228 research outputs found

    Advanced Compatibility Characterization Of AF-M315E With Spacecraft Propulsion System Materials Project

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    All spacecraft require propulsion systems for thrust and maneuvering. Propulsion systems can be chemical, nuclear, electrical, cold gas or combinations thereof. Chemical propulsion has proven to be the most reliable technology since the deployment of launch vehicles. Performance, storability, and handling are three important aspects of liquid chemical propulsion. Bipropellant systems require a fuel and an oxidizer for propulsion, but monopropellants only require a fuel and a catalyst for propulsion and are therefore simpler and lighter. Hydrazine is the state of the art propellant for monopropellant systems, but has drawbacks because it is highly hazardous to human health, which requires extensive care in handling, complex ground ops due to safety and environmental considerations, and lengthy turnaround times for reusable spacecraft. All users of hydrazine monopropellant must contend with these issues and their associated costs. The development of a new monopropellant, intended to replace hydrazine, has been in progress for years. This project will apply advanced techniques to characterize the engineering properties of materials used in AF-M315E propulsion systems after propellant exposure. AF-M315E monopropellant has been selected HQ's Green Propellant Infusion Mission (GPIM) to replace toxic hydrazine for improved performance and reduce safety and health issues that will shorten reusable spacecraft turn-around time. In addition, this project will fundamentally strengthen JSC's core competency to evaluate, use and infuse liquid propellant systems

    Historical Evolution of NASA Standard Materials Testing with Hypergolic Propellants and Ammonia (NASA Standard 6001 Test 15)

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    The NASA Johnson Space Center White Sands Test Facility (WSTF) has performed testing of hazardous and reactive aerospace fluids, including hypergolic propellants, with materials since the 1960s with the Apollo program. Amongst other test activities, Test 15 is a NASA standard test for evaluating the reactivity of materials with selected aerospace fluids, in particular hydrazine, monomethylhydrazine, uns-dimethylhydrazine, Aerozine 50, dinitrogen tetroxide oxidizers, and ammonia. This manuscript provides an overview of the history of Test 15 over a timeline ranging from prior to its development and first implementation as a NASA standard test in 1974 to its current refinement. Precursor documents to NASA standard tests, as they are currently known, are reviewed. A related supplementary test, international standardization, and enhancements to Test 15 are also discussed. Because WSTF was instrumental in the development and implementation of Test 15, WSTF experience and practices are referred to in this manuscript

    ISO 15859 Propellant and Fluid Specifications: A Review and Comparison with Military and NASA Specifications

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    This work presents an overview of the International Organization for Standardization (ISO) 15859 International Standard for Space Systems Fluid Characteristics, Sampling and Test Methods Parts 1 through 13 issued in June 2004. These standards establish requirements for fluid characteristics, sampling, and test methods for 13 fluids of concern to the propellant community and propellant characterization laboratories: oxygen, hydrogen, nitrogen, helium, nitrogen tetroxide, monomethylhydrazine, hydrazine, kerosene, argon, water, ammonia, carbon dioxide, and breathing air. A comparison of the fluid characteristics, sampling, and test methods required by the ISO standards to the current military and NASA specifications, which are in use at NASA facilities and elsewhere, is presented. Many ISO standards composition limits and other content agree with those found in the applicable parts of NASA SE-S-0073, NASA SSP 30573, military performance standards and details, and Compressed Gas Association (CGA) commodity specifications. The status of a current project managed at NASA Johnson Space Center White Sands Test Facility (WSTF) to rewrite these documents is discussed

    Hazard Assessment of Personal Protective Clothing for Hydrogen Peroxide Service

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    Selection of personal protective equipment (PPE) for hydrogen peroxide service is an important part of the hazard assessment process. But because drip testing of chemical protective clothing for hydrogen peroxide service has not been reported for about 40 years, it is of great interest to test new protective clothing materials with new, high-concentration hydrogen peroxide following similar procedures. The suitability of PPE for hydrogen peroxide service is in part determined by observations made when hydrogen peroxide is dripped onto swatches of protective clothing material. Protective clothing material was tested as received, in soiled condition, and in grossly soiled condition. Materials were soiled by pretreating the material with potassium permanganate (KMnO4) solution then drying to promote a reaction. Materials were grossly soiled with solid KMnO4 to greatly promote reaction. Observations of results including visual changes to the hydrogen peroxide and materials, times to ignition, and self-extinguishing characteristics of the materials are reported

    Removal of Perfluorinated Grease Components from NTO Oxidizer

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    Perfluorinated greases are typically used as a thread lubricant in the assembly of non-welded nitrogen tetroxide (NTO) oxidizer systems. These greases, typically a perfluoroalkylether, with suspended polytetrafluoroethylene (PTFE) micro-powder, have attractive lubricating properties toward threaded components and are relatively chemically inert toward NTO oxidizers. A major drawback, however, is that perfluoroalkylether greases are soluble or dispersible in NTO oxidizers and can contaminate the propellant. The result is propellant that fails the non-volatile residue (NVR) specification analyses and that may have negative effects on test hardware performance and lifetime. Consequently, removal of the grease contaminants from NTO may be highly desirable. Methods for the removal of perfluorinated grease components from NTO oxidizers including distillation, adsorption, filtration, and adjustment of temperature are investigated and reported in this work. Solubility or dispersibility data for the perfluoroalkylether oil (Krytox(tm)143 AC) component of a perfluorinated grease (Krytox 240 AC) and for Krytox 240 AC in NTO were determined and are reported

    Determination of Silicon in Hydrazine

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    Inductively coupled plasma-mass spectrometry (ICP-MS) is a highly sensitive technique sometimes used for the trace determination of silicon at a mass-to-charge (m/z) ratio of 28, the most abundant natural isotope of silicon. Unfortunately, ICP-MS is unable to differentiate between other sources of m/z 28 and false positive results for silicon will result when other sources of m/z 28 are present. Nitrogen was a major source of m/z 28 and contributes to the m/z 28 signal when hydrazine sample or nitric acid preservative is introduced into the plasma. Accordingly, this work was performed to develop a sample preparation step coupled with an ICP-MS analysis that minimized non-silicon sources of m/z 28. In the preparatory step of this method, the hydrazine sample was first decomposed predominately to nitrogen gas and water with copper-catalyzed hydrogen peroxide. In the analysis step, ICP-MS was used without nitric acid preservative in samples or standards. Glass, a potential source of silicon contamination, was also avoided where possible. The method was sensitive, accurate, and reliable for the determination of silicon in monopropellant grade hydrazine (MPH) in AF-E-332 elastomer leaching tests. Results for silicon in MPH were comparable to those reported in the literature for other studies

    Methods for Decontamination of a Bipropellant Propulsion System

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    Most propulsion systems are designed to be filled and flown, draining can be done but decontamination may be difficult. Transport of these systems may be difficult as well because flight weight vessels are not designed around DOT or UN shipping requirements. Repairs, failure analysis work or post firing inspections may be difficult or impossible to perform due to the hazards of residual propellants being present

    Ursinus College Alumni Journal, Spring 1948

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    Give the steward a break! • President\u27s page • College has full extra-curricular program: Dr. Miller forum speaker; Religious Emphasis Week; Ray Eberle for junior prom • Mrs. Smith resigns alumni secretaryship • College is recipient of paintings and furniture • Congratulations, alumni basketeers! • Women\u27s Club entertains Ursinus senior girls • New associate professor joins college faculty • Nineteen alumni attain doctorates • Still room for students in certain categories • College librarian resigns • A successful season was had by all: Men\u27s basketball; Girls\u27 basketball; Wrestling; Swimming • News about ourselves • Cost of living increase voted faculty members • News around town • Ursinus curriculum undergoes revision • Women\u27s rules liberalizedhttps://digitalcommons.ursinus.edu/alumnijournal/1032/thumbnail.jp

    Ursinus College Alumni Journal, Summer 1947

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    Word of appreciation • Old Timers\u27 Day • President\u27s page • Alumni Association tables special committee\u27s report • Student union chosen as war memorial • Women\u27s Club • Dr. Clawson new Ursinus Dean • Board of Directors creates new committee, adds five members • Campus to be used for astronomical observation • Kuhrt Wieneke named coach of football • Three resign from faculty • Fourteen members added to faculty • Dr. Distler addresses graduating class • Sports: Men\u27s basketball; baseball; men\u27s tennis; track; women\u27s swimming; women\u27s basketball; women\u27s tennis • Local alumni associations meet • Work progressing on alumni register • Summer assembly • News about ourselves • Necrology • News around townhttps://digitalcommons.ursinus.edu/alumnijournal/1031/thumbnail.jp

    Ursinus College Alumni Journal, Winter 1947

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    An auspicious beginning for a worthwhile project • President\u27s page • Committees plan new position at college • Status of the war memorial campaign • 964 students enrolled at Ursinus • Miss Moll resumes duties at Ursinus • General Arnold Founders\u27 Day speaker • Three faculty promotions, one appointment announced • New gymnasium nearing completion • Questionnaires outstanding from 900 alumni • Sports: football, soccer, hockey • The shape of things to come? • The attack on illiteracy in British Guiana • News around town • News about ourselves • Faculty members complete laboratory manual • Necrologyhttps://digitalcommons.ursinus.edu/alumnijournal/1029/thumbnail.jp
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