Back to Vespula / Darcy Umbilical

Architecture

Shared Vehicle Interface

How I reused one compact two-board mechanical platform across two vehicles while changing the electrical pinout where the missions differed.

2 vehicles

Shared Vehicle Interface

I designed the umbilical as a two-PCB system, not just a connector breakout. The ground-side and vehicle-side boards together are the actual electrical/mechanical handoff between GSE and the vehicle.

Common Platform

The Vespula and Darcy/Felicette implementations share the same core architecture:

GSE harness → ground PCB → magnetic pogo interface → vehicle PCB → flight harness

Umbilical integration design review
Ground-side and vehicle-side boards shown in the actual breakaway-interface context.

That common boundary carries three different classes of signal:

  • 48 V vehicle power;
  • Ethernet;
  • mission-specific safing/control.

The annoying part is that power, Ethernet, and safing all want different things electrically, but they still have to fit through the same tiny breakaway interface.

Reuse Across Two Vehicles

I designed both vehicle versions. Vespula established the ground/flight two-board architecture and connector geometry. The Darcy/Felicette implementation reused that mechanical envelope while changing the signal allocation to support its additional RBF requirements.

Umbilical Altium 3D view
The compact PCB geometry around the shared pogo/magnet interface.

I kept the outline, pogo geometry, and structural interface fixed on purpose. That let the electrical pinout change without making Structures and ground ops relearn the whole interface.

Vehicle-Specific Allocation

The Darcy/Felicette design needed both RBF1 and RBF2 through the interface. I reallocated contacts from VBUS/GND where the lower current requirement allowed it, then revised the copper/via implementation around the new assignment.

I like this as an example of reuse because it was not just 'Rev B of the same board.' The mechanical platform stayed the same while the electrical allocation changed for a different vehicle.