Technical Overview

ABSTRACT

Luna reimagines portable lighting through a helium balloon platform that combines high-efficiency LEDs, advanced thermal management, and sophisticated stabilization systems. This page provides a high-level technical overview of Luna’s core concept, system architecture, and key performance metrics.

Core Concept

Luna is a helium-filled balloon lighting system that elevates powerful LED arrays to heights of 10-50 meters, delivering superior illumination quality through diffused, uniform light distribution. The system operates as an integrated package of five major subsystems:

1. Buoyancy System: 5-10 m³ helium balloon providing lift capacity
2. Lighting System: High-efficiency LED modules (100 klm output)
3. Thermal Management: Forced helium convection cooling
4. Stabilization System: Multi-point anchoring with calculated tension
5. Safety & Control: Redundant sensors with autonomous emergency response

Why a Balloon Platform?

Traditional light towers are constrained by their mechanical structure - heavy, expensive to transport, and limited to heights of 4-9 meters. Luna’s helium platform eliminates these constraints:

• Height Advantage: 10-50m operation vs 4-9m for towers → dramatically larger illumination area
• Weight Advantage: <2kg total vs 400kg+ for plug-in towers → negligible transport cost
• Quality Advantage: Elevated diffused light vs ground-level point sources → uniform illumination without glare
• Cost Advantage: €750 production cost vs €2,000-5,200 for comparable towers

System Architecture

┌─────────────────────────────────────┐
│   Helium Envelope (5-10 m³)         │
│   ┌───────────────────────────┐     │
│   │  Internal Frame           │     │
│   │  ┌─────────────────┐      │     │
│   │  │ Computation     │      │     │
│   │  │ Centers (×2)    │      │     │
│   │  └─────────────────┘      │     │
│   │  ┌─────────────────┐      │     │
│   │  │ LED Arrays      │      │     │
│   │  │ (600W, 100klm)  │      │     │
│   │  └─────────────────┘      │     │
│   │  ┌─────────────────┐      │     │
│   │  │ Cooling Fans    │      │     │
│   │  │ (He circulation)│      │     │
│   │  └─────────────────┘      │     │
│   └───────────────────────────┘     │
│                                     │
│   Sensor Array (dual redundancy):  │
│   • Temperature (He gas + LEDs)    │
│   • Pressure (barometric)          │
│   • Tilt (inclinometers)           │
│   • Acceleration (3-axis)          │
│   • Gas composition                │
└─────────────────────────────────────┘
         ↓ Power + Data Cable
    ┌────────────────────┐
    │  Ground Station    │
    │  • Transformer     │
    │  • Data receiver   │
    │  • Power source    │
    └────────────────────┘
    
    Stabilization Anchors (×3)
    120° spacing, nylon tethers

Key Performance Specifications

Parameter	Specification	Rationale
Balloon Volume	5-10 m³	Optimized for lift vs drag balance
Operating Height	10-50 m	Maximum illumination area per watt
LED Power	600W	Target 100 klm output
Luminous Output	100,000 lumens	Comparable to mid-range light towers
Luminous Efficacy	190 lm/W	High-efficiency LEDs + helium cooling
Total Weight	<2 kg	Solid components only (excludes helium)
Illumination Radius	25 m at ≥10 lux	Usable work area
Maximum Wind	35 m/s	With 3-point stabilization
Operating Temp Range	-10°C to +45°C ambient	Thermal management validated
Max Internal Temp	<50°C (LED surface)	Sustained cooling performance

Five Core Subsystems

1. Buoyancy & Lift System

Purpose: Provide sufficient lift to suspend all internal components and cable

Key Components:

• Mylar envelope (125μm, dual-zone: aluminized + transparent)
• Helium gas (5-10 m³ at 1.5× atmospheric pressure)
• Lightweight internal frame (<200g)

Performance:

• Gross lift: ~6-12 kg (helium volume dependent)
• Payload budget: ~4-10 kg available after envelope and cable
• Helium advantages: 6× thermal conductivity vs air, chemical inertness

Design Validation: Python models calculate lift capacity as function of:

• Balloon volume
• Envelope material density
• Cable length and mass
• Internal component weight

See Lift and Buoyancy for detailed buoyancy calculations and material selection.

2. Optical & Lighting System

Purpose: Deliver 100 klm luminous flux with optimal distribution pattern

Key Components:

• LED modules: 3-4× high-efficiency arrays (e.g., TCI SML280)
• Diffusion envelope: High-haze Mylar (80-90% haze, good transparency)
• Reflective cone: Directs light downward

Light Distribution Model:

• Point source approximation at height h
• Conical beam with optimized half-angle α
• Illuminance E(x,y) calculated from inverse-square law with cosine correction:

$E(x,y)=\frac{\Phi \cdot h}{4\pi (x^2+y^2+h^2{)}^{3/2}}$

Where:

• Φ = luminous flux (lumens)
• h = height above ground
• x, y = ground coordinates

Performance Advantage: At 20m height, Luna illuminates 3× the area per watt compared to 4m tower due to geometric efficiency and diffusion quality.

See Lighting System for complete optical modeling and LED specifications.

3. Thermodynamic & Cooling System

Purpose: Maintain LED temperatures <50°C and helium gas <40°C

Challenge: 600W LED input with ~30% waste heat (180W) inside closed envelope

Solution: Forced helium convection

Key Components:

• Cooling fans (4×): Aluminum blades, low power draw
• Fan configuration:
  • 2× below LEDs, angled upward
  • 2× above LEDs, pulling heat away
• Helium circulation: 6× thermal conductivity vs air enables efficient heat transfer

Heat Transfer Model:

Helium temperature equilibrium: $T_{He}=T_{ambient}+\frac{P_{waste}}{h_{conv}\cdot A_{envelope}}$

LED surface temperature (forced convection + radiation): $P_{in}=h_{conv}(v)\cdot A_{LED}\cdot (T_{LED}-T_{He})+\epsilon \sigma A_{LED}(T_{LED}^4-T_{He}^4)$

Validated Performance:

• LED surface temp: 45-48°C at 35°C ambient
• Helium bulk temp: 38-42°C at 35°C ambient
• Fan power: <20W total
• Convection coefficient: 50-80 W/m²K at 7 m/s helium flow

See Thermal Management for complete thermal analysis and fan specifications.

4. Wind Mitigation & Stability System

Purpose: Maintain position and prevent excessive tilt in wind up to 35 m/s

Challenge: Large surface area (4-6 m² projected) creates significant drag

Solution: Three-point nylon anchoring with calculated tension distribution

Stabilization Geometry:

• 3× nylon tethers at 120° spacing
• Anchor distance d = 2× operating height (optimal tension balance)
• Each tether rated for maximum tension (wind-aligned case)

Force Balance:

Horizontal drag: $F_D=\frac{1}{2}{\rho }_{air}{C}_{D}A{v}^2$

Tether tension (wind-aligned): $T_h=\frac{F_D}{\cos \alpha }$

Where α = arctan(h/d)

Performance:

• 15 m/s wind: <5° tilt, <3m lateral displacement
• 25 m/s wind: <15° tilt, <8m lateral displacement
• 35 m/s wind: <30° tilt, emergency protocols activate

See Wind Stability for complete stability calculations and tether specifications.

5. Safety Systems & Sensors

Purpose: Autonomous detection and response to emergency conditions

Architecture: Dual redundant computation centers

• Primary: Wired communication via power cable
• Secondary: Wireless (radio) communication
• Both: Independent sensor suites and processing

Monitored Parameters:

• Temperature (helium gas, LED surface) - 4× sensors
• Pressure (internal barometric) - 2× sensors
• Tilt angle (inclinometers) - 2× 3-axis units
• Acceleration (sudden movement) - 2× accelerometers
• Gas composition (helium concentration proxy) - 2× sensors
• Cable integrity (voltage/current monitoring)

Emergency Protocols:

1. Minor alerts: Log event, notify ground, continue operation
2. Moderate alerts: Reduce LED power, increase cooling, await acknowledgment
3. Critical alerts: Emergency descent via controlled helium release
   • Light-signal fallback if communication lost
   • Automatic power cutoff prevents fire risk
   • Slow descent rate (<2 m/s) for safe ground impact

Redundancy Strategy:

• Dual sensors for each parameter
• Statistical discrepancy detection
• Failsafe defaults (e.g., if pressure sensors disagree, assume worst case)
• Ground must acknowledge critical alerts within timeout window

See Safety and Sensors for complete safety system architecture and sensor specifications.

Physical Modeling Framework

All Luna subsystems are validated through Python-based physical models before prototyping:

1. External Fluid Dynamics: Wind drag, turbulence, tether forces
2. Internal Fluid Dynamics: Helium circulation, thermal convection
3. Optical Model: Illuminance distribution, diffusion efficiency
4. Thermodynamic Model: Heat generation, transfer, and dissipation
5. Barometric Pressure Model: Helium permeation through envelope

These models enable rapid iteration on:

• Material selection (Mylar thickness, fan size, cable gauge)
• Dimensional optimization (balloon size, height, tether length)
• Safety parameter definition (critical temperature, pressure, tilt)

Models are implemented in NumPy/SciPy with full documentation on GitHub and Overleaf.

See Physical Models and Software Architecture for complete modeling framework.

Materials and Construction

Primary Materials

Envelope: Mylar (PET film) 125μm thickness

• Upper 70%: Aluminized (helium barrier, light reflection)
• Lower 30%: Transparent high-haze (light diffusion)
• Sealed via heat fusion (200°C, superior to adhesive)

Frame: Lightweight aluminum or carbon fiber

• 4-pod design: distributes weight over circular base
• Total frame mass: <200g
• Transparent sections where light path crosses

Tethers: Nylon rope (3× anchors)

• Rated for 200-300N tension per line
• UV-resistant outdoor grade
• Total mass: ~150g

Cable: Copper power + data (twisted pair)

• Voltage: 120-240V AC stepped up for efficiency
• Data: Redundant channels for sensor telemetry
• Mass: ~15-20 g/m, optimized gauge

See Materials Guide for complete materials specifications, suppliers, and cost breakdown.

Cost Structure

Component Category	Cost Estimate
Envelope (Mylar)	€50-100
Frame	€10
LED modules	€80-110
Electronics (sensors, Arduino, fans)	€120-150
Cable & connectors	€20
Helium (per use)	€30-50
Tethers & hardware	€10
Total COGS	€320-450
With assembly & overhead	€650-750

Compare to light tower COGS of €2,000-5,200 for similar performance.

See Business Model for complete cost analysis and pricing strategy.

Competitive Advantages Summary

Advantage	Luna	Traditional Towers	Impact
Height	10-50m	4-9m	4-10× illumination area
Weight	<2kg	400-800kg	Negligible transport cost
Light Quality	Diffused, uniform	Point source, harsh	Superior work environment
Efficiency	190 lm/W	80-120 lm/W	50-100% better
Cost	€750 COGS	€2,000-5,200 COGS	60-85% cost reduction
Portability	Single person carry	Truck + forklift	Deployment flexibility
Ecological	0.05 g CO₂/hr·m²	0.77 g CO₂/hr·m²	94% emissions reduction

Development Resources

• GitHub: Luna Software Repository
• Overleaf: Complete Technical Documentation
• Colab: Physical Models Notebook

Next Steps

See detailed subsystem documentation:

• Lift and Buoyancy - Helium system and envelope design
• Lighting System - Optical modeling and LED selection
• Thermal Management - Cooling system design
• Wind Stability - Stabilization and tether calculations
• Safety and Sensors - Safety architecture and sensors
• Materials Guide - Component specifications and suppliers
• Software Architecture - Physical models and embedded systems

Return to Luna Homepage or explore Market Analysis.