JSC), United StatesICES207: Thermal and Environmental Control Engineering
Analysis and SoftwareThe 54th International Conference on Environmental Systems was held in Prague, Czechia, on 13 July 2025 through 17 July 2025.With the upcoming Artemis Missions and renewed interest in
lunar exploration, there is an ongoing concern about how to
analyze the impacts of lunar regolith on critical thermal
components like optical coatings. Often, the Rule of
Mixtures or similar relationships are considered sufficient
for calculating how optical properties should change on a
regolith-covered surface. However, recent studies by the
Lunar Dust Level Sensor and Effects on Surfaces (LDES) team
produced results that suggest lunar simulant coverage
impacts the effective emissivity of surfaces in a nonlinear
fashion, resulting from a complicated heat transfer path
through the regolith layer. This paper documents the
efforts to compare different methods of modeling dust in
Thermal Desktop (TD) based on the LDES effective emittance
values and the Lunar Highlands dust simulant’s (LHS-1D)
optical and thermophysical properties. Initial correlation
to the undusted coupon data was done using a TD model of
the test setup. Subsequent correlation for dusted coupons
determines modeling effectiveness by comparing the model’s
sensor heater power used to test data, and the model’s
estimated radiation versus theoretical calculated radiation
from the surface of the coating to the TVAC chamber shroud.
The study found that the best heater power comparison
resulted from modeling method 4, where error for the top
heater correlation was within +/-10% and the error for the
radiation check was within +/-5%. However, this study
depicts a very specific use case and is not recommended to
be adopted for general analysis until desired future work
can be completed
Environmental Testing of a Fully Automated Carbothermal Reactor for Lunar Oxygen Production
No full textNathan P. Haggerty, Sierra Space Corporation, United StatesBrant C. White, Sierra Space Corporation, United StatesAaron Paz, NASA Johnson Space Center (JSC), United StatesDesmond O'Connor, NASA Johnson Space Center (JSC), United StatesNilab Azim, NASA Kennedy Space Center (KSC), United StatesJanine Captain, NASA Kennedy Space Center (KSC), United StatesICES308: Advanced Technologies for In-Situ Resource
UtilizationThe 54th International Conference on Environmental Systems was held in Prague, Czechia, on 13 July 2025 through 17 July 2025.Oxygen comprises the majority of propellant mass required
for ascent from the lunar surface and for in-space chemical
propulsion. Using in-situ resource utilization (ISRU)
technologies to produce oxygen on the moon enables a robust
lunar economy through a dramatic reduction in lunar launch
costs. In the Summer of 2024 Sierra Space completed thermal
vacuum (TVAC) testing of a flight-like Carbothermal Oxygen
Production Reactor (COPR) through a NASA Tipping Point
program.
The COPR reactor uses a mass efficient, scalable
architecture optimized for a lunar technology demonstration
mission. Concentrated solar energy is directly applied to
the lunar regolith simulant. The insulating material
properties of the regolith isolate the corrosive molten
material from the reactor walls and other hardware. This
approach allows for a completely passive thermal control
system where high temperature (~1800°C) carbothermal
processing is performed without requiring exotic materials
or complex cooling systems. The reactor also includes an
end-to-end automated solid material handling system capable
of metering the lunar regolith simulant from a supply
hopper into a pressurized volume, weighing it, distributing
it into the carbothermal reactor, and removing the reduced
metallic slag.
Sierra Space demonstrated repeated use of the automated
material handling, gas handling and carbothermal reduction
processing systems inside NASA JSC’s “dirty” TVAC chamber
while at the relevant lunar topographical, vacuum, and
temperature conditions. This testing matured key hardware
to TRL 6. Oxygen extraction and performance measurements
were taken by the NASA KSC Mass Spectrometer Observing
Lunar Operations (MSolo) team using a commercial version of
their flight instrument. Oxygen extraction energy
efficiency and production yield from regolith exceeded the
program goals.
The COPR system will be integrated with a flight forward
solar concentrator, optical shutter, gas analysis system,
avionics, and software as a part of the NASA CaRD program
integrated testing in early 2025
Magnetohydrodynamic Bubble Removal for Water Electrolysis in Reduced-Gravity Environments
No full textTheo St. Francis, Georgia Institute of Technology, United StatesTryston Schmitt, Georgia Institute of Technology, United StatesJaroslaw Syzdek, Biologic, United StatesÁlvaro Romero-Calvo, Georgia Institute of Technology, United StatesICES500: Life Science/Life Support Research TechnologiesThe 54th International Conference on Environmental Systems was held in Prague, Czechia, on 13 July 2025 through 17 July 2025.Water electrolysis is an essential electrochemical process
for oxygen production in space and high-purity hydrogen
production on Earth. As with all gas-evolving liquid phase
reactions, the presence of bubbles over the electrodes
increases cell resistivity and hinders mass transport of
the liquid electrolyte to the electrode surfaces. On Earth,
efficiency losses due to the presence of bubbles can be as
high as 30%. In a reduced-gravity environment, the lower
buoyancy force will delay bubble detachment further,
leading to additional efficiency losses. Among a variety of
methods proposed and in use for accelerating bubble
evacuation, magnetohydrodynamic pumping via a magnetically
induced Lorentz force has shown promise in controlled lab
trials. In this paper, we describe the modeling and testing
of a magnetohydrodynamic alkaline water electrolysis
architecture where the magnetic field is produced by
off-the-shelf rare-Earth N52 permanent magnets arranged in
a Halbach pattern. The arrays are located just behind the
electrodes to amplify the strength of the field and
facilitate follow-on scale-up efforts. Benchtop tests of
three magnet sizes at current densities between 10-500
mA/cm2 show little or no improvement in
chronopotentiometric trials with magnetic forcing aligned
with and against gravity. However, potentiostatic EIS data
show a 34.5% reduction in diffusion resistance and a 132.5%
increase in diffusion capacitance, which are promising mass
transport benefits that hint at potential benefits for
improved magnetic configurations
Habitation Life Support Breakeven Analysis for Lunar-derived Oxygen and Water
No full textJames E. Johnson, Colorado School of Mines, United StatesICES308: Advanced Technologies for In-Situ Resource
UtilizationThe 54th International Conference on Environmental Systems was held in Prague, Czechia, on 13 July 2025 through 17 July 2025.Lunar-derived oxygen and water have been postulated as
commodities that could enable a cislunar-based economy.
Water, electrolyzed hydrogen, and oxygen obtained from
lunar resources could refuel landers, replenish cislunar
fuel depots for deep space exploration, and support crew
survival. While numerous analyses have investigated
breakeven points in Earth vs. lunar-derived propellants,
similar analyses focused on the smaller scale consumable
demand from human crews have not garnered as much attention
due to the economies of scale in propulsion-based use
cases. Despite the lower demand of oxygen and water from
initial lunar habitats, the de-risking of in-situ resource
utilization (ISRU) technologies while reducing logistical
resupply from Earth could yield increasingly sustainable
mission architectures while fundamentally demonstrating the
economic validity of a lunar-based commodity market.
Considering the deferment of mass and energy intensive
liquefaction systems and leveraging the power generation
capabilities of initial lunar habitats during uncrewed
periods, ISRU technologies may trade similarly to
regenerative environmental control and life support (ECLS)
systems, but with the prospect of longer-term economic
benefits. This paper investigates possible breakeven points
in system mass, logistical resupply, and associated cost
between representative ISRU and ECLS architectures
supporting near-term lunar habitation concepts
Biomass Thermal Vacuum Test Campaign Lessons Learned
No full textGlenn Kightley, Airbus Defence and Space, United KingdomAaron Valle-Lozano, Airbus Defence and Space, GermanyHeiko Ritter, ESA, NetherlandsICES203: Thermal TestingThe 54th International Conference on Environmental Systems was held in Prague, Czechia, on 13 July 2025 through 17 July 2025.Biomass was selected as the 7th Earth Explorer mission in
Spring 2013 at the User Consultation Meeting in Graz,
Austria. The overall objective of the mission is to reduce
the uncertainty in the worldwide spatial distribution and
dynamics of forest biomass in order to improve current
assessments and future projections of the global carbon
cycle. This objective will be achieved by implementation of
a novel P-band SAR mission, providing global maps of forest
biomass stocks, forest disturbance and growth. As part of
the satellite verification activities, a thermal vacuum
test was concluded in October 2024 in the SIMLES test
chamber at Airbus Defence and Space Toulouse. In the
absence of solar simulation, the test utilised IR lamp
arrays for the purposes of heat injection at critical
locations, in combination with direct test heating to
simulate environmental loads on the satellite. In
addition, dedicated excursions were performed during the
test to assess the robustness of PI control implemented on
the Star Tracker optical heads. This paper will summarise
the Biomass thermal control design and will discuss the
complexities of realising the idealised thermal design into
a fully testable test configuration. The paper also
addresses lessons learned for future satellite thermal
vacuum tests
Current Logistics Reduction Accomplishments and Plans to Support Exploration Missions
Get PDFMelissa K. McKinley, NASA Johnson Space Center (JSC), United StatesMichael K. Ewert, NASA Johnson Space Center (JSC), United StatesMelissa A. Borrego, NASA Johnson Space Center (JSC), United StatesPatrick Fink, NASA Ames Research Center(ARC), United StatesSteve Sepka, NASA Ames Research Center(ARC), United StatesICES304: Physico-Chemical Life Support- Waste Management
Systems- Technology and Process DevelopmentThe 54th International Conference on Environmental Systems was held in Prague, Czechia, on 13 July 2025 through 17 July 2025.Management of logistics on exploration missions includes
both looking for ways to minimize the quantities, mass and
volume of various consumables, supplies, spares, and
equipment as well as ways to minimize the crew time needed
for locating and handling those items. Also included are
ways to minimize the waste, handling, and resultant
products from the processes of maintaining a crew on these
missions. The Logistics Reduction project encompasses
technologies for management of waste, trash, autonomous
logistics, and clothing. This paper provides a status of
work completed in 2024 in these areas including recent
accomplishments and challenges encountered. Future
objectives and plans for 2025 will also be covered along
with the work currently in progress. Specifically, the
paper will cover technologies in waste management, namely,
the Universal Waste Management System (UWMS) or exploration
toilet and work on an alternative waste collection
container, the Alternate Fecal Canister. Trash management
technologies work on the Trash Compaction Processing System
(TCPS) is summarized with progress to date as well as
information on how Jettison as an option is related and
studies related to the trash management strategy. Progress
and summary of recent accomplishment on the RFID (Radio
Frequency ID) Enabled Autonomous Logistics Management
(REALM) technology is detailed. Advanced Clothing System
(ACS) and work in the area of Systems Engineering and
Integration (SE&I) is also included. Status of the
technologies, accomplishments and how the focus areas
inform program decisions are summarized
Literary Criticism Periodical Sources Neo-classical to France
Get PDFThe Boyd Carter Papers represent a significant archival collection housed in the Hispanic Studies Collection in Texas Tech University's CMLL building. Dr. Boyd Carter was a distinguished scholar of Latin American literature who was active from the 1940s to his death in 1980. He held professorships at the University of Nebraska, Southern Illinois University, and the University of Missouri before concluding his career at Texas Tech University (1978-1980). Upon joining TTU, Carter donated his extensive archive to the university, including rare books, microfilm collections, bibliographical notes, and periodicals focusing on Latin American literature from 1850-1950, with particular emphasis on the famed Mexican writer Manuel Gutiérrez Nájera