scholarly journals The use of space laser technology to develop the laser pulses system for the removal of space debris: استخدام اللادر لتطوير نظام النبضات الليزرية لإزالة الحطام الفضائي

Author(s):  
Mohammed Al - Osairy

  Several ideas we have been suggested to processing the problem of space debris, which pose a threat to the earth on the one hand and space missions and satellites on the other.  From these ideas what is logical and practical and can be implemented today, and another what is elusive. From these practical scientific studies research on the use of laser technology by sending high-intensity pulses to change the debris path and prevent collisions. These studies have varied between the proposal to send these pulses from earth or space. This research focuses on the use of space laser technology and identifies the weaknesses of this technique and provides the idea of avoiding the weaknesses through the use of LADAR system to help determine the dimensions and speed of space objects and their components, which contributes to improving the method of processing and providing data on debris and development of treatment to include even natural space objects that pose a threat to earth as asteroids.

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.


Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 577
Author(s):  
Luca Schirru ◽  
Tonino Pisanu ◽  
Angelo Podda

Space debris is a term for all human-made objects orbiting the Earth or reentering the atmosphere. The population of space debris is continuously growing and it represents a potential issue for active satellites and spacecraft. New collisions and fragmentation could exponentially increase the amount of debris and so the level of risk represented by these objects. The principal technique used for the debris monitoring, in the Low Earth Orbit (LEO) between 200 km and 2000 km of altitude, is based on radar systems. The BIRALET system represents one of the main Italian radars involved in resident space objects observations. It is a bi-static radar, which operates in the P-band at 410–415 MHz, that uses the Sardinia Radio Telescope as receiver. In this paper, a detailed description of the new ad hoc back-end developed for the BIRALET radar, with the aim to perform slant-range and Doppler shift measurements, is presented. The new system was successfully tested in several validation measurement campaigns, the results of which are reported and discussed.


2009 ◽  
Vol 27 (11) ◽  
pp. 4221-4227 ◽  
Author(s):  
J. F. McKenzie

Abstract. This paper provides an analysis of the combined theory of gravity-inertial-Rossby waves on a β-plane in the Boussinesq approximation. The wave equation for the system is fifth order in space and time and demonstrates how gravity-inertial waves on the one hand are coupled to Rossby waves on the other through the combined effects of β, the stratification characterized by the Väisälä-Brunt frequency N, the Coriolis frequency f at a given latitude, and vertical propagation which permits buoyancy modes to interact with westward propagating Rossby waves. The corresponding dispersion equation shows that the frequency of a westward propagating gravity-inertial wave is reduced by the coupling, whereas the frequency of a Rossby wave is increased. If the coupling is sufficiently strong these two modes coalesce giving rise to an instability. The instability condition translates into a curve of critical latitude Θc versus effective equatorial rotational Mach number M, with the region below this curve exhibiting instability. "Supersonic" fast rotators are unstable in a narrow band of latitudes around the equator. For example Θc~12° for Jupiter. On the other hand slow "subsonic" rotators (e.g. Mercury, Venus and the Sun's Corona) are unstable at all latitudes except very close to the poles where the β effect vanishes. "Transonic" rotators, such as the Earth and Mars, exhibit instability within latitudes of 34° and 39°, respectively, around the Equator. Similar results pertain to Oceans. In the case of an Earth's Ocean of depth 4km say, purely westward propagating waves are unstable up to 26° about the Equator. The nonlinear evolution of this instability which feeds off rotational energy and gravitational buoyancy may play an important role in atmospheric dynamics.


Traditio ◽  
1946 ◽  
Vol 4 ◽  
pp. 1-30 ◽  
Author(s):  
Philip Merlan

According to Aristotle all heavenly movement is ultimately due to the activity of forty-seven (or fifty-five) ‘unmoved movers'. This doctrine is highly remarkable in itself and has exercised an enormous historical influence. It forms part of a world-picture the outlines of which are as follows. The universe consists of concentric spheres, revolving in circles. The outermost of these bears the fixed stars. The other either bear planets or, insofar as they do not, contribute indirectly to the movements of the latter. Each sphere is moved by the one immediately surrounding it, but also possesses a movement of its own, due to its mover, an unmoved, incorporeal being. (It was these beings which the schoolmen designated as theintelligentiae separatae.) The seemingly irregular movements of the planets are thus viewed as resulting from the combination of regular circular revolutions. The earth does not move and occupies the centre of the universe. Such was Aristotle's astronomic system, essential parts of which were almost universally adopted by the Arabic, Jewish, and Christian philosophers of the Middle Ages.


Author(s):  
Martha Mejía-Kaiser

International space law is a branch of public international law. Norms of treaty law and customary law provide a foundation for the behavior of the subjects of international law performing space activities. Five multilateral space treaties are in effect, which are complemented by important recommendations of international organizations such as United Nations (UN) General Assembly Resolutions and International Telecommunication Union (ITU) Regulations. The Inter-Agency Space Debris Mitigation Coordination Committee (IADC), a non-governmental body composed of several space agencies (for instance, the European Space Agency, the United States National Aeronautics and Space Administration, the Japanese Aerospace Exploration Agency, the Russian Federal Space Agency), issued its Space Debris Mitigation Guidelines in 2002. The IADC defines “space debris” as “all man-made space objects including fragments and elements thereof, in Earth orbit or re-entering the atmosphere, that are non-functional” (IADC, 2002, Revision 1, 2007, 3.1. Space Debris). Although the term “space debris” was not included in any space treaty, the drafters of the space treaties considered space objects as “hazardous” because “component parts of a space object as well as its launch vehicles and parts thereof” detach in course of normal launching operations, because space objects can fragment during an attempted launch, and because space objects that re-enter Earth’s atmosphere and survive friction have the potential to cause damage. In addition, radioactive and chemical substances on board space objects may represent a hazard to populations and the environment on the Earth. Besides the threats to aircraft in flight and to persons and property on the surface of the Earth, space debris in orbit is increasing alarmingly and poses a threat to manned space missions and non-manned space objects. While the Convention on International Liability for Damages Caused by Space Objects (Liability Convention, 1972) considers the threats of space objects during launch, in outer space, and when entering the Earth’s atmosphere, there have been efforts to minimize the generation of space debris in orbit, outside the framework of the space treaties. The IADC Space Debris Mitigation Guidelines are a comprehensive list of recommendations to launching states, owners, and operators of space objects. They are increasingly recognized by states through the creation of codes of conduct, national legislation, recommendations of international organizations, and state practice. Furthermore, non-governmental institutions, like the International Organization for Standardization, are providing more detailed technical instructions for the implementation of the Space Debris Mitigation Guidelines, which are a breakthrough for the application of the guidelines by states of different economic and technical standing. Even though states are reluctant to accept new obligations through treaties, recommendations and state practice are becoming powerful instruments to avert the dangers of hazardous space debris that may create damage on the Earth or in orbit. Space debris also is becoming one of the drivers for the initiatives of the United Nations on the long-term sustainability of outer space activities to promote the existing mitigation guidelines and to formulate new guidelines for clearing outer space of debris.


2020 ◽  
Vol 7 (2) ◽  
pp. 125-137
Author(s):  
Boris Shoshitaishvili

The scientific discovery of our universe’s immense cosmological history and Earth’s vast geologic history has radically altered common perceptions of time, prompting us to think in terms of millions and billions of years rather than hundreds and thousands. Meanwhile human societies impact the Earth System at accelerating rates and more comprehensively than ever before, leading scientists to propose the new geological epoch of the Anthropocene. These two contrasting temporal transformations have mostly been considered separately: the expanding awareness of cosmological and geologic duration, on the one hand, and the acute sense of swift technological change, on the other. However, their contrast and coexistence are important to recognize. The challenge of understanding the Anthropocene’s complex timescales is partly due to the inability of human institutions to reconcile this twofold disruption whereby time has both expanded (into deep time) and compressed (in techno-social acceleration). After theorizing this transformation, I evaluate the current cosmic stories helping human beings reconceptualize the new timescape.


2019 ◽  
Vol 2 (1) ◽  
pp. 21-33 ◽  
Author(s):  
Sunday Adeniyi Fasoro

AbstractThe trend toward the concept of humanity in political theory has arisen largely as a reaction against the mistreatment of vulnerable people such as immigrants. The issue of immigrants’ vulnerability has led political thinkers to ponder on how to apply the principle of humanity to the question of the treatment of immigrants. I would like to address this matter by examining two questions: what is humanity, is it a value property, or a virtue? Does it really matter if the means by which an immigrant immigrates is demeaning to his own humanity as a person? The most common or intuitive reply to these questions would probably be: ‘humanity’ is simply a value-bestowing property, so regardless of immigrants’ actions they are owed respectful treatment. The aim of this paper is to emphasise instead that ‘humanity’ should be conceived as a virtue of actual commitment to act on moral principles. I explore three different meanings of humanity. First, I discuss ‘humanity’ as the common ownership of the earth. Second, I discuss ‘humanity’ as a value property. Third, I discuss humanity as a virtue of acting, on the one hand, with humanity, and on the other hand, on moral principles.


1988 ◽  
Vol 1 (1) ◽  
pp. 89-96
Author(s):  
Tanja L. Zwaan

Unfortunately, today's exploration of outer space is exposed to a rapidly expanding collection of what has come to be called space debris. Innumerous objects of variable size ranging from tiny paint chips to entire - defunct - satellites and produced by various causes, such as collisions, explosions, or simply exhaustion of fuel, are rotating around the Earth and create dangers to our space missions.


Geophysics ◽  
1964 ◽  
Vol 29 (6) ◽  
pp. 1031-1045
Author(s):  
Antonio C. Limón

In order to obtain the best possible seismic field record, it is indispensible on the one hand to know the response of the earth to the explosion, and on the other hand to operate the seismograph equipment with suitable settings.


1918 ◽  
Vol 5 (9) ◽  
pp. 385-393 ◽  
Author(s):  
W. G. Woolnough

During the last six or seven years a series of valuable papers bearing on the origin of laterite has appeared in the Geological Magazine. The conclusions arrived at have been somewhat diverse and contradictory. Dr. Fermor, on the one hand, regarded the laterites of India as residual in character, and believed that they represented the insoluble residues left in the process of rock weathering after the soluble constituents had been removed in solution. Mr. Simpson, at the other extreme, suggested that they represented the soluble material, leached out of the subjacent rocks during weathering under peculiar conditions, and deposited as a chemically-formed rock by precipitation at the surface of the earth.


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