EM2 is the Earth to Moon to Mars project, to develop and test technology for humankind’s colonisation of other worlds.
Major governments around the globe have decided to make detailed investigations of our Moon and the planet Mars.
Australia is working with the USA on the concept of using the Moon as a ‘springboard’ for the voyage to Mars. The main rocket systems for both legs of the flight will be accomplished using chemical propellants and it is proposed to set up bases on both the Moon and Mars that can support human life and, very importantly, manufacturing capabilities. On Mars the gravity is just 38 per cent that of Earth and on the Moon even less at 16 per cent that of the Earth; on Mars there is an atmosphere of CO2 at a pressure of one per cent of Earth’s atmosphere while on the Moon there is really no atmosphere.
For the present, Boswell Technologies will concentrate on the problem closer to home: how will a long term human habitat be constructed on the Moon? Atmospheric pressure on the Earth is about 10 tonnes per square metre, about the same as balancing four upended Toyota Landcruisers on top of each other.
So the Lunar habitat must be able to survive this huge force and it is why we see pictures of domes, spheres or cylinders in all studies of ‘Space-Port Moon’. On the Moon, the breathable atmosphere will be on the inside of the habitat and the force will be pushing outwards, so the structure will be in tensile stress. Rather than wait until we get to the Moon to test the habitats, it is best practice to conduct tests on the Earth and for that we need to create an environment that simulates that of the Moon. Now we have the opposite problem insofar as the atmosphere is on the outside pushing against the vacuum inside the habitat. Fortunately, the stress is now compressive, and many materials are immensely strong in compression. For example, concrete can support very tall buildings and is relatively inexpensive.
And so our first large scale experiment is going to be a 3 metre diameter dome made of concrete reinforced with basaltic fibre.
There are a number of challenges to overcome, concrete can be 20 per cent water and when that is pumped out becomes porous and will let atmospheric air into the vacuum chamber. We need to test the dome for leaks by pumping it down using a vacuum pump and measuring using pressure gauges. But before we do that we will try using a wet/dry vacuum cleaner to remove a lot of the water. Then it will be a competition between the speed the vacuum pump can remove gas from the dome, how fast the concrete outgasses and how badly it leaks.