In order for satellites to move around the Earth's orbit, Hall thrusters are used as electric rocket engine propellers. The technology used in these Hall thrusters can power up and accelerate the movements of satellites at great speed, thus controlling the orientation and position of these objects in space.
The use of Hall thrusters can lead to the consumption of 100 million times less fuel compared to traditional chemical rockets. The usual propellant gas used within Hall thrusters is xenon. At the same time, hall thrusters could also make room for more space cargo in support of space missions, scientists said. However, current Hall thrusters can only last for about 10,000 hours which is too short for space missions.
Now, French engineers have optimized a revolutionary and advanced wall-less Hall thruster which they believe could finally pave the way for cheaper space explorations to Mars and the edge of the solar system.
In a study issued in the journal Applied Physics Letters, experts from the French National Center for Scientific Research explained that they had enhanced the features of a wall-less Hall thruster prototype which the team created in 2014. After preliminary testing, the team said that the performance of the wall-less Hall thruster was satisfactory and that it could be the first step in creating wall-less Hall thrusters suitable for longer space missions.
Lead researcher Julien Vaudolon from the ICARE-CNRS Laboratory explained that the principle behind traditional Hall thrusters is the creation of low-pressure plasma discharges within an electric and magnetic field configuration.
The plasma discharges become magnetized and trapped inside the magnetic field. The propellant gas is injected into the chamber's anode or negatively charged side. The chamber's external cathode or positively charged side meanwhile injects electrons into the propellant gas. The propellant gas becomes ionized. It is accelerated by the electric field to produce enough thrust or force which enables the satellite to move at a high speed of 45,000 mph, Vaudolon said.
"The major drawback of Hall thrusters is that the discharge channel wall materials largely determine the discharge properties, and consequently, the performance level and the operational time," added Vaudolon.
With this, the researchers said that moving the ionization and acceleration process outside the chamber wall would be an efficient approach to avoid the clashing between the discharge channel wall and the low-pressure plasma.
The improved wall-less thruster is based on the PPS-Flex, a 1.5 kilowatt-thruster developed by the GREM3 team in France.
Scientists are planning to create an improved version of the new wall-less thruster in which they will test the extent of possibilities offered by the wall-less Hall thruster.