What do you see when you look at the moon? Beauty? Crater? Some people see dollar signs. You will occasionally see our only natural satellite, dubbed “Earth’s Eighth Continent” because it is full of resources that are difficult to ignore. A rare form of helium, helium-3, could be used in fusion power plants here on Earth. Rare elements like neodymium could be extracted and brought back home for use in smartphones and other electronics.
But how do we get them here without wasting all the profits on missiles? According to a study published in 2019 a moon elevator could be the answer. A cable anchored to the lunar surface would extend most of the 400,000 km (250,000 miles) long home. It might not be directly connected to Earth due to the relative motions of the two objects, but it could end up high in Earth orbit.
That would have the added benefit of being placed over most of our space junk, a growing problem as we launch more and more satellites. Solar powered robotic shuttles could move up and down the cable and act as a conveyor belt to move valuable resources in our direction.
It might sound like an outlandish prospect, but Zephyr Penoyre and Emily Sandford – the two University of Columbia graduate astronomers behind the study – believe we could do it for a few billion dollars.
To put that in context, Jeff Bezos liquidates $ 1 billion (over £ 700 million) of his Amazon stock every year to fund his space tourism company, Blue Origin. NASAs Artemis programSending the first female astronaut and the first colored astronaut to the moon later this decade, costs $ 86 billion (£ 60 billion). This is the value of the moon’s resources, a separate study estimates that a Moon elevator would pay for itself in just 53 trips.
The cable, no thicker than a pencil, would weigh 40 tons – good for modern rockets like SpaceX’s Starship. In contrast to a space elevator that would travel from the earth’s surface into space, a moon elevator that stops something in front of our planet would not have to struggle with enormous gravitational forces.
The moon also has no atmosphere, which simplifies matters. This means that the cable could be made from existing materials like Kevlar, rather than the yet-to-be-invented super-strong materials needed for an elevator from Earth to space.
We could also combine both. In April 2021, Chinese state media presented the country’s idea for a ‘Ladder to heaven‘. This would mean that a spaceship would take an elevator from the surface of the earth to a waiting space station before being hurled towards the moon, where it would meet another elevator that would lower it to the surface of the moon.
The idea of space elevators has been around for over a century without much advances. But if enough people – or more likely corporations – are excited about the chance to make big bucks, we could see the lunar equivalent of a gold rush in the coming decades. Elevators could be a way to keep costs down and literally drive profits up.