This paper focuses on a critical component of the situational awareness (SA), the control of autonomous vertical flight for vectored thrust aerial vehicle (VTAV). With the SA strategy, we proposed a linear-quadratic-Gaussian (LQG) flight control procedure for an unmanned helicopter model with vectored thrust configuration. This LQG control for chosen model of VTAV has been verified by simulatio...

Abstract. The operational advantages of electrodynamic tethers of moderate length are becoming evident from studies of collision avoidance. Although long tethers (of order of 10 kilometers) provide high efficiency and good adaptability to varying plasma conditions, boosting tethers of moderate length (~ 1 kilometer) and suitable design might still operate at acceptable efficiencies and adequate...

A micro-thrust stand developed by the National Physical Laboratory under ESA funding was calibrated and characterized. The balance is based on the nulled-pendulum principle. The thruster is positioned in a constrained pendulum that is free to move only along the line of thrust. A capacitive displacement sensor measures the movement of the pendulum and is connected via a servo closed loop to a f...

Small satellites are changing the space scene dramatically. By drastically reducing costs while still having impressive technological capabilities, their popularity among the space community is increasing at a very fast rate. Propulsion systems for these class of spacecraft are very limited. One promising technology is the ion Electrospray Propulsion System (iEPS) developed at the Space Propuls...

Results from numerical and coldow experimental investigations of aerodynamic thrust vectoring on a small-scale aerospike thruster are presented. Thrust vectoring was created by the injection of a secondary uid into the primary ow eld normal to the nozzle axis. The experimental aerospike nozzle was truncated at 57% of its full theoretical length. Data derived from coldow thrust vectoring tests w...

The sub-Himalayan thrust belt is an active thrust wedge which progresses southward over the northdipping Indian plate. The north–south compression resulted in severe deformation of sedimentary rocks in this belt. Distinct thrust geometries and topography have evolved under the interaction between tectonic and erosional environments. To better understand the relationship between tectonics and to...

Propulsion and maneuvering underwater by flapping foil motion, optimized through years of evolution, is ubiquitous in nature, yet marine propulsors inspired by examples of highly maneuverable marine life or aquatic birds are not widely implemented in engineering. Performance data from flapping foils, moving in a rolling and pitching motion, are presented at high Reynolds numbers, Re=Uc/nu, or O...

This paper captures trajectory analysis of a representative low thrust, high power Solar Electric Propulsion (SEP) vehicle to move a mass around cislunar space in the range of 20 to 40 kW power to the Electric Propulsion (EP) system. These cislunar transfers depart from a selected Near Rectilinear Halo Orbit (NRHO) and target other cislunar orbits. The NRHO cannot be characterized in the classi...

A systems-level trade study is presented comparing the propulsion requirements and associated Ž nal masses for different architectural implementations of the Terrestrial Planet Finder mission. The study focuses on the millinewton-level propulsion chores associated with rotating and repointing an array.Three interferometer conŽ gurations, free  ying, monolithic, and tethered, lead to estimates ...

Aircraft noise is a complex topic which is projected to increase with the increasing number of aircraft and size of the engines. Turbine-powered aircraft produce sounds that are considered pollutants at certain decibel levels. Turbofan engines are inherently quieter than turbojet engines for a given level of thrust. The purpose of this research is to determine if current turbofan noise reductio...