Organizing and managing satellite solar power

Building an organization and management structure to create, launch, utilize and protect a satellite solar power energy system will require a global policy for the beneficial use of SSP. The fundamental organizational tasks are: (1) R&D, achieved through a project organization characterized by the integrated management of applied science, development research and construction engineering; (2) investment, generated by a series of groups creating financial vehicles for public and private investment; (3) transmission and distribution, characterized by attention to an engineering and maintenance process emphasizing high reliability; and (4) crisis response, demanding readiness for instant response to potential internal or external scenarios. A differentiated global organization spanning the long timeframe of SSP will need to have a central management core representative of all parts of the organization, with the capacity for self-renewal and re-adaptation. To be successful over its long timeframe, the SSP organization will need to build continuity and public confidence through intergenerational communication, public education, and community outreach. Integrating structures must be created at all levels of the organization, and should encompass joint work tasks and information-sharing among both industrial and government members. Developmental and alliance partners who support the formation and financing of a differentiated satellite solar power organization will share commensurately in the technologies and competencies that are created.     

Pilot error in automated systems shown by altitude deviationreports

Over 8,000 altitude deviations are reported to NASA's Aviation Safety Reporting System each year. This is almost one an hour. The narratives of pilot incidents relate how errors made in the automation-assisted altitude change task are caused by the difficulty pilots are having interacting with automatic systems. This paper discusses the impact of increased automation in glass-cockpit airliners on the altitude deviations reported by pilots. By observing the way information is processed by the cockpit system, the author suggests that the philosophies of design and training need to change in order to facilitate, not debilitate, the aircrew     

Uncertainty ellipses and their application to interval estimation of emitter position

A method of interval estimation of position of an object emitting electromagnetic energy is presented. The problem is considered in cases of known and unknown errors of emitter position determination. Precise expressions concerning two-dimensional confidence regions for unknown position of the emitter have been obtained. Uncertainty regions defined as error ellipses and confidence ellipses have been determined. Qualitative and quantitative comparison of considered regions have been made. The presented approach and obtained results may be useful in electronic intelligence (ELINT) and electronic warfare (EW) applications, in radio navigation, ballistics, and in rescue operations at sea as well.     

DNA double strand break production and rejoining in V79 cells irradiated with light ions.

Low energy protons and other densely ionizing light ions are known to have RBE>1 for cellular end points relevant for stochastic and deterministic effects. The occurrence of a close relationship between them and induction of DNA dsb is still a matter of debate. We studied the production of DNA dsb in V79 cells irradiated with low energy protons having LET values ranging from 11 to 31 keV/micrometer, i.e. in the energy range characteristic of the Bragg peak, using the sedimentation technique. We found that the initial yield of dsb is quite insensitive to proton LET and not significantly higher than that observed with X-rays, in agreement with recent data on V79 cells irradiated with alpha particles of various LET up to 120 keV/micrometer. By contrast, RBE for cell inactivation and for mutation induction rises with the proton LET. In experiments aimed at evaluating the rejoining of dsb after proton irradiation we found that the amount of dsb left unrepaired after 120 min incubation is higher for protons than for sparsely ionizing radiation. These results indicate that dsb are not homogeneous with respect to repair and give support to the hypothesis that increasing LET leads to an increase in the complexity of DNA lesions with a consequent decrease in their repairability.     

Printed circuit board diagnosis using artificial neural networksand circuit magnetic fields

Testing of electronic systems using conventional testing methods has become more difficult and costly as these systems have become more complex and compact. Conventional testing methods and systems often require lengthy analysis to define testing strategies. These test systems may require lengthy test periods, complex stimulus and measurement instrumentation as well as complicated fixturing. The results are often ambiguous and require further interpretation. This paper presents an exploration of a “non-intrusive” test method based on interpreting changes in the magnetic field close to a Printed Circuit Board (PCB). Currents moving between devices on the PCB produce these magnetic fields. Changes of the PCB operational status due to faults cause changes in the associated magnetic field pattern that can be interpreted by Artificial Neural Networks (ANNs) for fault identification. An apparatus to collect magnetic field measurements is described along with some problems of collecting data. Typical magnetic field patterns for “known-good” and faulted PCBs are presented. Possible extensions of the method are discussed. This paper resulted from internally funded work at Southwest Research Institute (SwRI) concerning non-intrusive diagnostic techniques     

Composition and physical properties of starch in microgravity-grown plants.

The effect of spaceflight on starch development in soybean (Glycine max L., BRIC-03) and potato (Solanum tuberosum, Astroculture-05) was compared with ground controls by biophysical and biochemical measurements. Starch grains from plants from both flights were on average 20-50% smaller in diameter than ground controls. The ratio delta X/delta rho (delta X --difference of magnetic susceptibilities, delta rho--difference of densities between starch and water) of starch grains was ca. 15% and 4% higher for space-grown soybean cotyledons and potato tubers, respectively, than in corresponding ground controls. Since the densities of particles were similar for all samples (1.36 to 1.38 g/cm3), the observed difference in delta X/delta rho was due to different magnetic susceptibilities and indicates modified composition of starch grains. In starch preparations from soybean cotyledons (BRIC-03) subjected to controlled enzymatic degradation with alpha-amylase for 24 hours, 77 +/- 6% of the starch from the flight cotyledons was degraded compared to 58 +/- 12% in ground controls. The amylose content in starch was also higher in space-grown tissues. The good correlation between the amylose content and delta X/delta rho suggests, that the magnetic susceptibility of starch grains is related to their amylose content. Since the seedlings from the BRIC-03 experiment showed elevated post-flight ethylene levels, material from another flight experiment (GENEX) which had normal levels of ethylene was examined and showed no difference to ground controls in size distribution, density, delta X/delta rho and amylose content. Therefore the role of ethylene appears to be more important for changes in starch metabolism than microgravity.     

First radiobiological results of LDEF-1 experiment A0015 with Arabidopsis seed embryos and Sordaria fungus spores.

This article highlights the first results of investigations on the general vitality and damage endpoints caused by cosmic ionizing radiation in dry, dormant plant seeds of the crucifer plant Arabidopsis thaliana (L.) Heynh. and the ascomycete Sordaria fimicola after 69 month stay in space. Wild-type and mutant gene marker lines were included in Free Flyer Biostack containers and exposed on earth and side tray of the LDEF-1 satellite. The damage in biological endpoints observed in the seeds increased in the side tray sample compared to the earth tray sample. For the ascospores we found different effects depending on the biological endpoints investigated for both expositions.     

Potential vascular damage from radiation in the space environment.

Cultured endothelial cells of blood vessels have a Do of 2 Gy for X-rays. A dose of 0.5 Gy of X-rays has an acute effect on vessel diameter. The vessels may show other acute effects such as change in permeability including a change in the blood brain barrier. Changes occurring from late effects of chronic exposure in vascular architecture include telangiectasia and decrease in vascular density. Changes in the perivascular connective tissue particularly collagen may play a role in these changes. After charged particle exposure of 15 and 30 Gy, radiation changes in the blood brain barrier and vascular changes are noted in the nervous system. These long term changes are recorded by PET, MRI, and CT imaging. Chronic exposure to alpha particles causes vascular damage in compact bone resulting in bone infarcts. Using tandem scanning confocal microscopy in-situ imaging of the capillaries and collagen of the papillary dermis provides a non-invasive method of serial recording of changes in irradiated microvasculature.     

Particle trajectories in seeds of Lactuca sativa and chromosome aberrations after exposure to cosmic heavy ions on Cosmos Biosatellites 8 and 9.

The potentially specific importance of the heavy ions of the galactic cosmic radiation for radiation protection in manned spaceflight continues to stimulate in situ, i.e., spaceflight experiments to investigate their radiobiological properties. Chromosome aberrations as an expression of a direct assault on the genome are of particular interest in view of cancerogenesis being the primary radiation risk for man in space. In such investigations the establishment of the geometrical correlation between heavy ions' trajectories and the location of radiation sensitive biological substructures is an essential task. The overall qualitative and quantitative precision achieved for the identification of particle trajectories in the order of approximately 10 micrometers as well as the contributing sources of uncertainties are discussed. We describe how this was achieved for seeds of Lactuca sativa as biological test organisms, whose location and orientation had to be derived from contact photographies displaying their outlines and those of the holder plates only. The incidence of chromosome aberrations in cells exposed during the COSMOS 1887 (Biosatellite 8) and the COSMOS 2044 (Biosatellite 9) mission was determined for seeds hit by cosmic heavy ions. In those seeds the incidence of both single and multiple chromosome aberrations was enhanced. The results of the Biosatellite 9 experiment, however, are confounded by spaceflight effects unrelated to the passage of heavy ions.     

Synthetic vision for enhancing poor visibility flight operations

Visibility is important for the pilot controlling an aircraft in flight conditions close to the ground, particularly when landing. Therefore, poor visibility yields a great restriction for aircraft operations. Restrictions exist for landing sites which are equipped with facilities providing a landing approach aid like ILS since a minimum is required for visibility. For landing sites providing no approach aids, restrictions are much more severe. This holds even if aircraft are equipped with modern instrumentation and navigation devices. The natural view of the pilot is dependent on various meteorological conditions like darkness, dust, fog, rain etc. The degradation in view caused by these conditions can be compensated for partially or even completely by technical means providing artificial vision cues. Such technical means may be based on radar or optical sensor information. Concepts which employ these techniques are known as “Synthetic Visual Systems” or “Enhanced Visual Systems,” . The present paper is concerned with computer generated vision as a further technique providing visual cues for the pilot. Computer generated vision may be used in combination with the aforementioned sensor based techniques. Thus, it is possible to compensate for limitations which sensor based visual systems have in providing sufficient visibility range or in generating a normal looking image. In addition, computer generated imagery has the potential providing additional information to the pilot for controlling the flight path or for warning purposes. This potential can yield improved and/or more information as compared with the natural view when looking out of the cockpit window