Circuits and circuit testing for spaceborne redundant digital systems Special technical report no. 3

Design and testing of majority logic redundancy for spaceborne and GSE digital system

A possible radiation-resistant solar cell geometry using superlattices

A solar cell structure is proposed which uses a GaAs nipi doping superlattice. An important feature of this structure is that photogenerated minority carriers are very quickly collected in a time shorter than bulk lifetime in the fairly heavily doped n and p layers and these carriers are then transported parallel to the superlattice layers to selective ohmic contacts. Assuming that these already-separated carriers have very long recombination lifetimes, due to their across an indirect bandgap in real space, it is argued that the proposed structure may exhibit superior radiation tolerance along with reasonably high beginning-of-life efficiency

Studies of effects on optical components and sensors: LDEF experiments AO-147 (ERB components) and S-0014 (APEX)

Some additional results of testing of optical filters and window materials and thermopile sensors of the two experiments are included. The Advanced Photovoltaic Experiment (APEX) interference filters exhibited much greater degradation in space than the ERB filters. The adhesion of the Indium washers to the APEX interference filters is reported

The effect of the low Earth orbit environment on space solar cells

The results of a space flight experiment designed to provide reference cell standards for photovoltaic measurements as well as to investigate the solar spectrum and the effect of long-term exposure of solar cells to the space environment are presented. This experiment, the Advanced Photovoltaic Experiment (APEX), was launched into low Earth orbit as part of the Long Duration Exposure Facility in 1984 and retrieved 69 months later. APEX contained over 150 solar cells of a wide variety of materials, designs and coverglasses. Data on cell performance was recorded for the first year-on-orbit

An Assessment of the India Soy Protein Market

This research is a first step in determining India's future need for soy-based protein products. The objective of this study is to determine India's protein demand over the next ten years. Then, using the per capita protein demand derived from this study, along with income, population, and dietary information, per capita soy protein consumption was estimated for the same time period. It was found that income growth has a large positive affect on protein consumption.Demand and Price Analysis, Food Consumption/Nutrition/Food Safety,

The effect of the low Earth orbit environment on space solar cells: Results of the Advanced Photovoltaic Experiment (S0014)

The results of post-flight performance testing of the solar cells flown on the Advanced Photovoltaic Experiment are reported. Comparison of post-flight current-voltage characteristics with similar pre-flight data revealed little or no change in solar cell conversion efficiency, confirming the reliability and endurance of space photovoltaic cells. This finding is in agreement with the lack of significant physical changes in the solar cells despite nearly six years in the low Earth orbit environment

Preliminary results from the advanced photovoltaic experiment flight test

The Advanced Photovoltaic Experiment is a space flight test designed to provide reference cell standards for photovoltaic measurement as well as to investigate the solar spectrum and the effect of the space environment on solar cells. After a flight of 69 months in low earth orbit as part of the Long Duration Exposure Facility set of experiments, it was retrieved in January, 1990. The electronic data acquisition system functioned as designed, measuring and recording cell performance data over the first 358 days of flight; limited by battery lifetime. Significant physical changes are also readily apparent, including erosion of front surface paint, micrometeoroid and debris catering and contamination

Additions to the Vascular Flora of Ontario, Canada, from the Sutton Ridges, Hudson Bay Lowland Ecoregion

Field studies in the Hudson Bay Lowland ecoregion of northern Ontario during 2010 resulted in the discovery of four native vascular plant species not previously confirmed from the province: Arctic Bellflower (Campanula uniflora; Campanulaceae), Lapland Diapensia (Diapensia lapponica; Diapensiaceae), Alpine Azalea (Kalmia procumbens; Ericaceae), and Alpine Brook Saxifrage (Saxifraga rivularis; Saxifragaceae). These four species are widespread arctic plants occurring in both North America and Eurasia and were found on the Sutton Ridges, a Precambrian bedrock inlier surrounded by the extensive wetlands of the Hudson Bay Lowland

Final results of the advanced photovoltaic experiment

The Advanced Photovoltaic Experiment (APEX) was designed to generate laboratory reference standards as well as to explore the durability of a wide variety of space solar cells. In addition to the cells, it was equipped with an absolute cavity radiometer to measure solar intensity, a spectroradiometer to measure the spectral content of this radiation, and a sun angle sensor. Data from the solar cells and various sensors was obtained on a daily basis during the first eleven months of the 69 month flight. We compare pre-flight and post-flight laboratory measurements with on-orbit calibration data. Pre-flight and post-flight calibration data for the cavity radiometers as well as on-orbit data demonstrated the accuracy and durability of the Eppley Labs instrument flown on APEX

Final Results of the Advanced Photovoltaic Experiment Flight Test

The Advanced Photovoltaic Experiment was designed to generate laboratory reference standards as well as to explore the durability of a wide variety of space solar cells. In addition to the cells, it was equipped with an absolute cavity radiometer to measure solar intensity, a spectroradiometer to measure the spectral content of this radiation and a sun angle sensor. Data from the solar cells and various sensors was obtained on a daily basis during the first eleven months of the 69 month flight. In this paper pre-flight and post-flight laboratory measurements are compared with on-orbit calibration data. Pre-flight and post-flight calibration data of the cavity radiometer as well as on-orbit data demonstrated the accuracy and durability of the Eppley instrument flown on APEX