Orbital Station · LEO · 2025
A successor to the ISS built to validate artificial gravity and closed-loop life support.
Promethea Station is a modular platform in low Earth orbit designed to bridge the gap between the ISS and the demands of long-duration deep-space missions. An AG habitat rotates to generate Martian-equivalent gravity while the backbone runs a fully closed biological life support system — the two technologies most critical to a crewed Mars transit.
A commercial sector accommodates short-stay visitors, generating the revenue that sustains the research mission. The station reaches its final configuration after six Starship launches across four vehicle variants and three assembly phases.
Mission
Promethea Station addresses the two most critical unknowns of human deep-space travel: what sustained partial gravity does to the body over years, and whether biological systems can replace resupply chains entirely.
The AG habitat rotates at 5.6 rpm to simulate 0.38g — equivalent to Martian surface gravity — the station becomes a long-duration testbed for crew physiology before any Mars transit is attempted. The four ICELSS greenhouse modules provide a fully closed loop of oxygen, water, and food per crew unit, eliminating dependence on Earth resupply for those basic necessities.
The commercial sector is not decorative. Four short-stay tourism berths generate the operational funding that makes the research mission financially viable — a deliberate design constraint that shaped the station's modular structure.
Promethea is designed to remain operational for a minimum of 20 years, with modules replaceable on-orbit via Starship cargo flights. It is intended as the operational predecessor to any permanent Martian habitat: every system it tests is a system that Mars will require.
Launch & Assembly
Four vehicle variants (V1–V4) were derived of the station illustrated in three assembly phases. Each phase adds structural, habitation, and life-support capacity. The matrix below shows the progression: columns represent assembly phases, rows represent vehicle variants carrying progressively larger payloads.
Station Overview
The final configuration shows the four Space Crusader habitation arms extending symmetrically from the central hub. The ICELSS modules are separate inflatable modules connected to the microgravity backbone. The large solar array truss provides power for the full station. The microgravity backbone allows zero-g research.
Final configuration — top-down axonometric
Station Layout
Two distinct zones serve different gravity levels and user groups. The outer ring of Space Crusader modules provides Martian gravity, while the backbone provides a microgravity environment.
Martian gravity ring — complete station plan
Permanent research + microgravity — horizontal section
Microgravity zone — tether hub and experiment bays
Space Crusader Module
The Space Crusader is the primary habitation unit. Four modules extend from the central hub in a cross configuration and rotate together at 5.6 rpm, generating 0.38g at the habitat floor through centrifugal force. The station accommodates 12 individuals total across 4 modules — 8 permanent crew members separated in 2 modules and 4 tourists separated into 2 modules.
The module's cross-shaped plan allows four equal arms to extend radially, creating a balanced rotation system taking advantage of the present coriolis force. The modules are arranged parallel to the rotational axis to favor movement parallel to it and mitigate the effect of coriolis force on movement.
Space Crusader — axonometric
Frontal view — cross configuration
Commercial module — floor plan
Research module — floor plan
Construction Details
Space Crusader — horizontal section through rotating component axis
Rotating joint — tether deployment, ceramic bearings, and Whipple shield wall structure
ICELSS — Closed-Loop Life Support
The ICELSS — Inflatable Controlled Ecological Life Support System — consists of separate inflatable modules connected to the microgravity backbone. The units complete the biological loop: plants absorb the CO₂ and water produced by the crew, return oxygen, and yield food. Waste is preferably composted back into the growing medium.
The toroidal geometry creates a continuous growing surface. 40 m² of cultivated area per person is achieved through aeroponics and felt/NFT harvesting units. Autonomous robotic harvesting operates independent of crew schedules.
System Specification
| Daily caloric target | 2,500 kcal / person |
| Coverage per unit | 4 crew members |
| Aeroponic area | 4.421 m² / unit |
| Felt / NFT area | 1.341 m² / unit |
| Total per person | 40 m² |
| Harvesting | Autonomous robotic — 24 h cycle |
| Primary crops | Wheat, soy, potato, lettuce, tomato |
Bioregenerative Cycle
Crop Selection & Yield Data
Interior & Human Scale
Living at 0.38g in a rotating habitat is unlike any prior human spaceflight experience. The interior is designed to make this condition legible: curved floors follow the rotation radius, sightlines extend into the greenhouse, and natural light cycles are simulated to support circadian rhythm.
Technical Data
Artificial Gravity Parameters
| Rotation radius (R) | 10.8 m |
| Angular velocity (Ω) | 5.612 rpm |
| Tangential velocity (V) | 6.344 m/s |
| Centripetal acceleration | 0.38 g — Martian equivalent |
| Coriolis threshold | Within accepted comfort limits |
Wall Structure — Whipple Shield
| Outer bumper | Al6061-T6 · 2.032 mm |
| Intermediate layers | 6× Nextel AF62 + 6× Kevlar 120 |
| Rear wall | Al2219-T87 · 4.826 mm |
| Total shield depth | 4.5" front to back |
Full Project Overview
Bayraktar · Egg · Pejic — HB2 Orbital Shift booklet chapter