Abstract
Advances in human spaceflight depend not only on whether new technologies can perform, but also on how its risks are understood. My technical research focused on a low-cost facility designed to generate and contain detonation waves in curved channels relevant to rotating detonation engines. The STS portion of my thesis examined how NASA, the Federal Aviation Administration, Congress, commercial organizations, trade associations, and astronauts influence the safety standards governing U.S. human spaceflight. Together, these projects address the limits of technical certainty. Engineering analysis can reduce uncertainty by identifying hazards and improving system performance, but it cannot determine how much remaining risk society should accept. Engineers produce much of the evidence used in safety decisions without necessarily controlling how institutions interpret that evidence or convert it into policy. STS provides a framework for understanding the social forces connecting technical performance with human consequences.
The technical portion of my thesis contributed to the design, manufacture, and testing of a modular detonation-wave facility for rotating detonation engine research. RDEs may offer efficiency and hardware-complexity advantages over conventional propulsion systems, but their behavior remains difficult to isolate because detonation dynamics are strongly coupled with flow conditions and geometry. Costly experimental infrastructure also limits participation by smaller laboratories and undergraduate researchers. Our facility addresses these barriers through a quasi-two-dimensional design composed of a linear pre-detonator and a test section containing a curved rectangular channel. This channel represents the annular flow path of an RDE while allowing researchers to study the influence of curvature under controlled conditions. A replaceable test section supports the evaluation of different geometries without requiring a complete redesign, and a transparent polycarbonate plate provides optical access for laser-photodiode diagnostics. Gas, ignition, and diagnostic subsystems allow the facility to generate and measure ethylene-oxygen-nitrogen detonations. My work centered on the structural and thermal performance of the main test assembly. Using ANSYS Mechanical, I evaluated stress and deformation while comparing candidate materials based on strength, service temperature, cost, and manufacturability. The simulations showed that the assembly would remain within the selected safety factors. Subsequent test firing successfully generated and contained detonations, establishing the facility as a functional platform for future studies of curved detonation-wave propagation.
In my STS research, I found that institutional responsibility shapes risk tolerance, whereas institutional authority determines which definitions of acceptable risk become enforceable standards. I applied the Social Construction of Technology to agency policies, federal regulations, congressional documents, industry recommendations, and astronaut accounts. NASA and astronauts generally emphasize the reduction of preventable threats to human life. By contrast, the FAA currently governs commercial occupant safety largely through informed consent and regulatory compliance. Congress defines the extent of the FAA’s authority, while commercial participants often support gradual regulation intended to preserve technological and market development. These relationships reveal an uneven distribution of knowledge, authority, benefit, and exposure. Companies develop and test vehicles, regulators oversee selected activities, and lawmakers establish the boundaries of federal control. Astronauts and passengers, however, experience the physical consequences of failure. Acceptable risk is therefore produced through a governance system whose participants possess different responsibilities and unequal power.
Considering the technical, organizational, and cultural dimensions of these projects together changed how I understand ethical responsibility in engineering. The detonation facility demonstrated that modeling and testing can reduce uncertainty to an extent prior to operation. My STS analysis showed that uncertainty cannot be eliminated fully and that institutions must still decide who may accept the risk that remains. Engineering decisions therefore extend beyond calculations and hardware. Test results must be communicated accurately, analytical limitations must remain visible, and assumptions should be challenged when they become normalized within an organization. Engineers should also consider whether those with decision-making authority are accountable to the people who face the consequences of failure. Ethical engineering requires understanding who defines the risk, who controls the decision, and who ultimately bears its consequences.
Notes
School of Engineering and Applied Science
Bachelor of Science in Aerospace Engineering
Technical Advisor: Chloe Dedic
STS Advisor: William Davis
Technical Team Members: Brandon Dawson, Jonathan Wang, Josiah Martin, Luke Pritchard, Ryan Malatesta, Spence
Hartman, Alvin Kim, Derek Liu, Saif Rahman, Albert Castellon-Prado, Irion Thompson, Tyler Fischer, Connor Green, and Frederic Ramirez-Melenciano
