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:
Systems Considerations (Valving, tanks, etc) Characteristics of some monopropellants (Reprinted from H. Koelle, Handbook of Astronautical Engineering, McGraw-Hill, 1961.) Flame Chemical Density temp
Electrothermal Augmentation Concept Geostationary satellites are most of the time exposed to the sun, but they still are subject to eclipse periods around the two vernal points (March 21, September 21);
Ionization and Conduction in a High-pressure Plasma A normal gas at T <3000K is a good electrical insulator, because there are almost no ∼ free electrons in it. For pressure
These notes aim at providing order-of-magnitude results and at illuminating the mechanisms involved. Numerical precision will be sacrificed in the interest of physical clarity. We look first at the arc in a cooled constrictor, with no flow, expand the analysis
Colloidal thrusters are electrostatic accelerators of charged liquid droplets. They were first proposed and then intensively studied from around 1960 to 1975 as an alternative to normal ion engines. Their appeal at that time rested with the large “molecular mass” of the droplets, which was known to increase the thrust density of an ion engine
It is well known that rapidly pulsed current tends to concentrate near the surface of copper conductors forming a “skin”. A similar effect occurs when current flows through a highly conductive and rapidly moving plasma: current tends to concentrate near the entrance and exit of the channel. The reason is the appearance of a strong
1. Introduction Hall thrusters are electrostatic ion accelerators in which the grid system (which serves in classical ion engines to anchor the negative charges used to accelerate the ions) is replaced with a relatively strong magnetic field perpendicular to the flow
JB=Beam ion (and neutralizer electron current) JE=cathode emitted current Jc=ion current to cathode- potential surfaces JD=current through disch. power supply
