69,433 research outputs found
Feasibility of a 30-meter space based laser transmitter
A study was made of the application of large expandable mirror structures in future space missions to establish the feasibility and define the potential of high power laser systems for such applications as propulsion and power transmission. Application of these concepts requires a 30-meter diameter, diffraction limited mirror for transmission of the laser energy. Three concepts for the transmitter are presented. These concepts include consideration of continuous as well as segmented mirror surfaces and the major stow-deployment categories of inflatable, variable geometry and assembled-in-space structures. The mirror surface for each concept would be actively monitored and controlled to maintain diffraction limited performance at 10.6 microns during operation. The proposed mirror configurations are based on existing aerospace state-of-the-art technology. The assembled-in-space concept appears to be the most feasible, at this time
Report of the Electromechanical Subsystems Panel
Deficiencies in electromechanical flight technology are evaluated and development recommendations are made. Specific items discussed include magnetic bearings, lubrication for long life, signal and power transfer devices, servo sensing devices, deployment/retraction devices, cryogenic devices, data storage, and ordnance substitutes
CUSTARD (Cranfield University Space Technology Advanced Research Demonstrator) - A Micro-System Technology Demonstrator Nanosatellite. Summary of the Group Design Project MSc in Astronautics and Space Engineering. 1999-2000, Cranfield University
CUSTARD (Cranfield University Space Technology And Research Demonstrator) was
the group design project for students of the MSc in Astronautics and Space
Engineering for the Academic Year 1999/2000 at Cranfield University. The project
involved the initial design of a nanosatellite to be used as a technology
demonstrator for microsystem technology (MST) in space. The students worked
together as one group (organised into several subgroups, e.g. system,
mechanical), with each student responsible for a set of work packages. The
nanosatellite designed had a mass of 4 kg, lifetime of 3 months in low Earth
orbit, coarse 3-axis attitude control (no orbit control), and was capable of
carrying up to 1 kg of payload. The electrical power available was 18 W (peak).
Assuming a single X-band ground station at RAL (UK), a data rate of up to 1 M
bit s-1 for about 3000 s per day is possible. The payloads proposed are a
microgravity laboratory and a formation flying experiment.
The report summarises the results of the project and includes executive
summaries from all team members. Further information and summaries of the full
reports are available from the College of Aeronautics, Cranfield University
Conference Summary: HI Science in the Next Decade
The atomic hydrogen (HI) 21cm line measures the gas content within and around
galaxies, traces the dark matter potential and probes volumes and objects that
other surveys do not. Over the next decade, 21cm line science will exploit new
technologies, especially focal plane and aperture arrays, and will see the
deployment of Epoch of Reionization/Dark Age detection experiments and Square
Kilometer Array (SKA) precursor instruments. Several experiments designed to
detect and eventually to characterize the reionization history of the
intergalactic medium should deliver first results within two-three years time.
Although "precision cosmology" surveys of HI in galaxies at z ~ 1 to 3 require
the full collecting area of the SKA, a coherent program of HI line science
making use of the unique capabilities of both the existing facilities and the
novel ones demonstrated by the SKA precursors will teach us how many gas rich
galaxies there really are and where they reside and will yield fundamental
insight into how galaxies accrete gas, form stars and interact with their
environment.Comment: To appear in AIP Conference Proceedings, "The Evolution of Galaxies
through the Neutral Hydrogen Window", Feb 1-3 2008, Arecibo, Puerto Rico,
eds. R. Minchin & E. Momjian. 8 page
Liquid belt radiator design study
The Liquid Belt Radiator (LBR) is an advanced concept developed to meet the needs of anticipated future space missions. A previous study documented the advantages of this concept as a lightweight, easily deployable alternative to present day space heat rejection systems. The technical efforts associated with this study concentrate on refining the concept of the LBR as well as examining the issues of belt dynamics and potential application of the LBR to intermediate and high temperature heat rejection applications. A low temperature point design developed in previous work is updated assuming the use of diffusion pump oil, Santovac-6, as the heat transfer media. Additional analytical and design effort is directed toward determining the impact of interface heat exchanger, fluid bath sealing, and belt drive mechanism designs on system performance and mass. The updated design supports the earlier result by indicating a significant reduction in system specific system mass as compared to heat pipe or pumped fluid radiator concepts currently under consideration (1.3 kg/sq m versus 5 kg/sq m)
Applications technology satellite gravity gradient stabilization system Quarterly progress report, 1 May - 31 Jul. 1967
Technical state of design and development of gravity gradient stabilization systems for applications technology satellite
Tethers in space: Birth and growth of a new avenue to space utilization
The evolution of the ideas of tether applications in space are traced from its origin in the last century past a dormant period of sixty-five years to the mid-seventies. At that time as a consequence of major revival efforts, NASA entered into serious investigations of the theoretical and practical feasibility of a large number of tethered concepts in space. These efforts culminated in the establishment of the Tethered Satellite System Project now at NASA in the advanced development phase. Extensive planning efforts are described, first, through a Tether Applications in Space Workshop which generated additional concepts and provided overall assessments and recommendations to NASA, and then through a NASA inter-center Tether Applications in Space Task Group which generated a four year program plan in the areas of further studies, technology, work and science and applications of tethers in space. An outlook into the future of tether applications that approaches some of the goals of the early visionaries is offered
Skills for multiagency responses to international crises
Overview
Australian responses to international, complex emergencies and humanitarian crises, generated by natural disaster, conflicts or incidents, demand the coordinated responses of multiple civil-military-police actors and agencies.
A scoping study of Australian government agency training needs in the latter half of 2013 indicated that stakeholder agencies continue to have difficulty in identifying and developing individual skills to enable people to operate effectively in a high-pressure crisis environment that requires an integrated civil-military-police response. Agencies highlighted the need to develop a ‘whole-of-government’ set of skills for civil-military-police interaction that would complement agency specific skills.
In 2015, the Australian Civil-Military Centre (ACMC) commissioned Sustineo to undertake a project to address this gap. This report, based on Sustineo’s research and consultations, goes some way to identifying the skills needed for effective civil-military-police interaction. However, the list is not exhaustive. In fact, the report highlights the difficulty of articulating a specific set of multiagency, cross-cutting skills for civil-military-police interaction.
Practitioners gave consistent advice that specific skills were less important than other factors in successful civil-military-police interaction. Skills and training are only one component of success. The factors that can facilitate and enhance civil-military-police interaction and the strategies required to address those factors are much broader. The report highlights some of these broader factors and how they interrelate. It identifies the interdependence of individual knowledge, skills and attributes, the value of building relationships, the importance of tolerance and understandings of difference and the need for trust and credibility.
The report concludes that an individual’s ability to operate effectively in a civil-military-police environment is developed both prior to and during a mission or deployment and relates more to the type of person and their relationships than to specific skills.
Generic skills and attributes for effective civil-military-police interaction
Common and shared goals
Situational awareness
Understanding of whole-of-government
Personal attributes such as flexibility, resilience and working in a team
Professional skills, such as negotiation, mediation, conflict management and partnership brokering
Existing professional relationships and networks
Trust
Self-awareness (and social and emotional intelligence)
Tolerance of diversity (including of organisational differences and cultural diversity).
The report identifies considerations for developing people for deployments and it is hoped that these will inform agencies’ training and development strategies. The findings support the ongoing work that the ACMC is undertaking to develop an Australian Government Preparedness Framework (the Framework). The Framework will draw together several streams of work that are interrelated, including this report, to further build Australia’s whole-of-government effectiveness in responding to disasters and complex emergencies overseas
Leveraging Wireless Broadband to Improve Police Land Mobile Radio Programming: Estimating the Resource Impact
Despite rapid growth in criminological studies of police technology, examinations of police land mobile radios are absent in the literature. This is troubling given the central role mobile radios serve in police operations and their significant management costs. The present study seeks to fill this gap by introducing the functionality of wireless broadband radio programming. Current practice requires a police officer to physically drive to a radio programming location to manage their mobile radio. Wireless programming remedies this burdensome reality, thereby saving officer time and cost. Geospatial analyses are used to estimate distance saved associated with wireless programming. We then conduct a number of calculations to determine time and cost savings related to the observed differences between existing and wireless radio programming within the context of the North Carolina State Highway Patrol. Results suggest wireless radio programming can save significant personnel and financial resources. Implications are discussed
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