He prepared his web site mainly for school kids &
tourists, but it's quite instructive. Note all the special precautions the
base staff have to take against the cold, with anything exposed for any length
of time. The lowest temperatures they see all year are around
-60C. The VBP will operate at temperatures at least that
low year round, and will regularly reach temperatures lower than have
ever been recorded on the Earth's surface. We're going to see
cold related problems they've never dreamed of in Antarctica.
Everything that must be exposed to the outside for any length
of time must be evaluated to see if it needs a heater to operate or can even
survive at our platform's average temperatures.
We can't put anything in the airlock that won't resist being
subjected to alternating cycles of pressure and vacuum as it goes between room
temperature and cryogenic cold. That eliminates most plastics and all
but the simplest electronics. If there are systems that have to be ready
instantly without preheating (like the pressure door seals and the valves that
pressurize the airlock), the list of components that will survive that abuse is
even shorter.
The airlock -- especially its compressors, valves &
gauges -- will have to be heated and stay heated during any time the
airlock is open to the outside air. Antifreeze heating blankets wrapped
around the pumps and run behind the main valve panel should serve, with
insulation where necessary. Most components that lack moving parts won't
have to be heated, but the tool bay will. In fact, we should develop an
insulated toolbox with a small heater suitable to keep power tools above -10C
during trips up and down the keel. Anything else stored in the airlock
will have the same problem, so I think we should just go with insulated cabinets
inside as a matter of faith and provide for antifreeze heating of those,
too.
I think we should stick to a smaller airlock design.
A smaller airlock pressurizes faster and heats faster with
less energy. It won't have as much storage space, but there are severe
limits to what we can store there in the first place because of the extremes it
will be exposed to. Storage is not the primary function of an airlock, but
the VBP platform airlock will have it as an important secondary function.
This is because it is a convenient place to keep things warm.
