Asteria Project (Archived)
The Asteria Thruster was an ASPEN research project focused on developing and testing a solid-fuel plasma thruster using adamantane as its propellant. The project explored the potential of adamantane as a compact fuel source for electric propulsion and gave team members hands-on experience with thruster design, plasma generation, vacuum testing, and diagnostic equipment.
During testing, material from the thruster plume accumulated on the diagnostic probe tips, interfering with their ability to collect reliable data. This deposition became a significant obstacle to accurately characterizing the thruster’s performance. Although Asteria was ultimately retired before a fully operational system was achieved, the project provided valuable lessons in experimental plasma propulsion, diagnostic design, and the challenges of testing solid-fuel thrusters in a vacuum environment.
Take a look at our timeline of progress!
March 2024
Presentation at the AIAA Conference
This March 2025, USC ASPEN had the opportunity to share two presentations of our ongoing research at AIAA's Region VI Student Conference at UC Irvine! As part of our simulations team, Zolia Sarmiento and Haron Samhan presented "Optimizing Adamantane Plasma Thruster Efficiency via 2-D Simulations." Also, Nicholas Kiley, Jonathan Fisher, Marin Davis, and Brian Phu presented "Thrust Characterization and Plasma Diagnostics for an Adamantane Thruster" in a joint paper between the thrust stand and diagnostics teams.
This marks the first time ASPEN has submitted and presented two research papers at a conference, and demonstrates our continued refinement and development of our diagnostics, simulations, thrust stand, and testing team.
January/February 2024
All the subteams are hard at work. While the test team ensures our thruster iterations are capable of generating plasma in the vacuum chamber, diagnostics is busy developing our double Langmuir probe. Meanwhile, the thrust stand team is assembling and refining a torsional thrust stand to fit inside our new chamber. Simulations has been working with Starfish and Bolsig+ to explore geometry comparisons and conduct fragmentation analysis. Beyond the lab, we’ve also been engaging with the local community, including a visit to a high school STEM fair to share our work.
November 2024
Thruster Iteration Development
Now that we've settled into our new lab space, we are refocusing on thruster development, specifically by designing multiple geometry iterations that will be printed in resin at the Baum Family Makerspace's 3D printer lab for future testing to determine the optimal internal configuration.
October 2024
We've moved to the Baum Family Maker Space!
As of October 2024, ASPEN is now operating in one of the Makerspace's rooms. This space allows us access to all of the BFMS facilities and an upgraded space for collaboration and for our teams to have their own spaces.
Additionally, we have switched over to a different vacuum chamber which is set up in this new space!
Progress for plasma diagnostics
The diagnostics team is currently in the process of consolidating our electronic system for our Langmuir Probe into a small printed circuit board. They have also been planning the development of a motorized Double Langmuir Probe for more precise spatial profiling within the plasma plume.
This month ASPEN was given the opportunity to attend the Honeywell Hypersonics & Emerging Technologies Industry Day, where we were able to present our club’s goals and research to aerospace and defense industry professionals. Additionally, we heard about what industries are doing to reach hypersonic speeds and got a look into the research projects of several USC professors.
September 2024
Summer 2024
We were able to send four students to the IEPC Conference in 2024 where we gave a presentation on our continued research. Our paper can be found on the IEPC 2024 website.
We were also featured in a recent USC Viterbi School of Engineering article.
March 2023
Presentation at the AIAA Conference
We are pleased to share the outstanding achievement of Autumn Zaretsky and Cameron Coen, two freshmen enrolled in the USC Astronautical Engineering (ASTE) program. They were presented third place in their respective section at the AIAA regional conference. Their noteworthy contribution involves the development of a custom Langmuir probe, which has significantly advanced our understanding and characterization of the plasma environment of our system.
January/February
Continued work on thruster design and Langmuir Probe
We are currently testing new designs for our thruster, including a separate containment for our propellant and an integrated membrane to ensure no propellant is lost during the pump down. We are also removing the thruster's front panel and the small orifice to ensure no ions bounce back into the chamber and thrust is lost.
While our new thruster design is in development we have been using an external propellant chamber alongside our old thruster design. (as shown in the image to the left)
November 2023
Exploring CubeSat Integration and Redesigning our Thruster
As we plan to move to a new facility to improve our vacuum we have begun experimenting with various forms of steel plugs and membranes to ensure no propellant loss during spin-up. In addition, we have begun constructing a new thruster design with the help of 3D modeling and finalized the electronics for our new inverse pendulum thrust stand.
October 2023
Presentation at GEC
We had the opportunity to send two undergraduate students to give a talk at the Gaseous Electronics Conference. Here we were able to present our thrust results, discuss our plans for Cubsat integration, and get advice from numerous people in the field. We are thankful for this opportunity and hope to continue to attend these conferences.
September 2023
Measuring Thrust
We have successfully measured the thrust created by our prototype by attaching a piece of reflective aluminum to the end of our pendulum, allowing a laser to be deflected when plasma is being emitted. After running a number of tests, the displacement indicates that our thruster is outputting 18 ± 4 μN of thrust. The next steps for a more accurate measurement are to construct a test stand with the thruster mounted on the pendulum.
April 2023
Thrust Test
By repositioning the wires inside the chamber and pumping down to 50mTorr we have been able to limit some of the outgassing. Additionally, we have further shrunk the output orifice for a more defined plasma bloom. To test for thrust we have positioned a small piece of aluminum foil strung from a protractor to measure displacement. Due to the small size of the thruster, the displacement is currently too small to measure with our current setup. Efforts are being made to devise a way to measure the pixel displacement in the videos collected from each test.
March 2023
We have Plasma!
The image to the right is the first test of the smaller thruster design. There was a large amount of outgassing from the wires and our office is still too large to clearly see the plasma bloom produced by the adamantane. We believe the chamber should be pumped down to 50mTorr to better our results.
January/Feburary 2023
Initial Thruster Built
Two simplistic experimental thruster designs were created using two metal washers and clear plastic tubing. We attempted to minimize the output orifice to the best degree to ensure a plasma bloom could be seen. The plastic tubing is used to house a small amount of adamantane to limit contamination in the chamber.