Arcjet rocket
Arcjets are a form of electric propulsion, whereby an electrical discharge (arc) is created in a flow of propellant (typically
hydrazine or
ammonia). This imparts additional energy to the propellant, so that one can extract more work out of each kilogram of propellant, at theexpense of increased power consumption and (usually) higher cost. Also, the
thrust levels available from typically used arcjet engines are very low compared with chemical engines.
When the energy is available, arcjets are well suited to station keeping on orbit and can replace
monopropellant rockets.
In
Germany, researchers at the Institute of Space Aviation Systems at
Stuttgart University have been looking into these challenges for years and have developed various
hydrogen-powered arcjet engines capable of power outputs from 1 to 100
kW. The ignited hydrogen reaches exit speeds of just under 10 miles per second. In
2009, an arcjet-propelled test satellite by the name of
Baden-Württemberg 1 is scheduled to go to the moon.
In the future, (hydrogen-powered) advanced arcjet engines could replace conventional chemical jet engines, both in
spacecraft and
jet airplanes. The advantages are: higher output per fuel quantity, improved maneuverability especially with spacecraft, very high reliability, and, last but not least, less
air pollution. Hydrogen simply turns into water upon combustion, and under the premise that
hydrogen production will no longer rely on
fossil fuels as an
energy source in the future, a significant step towards protecting the environment could be made.
Lichtbogenantriebe für Weltraumaufgaben (Arcjet propulsion systems for space applications), Prof. Monika Auweter-Kurtz, B.G. Teubner Stuttgart 1992
Institute of Space Aviation Systems at the University of StutgartSee also:
spacecraft propulsion
