Date of Award


Access Type

Thesis - Open Access

Degree Name

Master of Science in Engineering Physics


Physical Sciences

Committee Chair

Dr. Aroh Barjatya

First Committee Member

Dr. Bereket Berhane

Second Committee Member

Dr. Charles Lee


One of the crucial measurements for characterizing any space weather event is absolute plasma density and plasma density fluctuations, both spatially and temporally. Langmuir probes are the oldest and most proven instruments for these in-situ measurements. This thesis enumerates the development of a miniaturized low-noise Langmuir probe intended for a dual CubeSat mission to study equatorial temperature and wind anomaly in the Earth’s ionosphere.

The Langmuir probe instrument developed is of a planar geometry and fix biased in the ion saturation region, i.e. negative w.r.t. spacecraft chassis. Operating the Langmuir probe in the ion saturation region avoids excessive spacecraft charging on small spacecraft platforms, while also avoiding high-risk deployables. Specific emphasis is placed on minimizing the physical footprint, power consumption, and measurement noise levels of the instrument, all while maintaining high measurement cadence. In this way, the device is also intended to be functionally dynamic and easily modifiable for future missions requiring similar instrumentation.

The effort toward this thesis included circuit design and simulation in National Instruments’ Multisim, printed circuit board layout design in National Instruments’ Ultiboard, instrument firmware development in Texas Instruments’ Code Composer Studio, mechanical design of the system in Dassault’s CATIA and SolidWorks, test article board population, extensive instrument testing, and temperature calibration in a TestEquity thermal chamber.