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1 – 10 of 714Xin Liu, Junhui Wu, Yiyun Man, Xibao Xu and Jifeng Guo
With the continuous development of aerospace technology, space exploration missions have been increasing year by year, and higher requirements have been placed on the upper level…
Abstract
Purpose
With the continuous development of aerospace technology, space exploration missions have been increasing year by year, and higher requirements have been placed on the upper level rocket. The purpose of this paper is to improve the ability to identify and detect potential targets for upper level rocket.
Design/methodology/approach
Aiming at the upper-level recognition of space satellites and core components, this paper proposes a deep learning-based spatial multi-target recognition method, which can simultaneously recognize space satellites and core components. First, the implementation framework of spatial multi-target recognition is given. Second, by comparing and analyzing convolutional neural networks, a convolutional neural network model based on YOLOv3 is designed. Finally, seven satellite scale models are constructed based on systems tool kit (STK) and Solidworks. Multi targets, such as nozzle, star sensor, solar,etc., are selected as the recognition objects.
Findings
By labeling, training and testing the image data set, the accuracy of the proposed method for spatial multi-target recognition is 90.17%, which is improved compared with the recognition accuracy and rate based on the YOLOv1 model, thereby effectively verifying the correctness of the proposed method.
Research limitations/implications
This paper only recognizes space multi-targets under ideal simulation conditions, but has not fully considered the space multi-target recognition under the more complex space lighting environment, nutation, precession, roll and other motion laws. In the later period, training and detection can be performed by simulating more realistic space lighting environment images or multi-target images taken by upper-level rocket to further verify the feasibility of multi-target recognition algorithms in complex space environments.
Practical implications
The research in this paper validates that the deep learning-based algorithm to recognize multiple targets in the space environment is feasible in terms of accuracy and rate.
Originality/value
The paper helps to set up an image data set containing six satellite models in STK and one digital satellite model that simulates spatial illumination changes and spins in Solidworks, and use the characteristics of spatial targets (such as rectangles, circles and lines) to provide prior values to the network convolutional layer.
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UNDER the auspices of the Gassiot Com‐mittee of the Royal Society a conference on rocket exploration of the upper atmosphere was held at Queen's College, Oxford, on August 24, 25…
Abstract
UNDER the auspices of the Gassiot Com‐mittee of the Royal Society a conference on rocket exploration of the upper atmosphere was held at Queen's College, Oxford, on August 24, 25 and 26. The majority of the papers pre‐sented were concerned with the instrumentations and techniques for physical measurements con‐cerning the atmosphere, but in addition there were some papers which outlined the develop‐ment of the high altitude sounding rocket, first using modified V‐2 rockets and then new vehicles constructed specifically for high altitude research.
The purpose of this paper is to attempt an aerospaceplane design with the objective of Low-Earth-Orbit-and-Return-to-Earth (LEOARTE) under the constraints of safety, low cost…
Abstract
Purpose
The purpose of this paper is to attempt an aerospaceplane design with the objective of Low-Earth-Orbit-and-Return-to-Earth (LEOARTE) under the constraints of safety, low cost, reliability, low maintenance, aircraft-like operation and environmental compatibility. Along the same lines, a “sister” point-to-point flight on Earth Suborbital Aerospaceplane is proposed.
Design/methodology/approach
The LEOARTE aerospaceplane is based on a simple design, proven low risk technology, a small payload, an aerodynamic solution to re-entry heating, the high-speed phase of the outgoing flight taking place outside the atmosphere, a propulsion system comprising turbojet and rocket engines, an Air Collection and Enrichment System (ACES) and an appropriate mission profile.
Findings
It was found that a LEOARTE aerospaceplane design subject to the specified constraints with a cost as low as 950 United States Dollars (US$) per kilogram into Low Earth Orbit (LEO) might be feasible. As indicated by a case study, a LEOARTE aerospaceplane could lead, among other activities in space, to economically viable Space-Based Solar Power (SBSP). Its “sister” Suborbital aerospaceplane design could provide high-speed, point-to-point flights on the Earth.
Practical implications
The proposed LEOARTE aerospaceplane design renders space exploitation affordable and is much safer than ever before.
Originality/value
This paper provides an alternative approach to aerospaceplane design as a result of a new aerodynamically oriented Thermal Protection System (TPS) and a, perhaps, improved ACES. This approach might initiate widespread exploitation of space and offer a solution to the high-speed “air” transportation issue.
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A.D. Baxter and S.W. Greenwood
ROCKET and ramjet engines have not the universal application that gas turbines command and possibly on this account they have not had, until recent years, the development effort…
Abstract
ROCKET and ramjet engines have not the universal application that gas turbines command and possibly on this account they have not had, until recent years, the development effort which gave such amazing results in turbine powered aircraft. Nevertheless, they have demonstrated quite dramatically in various parts of the world that they are power plants to be reckoned with. In Great Britain, their value for aircraft was appreciated somewhat belatedly and events have since decreed that the promise they showed should be smothered before it could become a vital fact. On the other hand their importance for missiles was realized at the conclusion of the 1939–45 war, but again they were not encouraged on anything like the scale that present events show would have been justified. Because of this lack of encouragement, British rockets and ramjets, instead of leading the world, as do gas turbines, are struggling hard to provide a modest rate of progress.
ALTHOUGH a new epoch in high‐speed flight opened with the introduction of the jet propulsion engine, new problems were presented by the thrust characteristics and high…
Abstract
ALTHOUGH a new epoch in high‐speed flight opened with the introduction of the jet propulsion engine, new problems were presented by the thrust characteristics and high fuel‐consumption of the gas turbine.
APPLICATION of the so‐called high energy liquid fuels and high energy liquid oxidizers to power plants based on the jet propulsion principle is receiving the increasing interest…
Abstract
APPLICATION of the so‐called high energy liquid fuels and high energy liquid oxidizers to power plants based on the jet propulsion principle is receiving the increasing interest and attention of rocket propellant chemists and power plant engineers universally. The aspect of substantially increased—as much as 50 per cent— energy per pound of propellant load or per cubic foot of propellant tankage over today's propellants has whetted scientific appetites and justified probing the field of high energy chemicals to determine, as logically and as practically as we can at the present time, the gains, problems, limitations and applications of these higher energy chemicals. The object of this paper is, in a general way, to discuss the subject of chemical rocket propellants in such a way that the following five questions will be, in part at least, answered or recalled to the minds of this audience for additional deliberation.
THE problem of providing engines suitable for high Mach number aircraft is a fascinating study which at the moment has only been taken to the stage where many solutions look…
Abstract
THE problem of providing engines suitable for high Mach number aircraft is a fascinating study which at the moment has only been taken to the stage where many solutions look feasible, thus the choice of engines for the different roles for which high Mach number aircraft may be used is still fairly wide open.
In the 1950s, a combination of technological and scientific advancement, political competition, and changes in popular opinion about spaceflight generated public policy in favor…
Abstract
In the 1950s, a combination of technological and scientific advancement, political competition, and changes in popular opinion about spaceflight generated public policy in favor of an aggressive space program. This and that of 1960s moved forward with a Moon landing and the necessary budgets. Space exploration reached equilibrium in the 1970s, sustained through to the present. The twenty-first-century progresses signals that support for human space exploration is waning and may even begin declining in the coming years. This chapter reviews this history and analyzes five rationales suggested in support of continued human spaceflight: discovery and understanding, national defense, economic competitiveness, human destiny, and geopolitics.
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With the great advances made during the last decade or so in the fields of rocket engineering, materials research, supersonic aerodynamics, electronics and nuclear physics, the…
Abstract
With the great advances made during the last decade or so in the fields of rocket engineering, materials research, supersonic aerodynamics, electronics and nuclear physics, the problem of extra‐terrestrial space flight has been removed from the realm of fantasy to the field of large‐scale engineering problems. Rocket‐powered reaction units occupy a leading position in the field of aeronautical research relating to high speeds, and the industrial application of atomic power is the object of many huge projects at present under development.