Independent Orbiter Assessment (IOA): Assessment of the life support and airlock support systems, volume 2

The McDonnell Douglas Astronautics Company (MDAC) was selected in June 1986 to perform an Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL). The IOA effort first completed an analysis of the Life Support and Airlock Support Systems (LSS and ALSS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. The discrepancies were flagged for potential future resolution. This report documents the results of that comparison for the Orbiter LSS and ALSS hardware. Volume 2 continues the presentation of IOA worksheets and contains the critical items list and NASA FMEA to IOA worksheet cross reference and recommendations

Independent Orbiter Assessment (IOA): Analysis of the life support and airlock support subsystems

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Life Support System (LSS) and Airlock Support System (ALSS). Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. The LSS provides for the management of the supply water, collection of metabolic waste, management of waste water, smoke detection, and fire suppression. The ALSS provides water, oxygen, and electricity to support an extravehicular activity in the airlock

Independent Orbiter Assessment (IOA): Assessment of the life support and airlock support systems, volume 1

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Life Support and Airlock Support Systems (LSS and ALSS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. The discrepancies were flagged for potential future resolution. This report documents the results of that comparison for the Orbiter LSS and ALSS hardware. The IOA product for the LSS and ALSS analysis consisted of 511 failure mode worksheets that resulted in 140 potential critical items. Comparison was made to the NASA baseline which consisted of 456 FMEAs and 101 CIL items. The IOA analysis identified 39 failure modes, 6 of which were classified as CIL items, for components not covered by the NASA FMEAs. It was recommended that these failure modes be added to the NASA FMEA baseline. The overall assessment produced agreement on all but 301 FMEAs which caused differences in 111 CIL items

Individual and Interactive Temporal Implications of UV-B Radiation and Elevated CO2 on the Morphology of Basil (Ocimum basilicum L.)

Temporal and spatial variations in ozone levels and temporal changes in solar radiation greatly influence ultraviolet radiation incidence to crops throughout their growth, yet the interactive effects of CO2 and UV-B radiation on Basil production under sunlight environmental conditions has not been studied. Basil ‘Genovese’ plants grown under sunlit plant growth chambers were subjected to a combination of supplemental UV-B (0 and 10 kJ m−2d−1) and ambient (420 ppm) and elevated (720 ppm) CO2 treatments for 38 days after 14 days of germination. UV-B radiation treatments caused a decrease in basil stem branching, fresh mass, and stem dry mass under both CO2 treatments when harvested after 17 and 38 days of treatment. There was also an increase in basil leaf surface wax under UV-B (10 kJ m−2d−1) treatment compared to controls (0 kJ m−2d−1). Elevated CO2 treatments caused a decrease in morphological features, including specific leaf area and fresh mass. Interactive effects between UV-B and CO2 treatments existed for some morphological features, including plant height, root surface area, and average root diameter. Understanding the impacts that CO2 and UV-B radiation treatments have on basilcan improve existing varieties for increased tolerance while simultaneously improving yield, plant morphology, and physiology

Yield, Physiological Performance, and Phytochemistry of Basil (Ocimum basilicum L.) under Temperature Stress and Elevated CO2 Concentrations

Early season sowing is one of the methods for avoiding yield loss for basil due to high temperatures. However, basil could be exposed to sub-optimal temperatures by planting it earlier in the season. Thus, an experiment was conducted that examines how temperature changes and carbon dioxide (CO2) levels affect basil growth, development, and phytonutrient concentrations in a controlled environment. The experiment simulated temperature stress, low (20/12 °C), and high (38/30 °C), under ambient (420 ppm) and elevated (720 ppm) CO2 concentrations. Low-temperature stress prompted the rapid closure of stomata resulting in a 21% decline in net photosynthesis. Chlorophylls and carotenoids decreased when elevated CO2 interacted with low-temperature stress. Basil exhibited an increase in stomatal conductance, intercellular CO2 concentration, apparent quantum yield, maximum photosystem II efficiency, and maximum net photosynthesis rate when subjected to high-temperature stress. Under elevated CO2, increasing the growth temperature from 30/22 °C to 38/30 °C markedly increased the antioxidants content of basil. Taken together, the evidence from this research recommends that varying the growth temperature of basil plants can significantly affect the growth and development rates compared to increasing the CO2 concentrations, which mitigates the adverse effects of temperature stress

Boron isotopes in Central American volcanics indicate a key role for the subducting oceanic crust

The geochemistry of arc magmas can shed light on chemical outfluxes from subducting slabs to the overlying mantle. Boron (B) abundances and isotope ratios are valuable tracers of slab-derived components due to the distinct compositions of the mantle and subducting materials and distinctive isotopic fractionation during dehydration. New Be/B and δ11B measurements in olivine-hosted melt inclusions (MIs) from three Nicaraguan volcanic centers (Telica, Cerro Negro, and Masaya) are consistent with a B-rich slab component that has δ11B ranging from +2.9‰ to +5.9‰, slightly higher than new measurements of hemipelagic (δ11B = +0.7‰±0.03 and +2.1‰±0.08; 1σ n = 3) and carbonate (δ11B = +2.9‰±0.06 and 3.7±0.09; 1σ n = 3) sediments sampled by DSDP Hole 495 on the Cocos plate. A thermochemical model of the Nicaraguan subduction zone is used to quantitatively model B loss and isotopic fractionation during slab dehydration and melting. In contrast to previous studies regarding B systematics in Central America and elsewhere, this model reproduces the range of δ11B preserved in Nicaraguan olivine-hosted MIs without the involvement of serpentinite-derived fluids. The model indicates that Nicaraguan MI δ11B signatures are primarily controlled by input from subducted altered oceanic crust (AOC), with a minor contribution from subducted sediments. This finding implies that the volatile element budget delivered from the slab to the volcanic arc is also mostly derived from the ocean crust, and that volatiles carried in deeper layers of the slab may be recycled beyond the arc into the deeper mantle beneath Central America