Moon-1: The Tether MVP

A commercially viable, reusable lunar transport system.

The Goal: Design a Minimum Viable Product (MVP) tether system that keeps initial costs low, performs useful work immediately, and generates revenue. This is not just a demo; it is a functional infrastructure project to lower payloads to the Lunar surface and eventually "catch" exports from the Moon.

The Concept: A rotating 50km tether in Lunar orbit. Using solar-electric propulsion to travel from Earth LEO to the Moon, and "Gravity Gradient Pumping" to manage momentum, this system can soft-land payloads without the need for complex chemical retro-rockets on every package.

1. Mission Profile

The mission consists of four distinct phases, allowing for incremental testing and revenue generation.

Phase 1: High-Efficiency Transit

The system launches to Low Earth Orbit (LEO) as a compact stack. It deploys a large solar array and uses high-ISP electric thrusters (Turion TIE-20 GEN2) to spiral out to the Moon. By using electric propulsion, we save thousands of kilograms in fuel compared to chemical rockets.

Transit Time: < 8 months
Propulsion: 4x Ion Thrusters (220 mN total thrust)
Delta-V: ~4,000 m/s

Phase 2: The Drop (Revenue Generation)

Once in Lunar orbit, the tether deploys to its full 50km length. The system enters an elliptical orbit where the tether rotation cancels the orbital velocity at perigee. Payloads are released 100m to 1000m above the surface with near-zero relative velocity.

Payloads: 50 to 100 units (initial batch).
Mass per Payload: 10 kg standard bag.
Impact Velocity: 18 m/s to 58 m/s (absorbed by airbags/crush material).
Momentum Management: Between drops, the "Mobile Module" (ballast) moves along the tether to pump energy back into the system (Gravity Gradient Pumping) and the ion thrusters fire to restore orbital momentum.

Phase 3: Surface Infrastructure & The Catch

Initial payloads contain parts for robotic backhoes and catapults. Once assembled, the backhoes fill payloads with lunar regolith. A surface catapult launches these payloads up to the tether tip.

Using a 10m diameter net and LIDAR guidance, the tether "catches" the payload. This closes the momentum loop—catching a payload from the surface restores the momentum lost by dropping one, reducing the need for propellant.

2. System Specifications

We have selected the Turion TIE-20 GEN2 as the primary propulsion unit due to its extreme efficiency (ISP 4500) and commercial availability.

Propulsion (Per Thruster)

Model: Turion TIE-20 GEN2
Thrust: 55 mN
ISP: 4,500 seconds
Power: 2,000 Watts
Mass: 23 kg
Cost: $150,000

Tether Specs

Material: High-Performance Polyethylene (e.g., Dyneema/Spectra) or Coated Zylon.
Length: 50 km
Structure: Tapered design to minimize mass.
Tip Assembly: Minimalist design (Release mechanism, Net, RF Beacon).

Mass & Power Budget

Component	Quantity	Est. Mass (kg)	Notes
Payloads (Initial)	50	500	10 kg each (Paying customers)
Tether	1	150	~10x Tip+Payload mass factor
Tip End Assembly	1	5	Minimal mass is critical here
Mobile Module (Ballast)	1	450	Includes structure, winches, avionics
- Thrusters	4	92	4x Turion TIE-20 (Total 220 mN)
- Solar Array	1	120	10kW Thin-film / Roll-out array
- Propellant	-	150	Krypton/Xenon for transit & drops
TOTAL LAUNCH MASS		~1,467 kg

3. Economics & Breakeven Analysis

The Moon-1 project is designed to be financially viable from the first mission. By utilizing rideshare launches and high-ISP propulsion, we drastically reduce the cost per kilogram delivered to the Lunar surface.

Launch Costs (1,500 kg Wet Mass)

Scenario	Price to LEO	Launch Cost
Falcon 9 (Rideshare target)	$1,000 / kg	$1,500,000
Starship (Future target)	$200 / kg	$300,000

Mission Cost vs. Revenue

Hardware Cost: ~$3,500,000 (Thrusters, Solar, Bus, Tether)
Launch Cost: ~$1,500,000 (Falcon 9 scenario)
Total Mission Cost: ~$5,000,000

Crowdfunding Revenue Model:
If we sell payload slots to universities, companies, and private backers:

20 slots @ $50,000 (1 kg) = $1,000,000
10 slots @ $400,000 (10 kg) = $4,000,000

Total Revenue: $5,000,000 (Breakeven achieved on Mission 1 direct costs)

4. Future Roadmap: L5 and Water

Once the surface delivery is routine, we scale up. Future payloads will be small satellites tossed from Lunar orbit to the Earth-Moon L5 point. This demonstrates the tether's ability to act as a "momentum exchange" hub, moving cargo between L5 and the Moon purely via orbital mechanics.

Eventually, the system will lift water produced on the Moon (ISRU) to orbit. This water can be used as reaction mass for the tether's thrusters, making the system fully self-sustaining.