Evolving Operations and Decommissioning of the Midcourse Space Experiment Spacecraft

he objective of the Midcourse Space Experiment (MSX) mission was to collect data on midcourse target and background phenomena and to support space situational awareness. To accomplish these objectives, the MSX spacecraft was designed for a 5-year lifetime. Launched in 1996, the MSX spacecraft exceeded its design lifetime by 7 years. It collected the first comprehensive set of multispectral midcourse target data and more than 10 years of space surveillance data in support of our nation’s space situational awareness objectives. In 2008 the MSX spacecraft was decommissioned, and with that event came the end of more than 12 years of successful operations. The decommissioning of MSX had to be planned and executed in a manner for which the spacecraft was not designed; however, this was not unusual for the MSX spacecraft: throughout the operational life of the MSX, much of what was accomplished was beyond its design. The operational life of MSX was one of adapting to challenges while maintaining a high level of productivity. That productivity lasted until decommissioning, and the operational challenges remained through the end of the decommissioning activities. MSX BACKGROUND The MSX spacecraft was launched on 24 April 1996, into an 898-km circular orbit with an inclination of 99.3 ° (Fig. 1). MSX was designed to collect data on multispectral target and background phenomena of ballistic missiles in the postboost phase of flight, or midcourse, to address the needs of the Ballistic Missile Defense Organization and, as a secondary objective, to support space situational awareness (SSA). 1 The midcourse objectives of the MSX mission were met through the successful implementation of a series of dedicated and cooperative target experiments. These target experiments included the Midcourse Dedicated Target experiment, which was launched on 31 August 1996, and was designed to acquire signature phenomena against a long-range target, as wel

An investigation into the Paulding Mystery Lights

The Paulding Mystery Lights are a purportedly unexplained optical phenomenon, occurring nightly, deep in the woods of Michigan\u27s Upper Peninsula. The Michigan Tech Student Chapter of the SPIE initiated a project in 2008 to understand the cause of the Paulding Lights. Previous investigations by skeptics attributed the lights to headlights without explicitly identifying a source location. Our team applied a number of straightforward techniques to identify and then verify the source location of the Paulding Light. Beginning with observation through a telescope, the team moved to using tools such as detailed topographical maps and more common tools such as Google Street View to identify a candidate source location. The candidate source location was then validated by first recreating the light using a vehicle parked in that location. Additional verification was achieved by examining the correlation between the occurrence of the light and the passing of cars at the source location. A spectrometer was also used to compare the visible spectrum of the light to automotive headlamps. Our findings, presented here, indicate that the source of the Paulding light is automobile traffic on a stretch of road about 7 km from the viewing location

Fat soluble vitamins in blood and tissues of free-ranging and captive rhinoceros

Several disease syndromes in captive rhinoceroses have been linked to low vitamin status. Blood samples from captive and free-ranging black (Diceros bicornis) and white rhinoceros (Ceratotherium simum) and tissue samples of captive individuals from four rhinoceros species were analysed for vitamins A and E. Circulating vitamin A levels measured as retinol for free-ranging versus captive black and white rhinoceros were 0.04 (+/- 0.03 SD) vs. 0.08 (+/- 0.08) and 0.07 (+/- 0.04) vs. 0.06 (+/- 0.02) microgram/ml, respectively. Circulating vitamin E levels measured as alpha-tocopherol were 0.58 (+/- 0.30) vs. 0.84 (+/- 0.96) and 0.62 (+/- 0.48) vs. 0.77 (+/- 0.32) microgram/ml, respectively. In contrast to earlier findings, there was no significant difference in vitamin E concentration between captive and free-ranging black rhinoceros. When the samples of captive black rhinoceros were grouped into those taken before 1990 and after 1990, however, those collected before 1990 had significantly lower (P < 0.001) vitamin E levels (0.46 +/- 0.83 microgram/ml) and those collected in 1990 or later significantly higher (P < 0.001) vitamin E levels (1.03 +/- 1.04 micrograms/ml) than the captive population as a whole. This is probably due to increased dietary supplementation. There were significant differences in circulating vitamin concentrations in black rhinoceroses from different regions in the wild. Serum 25-hydroxy (OH) vitamin D3 averaged 55.7 ng/ml in free-ranging rhinoceroses; no carotenoids were detected in any blood samples. Captive black and white rhinoceroses appear to be adequately supplemented in vitamin A and E. Captive Indian rhinoceroses (Rhinoceros unicornis) had significantly lower vitamin A concentrations in blood (P < 0.001) and higher vitamin A concentrations in liver tissue samples (P < 0.001) than other rhinoceros species. Equine requirements are not recommended as a model for rhinoceros vitamin requirements

Radiation-induced reductions in transporter mRNA levels parallel reductions in intestinal sugar transport

More than a century ago, ionizing radiation was observed to damage the radiosensitive small intestine. Although a large number of studies has since shown that radiation reduces rates of intestinal digestion and absorption of nutrients, no study has determined whether radiation affects mRNA expression and dietary regulation of nutrient transporters. Since radiation generates free radicals and disrupts DNA replication, we tested the hypotheses that at doses known to reduce sugar absorption, radiation decreases the mRNA abundance of sugar transporters SGLT1 and GLUT5, prevents substrate regulation of sugar transporter expression, and causes reductions in sugar absorption that can be prevented by consumption of the antioxidant vitamin A, previously shown by us to radioprotect the testes. Mice were acutely irradiated with 137Cs gamma rays at doses of 0, 7, 8.5, or 10 Gy over the whole body. Mice were fed with vitamin A-supplemented diet (100× the control diet) for 5 days prior to irradiation after which the diet was continued until death. Intestinal sugar transport was studied at days 2, 5, 8, and 14 postirradiation. By day 8, d-glucose uptake decreased by ∼10–20% and d-fructose uptake by 25–85%. With increasing radiation dose, the quantity of heterogeneous nuclear RNA increased for both transporters, whereas mRNA levels decreased, paralleling reductions in transport. Enterocytes of mice fed the vitamin A supplement had ≥ 6-fold retinol concentrations than those of mice fed control diets, confirming considerable intestinal vitamin A uptake. However, vitamin A supplementation had no effect on clinical or transport parameters and afforded no protection against radiation-induced changes in intestinal sugar transport. Radiation markedly reduced GLUT5 activity and mRNA abundance, but high-d-fructose diets enhanced GLUT5 activity and mRNA expression in both unirradiated and irradiated mice. In conclusion, the effect of radiation may be posttranscriptional, and radiation-damaged intestines can still respond to dietary stimuli