Nobuyuki Tomita

OPTIMIZATION OF MOTION CONTROL AT LANDING OF AEROSPACE PLANE ON EKRANOPLANE

Under prospect of realizing fully reusable launch vehicle, authors have proposed an Aerospace plane /EkeranopLane system concept[l][2][3]. The Aerospace plane/Ekranoplane system concept consists of a reusable winged launch vehicle and an Ekranoplane. Ekranoplane is a huge wing in groundeffect (WIG) craft which can move with a velocity of more than 0.5 M several meters high above sea level, carrying heavy payloads. Aerospace plane (ASP) will be launched and landed horizontally using Ekranoplane as a takeoff and landing assist. Ekranoplane with its own mass of 1500 tons has a capability of launching ASP with starting mass of about 600 tons from any point on the sea. Another advantageous feature of this system is an opportunity for ASP to land on moving Ekranoplane at the final phase of the recovery from the orbit. The landing concept consists in docking ASP with Ekranoplane, which consequently requires no undercarriage and runway. There are two major problems at landing of aerospace plane on Ekranoplane, approaching and docking. Both of them have to be solved with high reliability and accuracy. This paper discusses about the landing variants and principles of motion control laws optimization.

Investigation of space charge behavior in polyimide film during elevating temperature [spacecraft thermal blanket applications]

Spacecraft are covered by a, so-called, thermal blanket made of polyimide film to keep temperature stable in the spacecraft from drastic changes of temperature between -120 and 150/spl deg/C in the space environment. When the film is exposed to radioactive rays, like a high energy electron beam, under such a drastic change of temperature, the film may have degradation or suffered serious physical damage. To understand the interaction of electron beam irradiation on the polyimide film, we have observed the space charge formation process at room temperature using a pulsed electroacoustic method. In this paper, the decay process of space charge in electron beam irradiated polyimide film during elevating temperature was investigated, based on results obtained using simultaneous measurement of the pulsed electroacoustic method and thermally stimulated current.

Control Strategies and Means of Spaceplane Landing with Ekranoplane Assist

Abstract The concept of aerospace plane landing with ekranoplane assist is proposed. It is shown, that their docking on a final stage of aerospace plane alighting is favorable to expansion of functional capacity of the transport system. The requirements to corresponding systems of navigation and motion control of both wing craft are presented, the structure of the integrated system of relative motion control is offered

Control Aspects of Aerospace Plane Docking with Ekranoplane for Water Landing

Abstract The concept of aerospace plane horizontal launch and landing with the assist of large-scale ekranoplane is analyzed1. It is shown, that on a final stage of aerospace plane descent its docking with ekranoplane is favourable for expanse of functional capacity of the transport system. The variants of performance of such a docking or landing of aerospace plane on moving ekranoplane are discussed. Principles of landing, requirements to the main onboard systems of both wing craft including navigation systems, controllers of absolute and relative motion, are considered. The structure of an integrated system of relative motion control is proposed.

Effective WIG-Craft – Large Ekranoplane with Facilities of Automatic Control

Abstract The effectiveness of large ekranoplanes with automatic control facilities development and commercial application is reasoned 1 . The requirements to motion control systems are analyzed. The statement of the main problems of equipment and software design for flight control at small altitude above the disturbed surface is given. The aim of investigation is to define the way for operational performance improving of the vehicles of advanced design. This way is implementation of modern navigation and motion control systems. The facilities of ekranoplanes with perfect control systems double application are studied. One of such options consists in assist of aerospace plane horizontal launch and landing.

Monitoring system for high energy cosmic ray observation in space environment using advanced electro-optic Pockels techniques

In order to monitor high-energy cosmic rays in a space environment, we succeeded initially in measuring the 2-dimensional birefringence produced due to space charges in dielectric material using a Pockels effect. If high-energy charged particles penetrate into the Pockels crystal and accumulate in it, 2-dimensional birefringence properties are formed in the crystal. In this paper, we introduce the experimental results of measured space charge distribution in the crystal produced due to corona discharges instead of cosmic rays.

Concept and advantages of spaceplane water landing with ekranoplane assist

The concept of spaceplane landing with ekranoplane assist is developed. It is shown, that realizability of their docking at a final stage of spaceplane alighting gives hopeful prospect for expansion of functional capacity of aerospace transport system. The possible versions of spaceplane landing without application of wheeled gear are described. The requirements to applicable automatic systems of motion control of both winged vehicles are discussed. Some physical approached for navigation devises and integrated system of relative motion control design are suggested.

Control Aspects of Aerospace Plane Docking and Undocking with Moving Ekranoplane

Abstract The concept of aerospace plane (ASP) horizontal launch and landing with the assist of large-scale ekranoplane is analyzed1. Undocking of these two winged vehicles after ASP acceleration up to the necessary initial velocity for independent flight and their docking at the final stage of ASP descent for water landing are the critical points of the concept feasibility. The requirements to appropriate systems of navigation and motion control of both wing craft are presented. The structure of the integrated system of relative motion control is suggested. Principles of docking and undocking, requirements to the main onboard systems of both vehicles are considered.

Space charge formation in glass materials after electron-beam irradiation

Charge distribution in various glass materials irradiated by electron beam was observed using PEA measurement system. Glass is used as a cover material for solar array panel of spacecraft. In space environment, the glass materials are sometimes charged up by irradiation of radioactive rays or plasma. The charging sometimes induced unexpected discharge accidents, which give serious damages to the spacecraft. Therefore, it is necessary to investigate the charge accumulation in glass materials irradiated by radioactive rays. In this experiment, we measured some kind of glasses with and without oxidized metal impurities. In the case of glass without impurity, almost no charge was observed after e-beam irradiation. On the other hand, negative or positive charge accumulations were observed in glass including oxidized metal impurities. The polarity of accumulated charge in samples irradiated by e-beam was related with the species of oxidized metal impurities.