Moon Miners' Manifesto

#5 May 1987

Essays in "M"

On the Moon, exiting an airlock in a space suit is something that architecture and engineering will both seek to make as unnecessary as possible. This for two reasons. First the high Lunar vacuum ( 10E-12 torr daytime facing the solar wind, 10E-14 torr nighttime sheltered from the solar wind ) is a precious industrial and scientific resource especially in combination with the Moon's substantial gravity. Opening airlocks for exit or entry and purging atmosphere into the vacuum, if done frequently enough, will degrade the vacuum to a point that the solar wind can't restore through its flushing action. Second, the nitrogen used as a buffer gas and biogenic ingredient in the colony's atmospherule must be imported and therefore must be conserved. Making up for preventable losses could well tax the colony's capacity for growth.

M IS FOR MIDDOORS:

On Earth we have been familiar with the distinction between indoors and outdoors for many thousands of years. In the last two decades or so, a new environment, the middoors, has become familiar to most of us in the form of the enclosed, climate-controlled streets and plazas of many a shopping mall. The "landscaped", sunlit central atrium in some new hotel and office buildings offers another class of examples.

In Lunar cities, except to enter and exit those (e.g. industrial) facilities which for safety's sake must keep their air unmixed with that of the city at large, it will be possible to go most anywhere without donning a space suit. Homes, schools, offices, farms, factories, and stores will exit, not to the airless, radiation-swept surface, but to a pressurized, soil-shielded, indirectly sunlit grid of walkways, residential streets, avenues, and parkways, parks, squares, and playgrounds.

While the temperature of traditionally indoor places could easily be maintained at "room comfort" levels, that of the interconnecting middoors of the city could be allowed, through proper design, to register enough solar gain during the course of the long Lunar day (dayspan), and enough radiative loss during the long nocturnal period (nightspan) to fluctuate 10 degrees F on either side, for example from 55-85 degrees F during the course of the month. "The Great Middoors" could be landscaped with plants thriving on this predictable variation. This would be both invigorating and healthy for people, plants, and animals alike, providing a psychologically beneficial monthly rhythm of tempered mini-seasons. Of course the middoors could also be designed to keep a steady temperature. But oh how boring that would be!

M IS FOR MATCHPORT:

To go from one Lunar city to another, or from the city to the space port or other outlying installations, or to transfer from one vehicle to another, all vehicles and city docks or marinas will be equipped with standardized matchports or interlocks. These will probably be of unisex design rather than male-female, and with either able to do the necessary aligning for safety's sake ( although there will undoubtedly be protocols ). When the two matchports are aligned and locked ( vehicle-vehicle or vehicle-city ), the narrow -- hopefully less than 1 cm -- vacuum gap will be slightly over-pressurized allowing port doors to unseal and open easily inward ( into vehicle, into city ).

Prior to disengagement, the port doors closed, the narrow inter-door gap would first be flushed with pure oxygen and then this would be pumped out ( into vehicle, into city ) to provide a low grade vacuum which would seal both port doors by internal pressure ( vehicle, city ) allowing the vehicle to pull back its matchport and depart, with the escape to the outdoors of only a minuscule amount of cheap oxygen -- no precious nitrogen would escape.

There would probably be three common matchport sizes: for personal surface vehicles, for public surface transports, and for cargo rigs. Outside of safety drills held periodically, perhaps most Lunans will live and travel widely about the Moon without ever putting on a spacesuit. It won't be necessary.

Contents of this issue of Moon Miners' Manifesto