Megaprojects of the Future

Science fiction has made a lot of crazy promises over the years, from hoverboards to flying cars to entire floating cities built above the clouds on Venus. Basically sci-fi authors hate gravity. But not every idea popularized in science fiction is unrealistic, nor are they all still centuries away. Today we’ll be looking at some seemingly futuristic megaprojects that could be built a lot sooner than you might expect.

Space Elevators

Constantly sending rockets into space is an expensive process with a lot of limitations, so what if there was a better way? What if we could just build an elevator all the way to space? This was first proposed in a scientific context in the late 1800s, though the original idea was to just build a massive tower that was 35,786 km tall, the height of geostationary orbit. However, this was quickly determined to be completely unrealistic as there is no substance on Earth we could use to build a tower that tall without it being crushed under its own weight.

In 1959, Russian engineer Yuri Artsutanov suggested a more realistic design. Instead of building up from the Earth, the elevator could be lowered down from space. A satellite could be deployed to geostationary orbit from which the elevator would descend. At the same time the elevator was lowered, the satellite would also extend a counterweight in the opposite direction to ensure that the whole system remained balanced and stationary, rather than being pulled back down to Earth.

Once the elevator was in place, a mechanical climber would be able to ascend the cable to carry supplies to the satellite.

While this was a more realistic alternative for a space elevator, for a long time it wasn’t that much more realistic. The cable would need to be as lightweight as possible while also having an extremely high tensile strength. Steel was the best option available, but it wasn’t strong enough relative to its weight. It wasn’t until carbon nanotubes were first developed in the 1990s that it seems like a space elevator could actually become a reality.

Since then, researchers have been trying to figure out the most practical way to construct a space elevator. Organizations like NASA have even held yearly competitions with large cash prizes, though to date there have not been any winners. As disheartening as that may be, this megaproject is still within humanity’s grasp.

The design itself and the math supporting it are relatively simple. The only real obstacle standing in our way is the construction of the tether. Carbon nanotubes were promising, but the discovery of graphene in 2004 may be the key. Graphene is essentially the same thing as carbon nanotubes, but it’s only one atom thick creating a two dimensional structure. When rolled into cylinders graphene creates carbon nanotubes, but ribbons of graphene provide an even better option for a space elevator.

Japan’s Obayashi Corporation is currently trying to work out all the details to make this a reality, and they currently project that they will be able to complete a space elevator by 2050. They’re not alone in that belief, either. In 2019, the International Academy of Astronauts published a study analyzing the current progress and possible development of a functional space elevator. All of the scientists involved came to the same two conclusions: a space elevator is absolutely feasible, and they’re a lot closer than people think.

The only hurdle remaining is the ability to manufacture graphene on a larger scale.

Once it’s completed, a space elevator has the potential to revolutionize the world. The Obayashi Corporation believes that their climber would be able to ascend the elevator at a speed of about 150 km/h. This is on the low end of estimates, with many scientists assuming it would be able to travel twice that speed. While that’s certainly fast, it would take 8 days for the climber to travel the over 35,000 km to the satellite in geostationary orbit.

However, the climber doesn’t actually have to travel that entire distance. For example, the International Space Station orbits Earth at a height of only 400 km, meaning that the elevator ride would only take about 2.5 hours. That means that not only supplies but people as well could be quickly and easily transported to and from the space station through the use of a space elevator.

Moon Bases

The idea of having bases on the moon has been a part of science fiction for so long that it probably felt like it would remain fiction forever. But if all goes according to plan, the first lunar base will be completed before the end of the decade.

The efforts are being undertaken by the Artemis program, an international collaboration to get humans back on the moon. Artemis is led by NASA alongside the European Space Agency, the German Aerospace Center, the Japan Aerospace Exploration Agency, the Canadian Space Agency, the Israel Space Agency, and the Italian Space Agency. In addition to these government entities, there are over a dozen private companies involved in the Artemis program as well, ranging from aerospace companies to Toyota.

Artemis 1 was launched in 2022, and it was an uncrewed mission to have a craft orbit the moon before returning back to Earth. The mission was successful, and Artemis 2 is currently scheduled to launch in November of 2024. This will be another lunar orbiting mission, but this time it will be crewed, representing the first time astronauts have returned to the moon since 1972.

Following those missions is Artemis 3, currently scheduled for 2025. Artemis 3 will see astronauts finally set foot on the moon again. Future missions before the end of the decade will begin the construction of the first lunar base. NASA has even begun conducting studies using simulated bases, primarily to test the psychological effects that living in such a base for long periods of time will have on the occupants.

But the Artemis program isn’t alone, and China has their own plan to begin building a base on the moon in 2028. Although China isn’t part of the cooperative effort of the Artemis program, both groups have decided on the same solution to one of the biggest problems facing a moon base. That problem, of course, is how should we build it?

Building a base on Earth and shipping it to the moon in rockets would be extremely costly and inefficient. Instead of sending the base in pieces to be assembled on the moon, they are instead just going to send 3D printers. Artemis will be using the Olympus printer developed for NASA by ICON. ICON has already made architectural waves on Earth with its 3D printed houses, and now they look forward to doing the same thing on the moon and eventually Mars.

As for the building materials, Olympus will utilize a high powered laser to convert the lunar soil into building material. The Artemis Base Camp will be constructed on the moon’s south pole, largely because it is believed the area is full of water ice, though India’s recent mission to the moon failed to locate any of that ice. Though definitive plans are not yet known, members of the Artemis program have also stated that it is unlikely they would only build a single base on the moon.

There is a lot of data that could be collected by having a lunar base, but there is a longer term goal in mind as well. Having lunar bases could help facilitate manned missions to mars, as they could be used as a refueling station. This is why locating water ice on the south pole is so important. We already have a process by which water can be broken down into hydrogen and oxygen, meaning it could provide breathable air for the astronauts as well as additional rocket fuel.

Those trips to Mars are a little further in the future, but lunar bases are one megaproject we should see come to fruition relatively soon.

Solar Farms in Space

Despite perhaps being the most seemingly banal entry thus far, space-based solar farms are an idea straight out of science fiction. The idea was first described in Isaac Asimov’s 1941 short story “Reason”, and the concept wasn’t formally described in a scientific setting until 1968. But the idea itself is very simple: place a bunch of solar panels in space, then beam the energy they collect back to Earth. Not only does it sound like a straight forward plan, but it tackles two of the biggest problems facing solar energy here on Earth.

Those problems are space and efficiency.

While it should be possible to build enough solar farms on the surface of our planet to provide power for the entire world, those farms would take up a massive amount of space. For example, to generate enough solar power to meet the needs of the United States, it would require roughly the entire area of West Virginia to be covered in solar panels. To many people that’s a small price to pay, and there are certainly plenty of large, open areas spread across the United States where these farms could be built.

However, even if everybody could get on board with this plan, there’s a much bigger problem. And that’s the weather.

Despite humanity’s best efforts, we can’t actually control the weather. This means that the effectiveness of solar panels is reliant on sunny days. When factoring in both the day/night cycle and the frequency of cloudy and rainy days, solar panels on Earth are only able to collect power for an average of 29% of the time.

Building in space would solve both of those problems. The area in which satellites can orbit the Earth isn’t infinite and it would require taking up a sizeable chunk of that space, but with proper planning and coordination these farms could be safely placed into geosynchronous orbit to collect power. And once there, they would be able to collect far more power than photovoltaic cells back on Earth are able to.

To start, the sunlight in space is more intense. It isn’t being obstructed by our atmosphere, which means that the solar panels in space would be 44% more efficient than the absolute best case scenario for panels on Earth. And because in space there wouldn’t be any clouds, rain, or nighttime, the space-based solar farms would be able to collect this power 99% of the time. Those numbers seem pretty incredible, but unfortunately building these farms is only simple in theory, not in practice.

The financial cost of launching the necessary materials into space is extremely high, especially given how many solar panels we would actually need to power Earth, but we’ll come back to that in a moment. Even if the entire world was fully committed to building these farms and cost was no object, there are some additional problems.

There’s a lot of random crap floating around in space. It’s estimated that each day 25 million meteoroids and micrometeoroids enter Earth’s atmosphere. Most of these burn up long before reaching the ground and they pose absolutely no danger to our planet, but the same could not be said for our solar farm. Collisions from micrometeoroids, planetary dust, and space debris from broken and decommissioned satellites would all pose a threat to the panels.

Fixing damage would be a complicated task that required remote controlled robots, as it would be unacceptably dangerous for human astronauts to attempt repairs. Between debris and radiation, it’s estimated that the panels would suffer eight times as much damage as panels do here on Earth.

But perhaps the biggest hurdle is the wireless transmission of power. As a general principle, that is something that we already know is possible. You might even personally own a wireless phone charger. While these devices are highly efficient, the technology used isn’t an option for long distance transmission. Instead, we will need to rely on microwaves to send the electricity back down to Earth.

The solar energy from the sun would be collected by the panels, converted to microwaves, and beamed to Earth where it would be picked up by a special type of receiving antenna called a “rectenna”. Unfortunately, this provides a few additional problems. The panels convert the photons collected into electrons that provide energy, but those electrons are then converted back to microwave photons which are sent to the rectenna where they are then converted back to electrons again to be transmitted as usable power.

Each of those conversions results in a loss in the initial energy collected. Combined with losses from transmission through the atmosphere and the fact that microwave transmission is only 60-90% efficient in the first place, and we see the total output reduced multiple times. It’s still a massive amount of renewable energy, but unless a more efficient means of transmitting the power back to our planet can be created then it will increase the number of solar farms required to power the planet.

However, these problems can all be worked around. Even if solar farms aren’t going to be quite as efficient as they theoretically could be, enough of them could provide a virtually limitless supply of clean energy to fuel the entire planet. And as scientists and governments become increasingly concerned with carbon emissions, this plan becomes a whole lot more attractive.

The biggest singular hurdle is the cost, as the solar panels would need to be launched into space at a maximum cost of $200/kg in order to be competitive with other forms of energy. For the longest time that number was pretty much laughable, but in the last 15 years we have seen the cost plummet from over $50,000/kg to just $1,500/kg with SpaceX’s Falcon Heavy. Once SpaceX’s Starship is operational, that cost should be lowered even more.

As for when we will see this megaproject become a reality, various organizations estimate that sometime between 2035 and 2040 we could see the first space-based solar farm become operational. Tests have already begun, and in March of 2023 Caltech launched their Solar Space Power Demonstrator. The SSPD-1 performed a world’s first by beaming energy collected by its solar panels back to Caltech where it was successfully received. We now have proof that this method can work, so it’s just a matter of either making the technology cheaper or all agreeing that this form of solar energy is worth the investment.

Underwater Cities

When Plato first told the story of Atlantis thousands of years ago, the city was destroyed after the Atlanteans angered the gods. Over time, some retellings of Atlantis evolved into tales of a technologically advanced underwater city that very much still exists. With the majority of Earth’s surface covered in water, it only makes sense that humans would dream of utilizing that area to live in as well. Most importantly, we already know that it’s possible to live underwater.

While undersea life includes many of the same considerations as life in space, what with the lack of oxygen and all, it’s not that difficult for humans to build underwater habitats in which we can live. There are a number of underwater hotels you can stay in, both luxurious and economical, and the oldest one has been in business for over 35 years. These buildings don’t even need to be completely submerged, and having a top floor that is above the surface of the water makes it easier for people to get in and out.

A few small hotels are a nice novelty, but Japan’s Shimizu Corporation believes they can build an entire underwater city housed in a single structure. First unveiled in 2014, their proposed Ocean Spiral is an underwater city that would provide homes and workspaces for 4,000 people, with enough space for 1,000 daily visitors.

The Ocean Spiral would be a sphere half a km in diameter, with the top of the sphere poking out above the ocean to allow travel in and out. The spiral in its name refers to a long, spiral structure that would descend 4 km down to the ocean floor and would provide for most of the needs of the city. Water would be provided by reverse osmosis membrane desalination, a process that we already know how to use.

Clean, renewable energy would be provided by generators that are driven by ocean thermal energy conversion (OTEC), a process that takes advantage of the temperature difference between the icy waters of the deep and the warmer waters near the surface. While OTEC is an inefficient form of energy conversion, with only 7-10% of energy produced able to be extracted, the Shimizu Corporation is confident that the vastness of the ocean would provide enough power to run the entire city.

And of course, food would be primarily provided by large underwater farms of seafood and aquatic plants. Restaurants within the Ocean Spiral would undoubtedly be able to source other food from outside the city, but the plan is for the city to be as self sustaining as possible.

When Shimizu first announced their plan in 2014, they believed it would be ready to build within 15 years and would take 5 years of construction to complete. Those estimates don’t really seem to have changed, and most if not all of the technology required to construct Ocean Spiral already exists. Does that mean we should expect them to begin breaking ground on the project by 2029?

Unfortunately, probably not. The projected cost for Ocean Spiral is $26 billion, and Shimizu has had difficulty finding investors that are interested in shelling out that much money on an underwater city. But that doesn’t mean the end of underwater cities in general. Ocean Spiral may be the most famous and most concrete plan currently in place, but other organizations are looking into building underwater cities as well.

We don’t have an exact date, but if they are able to come up with a less expensive proposal, then we could certainly see one of these megaprojects become a reality within our lifetimes.

Key Takeaways

• Space elevators could revolutionize space travel by reducing costs and increasing efficiency.
• The Artemis program aims to establish a lunar base by the end of the decade.
• Space-based solar farms could provide a virtually limitless supply of clean energy.
• Underwater cities, like Japan’s proposed Ocean Spiral, face significant financial hurdles.
• Advancements in materials science and space technology are making megaprojects more feasible.

Sources

• Original Side Projects video: Megaprojects of the Future
• Hero image source by DiscoA340 / openverse, by-sa.

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