Doing without rubber gaskets
Air lock doors must be sealed when closed to prevent loss of the air in a lunar colony. An alternative to using polymeric gaskets is using glass rope gaskets. The edge of the round door, the door frame and the glass gasket itself should be heated to the temperature at which the glass is pliable. The gasket is forced into the space to be sealed and allowed to cool. This should provide an adequate seal. To open the door the gasket would either be reheated or broken.
In an example of standard operation there would be four silos each with an air lock door on the top and an opening to a chamber at the bottom in the form of a cylinder with a horizontal axis. Two silos would be for putting beneficiated ilmenite into an oxygen processing plant. For these silos the ilmenite goes in through the top door. The horizontal chamber at the bottom leads to an air lock door allowing the ilmenite to enter the plant. Ilmenite could be moved by a horizontal auger to empty the silo. Remote controlled equipment would fill one of these silos while the other would be in the process of being emptied. After eight hours the open doors would be sealed, one silo would be pumped to a vacuum while the other is pressurized, the closed doors would be opened and the two silos would switch rolls.
For the other two silos tailings from the plant would be put in the top door of the silo and the horizontal chamber would lead to an air lock door by which the tailings leave the plant. The doors might go through a cycle once every eight hours while the sun shines. Any process for collecting volatiles would require processing inside a pressure vessel, so there would be considerable need for air lock door gaskets.
By the time people arrive at the colony, polymeric gaskets would be available for the faster cycling air lock doors that impatient people use. Hydrogen for use in polymers should be available from deposits mined at the poles. It only needs to cost less than $70,000 per pound to cost less than hydrogen imported from Earth, so considerable effort will be made to obtain it. There may be carbon compounds in the polar deposits too.
This article is a life support stub. You can help Lunarpedia byit.