An elevator from Earth to Space sounds like something right out of a science fiction film. It seems like an impossibility – something an imaginative child might conjure up for a class project on the cosmos.

And the sci-fi-esqueness of a space elevator only increases the more you think about it.

After all, the tallest free-standing structure we’ve ever constructed, the Burj Khalifa, stands at just 828 metres.

An elevator into space would need to be astronomically tall, sticking out of Earth at the equator, almost like a chopstick lodged into the side of an orange.

But even though this all sounds improbable, or even impossible, a space elevator might actually be something that could be used for transportation from Earth to Space in the future.

A Pipe Dream or Scientific Reality?

The idea is not a new one either, and has its roots in Russia. One of the first visionaries who described a space elevator was Yuri Nikolaevich Artsutanov, who developed the idea of a ‘Cosmic Railway’ in 1960.

Decades before that, Russian rocket scientist Konstantin Tsiolkovsky envisioned overcoming gravity by means of an enormous sky ladder in his Dreams of Earth and Sky collection in 1895.

But in the 19th and 20th centuries, these ideas were just that – ideas. The technology wasn’t there to make an elevator into space a realistic possibility, much like when Da Vinci proposed an ‘aerial screw’ many centuries before we could build our first helicopter.

The difference here is that a space elevator might not be centuries away, and the idea of permanent transportation infrastructure from our planet to Space has evolved from a ‘dream into a scientific reality’.

That’s the view of the International Space Elevator Consortium (ISEC) at least.

The Green Road to Space – Why and How

The research and investment needed to achieve a ‘Green Road to Space’ is enormous – which means there must be a fairly good reason for its development.

Actually, there’s more than one. A cosmic railway would allow us to essentially defeat gravity, opening up countless possibilities.

Proponents of a space elevator argue that this permanent infrastructure would work similarly to a bridge, allowing for daily transportation which is not only safe and inexpensive, but also environmentally neutral.

It could also be the solution to one of the main obstacles we face in achieving our space aspirations – the enormous mass of the infrastructure required.

For example, ISEC says that a huge solar farm in space might weigh 3,000,000 tonnes, while Elon Musk has said that 1,000,000 tonnes of mission support may be required for his dream of colonising Mars.

To put this into context, humanity has only orbited 26,000 tonnes in its history.

A big part of the reason for this is the immense cost and challenge that comes from lifting any amount of material from the Earth into orbit.

When you see a giant rocket lifting off from Earth, from the Saturn V that first put men on the Moon to the SpaceX Starship, the majority of that bulk is dedicated to rockets and fuel needed to defeat Earth’s gravity.

A railroad to space could be the answer to these challenges, initially allowing for the movement of 30,000 tonnes per year, rising to 170,000 tonnes per year once fully operational.

This would be made possible by unbelievably fast transportation speeds, starting at 7 km per second, possibly allowing for much quicker transits to Mars – in under 100 days.

Those who argue that space elevators are the future believe that the infrastructure could also enable space solar farms, which could drastically improve the Earth’s environment with electricity from Space.

And work is already underway on just how solar farms in space could help solve the world’s energy needs. Researchers at Queen’s University Belfast working with SpaceSolar have developed and demonstrated a prototype satellite designed for just that purpose.

Such a satellite, when fully deployed, would have a solar antenna 2km in diameter, with the capacity to generate as much as 2GW of electricity 24/7.

Using a space elevator to bring the components of these solar satellites into orbit would make the process massively easier, faster, cheaper, and more environmentally friendly.

So that brings us to the all-important “how?”

Well unsurprisingly, ‘how’ has proved to be a much more difficult question to answer, with power and energy remaining significant barriers.

Most modern concepts of space elevators suggest using climbers – which means that moving cables wouldn’t be used like traditional elevators.

These mechanical climbers, ‘climbing’ up a stationary cable, would need to gain a large amount of potential energy as quickly as possible to clear the way for the following payload.

ISEC says that an array of PV solar panels could be used for power above 40 km, and various methods have been proposed to provide energy to these climbers.

These proposals include wireless energy transfer while the climber is ascending, and storing large amounts of nuclear energy in the climber before it begins its journey.

Laser power beaming along with mirrors and a solar PV array on the climber is probably the most likely method of making a green elevator a reality.

Another challenge, among many, is to find a suitable counterweight, with ideas ranging from captured asteroids to space stations or spaceports located beyond geostationary orbit.

Because of the many challenges, the idea of a green road to Space may never amount to anything. These difficulties include concerns about the cable’s material, deployment, and upkeep.

Whatever material such a cable is made from would have to deal with major changes in temperature, air resistance, gravity, and many other environmental conditions over its length.

These were the main issues raised in 2000 when a study was published following a NASA conference which explored the idea.

Ultimately, they concluded that a space elevator would not be viable for at least 50 years. And now that we’re halfway through that time period, significant challenges remain.

One such concern is the safety of this novel technology. Some say that it could pose a navigational hazard to aircraft and spacecraft. However, traffic control measures could combat this.

A more difficult problem to solve in terms of construction and operation is the possibility of impacts from space objects such as meteoroids, satellites and micrometeorites.

NASA estimates that there is more than 9,000 metric tonnes of material orbiting Earth. This includes more than 25,000 objects larger than 10cm, and another 500,000 between 1cm and 10cm in size circling up there.

Despite all of this, the ISEC believes that an environmentally friendly space elevator will become a reality, and the consortium is showing no signs of giving up hope due to advances in modern technology.

Maybe they’re right, and we’ll see a permanent transportation structure jutting out of Earth one day. Only time will tell.