Investigation of the lifetime limiting effects within electrospray thruster spacecraft propulsion

Supervisory Team:   Dr Charlie Ryan, Dr Alex Wittig

Project description

Typical high performance electric propulsion options for large satellites, such as gridded ion thrusters or Hall Effect thrusters, do not work well for nano satellites. Their efficiency falls considerably when scaled to the low power requirements of these smaller satellites, and in particular at the very low powers available on nanosatellite platforms such as CubeSats.

Electrospray thrusters are an alternative form of electric propulsion for smaller satellites. They operate through the extraction of charged particles from a liquid contained within a porous structure, through the application of a high electric field. As well as extracting the ions, the electric field accelerates them to a high velocity, resulting in a high specific impulse from a small device. This results in them being highly applicable to nano satellites; for example the leading company within the CubeSat propulsion sector (www.enpulsion.com) uses electrospray thruster technology, and it receiving considerable interest as a propulsion system of the future.

Currently electrospray thrusters are highly promising, but have yet to demonstrate the lifetime required for long duration operation. This is a key aspect for ion thrusters, wherein the thrust is intrinsically smaller and therefore the propulsion unit must be operated for much longer periods than higher thrust systems. This is fundamentally limiting their end use in space.

This PhD will investigate the lifetime limiting effects occurring in electrospray thrusters, how they occur, and methods to alleviate them. It will build upon the successful electrospray thruster development completed at the University of Southampton, developing one of the highest thrust electrospray thrusters in the world. For further information, please see some of our recent publications [1, 2, 3].

Lifetime limiting effects within electrospray thrusters include electrochemical effects, ion and droplet impingement on the electrodes, poor propellant distribution, and (indirectly) facility effects on the thruster. To evaluate these issues analytical models of the effects will be developed, and simulations created. Experiments will be completed within the David Fearn Electric Propulsion Laboratory (link), using our world-class electrospray diagnostics equipment. The work will be completed within the Space Propulsion Group at the University of Southampton, consisting of seven PhD students and several Research Fellows working within the area of space propulsion.

If you are interested in the PhD project, please feel free to contact Dr Charlie Ryan to discuss further ([Email Address Removed]). Please also see Dr Charlie Ryan’s personal webpage: https://www.southampton.ac.uk/people/5xg2p2/doctor-charlie-ryan

Entry Requirements

A very good undergraduate degree (at least a UK 2:1 honours degree, or its international equivalent).

Closing date: applications should be received no later than 31 July 2024 for standard admissions, but later applications may be considered depending on the funds remaining in place.

Funding: For UK students, Tuition Fees and a stipend of £18,622 tax-free per annum for up to 3.5 years.

How To Apply

Apply online: Search for a Postgraduate Programme of Study (soton.ac.uk). Select programme type (Research), 2024/25, Faculty of Physical Sciences and Engineering, next page select “PhD Engineering & Environment (Full time)”. In Section 2 of the application form you should insert the name of the supervisor Charlie Ryan

Applications should include:

Research Proposal

Curriculum Vitae

Two reference letters

Degree Transcripts/Certificates to date

For further information please contact: [Email Address Removed]