Snecma and French national scientific research agency CNRS have claimed a European first in successfully testing a 20kW electric plasma thruster for spacecraft.

The thruster, 13 times as powerful as the 1.5kW version Snecma already supplies for spacecraft orientation control, matches power outputs already achieved by Russian and US prototypes and helps open the way for the replacement of normal chemical rockets in propulsion during deep-space exploration missions.

A 20kW thruster would also be powerful enough to help geostationary satellites reach their final orbit, provided that satellite platforms can increase the electrical power available, says Noëlle Manesse, Snecma's head of plasma propulsion.

At the moment, low-power plasma thrusters like Snecma's 1.5kW PPS 1350 model are mainly used for stationkeeping, which involves small daily corrections to keep the satellite on orbit over its service life of about 15 years. Operating one to two hours a day, she says, these use about 10% of a satellite's electrical power.

However, the combination of greater electrical power generation by spacecraft and the development of more powerful electric thrusters should enable satellite designers to completely replace traditional chemical propulsion systems. The result, says Manesse, would be significant weight savings, of about 2,000kg (4,405lb) on a standard satellite weighing 5,500kg.

Plasma thrusters use xenon gas as a propellant and electrical power from the solar panels. They offer very high efficiency, with a PPS 1350 consuming five to six times less propellant than a chemical thruster for the same mission.

A plasma propulsion system also has the advantage of virtually constant efficiency, averaging 60%, over the entire power band from 5 to 22 kW.

Demonstrating the technology's potential for propulsion, a PPS 1350 pushed the European Space Agency's Smart-1 probe from Earth orbit to lunar orbit from 2005 to 2007.

Source: Flight International