Maintain a ~1 km, low-opacity cloud at L1 and prove the full closed loop: fountain injection → gentle EM guidance → electrostatic recovery → reuse at an L1 depot. Demonstrate real-time control (edge sharpening, density waves, scheduled “clear windows”) and publish a complete open dataset for independent verification. No climatic effect at this scale—this is a tech demo only.

• Residence time (median): 5–30 s, full distribution characterized

• Edge control: gradient width < 50 m (10–90%) on ≥1 axis

• Windows: ≥ 2 mrad beam with >80% attenuation drop inside

• Recovery efficiency: ≥90% (stretch goal ≥95%), independently verified by mass balance

• Make-up mass: ≤0.05–0.3 kg/hr (depends on τ and recovery)

• Abort/clear time: ≤24 h to background; ≤6 h with field assist

• Free-drift baseline — inject and map τ(x,y,t) & residence times with EM off.

• Edge shaping — enable milli-tesla guide fields; quantify gradients and stability.

• Scheduled windows — open/close holes for coordinated telescope/traffic passes.

• Density modulation — apply ≤0.5 Hz waves; tune control laws.

• Recovery trials — sustained ops; measure recycled vs. make-up mass.

• Abort demo — pause fountains, reverse polarity; document clearing dynamics.

Distributed EM guide satellites (milli-tesla coils); photometry & lidar cubesats for optical-depth maps; a downstream electrostatic collector with size/charge sorting feeding the L1 depot; open, time-stamped telemetry (flows, fields, τ maps) on a public dashboard.

No climate impact at 1 km. Published traffic corridors and scheduled “clear windows” protect spacecraft and observatories. Continuous public reporting, third-party audit hooks, and staged reviews precede any larger trial. Rapid abort ensures the cloud clears in hours–day. description

Cloud: ~1 km dia • Grains: 1–50 μm engineered silicates (optional thin coatings) • Through-flow (demo): ~0.1–1 kg/sduring tests (net make-up set by recovery) • Recovery goal: ≥90% (path to ≥95%).