Ethan Sheehan
Engine 1, Test 3 at steady state on the Airborne Engineering thrust stand
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I build and fire liquid rocket engines.
MEng Aerospace Engineering student at the University of Bristol and Propulsion Lead at HyPower Bristol, the university's rocketry team.
I led BristolSEDS Experimental Propulsion from Engine Lead to Propulsion Lead across four engine programmes, including the 5.94 kN regeneratively-cooled engine that set the UK student thrust record in January 2025.
Four liquid engine programmes from design to hot fire, including the 5.94 kN engine that set the UK student thrust record.
See the work → 02Controllers that had to survive real hardware or a simulation honest enough to argue back: cascade PID on an STM32, phased LQR, stability augmentation.
See the work → 03Reinforcement learning, computer vision and the measurement around them: gauntlets, held-out seeds, and a test-set leak found and killed.
See the work →Ignition, slow motion. The plume establishing on Test 3.
Regeneratively-cooled Inconel 718 bipropellant engine. 5.94 kN in January 2025: the UK student thrust record.
Lightweight CP1 chamber with a coaxial-swirl injector: the first use of the Al-Fe-Zr alloy in a liquid rocket engine.
Spiral-channel regen chamber for EuRoC 2026: designed, printed in CP1 aluminium and CT-scanned end to end, waiting on its first hot fire.
Bristol's first LOx/IPA engine, for Race 2 Space 2026.
Hydrogen/oxygen torch igniter: eight firings, retired after melting through 5 mm of stainless. Succeeded by Pascal.
Three burns in September 2025: a 7 s full-duration burn measured at 3.99 kN peak, and a 5.58 kN peak on the last.
HyPower's 2025 vehicle at the European Rocketry Challenge: 25 teams, first of the UK entrants, grounded 800 m from the pad.
A gain-scheduled cascade PID on an STM32, simulated and then verified bit-exact into the flight C before it was allowed near a bench. A phased LQR that lands a thrust-vectored rocket after its chute has already opened, scored over three hundred Monte Carlo runs rather than one good one.
The thread is the same as the propulsion work: build the loop, then build the rig that can prove it holds. Two more control units, an LQR stability augmentation for a Cirrus SR22 and a hand-written GA and PSO tuning spacecraft attitude controllers, sit under Coursework.
A software-defined pressure regulator for HyPower's pressure-fed rockets: a servo ball valve and a gain-scheduled cascade PID on an STM32, simulated, verified bit-exact into flight C, then bench-tested.
Landing a thrust-vector-controlled sounding rocket after main-chute deployment: a 3-DOF Simulink simulation, a phased LQR controller and a 300-run Monte-Carlo campaign.
Reinforcement learning, computer vision, and the instrumentation that says whether any of it actually worked. A CNN that looked right until a test-set leak was found and killed. A gauntlet of 140,000 games per arm before an agent was allowed to ship. A policy held out against twelve unseen seeds. Live crack-tip inference at about 25 fps on a single Jetson.
What interests me is the measuring apparatus around a model: what it is scored against, how it behaves on data it has never seen, and how you find out that a good-looking result is wrong.
A reinforcement-learning path planner for the MathWorks Minidrone Competition Europe 2026: a Parrot Mambo follows a red line and lands on the marker, with the policy shipped as baked weights and zero toolbox dependency.
Live AI crack-tip detection for composite fracture tests, running on a Jetson AGX Orin. Summer 2026.
Curvature-to-stress prediction for 3D-printed flax/PLA hygromorph strips: 72 specimens, 10 batches, a test-set leak found and killed, and a paper on why the shape transfers and the scale does not.
Kaggle Pokémon TCG AI Battle, summer 2026. The agent was three behaviour-cloned networks and a shallow search; the product was the measurement instrument that reversed six of our own decisions before they shipped.
Density-based OpenFOAM simulation of the ARIA sounding-rocket nosecone at Mach 1.8, validated against NACA wind-tunnel data to within the tunnel's own uncertainty.
AVDASI2 avionics teaching resources: the Cube guide, an example ground station and the docs site the Flight Lab still runs.
A Cirrus SR22 hand-flown in X-Plane and reduced to five dynamic modes against the military handling standard, then an LQR stability augmentation system that flies an F-16 with its centre of gravity pushed past the neutral point.
Flutter speed of a two-degree-of-freedom aerofoil read off its root locus, then spacecraft attitude controllers tuned by a hand-written genetic algorithm and particle swarm in MATLAB and Simulink.
EWB Challenge for a Cambodian village: a 50-drone delivery fleet chosen by weighted pairwise comparison, and a week-7 pencil study of a Merlin 1-D.
Year 1 lab unit. Young's modulus of a steel ruler to within 8%, from a microphone, a breadboard preamp and a Raspberry Pi Pico logging at 5 kHz.
STS-74 mission study: requirements, GMAT orbit, Hohmann transfer, configuration trade and power sizing for the Mir Docking Module.
Avionics test lead on a six-person team: Hall-effect flap sensing, servo calibration, aircraft integration and three days in the wind tunnel.
Hotfire 2, the full-duration burn. Shock diamonds hold the length of the plume.
MEng Aerospace Engineering student at the University of Bristol and Propulsion Lead at HyPower Bristol, the university's rocketry team.
I led BristolSEDS Experimental Propulsion from Engine Lead to Propulsion Lead across four engine programmes, including the 5.94 kN regeneratively-cooled engine that set the UK student thrust record in January 2025.
Before this year: a summer research internship at ILK Dresden on live crack-tip tracking, and a summer at the Bristol Flight Lab building the avionics teaching resources the unit still runs.
| Degree | MEng Aerospace Engineering, First class |
|---|---|
| Institution | University of Bristol |
| Dates | 2023-2027 |
| Prize | Roderick Collar Prize |
| Before | A levels: Maths, Further Maths, Chemistry, Physics. British International School of New York, 2021-2023 |
| Now | MEng year 4 at Bristol, Propulsion Lead at HyPower |