The P1 Liquefaction Unit is the technological core of Decarb Space Systems.
Deployed at 100 km altitude in the lower thermosphere, it captures rarefied air and
converts it into high-purity Liquid Air (L-Air) for refueling orbital stations,
interplanetary cargo ships, and future space infrastructure.
Context and Objectives
With the exponential growth of orbital and interplanetary activities, local production of propellants and gases has become strategically critical. The P1 unit is designed to produce approximately 239,500 tonnes of liquid air per year, primarily nitrogen, oxygen and argon, while significantly reducing reliance on expensive and polluting Earth-based launches.
Global Architecture
The total capture area of 10,000 m² is divided into three parallel linear structures of 3,333 m² each, arranged in an equilateral triangle. This configuration optimizes airflow channeling, mass distribution, and provides native operational redundancy.
Each line operates independently before converging into a single L-Air transfer line toward the 200 km segment.
Context and Objectives
With the exponential growth of orbital and interplanetary activities, local production of propellants and gases has become strategically critical. The P1 unit is designed to produce approximately 239,500 tonnes of liquid air per year, primarily nitrogen, oxygen and argon, while significantly reducing reliance on expensive and polluting Earth-based launches.
Global Architecture
The total capture area of 10,000 m² is divided into three parallel linear structures of 3,333 m² each, arranged in an equilateral triangle. This configuration optimizes airflow channeling, mass distribution, and provides native operational redundancy.
Each line operates independently before converging into a single L-Air transfer line toward the 200 km segment.
Detailed Process per Line
Each liquefaction line follows an optimized cycle:
-
1. Capture and Plenum
Two large cylindrical vessels (Ø 8 m) handle air reception, stabilization, and pressurization. The first vessel acts as a large buffer, while the second, after a centrifugal pressurization pump, prepares the air for downstream stages. -
2. Upstream Purification
Removal of residual particles and controlled recombination of highly reactive atomic oxygen present at 100 km. -
3. Multi-Stage Compression
Four high-speed centrifugal compressors equipped with magnetic bearings compress the air up to 35 bar, with inter-stage cooling. -
4. Intermediate Cooling
Four Shell & Tube heat exchangers cooled by a closed-loop N₂ system supported by space radiators. -
5. Deep Cryogenic Cooling
Main plate-fin heat exchanger (Brazed Aluminum) lowers the air temperature to approximately -148 °C using recycled cold gas. -
6. Expansion and Liquefaction
A radial cryogenic expansion turbine performs isentropic expansion. This is the primary stage where liquefaction occurs (exit temperature ≈ -182 °C). -
7. Separation
A gas/liquid separator (Flash Tank) with demister efficiently separates the liquid and gaseous phases. -
8. Buffer Storage and Transfer
A cryogenic buffer tank provides at least 1 hour of autonomy before transfer to 200 km via a single line.
Performance
Key Technologies and Innovations
Integration with Starship
P1 is fully designed to leverage SpaceX’s Starship. All components will be built on Earth and could be launched into orbit by Starship. This “Build on Earth, Made for Space” approach takes full advantage of Starship’s high payload capacity and reusability to progressively assemble the megastructure in orbit.
This liquefaction unit represents a decisive step toward a sustainable space economy, enabling local production of essential resources for orbital refueling and future missions to the Moon and Mars.
- Throughput per line: 8.47 kg/s of processed air
- Nominal liquefaction rate: 30 %
- Annual total production: ≈ 239,500 tonnes of liquid air
Key Technologies and Innovations
- Extensive use of space radiators for passive, free cooling
- Optimized closed-loop N₂ system to minimize product loss
- High-speed centrifugal compressors with active magnetic bearings
- Direct mechanical coupling between the expansion turbine and compressors for maximum energy efficiency
- Modular design enabling progressive maintenance without full system shutdown
Integration with Starship
P1 is fully designed to leverage SpaceX’s Starship. All components will be built on Earth and could be launched into orbit by Starship. This “Build on Earth, Made for Space” approach takes full advantage of Starship’s high payload capacity and reusability to progressively assemble the megastructure in orbit.
This liquefaction unit represents a decisive step toward a sustainable space economy, enabling local production of essential resources for orbital refueling and future missions to the Moon and Mars.
