PAGE CONTENTS
Objectives
The objective of the project is to mature the cathode of the PPS® low power thruster, namely the PPS®X00, for an optimized operation with Krypton as propellant, in view to offer a competitive efficient propulsion solution meeting the small satellite market demand, and of particular interest in the mega-constellation segment where the xenon availability is a key issue.
The following tasks are covered by the project activities:
-
First, the design and manufacture of a highly flexible device functionally and thermally representative of a hollow cathode, so-called BTC.
-
Then functional and thermal characterizations carried out with this hardware by varying the dimensions of the functional parts of the emitter’s housing, the material of the emissive element, and the propellant gases.
-
The third step consists in refining the cathode model developed by Safran by adjusting the modelling parameters after the measurements performed on the BTC
-
Finally, the design, manufacture and test a BBM “krypton hollow cathode” based on these results and complying with the specification.
-
The activities and logic defined at the beginning of the project benefit from synergies with the ARTES C&G PPS®X00 project.
Challenges
The world of space is constantly evolving. Depending on the health, economic and geopolitical context, the space market ecosystem is considerably affected and has to reinvent itself regularly. The compatibility of the propulsion system’s operation with an available propellant gas, krypton, is an asset enabling us to offer an effective, low-cost solution for a low-power Hall-effect thruster, within a very tight time-to-market.
System Architecture
A Hall thruster is composed of an anode assembly and a cathode assembly. To create the thrust a magnetic field is generated in a dielectric chamber to achieve the Hall effect required to ionise the gas, confine the plasma and accelerate the ions under an electrical potential. Electrons are supplied to the anode block by the external cathode to initiate and maintain the discharge. These assemblies consist mainly of an anode/gas distributor, a discharge chamber, a magnetic system, a hollow cathode, gas and power supply lines and mechanical interfaces.
The basis of the project is to generate an optimal design in terms of cost and performance.
The PPS®X00 cathode architecture and assembly processes simplifications compared to legacy designs enable to reduce drastically the manufacturing cycle.
Plan
The major phases of the project are:
-
Design and manufacture a highly flexible device functionally and thermally representative of a hollow cathode.
-
Perform functional and thermal characterizations of this device by varying: i/ the dimensions of the functional parts, ii/ the material of the emissive element, iii/ the propellant gases.
-
Refine the cathode model developed by Safran by adjusting the modelling parameters after the measurements performed on the device
-
Design, manufacture and test a BBM “krypton hollow cathode” based on these results and complying with the specification
Current Status
All the elements to pronounce a TRL6 maturity of the PPS®X00 cathode operating with krypton are available: necessary justifications, mitigation of risks associated with critical technologies, compliance with technical and commercial requirements, and industrial conditions such as the whole manufacturing chain consolidation.
The future development phase mainly consists in the assessment of the residual risks to consolidate the flight target definition through lifetime tests with Krypton, additional analyses and tests at component level. These activities are necessary inputs for the qualification phase, and entry into service in 2025.
