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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 289 records · Page 16
All sourcesNASA NTRSDOE OSTI
NASA NTRS2020

Evidence for Adsorption of Chlorine Species on Iron(III) (hydr)oxides in the Sheepbed Mudstone, Gale Crater, Mars

Chlorine is a widespread element on Mars present in dust, soils and rocks, including the Sheepbed mudstone at Yellowknife Bay, Gale crater. Combined elemental and volatile analyses of two drilled samples, Cumberland and John Klein, indicated that chloride (Cl-) and perchlorate (ClO4 -) are likely present in the mudstone. The nature of chlorine species in Sheepbed mudstone is still not well constrained. It has been proposed that both are present as amorphous or crystalline salts physically mixed with mudstone minerals. We alternatively hypothesize that adsorbed perchlorate and chloride exist in the mudstone and adsorption could occur, in particular, on Fe(III) (hydr)oxide phases as supported by laboratory observations on terrestrial materials. Mineralogical and compositional analyses of the drilled Cumberland mudstone sample revealed the presence of ~30 wt% of a Fe-rich X-ray amorphous phase. Ferrihydrite has been proposed as a component of the Fe-rich X-ray amorphous material. The objectives of this work were to determine adsorption of perchlorate and chloride on ferrihydrite and to enable data comparison by characterizing adsorbed chloride and perchlorate with thermal and evolved gas analysis run under operating conditions similar to the SAM instrument onboard the Curiosity rover.

Peretyazhko, T. S.↗
NASA NTRS2020

Volatile-rich Asteroids in the Inner Solar System

Bennu (101195), target of the Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) mission, is a type-B asteroid with abundant spectral evidence for hydrated silicates, low thermal inertia “boulders” and frequent bursts of particle emission. We suggest that Bennu’s parent body formed in the outer solar system before it was perturbed into the asteroid belt and then evolved into a near-Earth object. We show that this is consistent with models of planetesimal evolution. Bennu has many characteristics expected for a dormant comet, and could potentially contain a minimum of 1 wt.% adsorbed water if its gross mineralogy is consistent with the Orgueil meteorite. This is in addition to any ice or water contained within the hydrous minerals themselves. Based on this hypothesis, we predict the properties of the samples that will be returned to Earth by the OSIRIS-REx mission, including abundant phyllosilicate minerals, amorphous hydrated silicates and low-density, very high-porosity aggregates, already observed by the OSIRIS-REx instrument suite. We predict enrichments in D/H and 15N/14N, high C/Mg ratios (>∼7 wt%), and a greater range of organic compositions than found in meteorites, including an organic component poor in aromatics, and a more labile organic fraction. Ammonium salts, ranging from NH4Cl to ammonium–organic acid salts could carry much of the nitrogen in comets, yet only NH4CH3COO and heavier salts are sufficiently stable to be found in these returned samples. Water adsorbed onto highly porous grains should also be detected provided that the sample return capsule remains below 300 K during Earth return, and this water should be isotopically heavy.

Joseph A. Nuth, III↗
NASA NTRS2022

Passive Cooling in Aerogel-Based Insulation Systems for Liquid Hydrogen Upper Stage Launch Vehicle Tanks

Spray-On Foam Insulation (SOFI) is typically used to protect the windward-facing side of flight tanks for space launch vehicle liquid hydrogen (LH2) stages. SOFI is an excellent insulator in ambient pressure environments, however, its performance pales in comparison to reflective-type systems such as Multi-Layer Insulation in the thermal radiation dominated vacuum environment of space. If a windward insulation system employing radiation shields could be devised to replace or supplement SOFI, the on-orbit heat load could be drastically reduced, and the residual propellants could then be used to facilitate secondary missions. Such insulation systems, utilizing aerogel blanket insulation, have been explored by the Cryogenics Test Laboratory at NASA Kennedy Space Center. Owing to its nano-porous structure, aerogel is an excellent adsorbent as well as an insulator at cryogenic temperatures and will readily uptake condensable background gasses such as air when protecting a surface near LH2 temperatures. When an adsorbed blanket is rapidly exposed to a vacuum, such as during the ascent of a rocket, it will release the background gas, producing a passive cooling effect that could potentially reduce or eliminate the heat load on the propellant tank for a time. This work discusses the setup and results of a test program carried out to determine the effectiveness and impact of this cooling effect as it pertains to LH2 upper stage tanks. A vertical-cylindrical liquid nitrogen (LN2) calorimeter test instrument acted as the upper stage analog. The cold-mass was wrapped with two layers of 10 mm thick aerogel blanket material, with and without aluminum heat shields depending on the test, and interspersed with numerous thermocouple temperature sensors. Gaseous argon was used as a stand-in for air as the condensable background gas. The test procedure mimicked vehicle cryo-loading/stabilization, and ascent phases, with the ascent phase accomplished using parallel vacuum pumps. Results show that the desorption cooling effect was enough to not only eliminate the heat load on the LN2 cold-mass entirely, but further refrigerated the liquid below its boiling point.

A.M. Swanger↗
NASA NTRS2015

MARS - Multi-component Adsorption Recirculation System

Goals - Measure carbon dioxide adsorption isotherms on 13X zeolite - Measured using a volumetric method - Injected CO2 is adsorbed and measured using the pressure loss and the ideal gas law to attribute the pressure loss to moles of adsorbed CO2.

Jack Cunningham↗
NASA NTRS1967

Resonance scattering from absorbing spheres.

Electromagnetic scattering from adsorbing spheres near resonances calculated from extinction efficiency factor and angular scattering function dependence on refractive index

RESONANCE SCATTERING↗
NASA NTRS1963

Water in Lunar Materials

Two lines of evidence, suggest independently that materials which formed the Moon were not anhydrous: 1. Meteorites, our only sample of extraterrestrial material, contain water in varying amounts. Chondrites average about 0.25% water by weight. Carbonaceous chondrites, however, contain up to 20% water; and, although much of this water may be adsorbed atmospheric and surface water, the abundance of silicate hydrates in these objects indicates that considerable water existed in these meteorites before Earth impact. 2. The gas emission from Alphonsus observed by Kosyrev indicates that volatiles are diffusing out of the Moon. The observed emission was a C, band. Analyses of presumably juvenile gases reaching the Earth's surface show that water generally composes 95% or more of the gas. By analogy, it is suggested that water must be reaching the lunar surface. Consequently, it is reasonable to conclude that water existed in the materials which formed the Moon as well as those which formed the Earth or meteorites (or their source object). An estimate of the water content of the primordial Earth is 0.03%.

Speed, R. C.↗