The lunar space elevator

This paper examines lunar space elevators, a concept originated by the lead author, for lunar development. Lunar space elevators are flexible structures connecting the lunar surface with counterweights located beyond the LI or L2 Lagrangian points in the Earth-moon system. A lunar space elevator on the moon's near side, balanced about the LI Lagrangian point, could support robotic climbing vehicles to release lunar material into high Earth orbit. A lunar space elevator on the moon's far side, balanced about L2, could provide nearly continuous communication with an astronomical observatory on the moon's far side, away from the optical and radio interference from the Earth. Because of the lower mass of the moon, such lunar space elevators could be constructed of existing materials instead of carbon nanotubes, and would be much less massive than the Earth space elevator. We review likely spots for development of lunar surface operations (south pole locations for water and continuous sunlight, and equatorial locations for lower delta-V), and examine the likely payload requirements for Earth-to-moon and moon-to-Earth transportation. We then examine its capability to launch large amounts of lunar material into high Earth orbit, and do a top-level system analysis to evaluate the potential payoffs of lunar space elevators.