Barry Eichmiller's Internship Presentation
Report on work with SMAB in the summer of 2019 in support of STMD. Focuses on STMD Strategic Framework development and Power technology metric analysis.
Barry Eichmiller↗
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Results for “2018 NEON and 2025 CHESS Campaigns”
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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Spacecraft Antenna Pointing
In examining the characteristic inaccuracies of a pre-programmed high-gain antenna pointing system, the effects of spacecraft attitude errors, as embodied in pitch, yaw and roll limit cycle activity, are of major concern. If the pointing accuracy requirements for a particular mission allow the use of a single degree of freedom pointing system, it is doubtful whether a method of correcting antenna position for spacecraft attitude errors would be worthwhile. This is because the pointing error due to fitting a plane curve to a three-dimensional trajectory would probably be at least as large as the additional pointing errors due to attitude drift within the deadbands. Further, trying to correct pointing for pitch, yaw, and roll drifts by adjusting a single hinge angle is relatively ineffective.
ERROR SIGNAL↗
On the isotopic signature of recent solar-wind nitrogen
One of the most intriguing discoveries yielded by the Apollo samples was evidence pointing towards a significant long-term change in the composition of the sun. Such a change, of the size inferred from the lunar sample data, is inconsistent with present theories of solar evolution. Consequently, there is much interest in exploring this phenomenon as closely as possible, to determine exactly what compositional changes have taken place and whether those changes really did take place in the sun, or whether the cause lies elsewhere. The reason why we can use the moon to analyze the elements in the sun is that the sun emits a stream of ions, known as the solar wind, whose composition, on average, is believed to be the same as that in the surface regions of the sun. When the solar-wind ions hit the surface of the moon, many of them penetrate a short distance into the dust grains lying on the lunar surface. Thus, after a grain has sat on the lunar surface for a while, it has a rim of material that is partly lunar and partly solar in composition. For most chemical elements, the difference between lunar and solar composition is so sufficiently small that the solar elements cannot be detected, but for a handful of elements that are missing from the moon, their solar 'signature' can be observed in samples of lunar soil brought back by the astronauts. Among those elements is nitrogen, the most common element in the air we breathe, but very rare indeed on the moon. Our analytical techniques are not sophisticated enough yet to enable us to analyze individual lunar soil grains for nitrogen, much less to zero in on just the nitrogen in the surface of such a grain. Consequently we are forced to analyze samples consisting of many different grains, each of which could have experienced its own individual history. This makes it difficult to identify the nitrogen implanted in grain surfaces, and also to define the age of a sample.
Kim, Y.↗
Development of improved sealed Ag-Zn battery for Mariner 1969, part 1, 6 November 1967 - 3 May 1968
Development and testing of improved sealed Ag-Zn battery for Mariner 1969
Chreitzberg, A. M.↗
Assembly of catalytic complexes from randomized oligonucleotides
The early evolution of life relied on catalytic RNAs (ribozymes) for central functions. To test whether early catalysts could have assembled from multiple short nucleic acid fragments in random sequence environments, we performed an in vitro selection from a short RNA library in the presence of 256 different DNA 20-nucleotide oligomers. High-throughput sequencing and biochemical analysis showed that most of the selected 1331 RNA sequences required at least one DNA for activity. Representatives for four of six RNA clusters that depended on DNA cofactors were active even when the 256 DNAs were replaced by completely random DNA 20-nucleotide oligomers. The formation of these catalytic complexes and the recruitment of oligonucleotide cofactors from completely random libraries demonstrate an important principle for the emergence of the earliest oligonucleotide catalysts.
Xu Han↗
NASA Scatterometer Oceanic Wind Measurement System
Satellite scatterometers are active microwave radars designed to yield measurements of near surface horizontal wind velocity over the ocean. Scatterometers are unique in that they are the only existing microwave remote sensing instruments that allow measurements of both wind speed and wind direction. NASA will fly a scatterometer, NSCAT, aboard the Navy Ocean Remote Sensing System (N-ROSS) mission starting in late 1990. N-ROSS is a spaceborne ocean remote sensing system with a planned mission life of three years. In addition to the NSCAT, N-ROSS will have three other microwave instruments mounted on a single satellite flying in a near polar orbit: an altimeter; a special sensor microwave/imager (SSM/I); and a low frequency microwave radiometer. The NSCAT to be flown on N-ROSS is described.
M Freilich↗
The Use of Immersion Rigs for High Temperature Hydrogen Exposure Testing Within the Nuclear Thermal Rocket Element Environmental Simulator (NTREES): NTREES-5 Hydrogen Heat Exchanger (N5HHX-01)
The Nuclear Thermal Rocket Element Environmental Simulator (NTREES) facility at NASA’s Marshall Space Flight Center (MSFC) subjects materials and components typically found on nuclear thermal propulsion (NTP) systems to non-nuclear simulations of prototypic NTP reactor thermohydraulic environments. With 1.2 MW of inductive power available, the currently employed methods to simulate nuclear heating in NTREES consist of 1) inductively heating a test specimen, which typically cannot be performed on ceramic materials, or 2) heating gas that envelops the test specimen. The latter of these has provided a basis for developing so-called “immersion rigs” to be used in NTREES. Furthermore, immersion rigs are especially useful in the case of smaller, technically challenging test specimens. One such device, the “NTREES-5 Hydrogen Heat Exchanger” (N5HHX-01), designed and deployed to test small material coupons to ~0.5 g/s of 2800 K, 500 psi Hydrogen, is discussed herein. To achieve this desired delivery temperature level, the most suitable material for the N5HHX’s construction was pure tungsten, which imposed budgetary and manufacturing challenges. Also discussed in this paper is the design of the N5HHX rig’s sample container, which became the first iteration of improving NTREES small material coupon test operations by permitting rapid changeout of different material samples.
Reactor Testing↗
Nasa's Spacecraft Battery Evaluation Program
Acceptance testing, performance characteristics, life cycling, and failed cell analysis in NASA SPACECRAFT battery evaluation program
BATTERY↗
The heat sterilizable battery.
Sealed heat sterilizable high impact resistant battery for space missions, grafting acrylic acid and polyethylene by irradiation for separator
SPACECRAFT POWER SUPPLY↗
International Space Station Lithium-Ion Main Battery Thermal Runaway Propagation Test
In 2010, the ISS Program began the development of Lithium-Ion (Li-Ion) batteries to replace the aging Ni-H2 batteries on the primary Electric Power System (EPS). After the Boeing 787 Li-Ion battery fires, the NASA Engineering and Safety Center (NESC) Power Technical Discipline Team was tasked by ISS to investigate the possibility of Thermal Runaway Propagation (TRP) in all Li-Ion batteries used on the ISS. As part of that investigation, NESC funded a TRP test of an ISS EPS non-flight Li-Ion battery. The test was performed at NASA White Sands Test Facility in October 2016. This paper will discuss the work leading up to the test, the design of the test article, and the test results.
International Space Statio↗
A new quantitative ataxia test battery
Ataxia test battery to assess postural equilibrium under rotating conditions and for use in testing vestibular apparatus
EQUILIBRIUM↗
Determination of Local Experimental Heat-Transfer Coefficients on Combustion Side of an Ammonia-Oxygen Rocket
Local experimental heat-transfer coefficients were measured in the chamber and throat of a 2400-pound-thrust ammonia-oxygen rocket engine with a nominal chamber pressure of 600 pounds per square inch absolute. Three injector configurations were used. The rocket engine was run over a range of oxidant-fuel ratio and chamber pressure. The injector that achieved the best performance also produced the highest rates of heat flux at design conditions. The heat-transfer data from the best-performing injector agreed well with the simplified equation developed by Bartz at the throat region. A large spread of data was observed for the chamber. This spread was attributed generally to the variations of combustion processes. The spread was least evident, however, with the best-performing injector.
Curt H Liebert↗
High-density Boron Nitride Nanotube Composites via Surfactant-stabilized Lyotropic Liquid Crystals for Enhanced Space Radiation Shielding
Despite significant technological advancements in space exploration, human space travel and colonization remain limited by the health risks associated with space radiation. Boron nitride nanotubes (BNNTs) have been proposed as an advanced material for space applications due to their high specific strength and efficient radiation shielding capabilities. However, the practical implementation of BNNTs has been slow, primarily due to technological challenges in fabricating structural materials incorporating BNNTs. In this study, a method is presented for fabricating high-density BNNT films that are mechanically robust, exhibit high thermal conductivity, and effectively attenuate space radiation. The key advancement enabling high-density BNNT films is the successful preparation of BNNT liquid crystals (LCs), achieved through the strategic use of a commercial dodecylbenzenesulfonic acid surfactant. This surfactant ensures exceptional BNNT stability in aqueous dispersion, even at concentrations exceeding the LC phase transition threshold. Simulations, estimating the equivalent radiation dose to the human body in space, indicate that a high-density BNNT film with a surface density of 50 g cm−2 reduces the total dose equivalent rate by 56% compared to zero shielding. This enhancement would allow astronauts to extend their mission duration on the lunar surface by a factor of two.
Young-Kyeong Kim↗
TDRSS Battery Life Cycle Tests Interim Report
The design features of the tracking and data relay satellite system battery are described. Some of the life cycle tests performed on the battery are reported.
Kipp, E. W.↗
Diagnostics development for the Electric Propulsion Orbital Platform
We describe the development of the diagnostics systems for the first flight of the Electric Propulsion Orbital Platform (EPOP), which will center around the in-flight characterization of a 1.8 kW hydrogen arcjet system. In particular, we discuss a spacecraft communications experiment involving ground-to-spacecraft communications of the EPOP carrier; electrical probe measurements in the arcjet plume; and spectrally resolved plume imaging measurements of the same plume. The communications experiment is designed to measure small noise on the communications link which results from arcjet operation. The other two measurements primarily serve the purpose of characterization of the plume plasma. These measurements will be compared to similar measurements performed in a ground chamber to establish whether systematic differences exist between ground-based and in-flight performance of the arcjet system.
Wilhelmus M. Ruyten↗
OverFlight: Graphical Flight Operations Planning
OverFlight is an in-development graphical user interface (GUI) that implements a state-of-the-art rotorcraft maneuvering noise model using a source noise hemisphere approach coupled with the Aircraft NOise Prediction Program 2 (ANOPP2). This GUI stems from a demand for easy-to-use mission planning and community impact acoustic tools that can model the maneuvering flight of a rotary-wing vehicle. This paper covers the models used for the development of OverFlight and model validation efforts. Data from a joint NASA/Army flight test of an MD530F aircraft are used both for source noise hemispheres as well as maneuvering flight data. Analysis of the predicted maneuvering noise shows better agreement that traditional methods currently employed, while also demonstrating maneuvers where the underlying assumptions fail to hold.
rotorcraft↗
Life test of 50 AH NiH2 battery
Life cycle testing on a battery is reported. The cells were built in 1975, put into battery in 1976, and flown in 1977 in low Earth orbit.
Warnoc, D. H.↗
An analysis of digital phase-locked loops
This report focuses on second-order digital phase-locked loops (DPLLs) with uniformly sampled input, an amplitude-insenstive phase extractor and a conventional loop filter.
Thomas, J. B.↗