Space Systems Laboratory Massachusetts Institute of Technology Optimization of Separated Spacecraft Interferometer Trajectories in the Absence of A Gravity-Well Optimization of Separated Spacecraft Optimization of Separated Spacecraft Interferometer Trajectories in the Interferometer Trajectories in the Absence of A Gravity Absence of A Gravity-Well Edmund M. Edmund M. Kong Prof David W. Miller David W. Miller

1 Introduction Electrostatic thrusters (“ion engines”) are the best developed type of electric propulsion device, dating in conception to the ‘50’s,(1) and having been demonstrated in space in 1964 on a suborbital flight of the SERT I spacecraft(2). The early history

Seli ssessment Worksheet Please answer the questions in English Name: 1. What useful information have i learnt in this unit? 2. What language items have i learnt in this unit?

The only practical way to accelerate something in free space is by reaction. The idea is the same as in air breathing propulsion (to push something backwards) but in rockets the “something” must be inside and is lost. Here is a revealing derivation of the thrust equation for vacuum:

The result appears to be trivial, but it is not. Notice that the “velocity increment” ∆V is actually equal to the decrease in orbital velocity. The rocket is pushing forward, but the velocity is decreasing. This is because in a r-2 force field, the kinetic energy is equal in magnitude but of the opposite sign

2. Money plays a key role in the performance of the economy. The amount of money in the economy should not be too little or too much, but just“right?

Three Alternative strategies Take a position in the option and the underlying Take a position in 2 or more options of the same type(a spread Combination: Take a position in a mixture of calls puts(A combination)

Changes in the Nature of Work The Interweaving of Technology and Jobs Changes in the Design of Jobs (there will be no stable jobs in the future Integration of Contingent Workers into the Workforce Increased Emphasis on Continuous Learning

1- COMMERCIAL INVOICE IN QUADRUPLICATE GIVING FULL DESCRIPTIONS OF EACH GARMENT AND INDICATING STYLES NUMBER 2- CERTIFICATE OF ORIGIN IN 2 COPIES INDICATING THIS CREDIT NO 3- PACKING LIST IN TRIPLICATE INDICATING STYLE NO, DETAILS

Chapter 5 Electronic commerce information's search and selection In physical markets, consumer search activities include reading advertisements, calling endors, and visiting stores. In a virtual marketplace, all these activities seem to converge into Web searches and Web browsing. Not surprisingly, search services are the first market infrastructure to be built in the electronic marketplace