plasma propulsion

plasma propulsion

[′plaz·mə prə′pəl·shən]
(aerospace engineering)
Propulsion of spacecraft and other vehicles by using electric or magnetic fields to accelerate both positively and negatively charged particles (plasma) to a very high velocity.

Plasma propulsion

The imparting of thrust to a spacecraft through the acceleration of a plasma (ionized gas). A plasma can be accelerated by electrical means to exhaust velocities considerably higher than those attained by chemical rocks. The higher exhaust velocities (specific impulses) of plasma thrusters usually imply that for a particular mission the spacecraft would use less propellant than the amount required by conventional chemical rockets. This means that for the same amount of propellant a spacecraft propelled by a plasma rocket can increase in velocity over a set distance by an increment larger than that possible with a chemical propulsion system. Plasma propulsion is one of three major classes of electric propulsion, the others being electrothermal propulsion and ion (or electrostatic) propulsion. See Electrothermal propulsion, Ion propulsion, Specific impulse

Pure electromagnetic acceleration

The most promising and thoroughly studied electromagnetic plasma accelerator is the magnetoplasmadyamic (MPD) thruster. In this device the plasma is both created and accelerated by a high-current discharge. The discharge is due to the breakdown of the gas as it is injected in the interelectrode region. The acceleration process can be described as being due to a body force acting on the plasma. This body force is the Lorentz force created by the interaction between the current conducted through the plasma and the magnetic field. The latter could either be externally applied by a magnet or self-induced by the discharge, if the current is sufficiently high.

Microscopically, the acceleration process can be described as the momentum transfer from the electrons, which carry the current, to the heavy particles through collisions. Such collisions are responsible for the creation of the plasma (ionization) and its acceleration and heating (Joule heating).

Hybrid acceleration

The collision processes invariably heat the plasma. If the gas particles are exhausted hot, they are dissipating energy in kinetic modes useless to propulsion since their thermal motion is random. Moreover, if the exhausted atoms are in an excited or ionized state, the fraction of the internal energy tied in these internal modes is also not available for propulsion. If a fraction of these translational and internal modes is somehow recovered, the plasma acceleration is called hybrid (electromagnetic-electrothermal). Hybrid acceleration is an active area of research and is the most promising alternative for surpassing the 40% efficiency level of magnetoplasmadynamic thrusters.

Flight tests

Few tests of plasma thrusters in space are known publicly outside Russia. Most of the flown plasma propulsion systems are of the pulsed solid-fed (Teflon- ablative) type launched in the 1970s for satellite attitude control.

References in periodicals archive ?
It will rely fully on electric propulsion and will be equipped with an electric plasma propulsion system for orbit raising and in-orbit manoeuvres.
Bob Jahn, besides being one of the top tier officers of a major ivy league university, was a world class physicist running a NASA-funded plasma propulsion laboratory.
This satellite will utilise an electric plasma propulsion system for on-orbit manoeuvres and a chemical system for initial orbit raising and some on-orbit manoeuvres.
The company added that SES 10 is designed to operate for 15 years in geosynchronous orbit, utilising an electric plasma propulsion system for on-orbit manoeuvres and a chemical system for initial orbit raising and some on-orbit manoeuvres.
Sengupta's role at the Jet Propulsion Laboratory was to design and develop plasma propulsion and entry, descent and landing systems.
Along the lines of plasma propulsion systems, which require magnetic containment since plasma temperatures exceed the tolerances of solid containers, magnetic nozzles are being explored.
A number of other propulsion concepts are being explored for potential use in outer planet and interstellar space missions, including electric propulsion, fission propulsion, laser-powered propulsion, antimatter propulsion, mini-magnetospheric plasma propulsion that couples to the solar wind for thrust, and space sails (both solar and laser driven).
The plasma propulsion replaces chemical components in geostationary telecommunications satellites at a subs tantial savings in mass.
Plasma propulsion is more than a quarter of a century old, and it has long been disregarded in the West.
A University of Washington project funded by the National Aeronautics and Space Administration (NASA) is looking at the potential of plasma propulsion for deep space exploration.
The section on application technology covers polymer treatments, silicon solar cell, coating and spray, biomaterials, sterilization and waste treatment, plasma propulsion, plasma display panels, and anti-corrosion coatings.
This satellite will fully rely on electric propulsion and will be equipped with an electric plasma propulsion system for orbit raising and in-orbit manoeuvres.