Nose Cone Avionics Bay
A compact, serviceable avionics enclosure integrated into the nose cone of OLVT's Hokie 0.75 space shot rocket that relocates the avionics forward to improve stability and simplify ground maintenance. The design balances structural stiffness, thermal protection, dense electronic packaging, and rapid maintainability for a high-impulse flight.
Project Type
Leadership & Collaborative Work on Collegiate Design Team
Date
March. 2025 - Present
Progress
Nearing Completion
I led the structural design and iterative development of the nose-cone avionics bay from initial concept through multiple prototype generations, owning mechanical architecture, integration strategy, and verification planning while coordinating requirements with the avionics subteam. The project required cross-disciplinary engineering: packaging a primary high altitude, GPS-capable flight computer alongside power distribution and telemetry hardware within a small cylindrical volume, while meeting thermal, structural, and accessibility constraints far beyond the scope typical amateur high-altitude rocketry.
Early work emphasized rapid prototyping and design-for-assembly: quick laser-cut scale models and many 3D-printed prototypes were used to validate clearances, registration features, and connector access before committing to finished parts. Throughout development I solicited external technical reviews with faculty, industry engineers, and senior team members, conducted CAD and FEA validation in Fusion 360, performed material and tolerance testing, and presented the design in formal reviews to ensure design confidence.
Iteration 3 was guided by a rough set of requirements obtained throughout its previous iterations: relocate avionics forward to increase static margin without increasing fin area, provide tool-free, rapid access for maintenance and diagnostics, protect sensitive electronics from elevated internal temperatures while preserving required antenna clearances, and provide sufficient structural stiffness and retention for heavy flight computers under harsh external forces. These requirements were refined from lessons learned in earlier iterations and from manufacturing constraints (notably the inability to use threaded rods as a structural skeleton due to a restriction of the primary flight computer as posed by the designer) and informed tradeoffs between mass, manufacturability, and robustness.
To satisfy those requirements I partitioned the bay into two functional volumes: a forward cavity reserved for the Kate 3 primary GPS flight computer to preserve an antenna air-gap, and a shoulder volume housing power (18650 cell stack and in-house power distribution board), the secondary flight computer, the tertiary custom in house flight computer, and a wifi switch. Load paths were routed into two internal bulkheads so that aerodynamic and inertial loads transfer into the airframe rather than into a single plane of fasteners which risks ripping the bolts through the airframe. When it came to making these bolt decisions, I performed a bolt study as described below. Regions not carrying structural loads were designed as twist-lock, tool-free access panels to accelerate turnarounds and fault isolation. Wiring was managed using guided channels and keyed Molex disconnects sized for rapid disconnection on parachute deployment; these connector choices and routing approach aim to significantly reduce assembly error rates and improved troubleshooting speed during test campaigns.
To select fastener type, size, and layout I executed a study combining statics, FEA, and field consultation. I produced free-body diagrams and worst-case shear loads and ran stress studies in Fusion 360 to observe stress concentrations and failure modes for candidate fastener arrangements. After speaking with one of my professors, we were able to determine that several load cases were indeterminate, and as a result, I biased designs toward redundancy and distributed load paths rather than minimal fastener count.
I solicited input from multiple professors, industry contacts, and senior teammates to validate assumptions and converge on an auditable decision. The resulting solution uses paired internal bulkheads at each bolted segment, each secured with four staggered radial 10-32, 5/16, black-anodized steel alloy hex head fasteners, effectively an eight-fastener, layered configuration. This was chosen to reduce the risk of single-plane shearing through the body tube, provide redundancy against asymmetric side loads, and simplify procurement and inspection with a common philosophy in regards to hardware.
Iteration 2 was the first configuration designed for the finalized body-tube diameter and transitioned the concept from exploratory models to an architecture intended for manufacturing. The interior aesthetic and modularity took inspiration from compact cylindrical electronics enclosures (notably the 2013 Mac Pro "Trash Can"), which guided me towards a 3 panel, concentric design with a removable base and hollowed out center channel.
Several design features from this iteration were retained—internal cable guides, a removable base for easy maintenance, three mounting panels, bulkhead placement, and even the arms to hold the Kate 3—but the overall concept attempted to preserve too many aesthetic constraints from its inspiration, which limited practical maintenance and cohesive structure; those limitations motivated a redesign that emphasized function and maintainability in Iteration Three.
Iteration 1 (the “sushi-roll”) was a rapid, low-fidelity proof-of-concept created before final rocket dimensions were frozen. The concept prioritized fast manufacturing and serviceability by using a single central threaded rod to secure stacked panels that folded open for bench maintenance. These laser-cut panels and hinge features enabled a flat, table-top servicing workflow. I built a scale prototype in an afternoon to validate the concept: the prototype demonstrated rapid assembly and the advantages of a fold-out maintenance strategy, and it validated laser cutting as an alternative to slow additive processes for early iterations.
However, once the vehicle outer diameter and design constraints changed (no threaded rod near certain electronics) and load path realities were better understood, the single-rod approach no longer met structural requirements. Iteration 1 clarified that a single threaded load path and panel-based folding architecture were incompatible with the final vehicle diameter, revised avionics constraints, and the expected axial and lateral load environment. These limitations directly motivated the transition to bulkhead-supported load paths, elimination of threaded rods near avionics, and the separation of structural and serviceability features that define later iterations.
