What It Is
VIMANA is a complete vehicle engineering package built on the Glue Program axiom. It describes a spherical platform — 5.2 meters in diameter — with 24 identical sensing-computing-actuating modules mounted on an internal toroid ring. The modules manage an active electromagnetic skin across five spectral bands.
The package spans 10 volumes: system architecture, module engineering, control systems, EM/stealth domain, structure and thermal, power and energy, software architecture, build sequence, test certification, and open problems.
Every volume contains real specifications. Real BOMs. Real FPGA firmware block diagrams. Real thermal calculations. Real FMEA tables. This is not a concept sketch — it is a build package.
The Architecture
The platform is organized in four concentric zones. The outermost zone is an active metasurface skin — five layers managing visible, IR, RF-high, RF-low, and structural signatures. Below that sits a control ring of 24 universal modules, each running local control loops at 5 kHz. A core zone houses redundant supervisors, power distribution, and a coherence reference oscillator. At the center, a Faraday-shielded cabin.
Each module is self-contained: a Zynq-7020 FPGA, 14-bit ADCs sampling at 1 GSPS, phase shifter arrays, Peltier thermal control, and fiber optic interconnects. The modules communicate through a custom lightweight protocol with 74-byte frames at 1 Gbps — bus utilization sits at 1.4%.
The control law is elegant: each module maintains R = M/H at a target value using a PI controller in log domain. The supervisor distributes gradient-R commands to translate pilot intent into distributed phase coherence across the array.
The Honest Problem
Volume 10 is titled "Open Problems." The first entry — OP-1, marked CRITICAL — reads: "What physical process couples phase coherence to macroscopic force?"
The mass budget calculates 3,800 kg. Hover requires 37,278 N. At 5 kW hover power, the required thrust-to-power ratio is 7.5 N/W. The best electric helicopter achieves 0.06 N/W. The gap is 125×.
The entire avionics, control, EM, and structural system is valid engineering. It has value as an adaptive metasurface testbed regardless of whether OP-1 is ever resolved. But without OP-1, the vehicle does not fly.
The Build Path
The program is phased with hard gates. Phase 0 is a $5K single-module prototype. Phase 1 is a $12K three-module coherence ring. Phase 1E adds X-band EM for $8K. Later phases scale to full spherical integration and flight test. Total program estimate: $790K over 3-4 years.
The minimum viable investment — Phase 0 + 1 + 1E — is $25K in 6 months. Enough to validate the Glue framework in hardware.
Why It's Here
VIMANA exists because the question is worth asking with engineering rigor. If the control architecture works on an EM testbed, the platform has value. If OP-1 is ever resolved, the build package is ready. Either way, the engineering is real.