Bibliography
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Found 8 entries in the Bibliography.
Showing entries from 1 through 8
| 2018 |
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The Engineering Radiation Monitor (ERM) measures dose, dose rate and charging currents on the Van Allen Probes mission to study the dynamics of Earth\textquoterights Van Allen radiation belts. Over five years, results from this monitor show a variation in dose rates with time, a correlation between the dosimeter and charging current data and a comparison of cumulative dose to pre-launch modeling. Solar cell degradation monitor patches track the decrease in solar array output as displacement damage accumulates. The Solar Cell Monitor shows ~33\% cumulative degradation in maximum power after 5.1 years of the mission. The desire to extend the mission to ~2500 days from 800 days created increased requirements for the ionizing radiation hardness of spacecraft and science instrument electronics. We describe the investigations that insured compliance with these enhanced requirements. Maurer, R.; Goldsten, J.; Butler, M.; Fretz, K.; Published by: Space Weather Published on: 09/2018 YEAR: 2018 DOI: 10.1029/2018SW001910 |
| 2013 |
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The Engineering Radiation Monitor (ERM) measures dose, dose rate and charging currents on the Van Allen Probes mission to study the dynamics of earth\textquoterights Van Allen radiation belts. Early results from this monitor show a variation in dose rates with time, a correlation between the dosimeter and charging current data, a map of charging current versus orbit altitude and a comparison of cumulative dose to pre-launch modeling after 260 days. Solar cell degradation monitor patches track the decrease in solar array output as displacement damage accumulates. Maurer, Richard; Goldsten, John; Peplowski, Patrick; Holmes-Siedle, Andrew; Butler, Michael; Herrmann, Carl; Mauk, Barry; Published by: IEEE Transactions on Nuclear Science Published on: Jan-12-2013 YEAR: 2013 DOI: 10.1109/TNS.2013.2281937 |
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The Engineering Radiation Monitor (ERM) measures dose, dose rate and charging currents on the Van Allen Probes mission to study the dynamics of earth\textquoterights Van Allen radiation belts. Early results from this monitor show a variation in dose rates with time, a correlation between the dosimeter and charging current data, a map of charging current versus orbit altitude and a comparison of cumulative dose to pre-launch modeling after 260 days. Solar cell degradation monitor patches track the decrease in solar array output as displacement damage accumulates. Maurer, Richard; Goldsten, J.; Peplowski, P.; Holmes-Siedle, A.; Butler, Michael; Herrmann, C.; Mauk, B.; Published by: Published on: 11/2013 YEAR: 2013 DOI: 10.1109/TNS.2013.2281937 |
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Radiation Belt Storm Probes\textemdashObservatory and Environments The National Aeronautics and Space Administration\textquoterights (NASA\textquoterights) Radiation Belt Storm Probe (RBSP) is an Earth-orbiting mission that launched August 30, 2012, and is the latest science mission in NASA\textquoterights Living with a Star Program. The RBSP mission will investigate, characterize and understand the physical dynamics of the radiation belts, as well as the influence of the Sun on the Earth\textquoterights environment, by measuring particles, electric and magnetic fields and waves that comprise geospace. The mission is composed of two identically instrumented spinning observatories in an elliptical orbit around earth with 600 km perigee, 30,000 km apogee and 10o inclination to provide full sampling of the Van Allen radiation belts. The twin RBSP observatories (recently renamed the Van Allen Probes) will follow slightly different orbits and will lap each other four times per year, offering simultaneous measurements over a range of observatory separation distances. A description of the observatory environment is provided along with protection for sensitive electronics to support operations in the harsh radiation belt environment. Spacecraft and subsystem key characteristics and instrument accommodations are included that allow the RBSP science objectives to be met. Kirby, Karen; Artis, David; Bushman, Stewart; Butler, Michael; Conde, Rich; Cooper, Stan; Fretz, Kristen; Herrmann, Carl; Hill, Adrian; Kelley, Jeff; Maurer, Richard; Nichols, Richard; Ottman, Geffrey; Reid, Mark; Rogers, Gabe; Srinivasan, Dipak; Troll, John; Williams, Bruce; Published by: Space Science Reviews Published on: 11/2013 YEAR: 2013 DOI: 10.1007/s11214-012-9949-2 |
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Lithium Ion Battery Fault Management on the Van Allen Probes The Van Allen Probes (formerly known as the Radiation Belt Storm Probes or RBSP) mission launched on 30 August 2012 as part of NASA\textquoterights Living With a Star (LWS) Program. The ultimate goal of the mission is to understand how populations of relativistic electrons and penetrating ions in the Earth\textquoterights Van Allen Radiation Belts are affected by the Sun. The mission consists of two nearly identical observatories orbiting in highly-elliptical Earth orbits. The two satellite system allows for the study of the spatial and temporal effects the Sun has on the Earth\textquoterights radiation belts. Each observatory is equipped with a suite of instruments designed to continuously study ions, electrons and the local magnetic and electric fields. A brief overview of the Van Allen Probe mission is presented with an emphasis on the power subsystem and the fault management system. A unique challenge encountered on the Van Allen Probes mission was the health monitoring and management of the Lithium Ion battery. The fault management system employed three different strategies to monitor and protect the health of the battery: a hardware implemented low voltage sense, a software implemented low voltage sense, and a low battery state of charge calculation (coulometry). The pros and cons of each of these strategies are further discussed with respect to fault management system design and the battery test data collected during the integration, test and environmental testing phases of development. Smith, Evan; Butler, Michael; Fretz, Kristin; Wilhelm, Benjamin; Published by: Published on: 09/2013 YEAR: 2013 DOI: 10.2514/6.2013-5526 |
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The Van Allen Probes Power System Launch and Early Mission Performance The Van Allen Probes are twin NASA spacecraft that were launched August 30, 2012, into lapping highly elliptical earth orbits. The twin spacecraft will operate within the Van Allen radiation belts throughout their two-year mission. The Van Allen Probes are sponsored by NASA\textquoterights Living With a Star (LWS) Program. The Johns Hopkins University, Applied Physics Laboratory designed, fabricated, and operates the twin spacecraft for NASA. The power systems of the twin spacecraft are identical. A direct energy transfer topology was selected for the power system. The loads are connected directly to the eight-cell Lithium Ion battery. The solar panels consist of triple junction cells. The design average power of each spacecraft is about 350 Watts, nominal 28.8 volt bus. A single 50 AH Lithium Ion battery is used to support the spacecraft loads during launch and eclipse periods. The battery charge control is performed using constant current/constant voltage taper charging. The two Van Allen Probes are performing as designed. This paper will describe the power system launch and early mission performance results. Published by: Published on: 07/2013 YEAR: 2013 DOI: 10.2514/MIECEC1310.2514/6.2013-3737 |
| 2012 |
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The RBSP Spacecraft Power System Design and Development The RBSP (Radiation Belt Storm Probes) twin spacecraft are set to launch in August 2012. The spacecraft will be inserted into the highly elliptical regions of high energy particles trapped by the magnetic field of the earth. These regions are often referred to as the Van Allen Belts. The twin spacecraft will operate entirely within the radiation belts throughout their mission. Because of the intense environment of operation and to reduce cost and risk, the approach taken in the power system electronics was to use quasi conventional design, materials, and fabrication techniques encased in a 350mil thick aluminum enclosure. The spacecraft are spin stabilized with an axial boom that creates a shadow across the solar arrays. The power system topology selected was a 28V unregulated direct energy transfer (DET) system using an eight cell Li-Ion battery with cell balance electronics. The solar arrays are electrostatically clean with each string layout for magnetic self-cancellation. The spacecraft instruments electrostatic and magnetic cleanliness requirements impacted the design of the solar array, battery, and power system electronic boxes. The paper will cover the design and development of the RBSP spacecraft Power System including the battery, solar arrays, and the power electronics. Butler, Michael; Laughery, Sean; Published by: Published on: 08/2012 YEAR: 2012 DOI: 10.2514/MIECEC1210.2514/6.2012-4059 |
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Radiation Belt Storm Probe Spacecraft and Impact of Environment on Spacecraft Design NASA\textquoterights Radiation Belt Storm Probe (RBSP) is an Earth-orbiting mission scheduled to launch in September 2012 and is the next science mission in NASA\textquoterights Living with a Star Program. The RBSP mission will investigate, characterize and understand the physical dynamics of the radiation belts, and the influence of the sun on the earth\textquoterights environment, by measuring particles, electric and magnetic fields and waves that comprise the geospace. The mission is composed of two identically instrumented spinning spacecraft in an elliptical orbit around earth from 600 km perigee to 30,000 km apogee at 10 degree inclination to provide full sampling of the Van Allen radiation belts. The twin spacecraft will follow slightly different orbits and will lap each other 4 times per year; this offers simultaneous measurements over a range of spacecraft separation distances. A description of the spacecraft environment is provided along with spacecraft and subsystem key characteristics and accommodations that protect sensitive spacecraft electronics and support operations in the harsh radiation belt environment. Kirby, Karen; Bushman, Stewart; Butler, Michael; Conde, Rich; Fretz, Kristen; Herrmann, Carl; Hill, Adrian; Maurer, Richard; Nichols, Richard; Ottman, Geffrey; Reid, Mark; Rogers, Gabe; Srinivasan, Dipak; Troll, John; Williams, Bruce; Published by: Published on: 03/2012 YEAR: 2012 DOI: 10.1109/AERO.2012.6187020 |
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