The Xenon Crisis: Why Project Dyson Must Abandon Its Baseline Propellant

Our transport fleet design calls for Hall-effect ion thrusters using xenon propellant. There's just one problem: we would need 15-20x the entire world's annual xenon production.

This research definitively closes the door on xenon-primary architectures and charts a path forward through alternative propellants.

The Scale of the Problem

Using the Tsiolkovsky rocket equation with our transport vehicle specifications:

• 10-vehicle fleet
• 200,000 kg payload capacity
• 6-10 km/s delta-V per round trip
• 2,500s specific impulse (Hall-effect thruster)

Scenario	Per Mission (kg)	Annual Fleet (kg)	vs Global Production
Minimum	32,000	320,000	6-8× global
Expected	75,000	750,000	15-20× global
Maximum	185,000	1,850,000	37-46× global

Global xenon production is approximately 40-50 metric tons annually. Even our minimum scenario would require 6-8 years of global production for just one year of fleet operations.

Can We Mine Xenon from Asteroids?

No. Analysis of Hayabusa2 samples from asteroid Ryugu and meteorite studies reveals xenon concentrations measured in parts per trillion (ppt).

To extract 1 kg of xenon at 100 ppt concentration:

• Process 10 billion kg (10 million tonnes) of asteroid material
• Energy requirements far exceed practical limits
• Even at 1 ppm (hypothetically), still 1 million tonnes per kg

ISRU for xenon is a non-starter. This research direction should be removed from project planning.

The Alternatives: A Comparative Analysis

Krypton (Best Near-Term Option)

• Efficiency vs Xenon: 70-85%
• Cost: 30-50% of xenon
• TRL: 9 (proven on Starlink V1)
• Availability: 10× xenon production (~700 tonnes/year)

SpaceX operates over 4,000 satellites with krypton thrusters. The efficiency penalty is real but manageable for high-power applications.

Iodine (Compelling Future Option)

• Efficiency vs Xenon: 95-100% (near parity!)
• Cost: 1-2% of xenon
• TRL: 7-8 (demonstrated, needs maturation)
• Storage: Solid at ambient (3× density of pressurized xenon)

Iodine is the dark horse candidate. Flight heritage is limited (ThrustMe NPT30-I2, 2020) but performance matches xenon at a fraction of the cost. Challenges include corrosion and cathode compatibility.

Argon (Long-Term High-Volume)

• Efficiency vs Xenon: 60-70%
• Cost: 0.1% of xenon
• TRL: 9 (proven on Starlink V2)
• Availability: Essentially unlimited (0.93% of atmosphere)

SpaceX's Starlink V2 satellites use argon, achieving 2.4× higher thrust than their krypton V1 systems. For ultra-high-volume operations where fuel efficiency matters less than thrust, argon becomes attractive.

The Solution: Phased Hybrid Architecture

Single-propellant systems create supply chain single-points-of-failure. Our recommendation:

Dual-Propellant Configuration

• Xenon thrusters (10-20% of propellant): Precision maneuvers—docking, station-keeping, fine trajectory adjustments
• Alternative propellant thrusters (80-90%): Bulk delta-V—major orbital transfers

Phased Implementation

Phase	Timeline	Primary Propellant	Rationale
Phase 1	Years 1-5	Krypton	Best flight heritage + availability
Phase 2	Years 5-10	Iodine	Near-xenon performance at 1% cost
Phase 3	Years 10+	Argon	Highest volume operations

Trade-offs

Penalties:

• 15-25% increase in propulsion system dry mass
• Additional tanks and feed systems
• More complex power processing

Benefits:

• 50-90% reduction in propellant costs
• No supply chain single-point-of-failure
• Mission flexibility for varied profiles

Required Investment

$50-100M propellant strategy development:

1. Thruster qualification programs for krypton and iodine at 5-20 kW
2. Long-term supplier agreements with volume guarantees
3. Propellant-flexible vehicle design from day one
4. Depot infrastructure for multiple propellant types

Key Takeaways

1. Xenon cannot be the primary propellant at Project Dyson scale—the math simply doesn't work
2. ISRU for noble gases is not feasible—parts-per-trillion concentrations make extraction impractical
3. Krypton is the best near-term alternative with proven heritage and 10× availability
4. Iodine is the compelling future option with near-parity performance at 1-2% cost
5. Hybrid architectures eliminate supply chain risk while preserving precision capability

This finding has immediate implications for vehicle design. All propulsion system specifications must be updated to assume propellant flexibility, not xenon-only operation.

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This research answers RQ-0-20: Xenon propellant sourcing at scale. The full technical report is available in the project research archive.