Last century, with less computing power than you have in your smart phone, humanity worked out the methodology to travel to the Moon, establish an orbit, and descend to the surface.
That allowed 12 different men to wander around, collecting samples, studying geology, installing scientific equipment, and setting a new technological high-water mark for our race.
It all happened in a mere 3½ years that began on July 21st, 1969, and ended December 14th, 1972. Fuelled by national pride, politics, and the Cold War (between the Soviet Union and the USA), the Space Race stimulated all sorts of scientific advances in the field of medicine, food processing, automation, and many more.
Going to Mars is very expensive proposition. Currently we have some very brilliant and wealthy people who are interested in the idea, and there’s nothing wrong with having a powerful dream. There are two ways to go about it however, and one of them is a very poor choice.
The way popularised by Elon Musk, for example, involves a one-way trip, with no plans for a capability to return. It’s akin to using a catapult to deliver the passengers. If something goes catastrophically wrong, such as an incoming asteroid, we can’t help them. We can’t help them evacuate; we can’t ship emergency supplies expediently; these people would be entirely on their own except for radio communication.
The other way is the equivalent of using the Moon as a stepping stone. There’s an old expression in the space industry that goes:
“Once you’re out of the Earth’s gravity well, you are more than halfway to anywhere in the Solar System”,
but why is that so?
It’s a Question of Energy
The mathematics is intimidating, so let’s use an analogy instead. Let’s say you were growing something in the desert. You have a little fertile patch of ground, and some seeds, but you need water. Unfortunately the only water available is at the bottom of a 2 kilometre deep hole.
You need to haul a bucket up on a rope, by hand. The bucket and water weigh 20 kilograms, but the rope adequate to lift that bucket (polypropylene 3 strand @ 4mm) would mass 30 kilograms. Consequently you must lift 50 kilograms through 2,000 metres to obtain about 19 litres of water to grow your plants.
That would be very hard work that most people could not accomplish. Once the water was up at the surface, it would be simple to move it from one place to another. You could carry it for kilometres with less effort than bringing it up from the well.
Climbing up the Well
Earth’s gravity “well” is 200 miles deep to Low Earth Orbit (LEO); to actually escape Earth orbit, it would be the energy but the above equivalent of ascending about 6,400 kilometres. Its influence extends much further than that, but that is the biggest “hump” that a spacecraft needs to overcome. To get anywhere else in the solar system requires less energy than to escape Earth’s gravity in the first place.
Our visionary friend Elon Musk wants to build a spaceship that will take a large number of colonists directly to Mars. It would be preceded by (probably several) unmanned spacecraft to set up infrastructure on Mars so that the colonists would have somewhere to live when they arrived. His super ship would launch from Launchpad 39A (the one Apollo 11 used), getting the passengers and equipment to orbit.
The booster would then deorbit, pick up a fuel module and return to the spaceship to fill it with the propellant it would need to get to Mars. Thousands and thousands of tonnes would have crawled up that gravity well, at a cost between US$20,000 and $50,000 per kilogram.
How the Moon Helps
If we launched the same amount of equipment, just one time, to the Moon, we could build a base there, with access to Earth’s resources for support. It would be easier, safer, and faster. It would permit us to set up a mining operation so we could collect strong, lightweight metals such as titanium, beryllium, and aluminium and from which we could build spacecraft components.
These building materials would not have to be lifted from the face of the Earth into space. By mining them on the Moon and processing them there, we could save billions of dollars, euros, or pounds. The Moon’s gravity is so slight compared to the Earth’s that it is almost free in comparison! To escape the Moon’s gravity is similar to ascending 288 kilometres, or only 4.5% that of Earth.
As a consequence of the mining operations, we would have an immense amount of oxygen from smelting all the metal. Oxygen makes a wonderful fuel for spaceships. The permanently shadowed craters of the Moon also but have ice deposits from which we could derive hydrogen for the other part of our fuel needs.
We could also mine silica to make glass and solar cells, while collecting other minerals for different construction needs. Best of all, we could collect a rare isotope of Helium gas that is plentiful on the Moon, but seldom found on Earth, called Helium-3 (or 3He).
When 3He is combined with Deuterium (an isotope of Hydrogen that possesses a Neutron) it releases an immense amount of energy and produces a hydrogen nucleus and a normal Helium atom. Best of all, it produces absolutely no radioactive waste. About 25 tonnes of 3He would provide the entire energy requirements for North America.
Fill her up!
The Moon would become the Space Age’s equivalent of a gas station. Building a linear accelerator on the Moon’s surface will allow us to magnetically launch canisters of 3He back to Earth can, to splash down in the oceans and be retrieved by barges. In the early days, until the infrastructure of a Martian colony is set up, 3He would probably supply the energy needs on that planet, too.
Even wasting 4.5% in energy to get something from the Moon’s surface to lunar orbit could be thought of as an unnecessary expense. While we don’t yet have the technology or materials to build a Space Elevator here on Earth, with the Moon’s lower gravity, it is well within our capability to do that. A space elevator from the lunar surface to lunar orbit would cost next to nothing to operate, running on solar power, or 3He powered sources.
Current technology, with no new innovation, would even allow us to build a space elevator on Mars, with tough materials such as Kevlar™ or Spectra™. That eliminates the need to ferry equipment up and down by rocket.
An arriving spacecraft at either the Moon or Mars would merely have to dock with the top of the space elevator, unload its cargo and passengers, and then take on some fuel brought up from the surface. No landing is required, saving an immense amount of energy. Mars has no known sources of 3He to power the ship for its return journey to the Moon. Its airless moons, Phobos and Deimos, may well be sources that could be mined.
What Mars does have in abundance is deuterium, the other half of the 3He energy formula. In fact it has more than five times as much as is found on Earth. Extracting deuterium on Earth is costly, making deuterium worth US$10,000/kilogram.
And that is only right now, before we have developed advanced fission and fusion. Once this clean, pollution free energy source is powering our planet, 3He and deuterium will be the most valuable substances in human history. The country, or private company, that mines 3He on the Moon will become the most economically powerful nation on the planet. But
The importance of setting up a Lunar Base/Research Centre/Mining Facility, a small settlement for the construction workers, and probably a Vacation Resort, particularly before we attempt to go to Mars, in undeniable. Once the Moon base is established, we’ll be running regular flights to Mars, the asteroid field, and the moons of Jupiter and Saturn. And then it becomes feasible to have a Martian colony where the next ship is probably only a week or less away.
Dragging an asteroid or comet back to lunar orbit would provide things we need like nitrogen, phosphates, sulphur, iron and many other things that are rare on the Moon. Dragging a few comets to Mars to crash into the surface would provide hundreds of metric tonnes of water, which would become vapour, and act as a greenhouse gas to warm the planet up. Eventually it would condense as lakes, and we could import mosses and plankton to manufacture an oxygen atmosphere.
Without any further help it would only take a couple of centuries to sustain life on the surface without a spacesuit. Be it ever so humble, there’s no place like a second home for humanity.
The Moon Needs to Come First
We will end up with a way station for further exploration of the solar system, or sending people and robot miners to the asteroid field, Jupiter’s and Saturn’s moons (which can provide us with rare hydrocarbons), and most importantly Mars. The Moon is a huge advantage for us; failing to take advantage of its presence and location would be completely foolish.
Our companion moon is so extraordinarily large that it is unprecedented anywhere that we know of. Technically we should probably refer to ourselves as a double-planet system which circles each other, rather than as a planet-moon system. It’s huge; it’s nearby; it’s convenient; and most importantly, we already know that we can get there successfully.
We also know that we’re very specifically going to need its 3He resources in just a couple of years. We know about resources that exist there that will make getting set up relatively easy, including kilometres-long underground lava tubes, hundreds of feet high and wide, and where we could build cities safe from solar radiation.
There are so many reasons to go back to the Moon and build a successful colony there. One of the most important reasons is that all of humanity lives within 300 kilometres of Earth. One large space rock could wipe out every single human being.
In the last 570 million years we have had seven Major Extinction Events. They occur about every 40-100 million years, averaging 81 million years, but we haven’t had one for well over 65 million years. We’re overdue. We need to get some of our eggs out of this single basket before the cosmic shooting gallery targets Earth. We’re the first beings on this planet that can do something about it. Will we?
Read also: https://www.fthinking.org/science/space-elevator-making-access-space-affordable/