TEAM | alpe

Laboratory Team

Laboratory Director:

Kristina Lemmer, Ph.D.

Dr. Kristina Lemmer is a Professor in the Department of Mechanical and Aerospace Engineering at Western Michigan University. She is an expert in both physical and non-intrusive plasma diagnostics, electric propulsion, and experimental plasma engineering. Her research interests include the following:

Experimental plasmadynamics
Advanced spacecraft propulsion and electric propulsion
Plasma diagnostic development
Spectroscopic techniques for plasma analysis
Nanosecond pulsed plasma discharges
Small spacecraft development
Hypersonic plasma interactions

Dr. Lemmer is funded by the Air Force Office of Scientific Research, Space Force Space Strategic Technology Institute, NASA's Space Technology Mission Directorate, and the Michigan Space Grant Consortium. Previously, she was a recipient of the Air Force Office of Scientific Research's Young Investigator Program Award. In 2018 and 2019, Dr. Lemmer participated in the Air Force Research Laboratory's Summer Faculty Fellowship Program where she researched nanosecond pulsed plasma discharges using Raman, Rayleigh, and Thomson scattering techniques. In 2012, she participated in the Jet Propulsion Laboratory's Summer Faculty Research Program where she specialized in Hall thruster wall erosion measurements and diagnostics. She earned her Ph.D. in Aerospace Engineering from the University of Michigan in 2009 under Dr. Alec Gallimore at the Plasmadynamics and Electric Propulsion Laboratory.

Faculty

Nicholas Taylor

Dr. Nicholas Taylor is a research associate in the Department of Mechanical and Aerospace Engineering at Western Michigan University. He received his B.S. in chemistry from Winona State University in 2003 and his Ph.D. in analytical chemistry from the University of Florida in 2007 (advisor: James D. Winefordner). Dr. Taylor did postdoctoral fellowships at Brigham Young University (2008) and Pacific Northwest National Laboratory (2012). He joined ALPE in 2016.

Doctoral Students

Austen Thomas

Austen is a Ph.D. candidate in the Mechanical and Aerospace Engineering Department. He received both his B.S. and M.S. in Aerospace Engineering from Western Michigan University. At present Austen is pursuing a doctoral degree in Mechanical Engineering with his research focused on the investigation of the impact of electrical facility effects on time resolved behavior in Hall Thrusters. His research is facilitated through the use of two high-speed plasma diagnostics: a high-speed retarding potential analyzer and an electrical confinement coupling cage.

Nathaniel Allwine

Nathaniel is a Ph.D. student in the Department of Mechanical and Aerospace Engineering. He earned his B.S. in Aerospace Engineering from Western Michigan University in 2022, with minors in mathematics and physics. Nate started in 2019 as an undergraduate volunteer in ALPE, and later served as co-chief engineer for the Western Aerospace Launch Initiative CubeSat team. As part of his senior design project, he contributed to the development of a torsional thrust stand. His early doctoral research focused on characterizing facility effects in porous-emitter ionic liquid electrospray thrusters using high-resolution optical imaging. More recently, his work has shifted toward investigating the impact of extractor geometry and orientation on thruster performance, as well as optimizing an orthogonal acceleration time-of-flight mass spectrometer. His current efforts are aimed at understanding the neutral particle population in electrospray plumes.

David Sirbescu-Stanley

David is a doctoral student in the Mechanical and Aerospace Engineering department. He earned his Master’s in Aerospace Engineering from Western Michigan University in 2024, where he worked on the Novel Ion Trap project at ALPE, focusing on characterizing the device. He completed his Bachelor's degree in Mechanical Engineering at Central Michigan University. Currently, David is developing a test cell aimed at plasma diagnostics for inductively coupled plasmas using alternative diatomic propellants.

Master's Students

Hannah Sargent

Hannah is a Master's student in the Mechanical and Aerospace Engineering Department. She received her B.S. in Aerospace Engineering from Western Michigan University in 2021. Her research is focused on investigating the effects of extractor alignment on porous ionic liquid electrosprays with a single emitter.

Avery Adams

Avery is a Master’s student in the Mechanical and Aerospace Engineering department. He received his B.S. in Aerospace Engineering from Western Michigan University in 2024. Their research is focused on investigating emission location variability in single-emitter passively-fed porous media ionic liquid ion source electrosprays with Faraday probes. Avery joined ALPE in 2022 as an undergraduate research assistant, working on a team to develop an agnostic telemetry system for electric propulsion testing.

Logan Alvesteffer

Logan is an accelerated Master’s and Ph.D. student in the Mechanical and Aerospace Engineering Department. He received his B.S. in Aerospace Engineering from Western Michigan University in 2024. Logan joined the Aerospace Laboratory for Plasma Experiments in 2022 as an undergraduate volunteer researcher working with Austen Thomas in NASA’s Joint Advanced Propulsion Institute. Currently, Logan works with David Sirbescu-Stanley with their research focusing on RF test cell canonical focus experiments in an Inductively Coupled Plasma.

Carter Simmons

Carter is a Master’s student in the Mechanical and Aerospace Engineering Department. He received his B.S. in Aerospace Engineering in 2025 from Western Michigan University, with a minor in mathematics. Carter started in ALPE in 2024, focusing on electrospray emitter manufacturing and designing a system to measure the mass flow rate from linear electrospray emitters. Carter is now focusing on developing a liquid-to-gas-generation system with a capillary array.