On the concept of all electric propulsion spacecraft

Over the past several years the concept of the so-called “all electric propulsion spacecraft” has gained popularity among both customers and developers of geostationary (GEO) spacecraft; this issue is being actively discussed. The main advantages of the concept are the following: decreasing the mass of spacecraft and increasing its economic effi- ciency by means of pair orbital injection. There are some illustrative cases of implementation of this concept by Ameri- can, European and Russian companies. However, specialists interpret the content of the concept in different ways. That causes the problems connected to the development of the conceptual design of spacecraft. It is therefore very important to consider the concept in more detail, to compare various points of view in order to form understanding reflecting its essence the most accurately. At the same time, on the basis of the available examples, it would be feasible to analyze the advantages and disadvantages of this concept in comparison with other approaches to the construction of propulsion system of spacecraft. In the article we offer to interpret the concept as “ All electric propulsion spacecraft ”. This inter- pretation allows to understand its content unambiguously by the specialists of both Russian and Western Technical Schools. We offer to define “ All electric propulsion spacecraft ” as an apparatus that does not have in its composition an apogee engine unit that is chemically fuelled. It has to execute manoeuvres on geostationary orbit raising, orbit correc- tion and momentum wheel unloading by electrical propulsion only. We have shown that with the existing level of excel- lence of the equipment this concept does not have any advantages over the concept of separate propulsion subsystems for the correction and orientation by total mass as well as by the level of reliability.