Arcjet rocket

The thermal arcjet (TLT ) (English Arcjet ), is an electric space propulsion.

Function

Between a cathode and an anode, an arc is formed. The anode is usually interpreted as a whole nozzle chamber to the outlet. The approach of the arc is moved to it by means of a cold gas jacket as far back as possible. Between the fuel that is strongly heated by the arc flows (about 5000 K). Therefore the thrust is generated by only the effect of thermal expansion and not by electric or magnetic fields ( as opposed to the magneto- plasma- dynamic drive ). Arcjet thrusters are used for attitude control of satellites. This is used as the fuel, typically ammonia or hydrazine. For larger engines, the use of hydrogen is planned, since it can achieve a higher specific impulse. The term " fuel" is misleading in connection with electric propulsion, as the fuel only provides the pulse. The actual fuel is the current that can be supplied, for example, solar panels or by a nuclear reactor. The available thrust is compared to chemical rocket engines low and is typically in the milli - Newton to Newton range. In contrast, the running time is much higher and it will require less fuel.

Technical realizations

Thermal Arc engines are, inter alia, at the Institute of Space Systems (IRS ) of the Universität Stuttgart studied and developed. The power ratings ranging from 1 kW to 100 kW and a few amperes and about 1 kA. The exit velocities achieved are doing with hydrogen in the range of 15 km / s

For two scheduled as part of the Stuttgart Small Satellite Missions program a TLT is to be used as the main drive system: The Perseus mission of the Institute for Space Systems will serve as a test platform for a duo of electric drive systems. The probe BW 1 should then fly with the arc drive and several IMPD engines to the moon.