The Lunar Stairway: An Orbital-Platform-First Paradigm for Lunar Development and Its Engineering Rationale

Objective: To examine the mainstream premise that lunar development must be based on the lunar surface; to argue the engineering rationale for building long-term residential bases, production facilities, and logistics hubs first in circumlunar orbit rather than on the lunar surface; and to propose a system design for the “Lunar Stairway” (a distributed system of circumlunar platform ports). Methods: On the basis of orbital mechanics (the vis-viva equation and the rocket equation), the velocity increments and mass penalties of lunar-surface landing and departure were calculated and compared with those of residence in circumlunar orbit; the success rate of lunar soft-landing missions worldwide from 1966 to 2025 was tallied; scientific assessments of the Apollo moonquake network, the Chang’e-4 in situ radiation measurements on the lunar surface, and the health effects of lunar dust were compiled; and a ballistic delivery and interception–deceleration model for the “circumlunar platform–capsule projectile–cable-net/pit/sponge-lake splashdown” system was established. Results: A one-way landing on the lunar surface requires a velocity increment of approximately 1.9 km/s (with I sp = 300 s, propellant accounts for approximately 47.6% of the initial mass), and departure from the Moon requires a further approximately 1.85 km/s. The fully successful lunar soft-landing rate is approximately 50%, with failures concentrated in the powered-descent phase. Apollo seismometers recorded shallow moonquakes of magnitude up to approximately 5, lasting from tens of minutes to several hours, far longer than the tens of seconds of terrestrial earthquakes. The dose equivalent rate on the lunar surface is approximately 1.4 mSv/d (twice that on the International Space Station), and an extreme solar particle event of the 1972 type could deliver a dose of the order of 3–4 Sv without shielding. Lunar dust is fine, electrically charged, and sharp-edged; it is difficult to remove completely and causes irreversible damage to equipment and to the human respiratory system. With frozen orbits, the annual station-keeping velocity increment in low lunar orbit can be held to 10–50 m/s, corresponding to approximately 3–17 kg/(t·yr) of chemical propellant or approximately 0.6–3.2 kg/(t·yr) with electric propulsion, comparable to or lower than the ISS reboost level (approximately 18 kg/(t·yr)); ballistic delivery requires only an ejection increment of approximately 23 m/s and approximately 10 kg/t of propellant. Near-lunar orbits, although they require more orbit control, maintain closer contact with the lunar surface and receive less galactic radiation because of blockage by the Moon. Different orbits and distributed deployments should therefore be adopted according to actual requirements. Conclusions: Circumlunar-orbit platforms are comprehensively superior to lunar-surface residence in energy, safety, environment, astronomical observation, and logistics efficiency. It is recommended that the primary construction layer of lunar development be placed in lunar orbit rather than on the lunar surface, and that low-overload ballistic delivery and electromagnetic ejection be used to open a “lunar orbit–lunar surface” materials corridor (without which construction of the Stairway would be pointless). If a momentum-exchange mode is adopted between platform and cargo, substantial propellant and energy can be saved, coupling the efficient descent of cargo with platform orbit changes and orbit maintenance. The paper also proposes that spent spacecraft hulls be stored in lunar orbit as a reserve of scarce metals.