An Operational Algorithm for Evaluating Satellite Collision Consequence

Risk is properly considered as the combination of likelihood and consequence; but conjunction assessment has usually limited itself to the consideration of only collision likelihood. When considered from an orbital regime protection perspective, the focus shifts to the question of the amount of debris that a collision might produce (the consequence). The present paper presents an operational algorithm for determining the expected amount of debris production should a conjunction result in a collision, and an assessment of the algorithms fidelity against a database of characterized objects

Multivariate Normality of Cartesian-Framed Covariances: Evaluation and Operational Significance

Collision avoidance relies on representative Cartesian uncertainty volumes in order to calculate probabilities of collision. Among the potential shortcomings of a covariance matrix representation of state errors, the most worrisome is the coordinate mismatch between the Cartesian framework in which these matrices are distributed and the curvilinear path that satellite orbits actually follow. The present study compares curvilinear-based and Cartesian covariance representations for ~50,000 conjunctions to determine the frequency in which significant deviations from Gaussianity are observed, then compares the 2-D Pc result from the Cartesian covariance to a Monte Carlo Pc conducted in element space to assess operational significance

Assessment and Validation of Collision "Consequence" Method of Assessing Orbital Regime Risk Posed by Potential Satellite Conjunctions

Collision risk management theory requires a thorough assessment of both the likelihood and consequence of potential collision events. Satellite conjunction risk assessment has produced a highly-developed theory for assessing the likelihood of collision but neglects to account for the consequences of a given collision. While any collision may compromise the operational survival of a spacecraft, the amount of debris produced by the potential collision, and therefore the degree to which the orbital corridor may be compromised, can vary greatly among satellite conjunctions. Previous studies leveraged work on satellite collision modeling to develop a method to estimate whether a particular collision is likely to produce a relatively large or relatively small amount of resultant debris. The approximation of the number of debris pieces is dependent on a mass estimation process for the secondary objects utilizing the radar cross section of said object. This study examines the validity of the mass estimation process and establishes uncertainty bounds on the secondary object mass, which will be used to best approximate the possible consequences of a potential collision. This process is then applied to a large set of historical conjunctions to assess the frequency at which possible collisions may significantly augment the orbital debris environment in operational spacecraft

Правове регулювання безоплатної приватизації земель запасу

Досліджуються правові підстави безоплатної приватизації земель запасу. Автор виокремлює два її різновиди – гарантовану і негарантовану. Розкриваються особли­вості багатоетапної процедури реалізації права на безоплатну приватизацію земель запасу в Україні.Исследуются правовые основания бесплатной приватизации земель запаса. Автор разделяет два ее разновидности – гарантированную и негарантированную. Раскрыва­ются особенности многоэтапной процедуры реализации права на бесплатную прива­тизацию земель в Украине.Legal rules about free of payment land privatization are investigated. The author pro­poses dividing free of payment land privatization into two varieties: guaranteed and non­guaranteed ones. Legal peculiarities of multistoried procedure of free of payment land priva­tization in Ukraine are disclosed

An overview of the Haitian justice system

iv, 25 leaves ; 28 cm. Includes bibliographical references (leaves 23-25)

Rethinking Curation in School Libraries and School Library Education: Critical, Conceptual, Collaborative

School library educators often assign a curation assignment to preservice school librarians in the university classroom. However, these projects emphasize a product created by librarians for teachers and learners, rather than the collaborative and critical process that the National School Library Standards suggest. In this paper, we draw on data from a qualitative inquiry of several courses for preservice school librarians, looking at both curation assignment descriptions and the final products. Through a systematic content analysis of these projects, we have found that these assignments often fall short in asking our learners to critically consider conceptual connections and diverse perspectives. To this end, we identify revisions to these assignments that reframe curation as a collaborative, conceptual, critical endeavor