Search For Debris Research Articles

Prototype multi-agent robotic debris removal system: principles of development and experimental studies

Objectives. The article substantiates the relevance of the creation and the prospects of application of multi-agent robotic systems for elimination of consequences of emergency situations. The purpose of this work was to test the practical feasibility of algorithms for controlling a group of autonomous robots when performing multi-stage missions.Methods. The theses of the finite automata theory in planning actions of a multi-agent system, methods of automatic control in organizing a goal-directed movement of robots, and methods of computer vision in searching and analyzing debris geometry were used.Results. The principles of development, architecture, and composition are described for the software and algorithms of a prototype of the multi-agent robotic system created at RTU MIREA as part of integrated research for the creation of tools and methods of group control of robots. The multi-stage task of searching and removing debris in the process of eliminating the consequences of emergency situations is analyzed. A proposed algorithm for planning the actions of robotic agents determines the time sequence of the mission stages. Tasks are allocated among the performing robots according to assessments of their suitability. The autonomous functioning of robotic agents is determined by commands coming from the group control level, as well as an a priori embedded knowledge base with scenario models of appropriate actions. Compensation of local environmental uncertainties in the process of robot movement is based on a comprehensive analysis of visual and navigation information. Along with the main elements of the multi-agent system, the developed infrastructure of hardware and software for visual navigation and wireless communication is described.Conclusions. The results of the experimental studies demonstrated the efficiency of the developed approaches to the creation of intelligent technologies for group control of autonomous robots on the example of debris search and removal tasks. The feasibility of the multi-agent robotic system is demonstrated by the development and integration of a number of information management and infrastructure subsystems.

Quality assessment of building a geoinformation system for automated man-made debris search based on aerial video data

Quality assessment of building a geoinformation system for automated man-made debris search based on aerial video data

A dynamical systems approach to the surface search for debris associated with the disappearance of flight MH370

Abstract. The disappearance of Malaysia Airlines flight MH370 on the morning of 8 March 2014 is one of the great mysteries of our time. Perhaps the most relevant aspect of this mystery is that not a single piece of debris from the aircraft was found during the intensive surface search carried out for roughly 2 months following the crash. Difficulties in the search efforts, due to the uncertainty of the plane's final impact point and the time that had passed since the accident, bring the question on how the debris scattered in an always moving ocean, for which there are multiple data sets that do not uniquely determine its state. Our approach to this problem is based on the use of Lagrangian descriptors (LD), a novel mathematical tool coming from dynamical systems theory that identifies dynamic barriers and coherent structures governing transport. By combining publicly available information supplied by different ocean data sources with these mathematical techniques, we are able to assess the spatio-temporal state of the ocean in the priority search area at the time of impact and the following weeks. Using this information we propose a revised search strategy by showing why one might not have expected to find debris in some large search areas targeted by the Australian Maritime Safety Authority (AMSA), and determining regions where one might have expected impact debris to be located, which were not subjected to any exploration.

Orbital Evolution of Cloud Particles from Explosions of Geosynchronous Objects

Current orbital debris search strategies for telescopes observing in geosynchronous Earth orbit are designed around the known orbital distributions of cataloged objects. However, the majority of cataloged objects are believed to be intact spacecraft and rocket bodies, not the debris particles the searches are intended to locate. If there have been breakups in geosynchronous Earth orbit, the explosions may have put the debris into orbits that are significantly different from those in the catalog. Consequently, observation plans optimized for the catalog population may not be optimized for any unseen debris populations. Some hypothetical cases and a real near-synchronous U.S. Titan IIIC transtage explosion will be presented to demonstrate this effect. Perturbing accelerations to be considered for orbital evolution are the nonspherical part of the Earth’s gravitational attraction and gravitational attractions due to the sun and moon. Solar radiation pressure effects are omitted in this analysis, not because they are unimportant for this type of analysis, but to concentrate on the primary orbit perturbations.

On the Kinematics of Tidal Debris from Omega Cen's Progenitor Galaxy

AbstractThe kinematic properties of tidal debris from an orbiting Galactic satellite is presented, on the assumption that its central part once contained the most massive Galactic globular cluster, ω Cen. We simulate dynamical evolution of a satellite galaxy that follows the present-day and likely past orbits of ω Cen, and analyse the kinematic nature of their tidal debris and randomly generated Galactic stars comprising spheroidal halo and flat disk components. It is found that the debris stars show a retrograde rotation at ∼–100 km s–1, which may accord with a recently discovered stellar stream at a radial velocity of ∼300 km s–1 towards the Galactic longitude of ∼270°. These stars also contribute, only in part, to a reported retrograde motion of the outer halo in the north Galactic pole direction, without significantly modifying local halo kinematics near the Sun. The prospects for future debris searches and the implications for the early evolution of the Galaxy are briefly presented.

Kinematics of Tidal Debris from Centauri's Progenitor Galaxy

We present the kinematic properties of a tidally disrupted dwarf galaxy in the Milky Way, based on the hypothesis that its central part once contained the most massive Galactic globular cluster, ω Cen. Dynamical evolution of a self-gravitating progenitor galaxy that follows the present-day and likely past orbits of ω Cen is calculated numerically and the kinematic nature of their tidal debris is analyzed, combined with randomly generated stars comprising spheroidal halo and flat disk components. We show that the retrograde rotation of the debris stars at ~-100 km s-1 accords with a recently discovered large radial velocity stream at ~300 km s-1 toward the Galactic longitude of ~270°. These stars also contribute, only in part, to a reported retrograde motion of the outer halo at the north Galactic pole. The prospects for future debris searches and the implications for the early evolution of the Galaxy are briefly presented.

The search for debris in GEO

The debris population in and near the geosynchronous ring (GEO) is still poorly known. Most of the observational effort has been concentrated on low altitude regions where the spatial density of debris objects is higher than the estimated figures for GEO. However, the GEO ring is a unique environment for science and for commercial applications, and there is no natural removal mechanism in this region. Recent optical surveys with the NASA CCD-Debris-Telescope (CDT) and the ESA 1m telescope in Tenerife (Canary Islands) confirmed the existence of a previously suspected large population of small, uncatalogued debris objects in GEO. The number of detected debris per size class is steadily increasing down to the current observational limit of about 20 mag, corresponding to objects of 0.1 to 0.2 m in diameter. In total this new population outnumbers the catalogued population by a factor of two.

A Search for Tidal Stellar Debris from the Magellanic Clouds: Survey Results from the First Two Years

An important discriminant between leading models for the origin of the Magellanic Stream is the presence of a stellar counterpart to the HI gas stream: ram pressure stripping of gas by a putative hot Galactic halo would act only on Magellanic gas while gravitational tidal stripping would act on both gas and stars. Several previous attempts to find tidal stellar debris have failed to find carbon stars, A stars, or other main sequence stars in the Magellanic Stream (Mathewson et al. 1979; Recillas-Cruz 1982; Brück & Hawkins 1983; Guhathakurta & Lin 1999). However, there has long been a suggestion (Kunkel 1979; Lynden-Bell 1982) of a possible Magellanic association of satellite galaxies and globular clusters that have similar orbits and may derive from the break up of a greater Magellanic galaxy (Lynden-Bell & Lynden-Bell 1995; Majewski et al. 1997). Recent models (Moore & Davis 1994; Johnston 1998) of the tidal disruption of Large Magellanic Cloud (LMC)-like systems indicate a wide dispersal of debris, much wider than the rather confined HI stream, so that the contrast of tidal debris against the Galactic fore/background would be low. If true, this could explain some of the previous negative results for tidal debris searches.

Low altitude, one centimeter, space debris search at Lincoln Laboratory's (M.I.T.) experimental test system

The Experimental Test System of Lincoln Laboratory, the prototype observatory of the Ground-based Electro-Optical Deep Space Surveillance (GEODSS) network, has been used to search for, detect, and discriminate debris as small as ⋍ 1 cm in near-Earth orbit. Although constructed to observe and search for high altitude satellites, the observatory (two 80 cm, equatorially mounted, Cassegrain instruments) has been successfully modified to perform similar tasks on asteroids, daytime observations of near-Earth satellites, and the present endeavor. In particular, the separation of the instruments and their resolution element size allows the discrimination of artificial satellites from meteors. The parallax at ⋍ 80 km elevation is ⋍ 150″ and the video line spacing is ⋍ 4″. We have successfully combined the video signals from the two electron beam, bombarded silicon target cameras for this purpose. Furthermore, by observing at the optimum times, we have increased our sensitivity. Herein we present statistical summaries of tens of hours of observing and we calculate the elevation distribution of the debris population (to B ⋍ 16 ▪5). A summary of the data collected on meteors is also included. Debris is eight times as populous as tracked satellites.

Lunar crater Copernicus: search for debris of impacting body at Apollo 12 site

In an attempt to characterize meteoritic material at the Apollo 12 site, 4 KREEP concentrates from soil 12033 have been analyzed by neutron activation analysis. These contain a meteoritic component in which siderophile Ir, Re and Sb are depleted by about a factor of 2, while volatile Se, Zn, Ag and Bi are depleted by a factor of more than 5 relative to Au. This pattern does not closely resemble any major chondrite or iron meteorite group, but is very similar to that observed in high-alkali samples from Apollo 14. The meteoritic component in KREEP at both sites is therefore predominantly derived from Imbrian ejecta. However, a second, small component of primitive composition seems to be present in Apollo 12 KREEP, judging from the slight, uniform enrichments in Ir, Re, Sb, Se and Zn relative to Au. This component does not seem to be due to micrometeorites. If it is attributed to the Copernican projectile, the crater Copernicus may have been formed by a cometary nucleus, 4 km in diameter, with an impact velocity of 30–40 km/sec. These conclusions depend critically on the assumption that the meteoritic component in Apollo 12 KREEP is representative of the entire impact.