Pro-pel Orbital Services

Fuel Where You Need It.

Propellant on orbit. He-3 fusion fuel. No waiting. No planning around Earth's gravity well. Pro-pel is the first permanent, self-replenishing propellant infrastructure in LEO — built from asteroid-derived materials, resupplied continuously by the L4 factory fleet.

2
LEO Depot Stations
5
Tank Systems Per Depot
He-3
Fusion Fuel Available
23 min
Combined Rendezvous Freq.
Request Access Service Overview
Atlantic Depot28.5° / 420km
·
Pacific Depot28.5° / 420km
·
He-3 Lunar Phase 1Month 14.5+
·
LOX / LH₂Operational
·
LCH₄ / LOXOperational
·
NH₃Operational
·
GN₂ / LN₂Operational
·
GOX / GH₂Near-Term
·
H₂O₂ HTPNear-Term
·
N₂ONear-Term
·
N₂H₄ / MMH / NTO / UDMHComing Soon
·
C7 Tanker FleetContinuous Resupply
·
Atlantic Depot28.5° / 420km
·
Pacific Depot28.5° / 420km
·
He-3 Lunar Phase 1Month 14.5+
·
LOX / LH₂Operational
·
LCH₄ / LOXOperational
·
NH₃Operational
·
GN₂ / LN₂Operational
·
GOX / GH₂Near-Term
·
H₂O₂ HTPNear-Term
·
N₂ONear-Term
·
N₂H₄ / MMH / NTO / UDMHComing Soon
·
C7 Tanker FleetContinuous Resupply
01 / 03
Orbit Refuelling
Propellant on demand, in orbit. Every major propellant class available — LOX/LH₂, LCH₄/LOX, MMH/NTO, hydrazine, xenon. Automated docking. No Earth ground support required for the transfer. Two Atlantic and Pacific stations provide staggered rendezvous geometry — combined access frequency of 23 minutes at any point in the 28.5° orbit band.
02 / 03
C7 Tanker Fleet
The C7 is the factory-built workhorse of the Pro-pel network. Fusion-powered, fully autonomous, indefinitely reusable. Ferries propellant from L4 production to LEO depots on a continuous resupply schedule. Factory-built from asteroid iron and CVD materials — no Earth launch cost for the tanker itself after initial fleet deployment. DRAD-1 manages all routing, docking, and transfer operations.
03 / 03
He-3 Fusion Fuel
The rarest commercially available substance on Earth. Helium-3 sourced from atmospheric skimming at Uranus-Sun L4 — the only He-3 supply chain not dependent on terrestrial nuclear reactor byproduct. Available in cryogenic canisters via Tank 5 at both LEO depots. Serves fusion propulsion programmes, fusion reactor research, and medical imaging operations. Purity: 99.9999%.
Pro-pel Atlantic / Pacific Depot
Crystal dome tank array — LEO orbit
Depot Network
Two Stations.
Every Orbit.
Atlantic and Pacific depots at 28.5° inclination, 400–450 km altitude, staggered RAAN for maximum combined rendezvous frequency.
EARTH ATLANTIC 28.5° / 420km PACIFIC 28.5° / 420km C7 TANKER L4 → LEO 23 MIN COMBINED RENDEZVOUS FREQUENCY
Atlantic Station
Pro-pel Atlantic
28.5° INC · 400–450 KM ALT · RAAN-A
Primary depot for North American and European launch corridors. Five-tank configuration — LOX/LH₂, LCH₄/LOX, MMH/NTO, hydrazine, He-3 specialty. Factory-built titanium tankage from L4 production. Fully autonomous operations under DRAD-1. No crew. No life support. Resupplied continuously by C7 tanker fleet from L4.
LOX / LH₂
LCH₄ / LOX
NH₃
GN₂ / LN₂
He-3
GOX · GH₂ · H₂O₂ · N₂O ↑
Hypergolics ↑↑
Pacific Station
Pro-pel Pacific
28.5° INC · 400–450 KM ALT · RAAN-B
Identical tank configuration to Atlantic. RAAN staggered to maximise combined access frequency across both stations. Serves Asian Pacific and equatorial launch corridors. Together, Atlantic and Pacific provide a combined rendezvous window every 23 minutes for any spacecraft in the 28.5° orbit band.
LOX / LH₂
LCH₄ / LOX
NH₃
GN₂ / LN₂
He-3
GOX · GH₂ · H₂O₂ · N₂O ↑
Hypergolics ↑↑
He-3 Specialty — Tank 5
Helium-3 Supply
BOTH STATIONS · CRYOGENIC · 99.9999% PURITY
He-3 supply: Phase 1 from lunar south pole harvester fleet (Month 14.5+), Phase 2 from Uranus-Sun L4 atmospheric skimming (Year 20–30+). Cryogenic canisters, factory-sealed. Available for fusion propulsion programmes, fusion reactor research, and medical imaging (MRI lung ventilation). Continuous supply unaffected by terrestrial reactor production cycles.
He-3 Fusion Grade
He-3 Research Grade
He-3 Medical Grade
C7 Tanker Fleet
Autonomous Resupply
L4 PRODUCTION → LEO DELIVERY · CONTINUOUS
The C7 tanker is a factory-built fusion-powered autonomous vessel. No crew. No launch cost after initial fleet deployment. Operates on a continuous L4 ↔ LEO resupply loop. Propellant production at L4 from asteroid-derived feedstocks ensures the LEO depots are never empty. Supply is constrained only by factory output rate, not by Earth launch schedules.
Fusion Drive
DRAD-1 Nav
Auto Dock
C7 Tanker

The Workhorse
of the Network

The C7 tanker class is the logistical backbone of Pro-pel. Factory-built at Earth-Sun L4 from asteroid-derived titanium and CNT composite structures. No Earth launch vehicle constraint on size or mass. No crew. Indefinitely reusable.

DRAD-1 manages all navigation, depot docking, propellant transfer, and return routing autonomously. The tanker never lands. It cycles between L4 and LEO continuously, maintaining depot inventory levels above minimum threshold at all times.

PropulsionHe-3/D Fusion Drive
NavigationDRAD-1 Autonomous
ConstructionAsteroid Iron + CNT Composite
CrewNone
Transit L4 → LEO3–5 Months
DockingAutomated — Both Depots
CargoAll Propellant Classes + He-3
ReusabilityIndefinite
C7 Tanker Class
Fusion drive · LEO departure · Earth + Moon
HE
-3
Helium-3 fusion fuel.
The only non-terrestrial supply chain in existence.

Sourced from atmospheric skimming at Uranus-Sun L4. Delivered via Pro-pel Tank 5 at both LEO depots.
Source — Phase 1
Lunar south pole — Month 14.5 onward. LH-1 harvester fleet processes regolith through distillation columns at Shackleton base. He-3 canistered and mass-driver launched to L4 orbit. C7 tanker delivers to LEO depots. First commercial He-3 available well before any outer planet operations.
Source — Phase 2
Uranus-Sun L4 — Year 20–30+. Fusion-powered scoopships dive into the Uranian atmosphere, capture He-3 and He-4, separate on ascent. Uranus contains the largest accessible He-3 reservoir in the solar system after the Sun. Phase 2 supply dwarfs lunar output — effectively unlimited scale. Lunar supply continues as a reliable baseline alongside outer planet operations.
Purity
99.9999% He-3 after cryogenic distillation at the L4 factory. Separated from He-4 in dedicated distillation columns. Three grades available: Fusion Grade (FPP drives), Research Grade (laboratory applications), and Medical Grade (MRI lung ventilation imaging).
Delivery
Factory-sealed cryogenic canisters. Standard canister form factor compatible with all Pro-pel depot docking systems. Delivered to both Atlantic and Pacific LEO depots via C7 tanker fleet. No terrestrial handling required — canister is sealed at L4 and opened by the end customer.
Advantage
Terrestrial He-3 supply is a byproduct of tritium decay in nuclear weapons programmes — limited, politically constrained, and declining. Pro-pel He-3 is entirely outside the terrestrial supply chain. Continuous production, independent of any government programme, reactor type, or geopolitical condition.
Near-Term Product Line
Zero Additional Synthesis.

These products are byproducts or trivial derivatives of Pro-pel's existing operational processes. No new chemical pathways required. Just collect, separate, and deliver.

GOX · GH₂
Gaseous
Oxygen + Hydrogen
Direct byproducts of water electrolysis — the same process that makes LH₂ and LOX. Just don't liquefy. GOX: satellite oxidizer, EVA support, industrial. GH₂: cold gas thrusters, fuel cells, industrial hydrogen. Already produced continuously — marginal cost to collect and deliver.
GN₂ · LN₂
Gaseous + Liquid
Nitrogen
Factory N₂ surplus: 992 kg/day after all internal consumption. GN₂: satellite cold gas attitude thrusters, pressurant for propellant tanks, inert purge. LN₂: cryogenic coolant, propellant pressurisation. Water ship atmospheric dip (78% N₂) provides continuous free supply. Already delivered as Pro-pel Tank 4 pressurant.
LCO₂
Liquid
Carbon Dioxide
Straight from the cold trap volatile separation stream. Already separated — just collect and deliver. CO₂ pressurant for propellant systems, cold gas thruster propellant, supercritical CO₂ Brayton cycle working fluid, industrial uses. ARP atmospheric remediation programme produces surplus CO₂ as a captive stream.
H₂O₂ · HTP
High-Test
Peroxide
Electrochemical synthesis from asteroid water — one step from water and electricity. 90%+ concentration HTP is a viable monopropellant and standalone thruster propellant used in satellite attitude control. Also the key intermediate for hydrazine Raschig synthesis. Dual-use: propellant product and hypergolic feedstock.
N₂O
Nitrous
Oxide
Synthesis: NH₃ + O₂ at lower temperature than the Ostwald process → N₂O. One step from ammonia, which is already a Pro-pel product. Used in hybrid rocket motors (SpaceShipOne/Two used N₂O/rubber), satellite thrusters, and as a self-pressurising oxidizer. Growing market in new commercial launch vehicles.
D₂O · D₂
Deuterium
Water + Gas
Factory produces 10,880g deuterium per day surplus after all FPP drive consumption. D₂O: fusion reactor research, neutron moderation, isotope chemistry. D₂: fusion fuel partner with He-3 for FPP drives — supplied to fusion propulsion customers alongside He-3 for a complete fusion fuel package. Available via Pro-pel Tank 6 (proposed small D₂O vessel alongside He-3 Tank 5).
Extended Product Line — Coming Soon
Hypergolic Propellants.

All hypergolic propellants trace back to ammonia as a primary feedstock — and Pro-pel already makes ammonia at L4 via Haber-Bosch. The downstream synthesis pathways are fully mapped. Production follows factory maturation. Legacy hypergolic fleets currently launch with a full lifetime propellant load. Pro-pel hypergolics enable on-orbit life extension for the first time from a non-terrestrial supply chain.

Hydrazine · N₂H₄
Hydrazine
Monopropellant and hypergolic fuel. Used in satellite attitude control, spacecraft thrusters, and upper stages. Synthesis at L4: NH₃ + H₂O₂ → N₂H₄ + H₂O (Raschig process). H₂O₂ produced by electrochemical synthesis from asteroid water. NH₃ from Haber-Bosch. All feedstocks present at L4.
Coming Soon
MMH · CH₃N₂H₃
Monomethyl
Hydrazine
Primary fuel in MMH/NTO bipropellant systems. Used in most GEO satellites, the ISS, and many spacecraft. Synthesis: CO + 2H₂ → CH₃OH (methanol, Sabatier-adjacent) → methylamine → MMH + N₂H₄. CO and H₂ from asteroid cold trap and electrolysis. Multi-step but all feedstocks at L4.
Coming Soon
NTO · N₂O₄
Nitrogen
Tetroxide
Oxidizer for MMH/NTO systems. Hypergolic on contact with MMH — no ignition required. Synthesis: Ostwald process — NH₃ → NO → NO₂ → N₂O₄. Platinum catalyst (present in metallic asteroids) required for catalytic NH₃ oxidation. All feedstocks and catalysts available at L4.
Coming Soon
UDMH · C₂H₈N₂
Unsymmetrical
Dimethylhydrazine
Used in Ariane, Proton, Long March, and many legacy launch vehicles paired with NTO. Synthesis: N₂H₄ + 2CH₃OH → UDMH (via dimethylamine pathway). Both hydrazine and methanol already produced at L4 in prior synthesis steps. UDMH is a downstream product once those lines are established.
Coming Soon

Supply chain note: All hypergolic propellants trace back to ammonia (NH₃), which Pro-pel produces at L4 via Haber-Bosch using nitrogen captured free from Earth's atmosphere by the water ship dip fleet (78% N₂) and hydrogen from asteroid water electrolysis. Platinum-group catalysts required for Ostwald process are present in metallic asteroid feedstock. No Earth-derived chemical inputs required at any synthesis stage. Timeline: hypergolic product lines follow factory chemical processing module maturation. Current Pro-pel products (LH₂/LOX, LCH₄/LOX, NH₃, He-3) are operational from Month 14.5 onward.

Cryogenic Delivery System
Cold to Destination.

Pro-pel cryogenic containers maintain propellant temperature from L4 through mass driver launch, transit, and depot transfer — without active refrigeration. The container is the cold chain. No power required.

Container Layer Stack
Outer Shell
White paint · solar reflectance 0.85
Reflects solar input before reaching thermal layers. Container orientation-independent — no shadow routing required.
PRO-PEL LOGO
vacuum gap
CNT Emissivity Layer
Carbon nanotube coating · emissivity 0.99
Radiates heat directly to 3K deep space. Near-perfect black body. Passive — zero power, zero maintenance.
Silver Fluid Carrier
Silver tube wound on exterior · closed loop
Pre-cooled fluid from shadow pipe circuit. Pulls any residual heat from vessel wall. Fluid never contacts propellant.
vacuum gap · MLI
Inner Vessel
Glass-lined steel · IBCX standard
LOX · LH₂ · LCH₄ · LN₂ · He-3 — all propellant classes. Standard ISO fittings. DRAD-1 fill monitoring.
Performance
0.99
CNT emissivity — near perfect black body
0.85
White shell solar reflectance
3K
Deep space cold sink temperature
Any
Orbital orientation — no shadow required
Zero
Active refrigeration power required
ISO
Standard fittings — any depot compatible
How the cold chain works

At L4 the factory pre-cools propellant gases through permanently shadowed CNT-coated pipe runs — hydrogen reaches approximately −200°C before the final liquefaction stage. The filled container is wrapped with CNT emissivity coating and a silver fluid carrier circuit, enclosed in the white outer shell. Once sealed, the container maintains cryogenic temperature indefinitely through passive radiation to 3K space, regardless of solar exposure. Through mass driver launch, transit to depot, and final customer transfer — the propellant stays cold. The container is the refrigerator.

Pro-Pel branded container

Every Pro-pel container arrives white — the Pro-Pel logo visible from any approaching spacecraft. The white outer shell is not cosmetic — it is the first thermal protection layer. Solar reflectance 0.85 means the container rejects sunlight before it reaches the CNT insulation layer. The brand and the engineering are the same surface.

Container-compatible propellant classes
LH₂ −253°C LOX −183°C LCH₄ −162°C LN₂ −196°C He-3 −270°C NH₃ −33°C N₂H₄ hypergolic NTO −11°C
Supply Pipeline
Asteroid to Orbit.

The complete Pro-pel supply chain from raw asteroid material to propellant in your tank — fully autonomous at every stage.

01
Asteroid Acquisition
C4 Trawl drones capture target asteroids. Nudge thrusters stabilise at L4. Belt slicer complex at 3.2–3.3 AU feeds steady feedstock to the factory.
02
L4 Processing
Volatiles extracted by cold trap. Sabatier reactor produces CH₄ and water. Electrolysis produces LH₂ and LOX. Fractional distillation separates all product streams.
03
Canister Loading
Propellant loaded into factory-built titanium canisters. DRAD-1 inventory system logs each canister, mass, content, and destination before departure.
04
C7 Transit
C7 tanker departs L4 loaded. Fusion drive. 3–5 month transit to LEO. DRAD-1 navigates autonomously. No crew. No consumables beyond He-3 fuel.
05
Depot Restock
C7 docks at Atlantic or Pacific depot. Automated transfer to depot tanks. Tank levels logged. C7 departs for L4 for next load cycle. Continuous rotation.
06
Customer Transfer
Customer spacecraft rendezvous with depot. Automated docking and propellant transfer. DRAD-1 monitors transfer volume and closes valves at target mass. Mission continues.