testing grounds, not the final site yet

High-power rocketry

Rice Eclipse Rocketry · Level 1 certified · Avionics-Mechanical Lead, Jan 2025 to present

Two things on this page: the Level 1 certification rocket I designed, built, and flew, and the reusable avionics test rocket my subteam is building for the 2026-27 flight campaign.

Level 1 certification

A scratch-built 66 mm rocket, designed in OpenRocket and flown on a Cesaroni H255 for my Level 1 high-power certification. Cardboard airframe, birch plywood fins, and a nose cone I modeled in SolidWorks and printed in PLA at 100% infill. Stable flight and a clean recovery, which is what the certification requires. Flown with the Tripoli Rocketry Association.

The build

What I would change for next time

• The fin attachment. The way the fins were mounted on the L1 lowered the stability margin and left them prone to cracking. On the next rocket the fins mount through the body tube on a jig with epoxy fillets. [confirm and add how the L1 fins were actually attached]
• No flight data. The L1 flew with no avionics on board, so the OpenRocket prediction (804 m apogee, Mach 0.75, about 39 g) was never checked against a measurement. The next step is an avionics bay with custom electronics, so the next flight comes back with altitude and acceleration data I can actually compare to the simulation.

Next rocket: the L2 for the Avionics-Mechanical subteam I lead

Goal: a heavily modified L2 built around three things. Reusability, so the same rocket handles multiple flights in one campaign. Quick assembly of the avionics bay and the whole flight stack, so turnaround between flights is hours, not weeks. And sensor testing, because the avionics division is relying on this platform to fly and prove their custom flight computer, RF board, and power board. My subteam owns the airframe, the avionics bay, and the recovery system. My job as lead is to make sure the mechanical side is never the bottleneck.

Requirements

Design work so far

1. Requirements. The avionics division asked for altitude, reusability, and quick reassembly. The sensors cannot be maxed out on a 3 in rocket, so the target became a longer, faster flight at 8 g rather than an apogee number.
2. Motor class. Worked from the 8 g target to the impulse needed, not the other way around. An I-class motor is in range, which keeps the airframe simple and the cost near 180 dollars a flight.
3. Airframe. I first called fiberglass, then ran the mass budget and reversed it. A heavier airframe needs more impulse for the same 8 g, three flights over. The compromise is a cardboard tube wrapped in fiberglass.
4. OpenRocket. Motor class against stability margin and rail exit velocity, with the real stack and recovery masses in the model. Three fins.
5. MATLAB recovery model. Vendor parachute drag data in, descent rate, drift, and touchdown speed out, holding landings to 25 to 35 ft/s. The descent loads size the hardpoints.
6. Avionics bay, in iteration now. Built an Onshape component library from the club's past bays and the hardware team's board files, then committed a manifest with two independent flight computers. The flat sled died when the boards came back round and the competition rocket went minimum-diameter at 2.5 in. The bay is now a stack of circular boards on rods, about 2.4 in across, with bulkheads cut per airframe so one stack serves both the 3 in test rocket and the 2.5 in competition rocket. Design points: charge wells at the ends, switches and USB reachable from outside, antenna at the nose away from the batteries, the two redundant channels kept visibly separate.

What could go wrong, and how I am planning for it

• Motor class. The 8 g target is an acceleration target, so the first question is what speed and impulse actually get there. If an I-class motor does it, the airframe stays simpler. If it needs a bigger motor, the design goes minimum-diameter with a bulkhead-mounted motor instead of centering rings. That calculation comes before any hardware is ordered.
• Recovery failure. One failed deployment ends a three-flight campaign on flight one. That is why the design carries dual black powder charges, a backup flight computer, and ground separation testing with the real charges before the first launch.
• Fins. They break on shape and velocity, and the L1 taught that. Fiberglass fins, jig-aligned, epoxy fillets, no tip-to-tip layup because the time and cost do not buy enough on a subsonic flight.
• Touchdown speed. Faster than 35 ft/s the airframe breaks. Slower than 25 it drifts in the wind and the recovery walk gets long. The MATLAB model exists to land inside that window, and the shock cords are sized off the same descent loads.
• Sourcing. Fiberglass tubes, a reloadable motor casing, and shock cords all come from outside the subteam. Each one is an ask with a person's name on it, and each is on the schedule before the build, not during it. [update as the asks close]
• The bottleneck. The avionics subteam's whole year depends on this rocket being ready to fly this spring. My job as lead is to make sure they are iterating their flight computer, not waiting on an airframe.

Next steps

1. Fit study of the 2.4 in stack. Confirm every manifest item fits with the re-cut sensor board, the power board, the RF transponder, and the separate RTL-SDR board.
2. Close the OpenRocket design with the final stack mass and the wrapped airframe. Stability margin, rail exit velocity, and expected apogee on the chosen I-class motor.
3. Structural sizing. Run the 8 g launch loads and the ejection-charge shock on the bulkheads and shock-cord hardpoints against the MATLAB descent loads.
4. Order the airframe and recovery hardware. Borrow the reloadable casing.
5. Ground separation test with primary and backup charges, then the first launch of the three-flight campaign.

Tools

OpenRocket · MATLAB · ANSYS Mechanical · SolidWorks

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