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NASA NTRS2013

The Next Generation of Cold Immersion Dry Suit Design Evolution for Hypothermia Prevention

This new utility patent is an active design that relies on the lung's role as an organic heat exchanger for providing deep body core heating of air. It is based on the fact that the greatest heat loss mechanism for an insulated human body immersed in a cold water environment is due to heat loss through respiration. This innovation successfully merges two existing technologies (cold immersion suit and existing valve technologies) to produce a new product that helps prevent against the onset of hypothermia at sea. During normal operations, a human maintains an approximate body temperature of [98.6 F (37 C)]. A mechanism was developed to recover the warm temperature from the body and reticulate it in a survival suit. The primary intention is to develop an encompassing systems design that can both easily and cost effectively be integrated in all existing currently manufactured cold water survival suits, and as such, it should be noted that the cold water immersion suit is only used as a framework or tool for laying out the required design elements. At the heart of the suit is the Warm Air Recovery (WAR) system, which relies on a single, large Main Purge Valve (MPV) and secondary Purge Valves (PV) to operate. The main purge valve has a thin membrane, which is normally closed, and acts as a one-way check valve. When warm air is expelled from the lungs, it causes the main purge valve to open. Air forced from the MPV is dumped directly into the suit, thereby providing warmth to the torso, legs, and arms. A slight positive over-pressure in the suit causes warm waste air (or water if the suit is punctured) to be safely vented into the sea through large PVs located at the bottom of each arm and leg. The secondary purge valves act to prevent the buildup of large concentrations of CO2 gas and help guard against asphyxia. It is noted that the MPV causes the inhalation and exhalation cycles to be completely isolated from one another in the current suit design.

Galofaro, Joel↗
NASA NTRS2012

Free-Free Transitions of the e-H System Inside a Dense Plasma Irradiated by a Laser Field at Very Low Incident-Electron Energies

The free-free transition is studied for an electron-hydrogen atom in ground state when a low-energy electron (external) is injected into hydrogenic plasma in the presence of an external homogenous, monochromatic, and linearly polarized laser field. The effect of plasma screening is considered in the Debye-Huckel approximation. The calculations are performed in the soft photon limit. The incident electron is considered to be dressed by the laser field in a nonperturbative manner by choosing the Volkov solutions in both the initial and final channels. The space part of the scattering wave function for the electron is solved numerically by taking into account the electron exchange. The laser-assisted differential and total cross sections are calculated for single-photon absorption or emission and no-photon exchange in the soft photon limit, the laser intensity being much less than the atomic field intensity. The calculations have been carried out for various values of Debye parameter, ranging from 0.005 to 0.12. A strong suppression is noted in the laser-assisted cross sections as compared to the field-free situation. A significant difference is noted for the singlet and triplet cross sections. The suppression is much more in the triplet states.

Bhatia, A. K.↗
NASA NTRS2013

Toxicological Assessment of ISS Air Quality: Contingency Sampling - February 2013

Two grab sample containers (GSCs) were collected by crew members onboard ISS in response to a vinegar-like odor in the US Lab. On February 5, the first sample was collected approximately 1 hour after the odor was noted by the crew in the forward portion of the Lab. The second sample was collected on February 22 when a similar odor was noted and localized to the end ports of the microgravity science glovebox (MSG). The crewmember removed a glove from the MSG and collected the GSC inside the glovebox volume. Both samples were returned on SpaceX-2 for ground analysis.

Meyers, Valerie↗
NASA NTRS2013

Estimating the Mean Annual Surface Air Temperature at Armagh Observatory, Northern Ireland, and the Global Land-Ocean Temperature Index for Sunspot Cycle 24, the Current Ongoing Sunspot Cycle

As noted by Gray et al., Sir William Herschel was the first to suggest a possible close connection between the Sun and the Earth’s climate. The Sun, being the source of energy that impacts and drives the Earth’s climate system, displays a variety of changes over both short and long term time scales, the most obvious examples being the somewhat regular waxing and waning of sunspots with time (i.e., the sunspot cycle (SC)), first described by Samuel Heinrich Schwabe, a German apothecary and amateur astronomer who observed the Sun from Dessau, Germany, and the now well established variation of the Sun’s irradiance over the SC. Other factors related to the SC have been linked to changes in climate as well. Some of these other factors include the role of cosmic rays and the solar wind (i.e., the geomagnetic cycle) on climate, as well as the apparent close association between trends in global and northern hemispheric temperature and the length of the SC, although some investigators have described the inferred association between climate and, in particular, SC length as now being weak. More recently, Solheim et al. have reported on the relation between SC length and the average temperature in the same and immediately following SC for a number of meteorological stations in Norway and in the North Atlantic region. They noted that while they found no significant trend (correlation) between SC length and the average temperature when measured for the same cycle, in contrast, they found a significant negative trend when SC length was compared with the following cycle’s average temperature. From this observation, they suggested that average northern hemispheric temperature during the present ongoing SC (SC24) will be lower by about 0.9 °C than was seen in SC23 (spanning 1996–2007, based on yearly averages of sunspot number (SSN), and onset for SC24 occurring in 2008). The purpose of this Technical Publication (TP) is to examine the annual variations of the Armagh surface air temperature (ASAT) and the Global Land-Ocean Temperature Index (GLOTI) in relation to SSN and the SC in order to determine their likely values during SC24. Hence, it may provide insight as to whether solar forcing of global temperature is now lessening as a contributor to global warming, thereby indicating a possible cooling in the near term immediate future that potentially could ameliorate the effect of increased anthropogenic warming.

Wilson, Robert M.↗
NASA NTRS2009

Refractory Materials for Flame Deflector Protection System Corrosion Control: Refractory Ceramics Literature Survey

Ceramics can be defmed as a material consisting of hard brittle properties produced from inorganic and nonmetallic minerals made by firing at high temperatures. These materials are compounds between metallic and nonmetallic elements and are either totally ionic, or predominately ionic but having some covalent character. This definition allows for a large range of materials, not all applicable to refractory applications. As this report is focused on potential ceramic materials for high temperature, aggressive exposure applications, the ceramics reviewed as part of this report will focus on refractory ceramics specifically designed and used for these applications. Ceramic materials consist of a wide variety of products. Callister (2000) 1 characterized ceramic materials into six classifications: glasses, clay products, refractories, cements, abrasives, and advanced ceramics. Figure 1 shows this classification system. This review will focus mainly on refractory ceramics and cements as in general, the other classifications are neither applicable nor economical for use in large structures such as the flame trench. Although much work has been done in advanced ceramics over the past decade or so, these materials are likely cost prohibitive and would have to be fabricated off-site, transported to the NASA facilities, and installed, which make these even less feasible. Although the authors reviewed the literature on advanced ceramic refractories 2 center dot 3 center dot 4 center dot 5 center dot 6 center dot 7 center dot 8 center dot 9 center dot 10 center dot 11 center dot 12 after the review it was concluded that these materials should not be ' the focus of this report. A review is in progress on materials and systems for prefabricated refractory ceramic panels, but this review is focusing more on typical refractory materials for prefabricated systems, which could make the system more economically feasible. Refractory ceramics are used for a wide variety of applications. Figure 2 shows many ofthese applications, their life expectancy or requirement, and the exposure temperature for the refractory ceramic. Note that the exposure temperatures for refractory ceramics are very similar to the exposure conditions for specialty ceramics (rocket nozzles, space vehicle re-entry fields, etc.) and yet the life expectancy or requirement is relatively low. Currently NASA is repairing the refractory lining in the flame trench after every launch - although this is not a direct indication of low life expectancy, it does indicate that the current system may not be sufficiently durable to maximize economy. Better performing refractory ceramics are needed to improve the performance, economy, and safety during and after launches at the flame trenches at Kennedy Space Center (KSC). To achieve this goal a current study is underway to assess different refractory systems for possible use in the flame trenches at KSC. This report will target the potential applicability of refractory ceramics for use in the flame trenches. An overview of the different refractory ceramics will be provided (see Figure I). This will be followed with a brief description of the structure of refractory products, the properties and characteristics of different systems, the methodology for selecting refractories, and then a general design methodology. Based on these sections, future challenges and opportunities will be identified with the objective of improving the durability, performance, economy, and safety of the launch complex. Refractory ceramics are used for a wide variety of applications. Figure 2 shows many ofthese applications, their life expectancy or requirement, and the exposure temperature for the refractory ceramic. Note that the exposure temperatures for refractory ceramics are very similar to the exposure conditions for specialty ceramics (rocket nozzles, space vehicle re-entry fields, etc.) and yet the life expectancy or requirement is relatively low. Currently NASA is repairing the refractory lining in the flame trench after every launch - although this is not a direct indication of low life expectancy, it does indicate that the current system may not be sufficiently durable to maximize economy. Better performing refractory ceramics are needed to improve the performance, economy, and safety during and after launches at the flame trenches at Kennedy Space Center (KSC). To achieve this goal a current study is underway to assess different refractory systems for possible use in the flame trenches at KSC. This report will target the potential applicability of refractory ceramics for use in the flame trenches. An overview of the different refractory ceramics will be provided (see Figure I). This will be followed with a brief description of the structure of refractory products, the properties and characteristics of different systems, the methodology for selecting refractories, and then a general design methodology. Based on these sections, future challenges and opportunities will be identified with the objective of improving the durability, performance, economy, and safety of the launch complex.

Calle, Luz Marina↗
NASA NTRS2014

Are Medications Involved in Vision and Intracrancial Pressure Changes Seen in Spaceflight?

The Food and Drug Association Adverse Event Reports (FDA AER) from 2009-2011 were used to create a database from millions of known and suspected medication-related adverse events among the general public. Vision changes, sometimes associated with intracranial pressure changes (VIIP), have been noted in some long duration crewmembers. Changes in vision and blood pressure (which can subsequently affect intracranial pressure) are fairly common side effects of medications. The purpose of this study was to explore the possibility of medication involvement in crew VIIP symptoms. Reports of suspected medication-related adverse events may be filed with the Food and Drug Administration (FDA) by medical professionals or consumers. Quarterly compilations of these reports are available for public download. Adverse Event Reporting System (AERS) reports from 1/1/2009- 6/30/2012 were downloaded and compiled into a searchable database for this study. Reports involving individuals under the age of 18 and older than 65 were excluded from this analysis. Case reports involving chronic diseases such as cancer, diabetes, multiple sclerosis and other serious conditions were also excluded. A scan of the medical literature for medication-related VIIP-like adverse events was used to create a list of suspect medications. These medications, as well as certain medications used frequently by ISS crew, were used to query the database. Queries for use of suspected medications were run, and the nature of the symptoms reported in those cases were tabulated. Symptoms searched in the FDA AERS were chosen to include the typical symptoms noted in crewmembers with VIIP. Vision symptoms searched were: visual acuity reduced, visual impairment, and vitreous floaters. Pressure changes included: abnormal sensation in eye, intracranial pressure increased, intraocular pressure increased, optic neuritis, optic neuropathy, and papilloedema. Limited demographic information is included with the FDA AERS; relevant data were also sorted by age and sex from each report. RESULTS Steroid-containing oral contraceptives had the highest number of reports associated with vision (n=166) and pressure symptoms (n=54). Corticosteroid-containing medications were also high; prednisone, for example, had 137 reports of vision issues and 79 of pressure issues. Pain relievers were also a medication class with vision and pressure-related adverse events reported. Common over-the-counter medications such as acetaminophen, aspirin and ibuprofen each had multiple reports for both vision and pressure symptoms. Antimicrobial medications ciprofloxacin and diflucan were also associated with a number of vision and pressure-related AERS. Unexpectedly, pseudoephedrine and promethazine were mentioned in fewer than 20 reports each over the 3.5 years of data examined. The FDA AERS represents a wealth of data, but there are several limitations to its use. The data are entered by the public or medical professionals, but are not checked for accuracy or completeness and may even be entered multiple times. The causal relationship between a particular adverse event and a particular medication is not tested. The cases represent a broad spectrum of demographics, occupations, and health histories, and thus do not model the astronaut population well. There is no information on the frequency of use of a medication for comparison purposes; it is not possible to assign a rate for any particular adverse event. Nonetheless, there are compelling trends. Use of corticosteroid-containing medications, pain relievers (even over-the-counter), and oral contraceptives were associated with higher numbers of vision- or intracranial pressure-related adverse events. In general, there were more vision problems than pressure problems reported. Certain medications that were once suspected of playing a role in the crew VIIP syndrome, namely pseudoephedrine and promethazine, were found to have extremely low numbers of VIIP-like AERS in the FDA data. However, crew use of corticosteroid-containing medications and pain relievers may warrant additional investigation

Faust, K. M.↗
NASA NTRS2014

Magnet Architectures and Active Radiation Shielding Study - SR2S Workshop

Analyze new coil configurations with maturing superconductor technology -Develop vehicle-level concept solutions and identify engineering challenges and risks -Shielding performance analysis Recent advances in superconducting magnet technology and manufacturing have opened the door for re-evaluating active shielding solutions as an alternative to mass prohibitive passive shielding.Publications on static magnetic field environments and its bio-effects were reviewed. Short-term exposure information is available suggesting long term exposure may be okay. Further research likely needed. center dotMagnetic field safety requirements exist for controlled work environments. The following effects have been noted with little noted adverse effects -Magnetohydrodynamic (MHD) effects on ionized fluids (e.g. blood) creating an aortic voltage change -MHD interaction elevates blood pressure (BP) center dot5 Tesla equates to 5% BP elevation -Prosthetic devises and pacemakers are an issue (access limit of 5 gauss).

Westover, Shane↗
NASA NTRS2014

Surviving High-temperature Components in CI Chondrites

The CI1 chondrites, while having the most solar-like compo-sition of any astromaterial available for laboratory analysis, have also been considerably altered by asteroidal processes including aqueous alteration. It is of fundamental importance to determine their pre-alteration mineralogy, so that the state of matter in the early Solar System can be better determined. In the course of a re-examination of the compositional range of olivine and low-Ca pyroxene in CI chondrites Orgueil, Ivuna and Alais [1] we found the first reported complete CAI, as already reported [2], with at-tached rock consisting mainly of olivine and low-Ca pyroxene. The range of residual olivine major element compositions we have determined in the CIs (Fig. 1) may now be directly com-pared with those of other astromaterials, including Wild 2 grains. The abundance of olivine and low-Ca pyroxene in CIs is higher than is generally appreciated, and in fact much higher than for some CMs [1]. We also noted numerous rounded objects varying in shape from spheres to oblate spheroids, and ranging up to 100μm in size (Fig. 2), which have been previously noted [3] but have not been well documented or appreciated. We characterized the mineralogy by transmission electron microscopy and found that they consist mainly of rather fine-grained, flaky single phase to intergrown serpentine and saponite. These two materials in fact dominate the bulk of the host CI1 chondrites. With the exception of sparse spinels, the rounded phyllosilicate objects are remarka-bly free of other minerals, suggesting that the precursor from which the phyllosilicates were derived was a homogeneous mate-rial. We suggest that these round phyllosilicates aggregates in CI1 chondrites were cryptocrystalline to glassy microchondrules. If so then CI chondrites cannot be considered chondrule-free. Small though they are, the abundance of these putative microchondrules is the same as that of chondrules in the Tagish Lake meteorite.

Zolensky, M.↗
NASA NTRS2015

Enhanced Cleaning of Genesis Solar Wind Sample 61348 for Film Residue Removal

The Genesis mission returned to Earth on September 8, 2004, experiencing a nonnominal reentry. During the recovery of the collector materials from the capsule, many of the collector fragments were placed on the adhesive protion of post-it notes to prevent the fragments from moving during transport back to Johnson Space Center. This unknowingly provided an additional contaminate that would prove difficult to remove with the limited chemistries allowed in the Genesis Curation Laboratory. Generally when collector material samples are prepared for allocation to PIs, the samples are cleaned front side only with Ultra-Pure Water (UPW) via megasonic dispersion to the collector surface to remove crash debris and contamination. While this cleaning method works well on samples that were not placed on post-its during recovery, it has caused movement of the residue on the back of the sample to be deposited on the front in at least two examples. Therefore, samples placed on the adhesive portion on post-it note, require enhanced cleaning methods since post-it residue has proved resistant to UPW cleaning.

Allums, K. K.↗
NASA NTRS2015

Multiple Absorption Components in the Post-Periastron He I P Cygni Absorption Troughs of Eta Carinae

We have obtained more than 100 high spectral resolution (R approx. 90,000) spectra of the massive binary star eta Carinae since 2012 in an effort to continue our orbital and long-term echelle monitoring of this extreme binary (Richardson et al. 2010, AJ, 139, 1534) with the CHIRON spectrograph on the CTIO 1.5 m telescope (Tokovinin et al. 2013, PASP, 125, 1336) in the 4550-7500A region. We increased our monitoring efforts and observation frequency as the periastron event of 2014 has approached, and resumed observations in October. We note that since mid-October, we have observed unusual multiple absorption components in the P Cygni troughs of the He I lines (4714, 5876, 6678, and 7065; 4921 and 5015 are blended with Fe II). In particular, we note that these components extend to -700 km/s, well beyond the terminal wind speed of the primary. These absorptions are likely related to clumps and turbulence in the wind-wind collision region and bow shock, as suggested by the high-velocity absorption observed by Groh et al. (2010, A&A, 519, 9) in the He I 10830A transition and our pre-periastron observations (Richardson et al. 2014, ATel #6336). In these cases, we suspect that we look along an arm of the shock cone and that we see a fast absorption change from the other collision region shortly after periastron. Further, high spectral resolution data are highly encouraged, especially for resolving powers greater than 50,000. These observations were obtained with the CTIO 1.5 m telescope, operated by the SMARTS Consortium, and were obtained through both SMARTS and NOAO programs 2012A-0216, 2012B-0194, and 2013b-0328. We thank Emily MacPherson (Yale) for her efforts in scheduling the observations that we have and will obtain in the coming weeks and months.

multiple absorption components↗
NASA NTRS2008

Delay-Tolerant Networking for Space Flight Operations: Design and Development

Interplanetary Overlay Network (ION) is an implementation of the Delay-Tolerant Networking (DTN) architecture that is specifically intended to be usable for interplanetary communications. As such, its design differs in several ways from that of other implementations including DTN2, the reference implementation of the DTN Bundle Protocol. This paper briefly reviews the constraints on interplanetary communication that argue against the suitability not only of most off-the-shelf Internet technology but also of many DTN implementations. It then describes the operational components of ION, including its implementations of both the Bundle Protocol and the Licklider Transmission Protocol, noting the ways in which they address those constraints. Features of the system are explained with reference to their counterparts in the Internet architecture. The paper concludes with some notes on ION testing experience to date and plans for additional development in the future.

Interplanetary Overlay Network (ION)↗
NASA NTRS2008

Web Based Tool for Mission Operations Scenarios

A conventional practice for spaceflight projects is to document scenarios in a monolithic Operations Concept document. Such documents can be hundreds of pages long and may require laborious updates. Software development practice utilizes scenarios in the form of smaller, individual use cases, which are often structured and managed using UML. We have developed a process and a web-based scenario tool that utilizes a similar philosophy of smaller, more compact scenarios (but avoids the formality of UML). The need for a scenario process and tool became apparent during the authors' work on a large astrophysics mission. It was noted that every phase of the Mission (e.g., formulation, design, verification and validation, and operations) looked back to scenarios to assess completeness of requirements and design. It was also noted that terminology needed to be clarified and structured to assure communication across all levels of the project. Attempts to manage, communicate, and evolve scenarios at all levels of a project using conventional tools (e.g., Excel) and methods (Scenario Working Group meetings) were not effective given limitations on budget and staffing. The objective of this paper is to document the scenario process and tool created to offer projects a low-cost capability to create, communicate, manage, and evolve scenarios throughout project development. The process and tool have the further benefit of allowing the association of requirements with particular scenarios, establishing and viewing relationships between higher- and lower-level scenarios, and the ability to place all scenarios in a shared context. The resulting structured set of scenarios is widely visible (using a web browser), easily updated, and can be searched according to various criteria including the level (e.g., Project, System, and Team) and Mission Phase. Scenarios are maintained in a web-accessible environment that provides a structured set of scenario fields and allows for maximum visibility across the project. One key aspect is that the tool was built for a scenario process that accounts for stakeholder input, review, comment, and concurrence. By creating well-designed opportunities for stakeholder input and concurrence and by making the scenario content easily accessible to all project personnel, we maximize the opportunities for stakeholders to both understand and agree on the concepts for how their mission is to be carried out.

Boyles, Carole A.↗
NASA NTRS2016

CO2 on the International Space Station: An Operations Update

PROBLEM STATEMENT: We describe CO2 symptoms that have been reported recently by crewmembers on the International Space Station and our continuing efforts to control CO2 to lower levels than historically accepted. BACKGROUND: Throughout the International Space Station (ISS) program, anecdotal reports have suggested that crewmembers develop CO2-related symptoms at lower CO2 levels than would be expected terrestrially. Since 2010, operational limits have controlled the 24-hour average CO2 to 4.0 mm Hg, or below as driven by crew symptomatology. In recent years, largely due to increasing awareness by crew and ground team, there have been increased reports of crew symptoms. The aim of this presentation is to discuss recent observations and operational impacts to lower CO2 levels on the ISS. CASE PRESENTATION: Crewmembers are routinely asked about CO2 symptoms in their weekly private medical conferences with their crew surgeons. In recent ISS expeditions, crewmembers have noted symptoms attributable to CO2 starting at 2.3 mmHg. Between 2.3 - 2.7 mm Hg, fatigue and full-headedness have been reported. Between 2.7 - 3.0 mm Hg, there have been self-reports of procedure missed steps or procedures going long. Above 3.0 - 3.4 mm Hg, headaches have been reported. A wide range of inter- and intra-individual variability in sensitivity to CO2 have been noted. OPERATIONAL / CLINICAL RELEVANCE: These preliminary data provide semi-quantitative ranges that have been used to inform a new operational limit of 3.0 mmHg as a compromise between systems capabilities and the recognition that there are human health and performance impacts at recent ISS CO2 levels. Current evidence would suggest that an operational limit between 0.5 and 2.0 mm Hg may maintain health and performance. Future work is needed to establish long-term ISS and future vehicle operational limits.

Law, Jennifer↗
NASA NTRS2015

[Fall 2015 Abstract by Stephanie Scharf]

This Fall I worked on two different projects that culminated into a redesign of the spacesuit LLB (long life battery). I also did some work on the PLSS (personal life support system) battery with EC. My first project was redlining the work instruction for completing DPAs (destructive physical analysis) on battery cells in the Branch. The purpose of this document is to create a standard process and ensure that the data is collected in the same way, no matter who carries out the analysis. I observed three DPAs, conducted one with help, and conducted two on my own, all while taking notes on the procedure. These notes were used to write the final work instruction, which will become the Branch standard. My second project continued the work of the Summer co-op before me. I tested aluminum heat sinks for their ability to provide good thermal conduction and structural support during a thermal runaway event. The heat sinks had been designed by the previous Summer co-op, but there was not much time for testing before he left. We thus ran tests with a heater on the bottom of a trigger cell to try to drive thermal runaway and ensure that it will not propagate to adjacent cells. We also ran heat-to-vent tests in an oven to see if the assembly provided structural support and prevented sidewall rupture during thermal runaway. These tests were carried out at ESTA (Energy Systems Test Area) and are providing very promising results, indicating that safe, high performing (>180 Wh/kg) designs are possible. My main project was a redesign of the LLB (Lightweight Lithium Battery). Another summer intern had done some testing and concluded that there was no simple fix to mitigate thermal runaway propagation hazards in the existing design. The only option was a clean sheet redesign of the battery. I was given a volume and ideal energy density, and the rest of the design was up to me. First, I created new heat sink banks in CREO, using the information gathered in the metal heat sink tests from the summer intern. After this, I made capture plates to hold the cells in place, and I worked on nickel bussings for the electrical connections between the cells. Finally, I designed the test box enclosure that included sections for flame arresting materials. The battery brick design, which is the heart of the battery, promises to become the first for a manned spacecraft application to achieve > 180 Wh/kg. My work in redlining the DPA work instructions will also be used in selecting the cells for the battery. We had a few options for cells that would provide the necessary power output and needed to make a choice. We repeatedly charged and discharged cells for around a month until they went through 100 lifecycles. The plan was to compare the DPA results on fresh and cycled cells from each manufacturer to see if cycling introduces any differences. After the complete LLB design was approved, the parts were ordered and testing should begin the first week of December. Cutting open a cell for DPA After photo from oven heat-to-vent test

Scharf, Stephanie↗
NASA NTRS2015

[Redesign of the Spacesuit Long Life Battery and the Personal Life Support System Battery]

This fall I was working on two different projects that culminated into a redesign of the spacesuit LLB (long life battery). I also did some work on the PLSS (personal life support system) battery with EC. My first project was redlining the work instruction for completing DPAs (destructive physical analysis) on battery cells in the department. The purpose of this document is to create a standard process and ensure that the data in the same way no matter who carries out the analysis. I observed three DPAs, conducted one with help, and conducted two on my own all while taking notes on the procedure. These notes were used to write the final work instruction that will become is the department standard. My second project continued the work of the summer co-op before me. I was testing aluminum heat sinks for their ability to provide good thermal conduction and structural support during a thermal runaway event. The heat sinks were designed by the summer intern but there was not much time for testing before he left. We ran tests with a heater on the bottom of a trigger cell to try to drive thermal runaway and ensure that it will not propagate to adjacent cells. We also ran heat-to-vent tests in an oven to see if the assembly provided structural support and prevented sidewall rupture during thermal runaway. These tests were carried out at ESTA (energy systems test area) and are providing very promising results that safe, high performing (greater than 180 Wh/kg) designs are possible. My main project was a redesign of the LLB battery. Another summer intern did some testing and concluded that there was no simple fix to mitigate thermal runaway propagation hazards in the current design. The only option was a clean sheet redesign of the battery. I was given a volume and ideal energy density and the rest of the design was up to me. First, I created new heat sink banks in Creo using the information gathered in the metal heat sink tests from the summer intern. After this, I made capture plates to hold the cells in place and I worked on nickel bussings for the electrical connections between the cells. Finally, I designed the test box enclosure that included sections for flame arresting materials. The battery brick design, which is the heart of the battery, promises to become the first for a manned spacecraft application to achieve greater than 180 Wh/kg. My work in redlining the DPA work instructions will also be used in selecting the cells for the battery. We had a few options of cells that would provide the necessary power output and needed to make a choice. We repeatedly charged and discharged cells for around a month until they went through 100 lifecycles. The plan is to compare the DPA results on fresh and cycled cells from each manufacturer to see if cycling introduces any differences. After the complete LLB design was approved, the parts were ordered and testing should begin the first week of December. Some of my side projects included working on the CAD data for the PLSS with EC and attending the NASA Aerospace Battery Workshop in Huntsville. I was also a member of the Tours and Lectures Committee for the USRA and Pathways interns. I coordinated Apollo Evening and was on the committee for touring KSC and seeing an Atlas 5 launch. I really enjoyed my time at JSC and I would like to continue working for NASA or another aerospace company in the future. I have worked other internships prior to this, but I think the heavy research and development focus is the best fit for me. I originally thought I would need to go to grad school to work in an environment like this, but I now see it is possible with a bachelor’s degree and hard work. I would like to go into the workforce and maybe continue my education with night classes.

Scharf, Stephanie↗
NASA NTRS2016

Forward Skirt Structural Testing on the Space Launch System (SLS) Program

Structural testing was performed to evaluate heritage forward skirts from the Space Shuttle program for use on the Space Launch System (SLS) program. One forward skirt is located in each solid rocket booster. Heritage forward skirts are aluminum 2219 welded structures. Loads are applied at the forward skirt thrust post and ball assembly. Testing was needed because SLS ascent loads are roughly 40% higher than Space Shuttle loads. Testing objectives were to determine margins of safety, demonstrate reliability, and validate analytical models. Two forward skirts were structurally tested using the test configuration. The test stand applied loads to the thrust post. Four hydraulic actuators were used to apply axial load and two hydraulic actuators were used to apply radial and tangential loads. The first test was referred to as FSTA-1 (Forward Skirt Structural Test Article) and was performed in April/May 2014. The purpose of FSTA-1 was to verify the ultimate capability of the forward skirt subjected to ascent ultimate loads. Testing consisted of two liftoff load cases taken to 100% limit load followed by an ascent load case taken to 110% limit load. The forward skirt was unloaded to no load after each test case. Lastly, the forward skirt was tested to 140% limit and then to failure using the ascent loads. The second test was referred to as FSTA-2 and performed in July/August of 2014. The purpose of FSTA-2 was to verify the ultimate capability of the forward skirt subjected to liftoff ultimate loads. Testing consisted of six liftoff load cases taken to 100% limit load followed by the six liftoff cases taken to 140% limit load. Two ascent load cases were then tested to 100% limit load. The forward skirt was unloaded to no load after each test case. Lastly, the forward skirt was tested to 140% limit and then to failure using the ascent loads. The forward skirts on FSTA-1 and FSTA-2 successfully carried all applied liftoff and ascent load cases. Both FSTA-1 and FSTA-2 were tested to failure by increasing the ascent loads. Failure occurred in the forward skirt thrust post radius. The forward skirts on FSTA-1 and FSTA-2 had nearly identical failure modes. FSTA-1 failed at 1.72 times limit load and FSTA-2 failed at 1.62 times limit load. This difference is primarily attributed to variation in material properties in the thrust post region. Test data were obtained from strain gages, deflection gages, ARAMIS digital strain measurement, acoustic emissions, and high-speed video. Strain gage data and ARAMIS strain were compared to finite element (FE) analysis predictions. Both the forward skirt and tooling were modeled. This allows the analysis to simulate the loading as close as possible to actual test configuration. FSTA-1 and FSTA-2 were instrumented with over 200 strain gages to ensure all possible failure modes could be captured. However, it turned out that three gages provided critical strain data. One was located in the post bore and two on the post radius. More gages were not specified due to space limitations and the desire to not interfere with the use of the ARAMIS system on the post radius. Measured strains were compared to analysis results for the load cycle to failure. Note that FSTA-1 gages were lost before failure was reached. FSTA-2 gages made it to the failure load but one of the radius gages was lost before testing began. This gage was not replaced because of the time and cost associated with disassembly of the test structure. Correlation to analysis was excellent for FSTA-1. FSTA-2 was not quite as good because there was more residual strain from previous load cycles. FSTA-2 was loaded and unloaded with 12 liftoff cases and two ascent cases before taking the skirt to failure. FSTA-1 only had two liftoff cases and one ascent case before taking the skirt to failure. The ARAMIS system was used to determine strain at the post radius by processing digital images of a speckled paint pattern. Digital cameras recorded images of the speckled paint pattern. ARAMIS strain results for FSTA-2 just prior to failure. Note a high strain location develops near the left side. This high strain compares well to analysis prediction for both FSTA-1 and FSTA-2. The strain at this location was also plotted versus limit load. Both FSTA-1 and FSTA-2 had excellent correlation between ARAMIS and analysis strains. Acoustic emission (AE) sensors were used to monitor for damage formation that may occur during testing (e.g., crack formation and growth or propagation). AE was very important because after disassembly of FSTA-1, a crack was observed in the ball fitting radius. The ball fitting did not crack on FSTA-2. AE data was used to reconstruct when the crack occurred. The AE energy versus time plot for FSTA. The energy increased considerably at 850 seconds (152% limit load), indicating a crack could have formed at this point. The only visual evidence found that could have corresponded to this was the crack that initiated in the ball fitting. The cracks in the forward skirt aluminum structures would likely have been lower energy due to a lower modulus and all that were found after failure correlated to occurring after the initial crack in the post radius. This was verified by high-speed cameras used to record the failure.

Lohrer, J. D.↗
NASA NTRS2016

Spacecraft Risk Posed by the 2016 Perseid Outburst

The Perseids are one of the more prolific annual showers, known for high rates and for producing bright meteors. Outbursts of this shower have been noted in the 1860s, the early 1990s, 2004, and 2009, with the 1993 outburst being especially active (peak ZHR above 300). The 1993 Perseids also affected the space-faring nations, as the launch of the STS-51 mission was delayed by NASA until after the shower maximum due to an inability to predict the shower intensity, and the ESA telecommunications satellite Olympus suffered a mission-ending anomaly attributed to a static discharge caused by a Perseid impact [1]. Rates were again high (peak ZHR around 200) in 2009, when the NASA/USGS imaging satellite Landsat-5 experienced a gyro anomaly just before the shower peak; however in this case, the satellite was recovered and normal operations resumed one week later [2]. It is interesting to note that both spacecraft anomalies were not what is typically expected from meteoroid strikes, i.e., physical damage or an attitude displacement due to transfer of momentum. It would appear that the very fast Perseids (59 km s(sup -1) have a marked ability to produce plasma upon impact, which can then serve as a conductive path for discharge currents. The shower is expected to outburst again in 2016, and we present the results from the MSFC Meteoroid Stream Model [4], which predicts enhanced activity on a level similar to that of 2009 as the Earth passes through several debris trails on the night of August 11-12 (UT). We then compare our results to those of other modelers.

Cooke, W. J.↗
NASA NTRS2016

Martian Environment Electrostatic Precipitator

As part of the planned manned mission to Mars, NASA has noticed that shipping oxygen as a part of life support to keep the astronauts alive continuously is overly expensive, and impractical. As such, noting that the Martian atmosphere is 95.37% CO2, NASA chemists noted that one could obtain oxygen from the Martian atmosphere. The plan, as part of a larger ISRU (in-situ resource utilization) initiative, would extract water from the regolith, or the Martian soil which can be electrolyzed by solar panel produced voltage into hydrogen and oxygen. The hydrogen can then be used in the Sabatier reaction with carbon dioxide to produce methane and water producing a net reaction that does not lose water and outputs methane and oxygen for use as rocket fuel and breathing.

Dust↗