Magnetospheric Models and Trajectory Computations

The calculation of particle trajectories in the Earth's magnetic field has been a subject of interest since the time of Störmer. The fundamental problem is that the trajectory-tracing process involves using mathematical equations that have `no solution in closed form'. This difficulty has forced researchers to use the `brute force' technique of numerical integration of many individual trajectories to ascertain the behavior of trajectory families or groups. As the power of computers has improved over the decades, the numerical integration procedure has grown more tractable and while the problem is still formidable, thousands of trajectories can be computed without the expenditure of excessive resources. As particle trajectories are computed and the characteristics analyzed we can determine the cutoff rigidity of a specific location and viewing direction and direction and deduce the direction in space of various cosmic ray anisotropies. Unfortunately, cutoff rigidities are not simple parameters due to the chaotic behavior of the cosmic-ray trajectories in the cosmic ray penumbral region. As the computational problem becomes more manageable, there is still the issue of the accuracy of the magnetic field models. Over the decades, magnetic field models of increasing complexity have been developed and utilized. The accuracy of trajectory calculations employing contemporary magnetic field models is sufficient that cosmic ray experiments can be designed on the basis of trajectory calculations. However, the Earth's magnetosphere is dynamic and the most widely used magnetospheric models currently available are static. This means that the greatest uncertainly in the application of charged particle trajectories occurs at low energies.     

Antideuterons as an indirect dark matter signature: Si(Li) detector development and a GAPS balloon mission

The General AntiParticle Spectrometer (GAPS) is a novel approach for indirect dark matter searches that exploits cosmic antideuterons. GAPS complements existing and planned direct dark matter searches as well as other indirect techniques, probing a different and unique region of parameter space in a variety of proposed dark matter models. The GAPS method involves capturing antiparticles into a target material with the subsequent formation of an excited exotic atom. The exotic atom decays with the emission of atomic X-rays and pions from the nuclear annihilation, which uniquely identifies the captured antiparticle. This technique has been verified through the accelerator testing at KEK in 2004 and 2005. The prototype flight is scheduled from Hokkaido, Japan in 2011, preparatory for a long duration balloon flight from the Antarctic in 2014.     

Three-dimensional numerical studies of a jet airflow around the duct platforms of the turbine nozzle clusters

This paper presents the results of three-dimensional numerical studies of hydrodynamics and heat exchange on the models of flat plates in the jet airflow. These results are compared with the experimental data. A three-dimensional model for determining the thermal condition of the nozzle clusters in the conjugated formulation is proposed. Also presented are the data on optimization of the system used for the jet airflow around the duct platforms of the nozzle clusters.     

A method for calculating the resistance of spacecraft design elements under the action of space debris particles

In this paper, the problems of the application and development of models of space debris when designing means of the anti-meteorite spacecraft protection are considered. The developed method enables us to calculate the resistance of design elements based on the conjugation of a modified spatial model of the distribution of space-debris particles and ballistic limit dependences for a calculated element.     

The Education and Public Outreach Program for NASA��s Dawn Mission

The Dawn mission??s Education and Public Outreach (E/PO) program takes advantage of the length of the mission, an effort to maintain level funding, and the exceptional support of the science and engineering teams to create formal and informal educational materials that bring STEM content and modes of thinking to students of all ages. With materials that are based on researched pedagogical principles and aligned with science education standards, Dawn weaves together many aspects of the mission to engage students, teachers, and the general public. E/PO tells the story of the discovery of the asteroid belt, uncovers principles of physics behind the ion propulsion that powers the spacecraft, and explains what we can learn from the instrumentation and how the mission??s results will expand our understanding of the origins of the solar system. In this way, we not only educate and inform, we build anticipation and expectation in the general public for the spacecraft??s arrival at Vesta in 2011 and three years later at Ceres. This chapter discusses the organization, strategies, formative assessment and dissemination of these materials and activities, and includes a section on lessons learned.     

Medical survey of European astronauts during Mir missions

This paper reviews the medical operations performed on six European astronauts during seven space missions on board the space station Mir. These missions took place between November 1988 and August 1999, and their duration ranged from 14 days to 189 days. Steps of pre-flight medical selection and flight certification are presented. Countermeasures program used during the flight, as well as rehabilitation program following short and long-duration missions are described. Also reviewed are medical problems encountered during the flight, post-flight physiological changes such as orthostatic intolerance, exercise capacity, blood composition, muscle atrophy, bone density, and radiation exposure.     

A mission template for exploration and damage mitigation of potential hazard of Near Earth Asteroids

The Apophis Exploratory and Mitigation Platform (AEMP) concept was developed as a prototype mission to explore and potentially deflect the Near Earth Asteroid (NEA) 99942 Apophis. Deflection of the asteroid from the potential 2036 impact will be achieved using a gravity tractor technique, while a permanent deflection, eliminating future threats, will be imparted using a novel albedo manipulation technique. This mission will serve as an archetypal template for future missions to small NEAs and could be adapted to mitigate the threat of collision with other potential Earth-crossing objects.     

The conundrum of software estimation models

There are many sophisticated models and methods for estimating the size, cost, and schedule of software projects. However, the ability to accurately estimate software cost, size, or schedule is still dubious. In general, the predictive accuracy of models for estimating software development cost and schedule has not been shown to be better than “within 25 percent of actual cost or schedule, about one half of the time”, especially for Department of Defense software efforts. The same is true for software size estimating models and methods, although there are some studies that have shown superior results. For software support (or maintenance) cost estimation, no model has been demonstrated to be accurate. This paper presents a summary of efforts performed to date which demonstrate the accuracy (or lack thereof) of software models. The results of several studies in the areas of software development cost and schedule estimation, size estimation, and support cost estimation are presented to show what these models can and cannot do. Some ideas for improvement are also presented, including the results of some studies which may lead to a resolution of the accuracy conundrum which currently exists     

Embedded information system re-engineering

Currently fielded embedded information systems face readiness challenges imposed by evolving missions and extended service lifespans. The ability to overcome these challenges is constrained by such factors as shrinking budgets, limited computational capacity and diminished manufacturing sources effects that impact both hardware and software options. Wholesale redevelopment is often cost prohibitive, particularly since large portions of embedded applications continue to fulfil mission requirements. Solutions must preserve prior investments while providing efficient pathways for continued technology refresh. A technology solution for affordable modernization of legacy system software is being development. The Embedded Information System Re-engineering (EISR) project is developing an automation-assisted JOVIAL-to-C re-engineering capability that permits simultaneous modernization of both the structure and source language of legacy embedded applications. Engineers will be able to apply the proven labor-saving visualization and analysis features of modern CASE tools to legacy JOVIAL applications. EISR will thus allow the DoD to recapture previous investments in proven legacy algorithms and mission capabilities while permitting the full exploitation of COTS economies of scale. This paper describes in brief the goals and objectives of the EISR project, and provides the current status of the EISR capability.     

On The 53Mn Heterogeneity In The Early Solar System

It is well established that the prolonged and thorough mixing of numerous nucleosynthetic components that constitutes the matter in the solar nebula resulted in an essential isotopic homogeneity of the solar system material. This may or may not be true for the short-lived radionuclides which were injected into or formed within the solar nebula just prior to or during solar system formation. Distinguishing between their heterogeneous or homogeneous distribution is important because the short- lived radionuclides are now widely used for the relative chronology of various objects and processes in the early solar system and as constraints for models of nucleosynthesis. The recent studies of the ⁵³Mn-⁵³Cr isotope system (half life of ⁵³Mn is 3.7 Ma) in various solar system objects have shown that the relative abundance of radiogenic ⁵³Cr is consistent with essentially homogeneous distribution of ⁵³Mn in the asteroid belt. Thus, the relative ⁵³Mn-⁵³Cr chronometer can be directly used for dating samples which originated in the asteroid belt. Importantly, however, all meteorite groups studied so far indicate a clear excess of ⁵³Cr as compared to Earth and to a lunar sample, which exhibits also a terrestrial ⁵³Cr/⁵²Cr ratio. The results from the Martian (SNC) meteorites show that their ⁵³Cr excesses are less than half of those found in the asteroid belt bodies. Thus, the characteristic ⁵³Cr/⁵²Cr ratio of Mars is intermediate between that of the Earth-Moon system and those of the other meteorites. If these ⁵³Cr variations are viewed as a function of the heliocentric distance, the radial dependence of the relative abundances of radiogenic ⁵³Cr is indicated. This observed gradient can be explained by either an early, volatility controlled, Mn/Cr fractionation within the nebula or by an initial radial heterogeneous distribution of ⁵³Mn. Although model calculations of the Mn/Cr ratios in the bulk terrestrial planets seem to be inconsistent with the volatility driven scenario, the precision of these calculations is inadequate for eliminating this possibility. In contrast, recent studies of the ⁵³Mn-⁵³Cr system in the enstatite chondrites indicate that, while their bulk Mn/Cr ratios are essentially the same as in ordinary chondrites, the ⁵³Cr excess in bulk enstatite chondrites is three times lower than that in the bulk ordinary chondrites. This difference cannot be explained by a Mn/Cr fractionation and, thus, strongly suggests that a radial heterogeneous distribution of ⁵³Mn must have existed in at least the early inner solar system. Using the observed gradient and the ⁵³Cr/⁵²Cr ratio of the bulk enstatite chondrites, their parent body(ies) formed at ∼1.4 AU or somewhat closer to the Sun. This revised version was published online in June 2006 with corrections to the Cover Date.