Design and manufacture of the next generation of ion electrospray thrusters

In this thesis, a full re-design of the iEPS 2.3 system developed by the Space Propulsion Lab has been undertaken, producing its 3.0 incarnation. Each sub-component and assembly has been investigated and improvements to them explored, recommended and implemented. The supporting frames and extractor electrodes have undergone modifications and a full process re-design, respectively, in order to improve the reliability and performance thereof. Much of the work described in the following pages has focused around solving a core problem of emitter flooding - that is, excessive wetting of the emitter substrate before it can be fired, leading to a short-circuit and a failed engine. To this end, a solid-state valve which employs the electro-wetting phenomenon, and the supporting architecture for the same has been developed and integrated into a full thruster package. This has been tested in flight-like conditions and shown to reliably prevent the described failure mode without interfering in the overall performance, even rendering it more resilient to intermittent spikes in emission. In addition, two new materials to replace the current borosilicate glass emitter chips have been investigated, one made in-house and the other purchased off-the-shelf. Both were tested in overall current vs. voltage performance, time-of-flight spectroscopy and retarding potential analysis. The former material, while not fully developed, has nonetheless displayed remarkably promising results, outputting very high current in the pure ionic regime.

Name thesis:degree_name

Master

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Aeronautics and Astronautics

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2019

Author dc:creator

• Freeman, Dakota S.(Dakota Samuel)

Advisor dc:contributor.advisor

• Paulo C. Lozano.

• Aeronautics and Astronautics.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/122411

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/122411