Radiative energy transfer on entry into Mars and Venus Quarterly report, period ending Oct. 1968
Integrated absorption values for infrared bands of ethylene, ethane, carbon tetrafluoride, and sulfur dioxide
Helbron, J. W.↗
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Space storage propellant performance Final report, 25 Jul. 1967 - 21 Jul. 1968
Propulsion efficiency tests of FLOX and ethane- methane space storable propellant blend
Mageean, J. V.↗
Synthesis of cystine in simulated primitive conditions
Cystine synthesis in simulated primitive conditions by UV irradiation of methane, ethane, ammonia, water vapor and hydrogen sulfide in spherical vessel
Khare, B. N.↗
Experimental interstellar organic chemistry: Preliminary findings
In a simulation of interstellar organic chemistry in dense interstellar clouds or on grain surfaces, formaldehyde, water vapor, ammonia and ethane are deposited on a quartz cold finger and ultraviolet-irradiated in high vacuum at 77K. The HCHO photolytic pathway which produces an aldehyde radical and a superthermal hydrogen atom initiates solid phase chain reactions leading to a range of new compounds, including methanol, ethanol, acetaldehyde, acetonitrile, acetone, methyl formate, and possibly formic acid. Higher nitriles are anticipated. Genetic relations among these interstellar organic molecules (e.g., the Cannizzaro and Tischenko reactions) must exist. Some of them, rather than being synthesized from smaller molecules, may be degradation products of larger organic molecules, such as hexamethylene tetramine, which are candidate consitituents of the interstellar grains. The experiments reported here may also be relevant to cometary chemistry.
Khare, B. N.↗
Shock synthesis of amino acids in simulated primitive environments.
A single pulse shock tube of a uniform bore was used in the experiments. The reaction mixture consisted of 3.3 per cent methane, 11 per cent ethane, and 5.6 per cent ammonia, diluted with ultra-pure argon. The formation of glycine, alanine, valine, and leucine under conditions of shock heating was observed. Thermodynamic relations are discussed together with questions of conversion efficiency.
Bar-Nun, A.↗
Characteristics of slush and boiling methane and methane mixtures.
Methane gas of two purities, 99.97% and 99%, was condensed to study the characteristics of the boiling liquid and the slush. In addition, binary mixtures of nitrogen and methane, and those of ethane and methane, and propane and methane, were also studied. Potential advantages of these gases when employed as fuels for high-performance aircraft, rocket engines, and motor vehicles are emphasized.
Sindt, C. F.↗
A portable self-contained gas chromatograph.
The design and fabrication of a completely portable, self-contained gas chromatograph is described. This instrument utilizes a closed-loop hydrogen carrier gas flow as maintained by a hydrogen generator-separator. It employs an auxiliary hydrogen generator to keep a positive flow of hydrogen through the detector. The detector is an ionization cross section detector. The only maintenance required is the addition of water (5-15 cc/day) to the auxiliary hydrogen generator. Lower limit of detection for the present system is of the order of 1-10 ppm ethane.
Stevens, M. R.↗
Part A: Hydrocarbon Suspension in Slush Hydrogen
Methods of preparing suspensions of a hydrocarbon in slush hydrogen for nuclear fuel element corrosion inhibition in rocket engines were investigated. Suspensions were prepared using approximately 5000 ppm by mass of methane, ethane, or cyclopropane in slush hydrogen. The suspensions were stable in the slush, but the hydrocarbons settled out of the liquid melt.
Sindt, C. F.↗
Characteristics of a gelled liquid hyprogen polyphenylene oxide (PPO) foam open-cell insulation system, phase 1
A large scale gel production and storage facility and a small scale facility, the latter used for detailed visual examination of the gel/PPO foam interface, were developed. A subcontract was given to investigate techniques for the production of gelled liquid hydrogen, develop a process design for scale-up to a 1.89 cu m (500 gallon) gel production and storage facility, determine gel transfer characteristics, determine the solubility rate of gaseous helium in the gel, and investigate the gross gel/PPO foam interfacial phenomena. An inside-tank process for scaled-up production of gelled liquid hydrogen was selected. No detectable gel structure degradation occurred during repeated shearing. The viscosity of gelled liquid hydrogen at shear rates of 300/sec and higher is 2 to 5-fold greater than that of neat liquid hydrogen. No clogging problems were encountered during the transfer of gelled liquid hydrogen through warmed transfer lines. The solubility rate of helium in liquid hydrogen was significantly reduced by the presence of gel structure. The boil-off rates from gelled liquid hydrogen were reduced from 25 to 50 percent compared to those observed for the neat liquid hydrogen under compatible conditions. The polyphenylene oxide (PPO) foam insulation was found to be compatible with liquid ethane.
Source record↗
Review of methods used in lunar organic analysis - Extraction and hydrolysis techniques.
Extraction, hydrolysis, and crushing procedures have been useful in discovering some of the carbon compounds in lunar samples from the Apollo 11 and 12 missions. The nonaqueous solvent system used mostly in lunar sample work has been benzene:methanol. Two methods of extraction have been sonication and Soxhlet extraction, sonication appearing to be the preferred method. Extraction of lunar samples with water and acid hydrolysis of the water extract has proved to be the best method in the search for amino acids or their precursors. Direct acid hydrolysis of lunar samples provided evidence for the presence of carbides or carbide-like materials in lunar surface samples. Hydrolysis of lunar samples with DF, DC1, and NaOD has shown that methane and ethane are indigenous to the moon.
Kvenvolden, K. A.↗
Compounds of carbon and other volatile elements in Apollo 14 and 15 samples.
DF dissolution and pyrolysis showed that the indigenous methane and ethane contents in Apollo 14 and 15 lunar samples correlated with the amounts of solar wind gases and the deutero-carbon reaction gases. Pyrolysis evolved mainly CO and N2 and lower amounts of CO2. Other compounds detected and quantitated by these techniques were DCN, HCN, CS2, D2S, and PD3.
Holland, P. T.↗
An inversion in the atmosphere of Titan
A very detailed greenhouse model derives a methane to hydrogen ratio of unity and a minimum surface pressure of 0.4 atm. Based on a surface gravity g = 140 cm sec/2, the minimum CH4 abundance is 30-40 km-A and the minimum H2 abundance varies from 15 to 85 km-A. A model of the atmosphere of Titan is proposed which seems to be consistent with observations and requires a much smaller CH4 abundance (of the order or 2 km-atm). Although no H2 is required, the presence of some H2 is readily accommodated. In this model, a temperature inversion exists in the atmosphere due to absorption of blue and ultraviolet solar radiation by small particles. The absorbed radiation is re-radiated by the dust and by molecules having long wavelength bands such as CH4 7.7 micrometer and ethane at 12.2 micrometer. The brightness temperature at 20 micrometer is primarily due to re-radiation by the dust.
Danielson, R. E.↗
Characteristics of slush and boiling methane and methane mixtures
Review of investigation results on the characteristics of slush (i.e., mixtures of liquid and solid) and boiling methane, and of binary mixtures of methane and other natural gas constituents, intended for use as fuels for high performance aircraft, rocket engines, and motor vehicles. The investigation extends to the characterization of slush prepared from pure methane and binary mixtures of methane with nitrogen, ethane, and propane, and the boiling properties of these mixtures.
Sindt, C. F.↗
Development of a blocking orifice thermal diode heat pipe
A new geometry is described for low temperature diode heat pipes employing excess liquid to block the vapor space of the evaporator and part of the transport section during reverse mode conditions. An orifice plate is placed in the pipe at the blocking meniscus location, with the opening arranged to permit proper liquid distribution in both ground tests and zero 'g' operation. Parametric analytical results are presented for several fluids (carbon tetrafluoride, methane, and ethane). Experimental data is presented for a room temperature diode verifying feasibility, and a 1/4 in. O.D. cryogenic diode with methane working fluid.
Kosson, R. L.↗
Studies of chemical abundances in the outer solar system
Ground-based observations and the Pioneer 10 mission have led to new discoveries and revisions of previous ideas about the outer solar system. Among these are the discovery of atmospheres on Io and Ganymede, emission from sodium and hydrogen in a cloud around Io, and the presence of acetylene, ethane, and phosphine in the atmosphere of Jupiter. Titan, the largest satellite of Saturn, continues to be an extremely interesting and baffling object, clearly very different in composition from the bodies familiar with in the inner solar system - which is also true of Ganymede and Callisto. New data on the abundances of methane and hydrogen in the atmospheres of Uranus and Neptune suggest that the values of C/H in these atmospheres may be much lower than had been previously thought. This result reinforces the apparent compositional difference between these two planets and Jupiter and Saturn, whose atmospheres exhibit a near-solar value for this ratio.
Owen, T.↗
Hot hydrogen atoms reactions of interest in molecular evolution and interstellar chemistry
Hot hydrogen atoms which are photochemically generated initiate reactions among mixtures of methane, ethane, water and ammonia, to produce ethanol, organic amines, organic acids, and amino acids. Both ethanol and ethyl amine can also act as substrates for formation of amino acids. The one carbon substrate methane is sufficient as a carbon source to produce amino acids. Typical quantum yields for formation of amino acids are approximately 0.00002 to 0.00004. In one experiment, 6 protein amino acids were identified and 8 nonprotein amino acids verified utilizing gas chromatography-mass spectroscopy. We propose that hot atoms, especially hydrogen, initiate reactions in the thermodynamic nonequilibrium environment of interstellar space as well as in the atmospheres of planets.
Becker, R. S.↗
Observational constraints on model atmospheres for Uranus and Neptune
We have re-examined the visible and near-IR regions of the spectra of Uranus and Neptune to provide additional data for constructing atmospheric models. We find that a true continuum exists only at wavelengths below 4700 A, that the 6420 A absorption previously attributed to hydrogen is probably caused by methane, that there is no evidence for ammonia, ethylene or ethane absorptions in our spectra, and that the abundance of methane is probably much higher than previous estimates suggest. This last finding implies that the value of H/C in the atmospheres of both planets is much less than 1/10 the solar (or Jovian) value. Clear, Rayleigh-scattering model atmospheres are not compatible with the observations, but more work is needed to establish viable alternatives.
Encrenaz, T.↗
Parametric performance of circumferentially grooved heat pipes with homogeneous and graded-porosity slab wicks at cryogenic temperatures
A recently developed, potentially high-performance nonarterial wick has been extensively tested. This slab wick has an axially varying porosity which can be tailored to match the local stress imposed on the wick. The purpose of the tests was to establish the usefulness of the graded-porosity slab wick at cryogenic temperatures between 110 K and 260 K, with methane and ethane as working fluids. For comparison, a homogeneous (i.e., uniform porosity) slab wick was also tested. The tests included: (1) maximum heat pipe performance as a function of fluid inventory, (2) maximum performance as a function of operating temperature, (3) maximum performance as a function of evaporator elevation, and (4) influence of slab wick orientation on performance. The experimental data was compared with theoretical predictions obtained with the computer program GRADE.
Groll, M.↗