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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS2005

NASA GRC and MSFC Space-Plasma Arc Testing Procedures

Tests of arcing and current collection in simulated space plasma conditions have been performed at the NASA Glenn Research Center (GRC) in Cleveland, Ohio, for over 30 years and at the Marshall Space flight Center (MSFC) for almost as long. During this period, proper test conditions for accurate and meaningful space simulation have been worked out, comparisons with actual space performance in spaceflight tests and with real operational satellites have been made, and NASA has achieved our own internal standards for test protocols. It is the purpose of this paper to communicate the test conditions, test procedures, and types of analysis used at NASA GRC and MSFC to the space environmental testing community at large, to help with international space-plasma arcing testing standardization. To be discussed are: 1. Neutral pressures, neutral gases, and vacuum chamber sizes. 2. Electron and ion densities, plasma uniformity, sample sizes, and Debye lengths. 3. Biasing samples versus self-generated voltages. Floating samples versus grounded. 4. Power supplies and current limits. Isolation of samples from power supplies during arcs. Arc circuits. Capacitance during biased arc-threshold tests. Capacitance during sustained arcing and damage tests. Arc detection. Preventing sustained discharges during testing. 5. Real array or structure samples versus idealized samples. 6. Validity of LEO tests for GEO samples. 7. Extracting arc threshold information from arc rate versus voltage tests. 8 . Snapover and current collection at positive sample bias. Glows at positive bias. Kapton pyrolization. 9. Trigger arc thresholds. Sustained arc thresholds. Paschen discharge during sustained arcing. 10. Testing for Paschen discharge thresholds. Testing for dielectric breakdown thresholds. Testing for tether arcing. 11. Testing in very dense plasmas (ie thruster plumes). 12. Arc mitigation strategies. Charging mitigation strategies. Models. 13. Analysis of test results. Finally, the necessity of testing will be emphasized, not to the exclusion of modeling, but as part of a complete strategy for determining when and if arcs will occur, and preventing them from occurring in space.

Ferguson, Dale C.a↗
NASA NTRS1992

Automated rendezvous and capture development infrastructure

The facilities at Marshall Space Flight Center and JSC to be utilized to develop and test an autonomous rendezvous and capture (ARC) system are described. This includes equipment and personnel facility capabilities to devise, develop, qualify, and integrate ARC elements and subsystems into flight programs. Attention is given to the use of a LEO test facility, the current concept and unique system elements of the ARC, and the options available to develop ARC technology.

Bryan, Thomas C.↗
NASA NTRS1987

Failure analysis of a 3.5 inch, 50 ampere-hour nickel-hydrogen cell

The 3.5 inch, 50 ampere-hour nickel-hydrogen cell was on a Low Earth Orbit (LEO) test regime and was being cycled at 10 C and 60 percent depth of discharge. At cycle number 511 the Automatic Control and Data Acquisition System (ACDAS) terminated the test when the end of discharge voltage dropped below the 1.00 volt cutoff. Upon removal of the stack assembly from the pressure vessel, portions of the zircar separator were found to be completely missing. Upon further examination portions of both the positive and negative plates were found to be missing from its substrate and several gas screens were damaged due to excessive heat which caused fusing. The postulated cause of failure is free electrolyte in the cell which caused oxygen channelization resulting in localized recombination which degraded the stack components.

Fuhr, Kenneth H.↗
NASA NTRSDate not supplied

Orion's Powered Flight Guidance Performance During Artemis I

Artemis is NASA’s campaign to explore the Moon and beyond. Artemis I, the un-crewed exo-LEO test flight, was completed in 2022. The Artemis I mission provided the means to prove-out both vehicle and systems as a pre-cursor to more advanced missions. The Orion capsule and service module had to be capable of accurately executing all major orbital burns and numerous correction burns to successfully execute the mission profile. In support of this needed translation maneuver capability, a powered flight guidance algorithm has been designed that provides a number of guided burn options depending on the burn objective. Some of these guidance options are based on classic orbit transfer problems, such as Lambert's time-of-flight problem. Some are based on proven NASA heritage manned space programs like Apollo and Shuttle. Some are new concepts that fill unique niche requirements. All of these options are integrated into an architecture based on a proven Shuttle heritage design, with a simple closed-loop guidance strategy, that provides both modularity, simplicity and adaptability to future, as yet to be defined, mission profiles. This paper will summarize the performance of Orion’s orbital powered flight guidance during the mission.

space guidance↗
NASA NTRS1986

Development of flight ready fifty-micron-thick silicon solar cell array module technology

The development of ultrathin silicon solar cell array modules from initial design to flight testing is discussed. Three 80-cell modules were subjected to the thermal soak test, the LEO thermal cycle test, and the solar array flight experiment, and six 48-cell welded modules were evaluated in the geosynchronous orbit thermal cycle test. It is observed that the electrical performance of the modules was not affected by the different environmental conditions. The automatic assembly of the cell modules, in particular the welding and solar cell glassing operation, is described. The specific power capabilities of Kapton, Kapton-Kevlar-Kapton, Kapton-graphite-Kapton, and Kapton-graphite-aluminum honeycomb-graphite solar array designs are assessed.

Patterson, R. E.↗
NASA NTRS1989

Planetary nebulae as standard candles. IV - A test in the Leo I group

In this paper, PN are used to determine accurate distances to three galaxies in the Leo I group - The E0 giant elliptical NGC 3379, its optical companion, the SB0 spiral NGC 3384, and the smaller E6 elliptical NGC 3377. In all three galaxies, the luminosity-specific PN number densities are roughly the same, and the derived stellar death rates are in remarkable agreement with the predictions of stellar evolution theory. It is shown that the shape of the forbidden O III 5007 A PN luminosity function is the same in each galaxy and indistinguishable from that observed in M31 and M81. It is concluded that the PN luminosity function is an excellent standard candle for early-type galaxies.

Ciardullo, Robin↗
NASA NTRS1996

Assessment of Corona/Arcing Hazard for Electron Beam Welding in Space Shuttle Bay at LEO for ISWE: Test Results

Test welds were made in argon over a range of pressures from 10-5 to 10-3 torr (the latter pressure an order of magnitude above pressures anticipated in the space shuttle bay during welding) with and without plasma on 304 stainless steel, 6Al-4V titanium, and 5456 aluminum in search of any possible unwanted electrical discharges. Only a faint steady glow of beam-excited atoms around the electron beam and sometimes extending out into the vacuum chamber was observed. No signs of current spiking or of any potentially dangerous electrical discharge were found.

Nunes, A. C., Jr.↗
NASA NTRSDate not supplied

Extending ISS Life Beyond 2030

The United States On-orbit Segment (USOS) of the International Space Station (ISS) was designed to meet a 15-year on-orbit life. Since the first hardware was launched in late 1998, the ISS would have reached its end of life in 2013. With the realization that the ISS would be needed well into the next decade, and beyond, a multi-disciplinary effort was undertaken to extend the ISS’ life through 2028 and to show that further extension to 2040 and beyond is not only feasible but achievable. Currently, NASA and the ISS international partners have agreed to extend its operations through 2030. This collaborative effort ensures that the ISS will continue to serve as a hub for scientific research, international cooperation, and educational endeavors for the next decade. Maintaining a continuous human presence in Low Earth Orbit (LEO) is desirable for testing new LEO, lunar, and deep-space technologies; conducting scientific research in micro-gravity for the benefit of life on Earth; and enabling a seamless transition of capabilities to one or more commercially owned and operated destinations. This paper provides an overview of the ISS life extension project with a particular focus on the analytical approach used to assess the primary structure. This analytical approach includes future operations planning, critical location screening, on-orbit dynamic load simulation, on-orbit optical property degradation studies, on-orbit thermal analyses, spectra generation, crack model idealization, fracture analyses, and post processing. Structural life results and identification of the most critical on-orbit events are presented. Also addressed are life extension approaches for other affected sub-systems, including: 1. Secondary Structure. 2. Materials. Evaluations consider environmental exposure to atomic oxygen, ionizing and gamma radiation, fluids, etc. Life limited materials, wear, and usage effects are also considered. 3. Environmental Control and Life Support Systems, including oxygen supply and generation, water recovery and management, and regenerative hardware. Evaluations are performed to determine which hardware can be run to failure and which are assessed for life extension. 4. Electrical power system. ISS is powered by eight channels of solar arrays and an electrical energy storage system providing 357 kWh power. Power generation and balance analyses are performed considering hardware degradation and increasing power demand. 5. Logistics and maintenance. Analyses are performed to determine critical spares required to maintain functionality. Consideration is given to supply chain health, obsolescence issues, onboard stowage availability, and up-mass capability. The successful life extension results have built confidence to safely operate, maintain and enhance the ISS well beyond the current decade. Extending the operational life of the ISS maintains an international presence in LEO and serves to avoid a gap in capability necessary to fulfill the exploration and research needs of NASA, international partners, and industry without interruption until a commercial space station is operational.

design life↗
NASA NTRS1992

Air Force Phillips Laboratory Battery Program overview

Battery development and testing efforts at Phillips Laboratory fall into three main categories: nickel hydrogen, sodium sulfur, and solid state batteries. Nickel hydrogen work is broken down into a Low Earth Orbit (LEO) Life Test Program, a LEO Pulse Test Program, and a Hydrogen Embrittlement Investigation. Sodium sulfur work is broken down into a Geosynchronous Earth Orbit (GEO) Battery Flight Test and a Hot Launch Evaluation. Solid state polymer battery work consists of a GEO Battery Development Program, a Pulse Power Battery Small Business Innovation Research (SBIR), and an in-house evaluation of current generation laboratory cells. An overview of the program is presented.

House, Shaun↗
NASA NTRS1986

The voltage threshold for arcing for solar cells in LEO: Flight and ground test results

Ground and flight results of solar cell arcing in low Earth orbit (LEO) conditions are compared and interpreted. It is shown that an apparent voltage threshold for arcing may be produced by a strong power law dependence of arc rate on voltage, combined with a limited observation time. The change in this apparent threshold with plasma density is a reflection of the density dependence of the arc rate. A nearly linear dependence of arc rate on density is inferred from the data. A real voltage threshold for arcing for 2 by 2 cm solar cells may exist however, independent of plasma density, near -230 V relative to the plasma. Here, arc rates may change by more than an order of magnitude for a change of only 30 V in array potential. For 5.9 by 5.9 solar cells, the voltage dependence of the arc rate is steeper, and the data are insufficient to indicate the existence of an arcing increased by an atomic oxygen plasma, as is found in LEO, and by arcing from the backs of welded-through substrates.

Ferguson, D. C.↗
NASA NTRS1986

The voltage threshold for arcing for solar cells in Leo - Flight and ground test results

Ground and flight results of solar cell arcing in low earth orbit (LEO) conditions are compared and interpreted. It is shown that an apparent voltage threshold for arcing may be produced by a storage power law dependence of arc rate on voltage, combined with a limited observation time. The change in this apparent threshold with plasma density is a reflection of the density dependence of the arc rate. A nearly linear dependence of arc rate on density is inferred from the data. A real voltage threshold for arcing for 2 by 2 cm solar cells may exist however, independent of plasma density, near -230 V relative to the plasma. Here, arc rates may change by more than an order of magnitude for a change of only 30 V in array potential. For 5.9 by 5.9 solar cells, the voltage dependence of the arc rate is steeper, and the data are insufficient to indicate the existence of an arcing increased by an atomic oxygen plasma, as is found in LEO, and by arcing from the backs of welded-through substrates.

Ferguson, Dale C.↗
NASA NTRS2006

Experimental Results of Thin-Film Photovoltaic Cells in a Low Density LEO Plasma Environment: Ground Tests

Plasma ground testing results, conducted at the Glenn Research Center (GRC) National Plasma Interaction (N-PI) Facility, are presented for a number of thin-film photovoltaic cells. The cells represent a mix of promising new technologies identified by the Air Force Research Laboratory (AFRL) under the CYGNUS Space Science Technology Experiment (SSTE-4) Program. The current ground tests are aimed at characterizing the performance and survivability of thin film technologies in the harsh low earth orbital space environment where they will be flown. Measurements of parasitic current loss, charging/dielectric breakdown of cover-slide coatings and arcing threshold tests are performed for each individual cell. These measurements are followed by a series of experiments designed to test for catastrophic arc failure mechanisms. A special type of power supply, called a solar array simulator (SAS) with adjustable voltage and current limits on the supply s output, is employed to bias two adjacent cells at a predetermined voltage and current. The bias voltage is incrementally ramped up until a sustained arc results. Sustained arcs are precursors to catastrophic arc failure where the arc current rises to a maximum value for long timescales often ranging between 30 to 100 sec times. Normal arcs by comparison, are short lived events with a timescale between 10 to 30 sec. Sustained arcs lead to pyrolization with extreme cell damage and have been shown to cause the loss of entire array strings in solar arrays. The collected data will be used to evaluate the suitability of thin-film photovoltaic technologies for future space operations.

Galofaro, Joel T.↗
NASA NTRSDate not supplied

TBIRD, a rapid prototyping approach for design, assembly, and test of a LEO-to-ground lasercom CubeSat

The TeraByte InfraRed Delivery (TBIRD) system is a 3U payload on a 6U CubeSat launched in May 2022 which has now demonstrated space to ground links of >1 Terabyte (TB) per pass at a max data rate of 200Gbps. As a CubeSat mission, the development of the TBIRD payload was focused on low SWaP and a “rapid prototyping” approach which accepted higher risks to accelerate the schedule and reduce costs. The optomechanical design process followed standard in-house processes to develop a system that would be robust to LEO environmental loads, with a focus on the stability of the transmit (Tx) and receive (Rx) channel performance metrics. The driving requirement of maintaining 20μrad pointing error between the TX and Rx channels forced specific attention to thermal and mechanical load changes over operational conditions, which drove major design decisions. This paper describes some of engineering challenges overcome and approaches used to make TBIRD a successful program, as well as some of the tradeoffs of rapid prototyping precision optical payloads. TBIRD successfully met and exceeded the total downlink requirements listed above, with a bandwidth of 200Gbps and a total downlink of 4.8TB of information in a single pass.

TBIRD↗
NASA NTRS1999

International Low-Earth-Orbit Spacecraft Materials Test Program Initiated for Better Prediction of Durability and Performance

Spacecraft in low Earth orbit (LEO) are subjected to many components of the environment, which can cause them to degrade much more rapidly than intended and greatly shorten their functional life. The atomic oxygen, ultraviolet radiation, and cross contamination present in LEO can affect sensitive surfaces such as thermal control paints, multilayer insulation, solar array surfaces, and optical surfaces. The LEO Spacecraft Materials Test (LEO-SMT) program is being conducted to assess the effects of simulated LEO exposure on current spacecraft materials to increase understanding of LEO degradation processes as well as to enable the prediction of in-space performance and durability. Using ground-based simulation facilities to test the durability of materials currently flying in LEO will allow researchers to compare the degradation evidenced in the ground-based facilities with that evidenced on orbit. This will allow refinement of ground laboratory test systems and the development of algorithms to predict the durability and performance of new materials in LEO from ground test results. Accurate predictions based on ground tests could reduce development costs and increase reliability. The wide variety of national and international materials being tested represent materials being functionally used on spacecraft in LEO. The more varied the types of materials tested, the greater the probability that researchers will develop and validate predictive models for spacecraft long-term performance and durability. Organizations that are currently participating in the program are ITT Research Institute (USA), Lockheed Martin (USA), MAP (France), SOREQ Nuclear Research Center (Israel), TNO Institute of Applied Physics (The Netherlands), and UBE Industries, Ltd. (Japan). These represent some of the major suppliers of thermal control and sensor materials currently flying in LEO. The participants provide materials that are exposed to selected levels of atomic oxygen, vacuum ultraviolet radiation, contamination, or synergistic combined environments at the NASA Lewis Research Center. Changes in characteristics that could affect mission performance or lifetime are then measured. These characteristics include changes in mass, solar absorptance, and thermal emittance. The durability of spacecraft materials from U.S. suppliers is then compared with those of materials from other participating countries. Lewis will develop and validate performance and durability prediction models using this ground data and available space data. NASA welcomes the opportunity to consider additional international participants in this program, which should greatly aid future spacecraft designers as they select materials for LEO missions.

Rutledge, Sharon K.↗
NASA NTRS1985

Life cycle test results of a bipolar nickel hydrogen battery

A history is given of low Earth orbit (LEO) laboratory test data on a 6.5 ampere-hour bipolar nickel hydrogen battery designed and built at the NASA Lewis Research Center. The bipolar concept is a means of achieving the goal of producing an acceptable battery, of higher energy density, able to withstand the demands of low-Earth-orbit regimes. Over 4100 LEO cycles were established on a ten cell battery. It seems that any perturbation on normal cycling effects the cells performance. Explanations and theories of the battery's behavior are varied and widespread among those closely associated with it. Deep discharging does provide a reconditioning effect and further experimentation is planned in this area. The battery watt-hour efficiency is about 75 percent and the time averaged, discharge voltage is about 1.26 volts for all cells at both the C/4 and LEO rate. Since a significant portion of the electrode capacity has degraded, the LEO cycle discharges are approaching depths of 90 to 100 percent of the high rate capacity. Therefore, the low end-of-discharge voltages occur precipitously after the knee of the discharge curve and is more an indication of electrode capacity and is a lesser indicator of overall cell performance.

Cataldo, R. L.↗