Helical Cathode Motion for Vacuum Arc Thruster Propulsion

Solution Overview

Problem

Vacuum Arc Thruster (VAT) propulsion systems face limitations in cathode material consumption, restricting mission duration due to the erosion of a few grams of cathode material, which is insufficient for conventional space vehicle missions.

Innovation Solution

Guiding an annular cathode in a helical movement around a central axis with regularly distributed anodes, adjusting the pitch and intensity of electronic discharges to optimize cathode consumption and straighten the plasma jet for enhanced thrust, allowing for the consumption of several kilograms of cathode material.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If a spring-driven propulsion mechanism is used to consume cathode material, then the propulsion module can operate, but the cathode consumption is limited to a few grams which greatly limits thrust duration

Engineering Contradiction:

Improvethrust durationVSAvoidcathode material consumption

Core Design Contradiction:

Duration of action of moving objectVSQuantity of substance

Solution Approach 1:

The cathode is transformed from a static component to a dynamic one by implementing helical motion. The cathode moves along a helical trajectory around the central axis, allowing different portions of the cathode surface to sequentially interact with the anodes. This dynamic configuration enables consumption of several kilograms of cathode material by systematically utilizing the entire cathode surface area, thereby extending thrust duration from minutes to potentially much longer operational periods.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention introduces a helical dimensional path for cathode movement, transforming the interaction from a simple linear or radial approach to a three-dimensional helical trajectory. This dimensional change allows the cathode to engage with multiple anodes positioned at different angular positions, maximizing material utilization and enabling sustained thrust generation through systematic consumption of the entire cathode surface.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Device complexity

If the cathode is made stationary with a spring mechanism, then the system structure is simple, but the thrust intensity and duration are insufficient for conventional space vehicle missions

Engineering Contradiction:

Improvepropulsion mechanism complexityVSAvoidthrust duration

Core Design Contradiction:

Device complexityVSDuration of action of moving object

Solution Approach 1:

The cathode is transformed from a static component to a dynamic one by implementing helical motion. The cathode moves along a helical trajectory around the central axis, allowing different portions of the cathode surface to sequentially interact with the anodes. This dynamic configuration enables consumption of several kilograms of cathode material by systematically utilizing the entire cathode surface area, thereby extending thrust duration from minutes to potentially much longer operational periods.

Inventive Principle:

Principle #15Dynamics

3Volume of moving object

If conventional VAT propulsion is used with a few grams of cathode, then the system is compact, but the specific impulse level is insufficient for traditional space vehicle missions

Engineering Contradiction:

Improvepropulsion module volumeVSAvoidmission duration

Core Design Contradiction:

Volume of moving objectVSDuration of action of moving object

Solution Approach 1:

The cathode is transformed from a static component to a dynamic one by implementing helical motion. The cathode moves along a helical trajectory around the central axis, allowing different portions of the cathode surface to sequentially interact with the anodes. This dynamic configuration enables consumption of several kilograms of cathode material by systematically utilizing the entire cathode surface area, thereby extending thrust duration from minutes to potentially much longer operational periods.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The helical trajectory parameters (pitch, radius, speed) are pre-configured to optimize the sequence and timing of cathode-anode interactions. This preliminary arrangement ensures that the cathode material is consumed in a controlled manner that maximizes thrust duration while maintaining compact module dimensions, allowing several kilograms of material to be utilized systematically over extended mission periods.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP3350441B1Method of feeding propellant for the propulsion of a satellite and satellite propulsion module fed according to said method

Publication Date: 2019.08.07 COMAT CONCEPT MECANIQUE & ASSISTANCE TECHN

Figure 1~2a
Figure 2b~3

AI summary

The invention aims to produce a consumption of several kilograms of cathode, or even more, as part of a vacuum arc propulsion (VAT). To do this, the invention drives the cathode in a helical movement optimised so as to allow the consumption of substantially all of the usable cathodic material. According to one embodiment, the propulsion module comprises an annular frame (20), with central axis (X'X), in which an annular cathode (2) is arranged, guided by a helical thread/tapping (2L) with said frame (20). A central shaft (2A) has a wall (21A) on which an insulating support (10) is attached, equipped with anodes (1) spaced regularly around the circumference, and optical connections (5) in the vicinity of the anodes (1) for emitting ionising radiation (1p). Energy storage capacitors (4) connect each anode (1) to the cathode (2) in order to supply the discharges after the formation of an initial plasma (2p) and an annular coil (3) is integrated on the external face (20e) of the frame (20) for axially straightening the plasma (3p). A mechanism for rotating (7 to 9) is connected to the cathode (2) to provide it with a movement in connection with the helical guide.