- SpaceX and Virgin Galactic could bring us to the Moon.
- The Moon is an ideal step-off point for other space missions.
- Construction on the Moon is becoming more feasible by the day.
The rise of SpaceX and Virgin Galactic has brought the Moon back into focus as a potential jumping-off point for missions to Mars and other destinations. Building, living, and working on the Moon may no longer be science fiction. So is a moon-base in our near future? And what are the main challenges of colonizing Earth’s beloved satellite?
Why Go to the Moon?
The Moon may be the perfect take-off point for missions to other planets and deep-space exploration. Its gravity is only 15 percent that of the Earth’s, and the satellite contains natural resources that can be used in building and manufacturing.
A moon colony is not out of the question. Professor Bernard Foing of the European Space Agency observes that the Moon’s surface area is equal in size to the African continent. He sees a potential “eighth” continent that could be a hub for manufacturing, a spaceport, or a tourist destination.
NASA has received funding to send a manned mission to Mars by the 2030s. Establishing a moon base may be the best way to (pardon the pun) get that mission off the ground.
Loading and Structural Challenges
When it comes to moon-based construction, loading and structural considerations are obviously different from those we face on Earth.
The internal pressure differential is crucial to the success of any structure in an airless environment. A differential of up to 2090 psf (pound-force per square foot) across an enclosure is required to sustain Earth-level pressure inside, resulting in outward pressure on a structure much greater than would be present on a similar earthbound construction.
Instead of compression-induced stress from gravity loading, a moon-based structure must withstand tensile stress. While the internal pressure of a habitat could be reduced below Earth-normal, the subsequent increase in oxygen needed for survival would create a high risk of flammability, potentially higher than the current maximum allowed for non-metallic flammability certification level.
Mining and Manufacturing
While the presence of volatile chemicals is low on our favorite “hunk of green cheese,” the Moon does contain many other chemicals and minerals valuable to mining and manufacturing interests:
- Ilmenite can be used to produce oxygen. The byproducts of iron and titanium can be used in living space construction, vehicle manufacturing, and making other rigid objects.
- Silicon is used in the manufacture of solar cells. Phosphorus and boron are used for semiconductor dopants.
- Helium 3 is available for potential use in fusion reactors that produce no radiation but substantial energy.
Behrokh Khoshnevis of the University of Southern California, also the president and CEO of Contour Crafting in El Segundo, CA, has developed a 3D-printing technology that he claims would be ideal for construction and manufacturing on the Moon.
The moisture in Earth’s soil makes it an ideal electrical ground. Lunar soil, on the other hand, is dry and will not work as a grounding source. Still, grounding could be achieved by connecting structures together with cables to create a common potential.
However, this is not the end of problems lunar soil—dust, really—creates. As the Apollo astronauts found out, it sticks to everything. It clogged on-board vacuums, human nasal passages, and filters. The dust can also become highly charged during solar storms; it discharges only when solar radiation hits the particles, which may not occur for some time.
Water is the primary concern after oxygen generation. Fortunately, there is evidence of water on the Moon’s surface. Most hydrogen and oxygen escapes from the Moon as solar radiation passes, but there may be permanent collections of water available at the poles.
The European Space Agency is already planning a “moon village” that would be a collaboration between national space agencies and private corporations. The permanent base is expected to act as a lab for learning how to live away from Earth.
We are rapidly approaching the technological capability for feasible off-Earth construction. If we made it to the Moon and back before integrated circuit chips were developed, just think what we can do now. Can meeting the Vulcans really be far behind?