2022 NC Space Symposium Student Presentations

Letice Bussiere

NASA Internship Award at Marshall Space Flight Center – Summer 2021
University of North Carolina at Charlotte
Graduate Student (doctoral), Mechanical Engineering

Creation of a Technical Handbook for NASA’s Disruptive Modal Coupling Concepts and Technologies

In 2009, a team within the Spacecraft and Vehicle Systems Department at the Marshall Space Flight Center was tasked with mitigating vibrations in the ARES I rocket that stemmed from thrust oscillations. The team selected was a group of engineers and mathematicians responsible for NASA’s Disruptive Modal Coupling concepts and technologies. In the summer of 2021, I worked alongside six other interns to analyze the documentation created by the team from the years 2009 to 2011. This documentation included all of the work completed to research and mitigate the vibrations present in the ARES I rocket. The interns worked to compile the team’s efforts into one complete document that, upon completion, resulted in a Technical Handbook that laid out the origins of certain Disruptive Modal Coupling concepts.

Mentor: Robert Berry, NASA Marshall Space Flight Center

Ramses Gonzalez

2021-22 NC Space Grant Graduate Research Fellow
University of North Carolina at Chapel Hill
Graduate Student (Doctoral), Physics and Astronomy

Ultra-cool EvryFlare Survey: The Search for Ultra-cool Dwarf Superflares in the Evryscope Database

Ultra-cool dwarfs (UCDs) are star-like objects with effective temperatures ≤ 2700K. They represent about 15% of the astronomical objects within 10 parsecs from our solar system and can have a mass as low as 8% of the Sun’s. Because of their low mass, UCDs fuse hydrogen at a much lower rate than larger stars and consequently have much longer life spans ranging from about 1 trillion years up to ≈ 13 trillion years. These long lifespans are particularly appealing to habitable planets because it would provide them a stable source of radiation and heat. However, UCDs can produce flares with 10 to 1000 times the energy of the Carrington Event – the largest solar flare on record with an energy of 10^32 ergs. These types of flares pose a great threat to the habitability of orbiting terrestrial planets as they could irreversibly change or completely strip off a planet’s atmosphere. This is of greater concern for UCDs because their planets orbit much closer to the star thus increasing their probability of a direct hit by the flare. However, due to the difficulties in observing them, very little is known about the frequency and magnitude of UCD superflares and how they evolve over time. Current surveys of ultra-cool dwarf superflares are either sample-size limited to known active stars due to the limited field-of-view (FOV) of their telescopes, or they have a large FOV but observe the night sky at low cadence: on the order of days. Since these flares evolve rapidly, on minute timescales, high-cadence observations are necessary in order to understand the impact of superflares on their planetary systems and the implications they would have on habitability. The all-sky fields of the Evryscopes span over 16,000 square degrees and allow for the monitoring of the entire overhead night sky at a 2-minute cadence, combined they monitor over 30 million targets. The Evryscope database contains the entire record of the night sky observed by the Evryscopes since they began operation. We used the Evryscope Fast Transients Engine (EFTE) pipeline to query the Evryscope database for transient events at the location of known UCDs provided by The UltraCool Sheet – the largest list of spectroscopically confirmed ultra-cool objects. Here we present several superflare candidates, our method for verifying whether they originated from ultra-cool dwarfs and what impact they could have on habitability of orbiting planets.

Faculty Advisor: Nicholas Law, University of North Carolina at Chapel Hill

Richard Hollenbach

2021-22 NC Space Grant Graduate Research Fellow
Duke University
Graduate Student (Doctoral), Mechanical Engineering

Investigation of Unsteady Aerodynamics in Turbofan Aircraft and Turbopump Rocket Engines Exhibiting Nonsynchronous Vibrations Part II

When an unsteady aerodynamic instability interacts with the natural modes of vibration of a rigid body, lies a phenomenon known as Non-Synchronous Vibrations (NSV), also known as Vortex-Induced Vibrations (VIV). These vibrations cause blade failure in jet engines and turbomachinery; however, the underlying flow physics are much less understood compared to other aeroelastic phenomena such as flutter or forced response. Although this phenomenon has been documented experimentally and computationally, the unsteady pressures associated with this phenomenon have not been measured. First, we collected the spectra of pressure frequencies around a cylinder, a NACA 0012 airfoil, and a turbine blade exhibiting NSV both in CFD and in a low-speed wind tunnel. Then the time domain pressure data is Fast Fourier Transformed into frequency domain results. Finally, the unsteady pressure content from the aerodynamics is separated from the content from the motion of the airfoil, allowing for greater understanding of the unsteady aeroelastic behavior. Understanding the pressures and how they affect the flow physics of NSV allows for further studies into this phenomenon, paving the way for the design of more efficient and safer jet engines.

Faculty Advisor: Robert Kielb, Duke University

Jessica Richter

2021-22 NC Sea/Space Grant Graduate Research Fellow
East Carolina University
Graduate Student (Masters), Geography

Shoreline Mapping in the Neuse River Estuary, NC using Object-Based Ensemble Analysis, Aerial Imagery, and LiDAR

The Albemarle-Pamlico Estuarine System (APES), the second largest estuarine complex in the United States, is experiencing significant shoreline change in response to extreme storms and rising sea levels. The Neuse River Estuary, a major tributary to the APES, has been impacted by a significant portion of the extreme storms that have swept coastal North Carolina in the past three decades. Shoreline classification maps are critical to understanding the context and magnitude of storm-induced erosion along the Neuse River Estuary shoreline. Object-based ensemble analysis has emerged as a successful framework to improve image classification but this approach has yet to be tested in classifying an estuarine shoreline environment. This study assessed the ability of an object-based ensemble analysis to map natural and engineered shoreline types observed within the Neuse River Estuary. The approach integrated in-situ reference data, high-resolution aerial imagery, and LiDAR point data to train five machine learning algorithms, including Random Forest (RF), Support Vector Machine (SVM), LibLINEAR (LL), Artificial Neural Network (ANN), and k-Nearest Neighbors (kNN). The algorithms were assessed individually and as an ensemble to improve the accuracy of the overall classification results. The ensemble produced the highest overall classification accuracy at 76.4% (Kappa value = 0.66) and was used to produce the final shoreline classification map. The highest individual class accuracies within the ensemble were marsh, modified, and low sediment bank shoreline classes. This approach was marginally higher than the top individual algorithm, ANN, at 75.1% accuracy (Kappa value = 0.65). The object-based ensemble analysis showed promising results for predicting shoreline classes within an estuarine environment. The resulting shoreline classification map will aid local stakeholders in mitigating erosional hazards and support applications such as shoreline vulnerability assessments and tracking natural and engineered land cover changes.

Faculty Advisor: Hannah Sirianni, East Carolina University

Mariam Shah

NASA Internship Award at Glenn Research Center – Summer 2021
North Carolina State University
Undergraduate Student (Senior), Chemical Engineering

Capillary Action Research Review and its Application in NASA Experiments and Initiatives

On Earth liquids naturally flow downwards due to gravity and equipment is designed to take advantage of this natural pull. However, in microgravity settings liquids flow due to capillary action making it critical to many NASA missions and a vital component in liquid-based systems on a spacecraft. On a spacecraft, different types of liquids are used and capillary flow research supports many GRC competencies and NASA initiatives. Researchers Paul Concus and Robert Finn experimented with wedge-shaped capillary tubes and their proofs and experimental observations laid the groundwork for capillary action knowledge for the ISS. In summary, their work focused on capillary flow under different gravitational settings. This paper delves into the background knowledge and research of capillary action by Concus and Finn. It also analyzes the work by researcher Rihana Mungin’s work on pinning flow in capillary tubes. The paper describes how the results from the work of this research can be applied in current NASA and GRC initiatives such as the coffee cup, CELERE, PWM, and the ISS washing machine challenge.

Mentor: Tyler Hatch, NASA Glenn Research Center

Kelyah Spurgeon  

2021-2022 NC Space Grant Graduate Research Fellow
North Carolina Agricultural and Technical State University
Graduate Student (Masters), Biology

Assessing the Effect of Microgravity on the Evolution of Streptococcus mutans Biofilms

In 2012, the Space Medicine Exploration Medical Conditions List predicted that dental emergencies will be one of the top five medical conditions that negatively impact future space missions. Of all bacterial species residing in the human mouth, 20% are Streptococci and S. mutans, a gram-positive, facultative anaerobe is an etiological agent of dental caries. It’s known that microgravity promotes the development of enhanced survival mechanisms in microbes aboard the International Space Station. Developing a method to assess the impact SMG has on S. mutans biofilm formation has the potential to help us understand ways in which both single and multispecies Streptococcal communities can acclimate, evolve, and change behavior in response to extended spaceflight. This study incorporates Experimental Evolution (EE) and Simulated Microgravity (SMG) to assess physiological and genomic changes that occur in S. mutans in SMG over 100-days. The phenotypes of S. mutans have been well-studied here on Earth, but none observe long-term genomic or physiological changes in spaceflight. In this study, samples from our previous EE research with planktonic S. mutans are used to evaluate changes in virulence of their corresponding biofilms. Biofilm populations in SMG and normal gravity (NG) are evaluated phenotypically and genotypically using acid-stress tolerance, oxidative stress tolerance, adhesion, and whole genome assessment. From the previous planktonic study, we found changes in virulence non-specific to evolution in SMG. From the biofilm study, we have found similar phenotypic adaptations in SMG and NG populations that may be specific to biofilm formation in SMG. Potential limitations of this study include the ability to grow and harbor biofilms in microgravity using Hydroxyapatite (HA). The use of HA is common practice in oral biofilm research and has been incorporated into the microgravity simulation portion of this research project. Here, we present a method to monitor oral biofilm evolution in SMG.

Faculty Advisor: Misty Thomas, North Carolina Agricultural and Technical State University