Electrospray Thruster
Overview:
Electrospray propulsion promises to meet many miniaturization and specific impulse requirements of propulsion systems for future space missions. It is a novel micro-propulsion technology with applications for precision attitude control , such as gravity wave detection and exoplanet imaging on larger spacecraft.
Improving thruster lifetime has been noted as a key area of high specific impulse electrospray development by NASA. Misalignments between the tip and extractor can hinder lifetime by accentuating the impingement of the ion beam onto the extractor and increasing the rate at which propellant accumulates and causes overspray.
This study aims to rectify ASTRALab’s existing electrospray thruster and redesign it into one that supports stiff, accurate positioning of the emitter and essentially reduces overspray to the extractor grid in efforts to extend lifespan.
Design Process
ASTRALab's Existing Thruster:
Redesign Objectives:
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Ensure stiff and accurate positioning of the emitter
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Robust design: difficult to break, tolerant to process variation, easy to assemble
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Minimal intercepted current at extractor grid (no overspray).
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Better setup repeatability compared to current design
New Design
Source CAD
Single-Emitter Thruster Assembly
Design Overview & Results:
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A Teflon cylinder boasting a 0.55mm to support the needle as perfectly centered and vertical, attached to a second bit that holds the reservoir (0.25'' hole), and the threaded end screwed directly into an XYZ stage used for micro precision positioning for extreme accuracy and repeatability (mil & lathe for machining)
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New setup with redesigned base plates, extractor grids machined using lathe & mill
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All components designed and checked for fit in Fusion 360
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Setup tested under vacuum chamber with excellent firing results