Next Floor, Space

Imagine walking into an elevator. You press a button, the doors close and you stand back. Some hours later, you hear a ding, and the doors open. You step outside the elevator into a hub in SPACE. Although it may sound like a far-fetched idea, creating a space elevator may be possible in the near future and could completely change how we travel in space.

Traditional Rockets vs. Space Elevators

A hilarious video from the Netflix show, the Space force, puts this restocking cost in perspective. In the clip, the congresswoman tries to claim that the Space Force isn’t effectively using its money. She brings up a receipt for sending an orange sent to space for $10,000. Satiricalness of this joke points out one of the biggest barriers in space flight, cost.

The traditional rockets we use today are chemical rockets, as hinted by their name, get their propulsion from the reaction of chemicals. Much of the chemical rocket’s design relies on the fact of storing more chemicals/fuel based on the journey. This is an okay system when making trips to the ISS or the moon, but you end up having to work with repairing a rocket each time you go to space and refueling. These costs can add up, making a restocking mission quite expensive.

One of the many advantages of the space elevator is cost. Although it will take $10 million to create, the elevator would be cheaper in the long run. It takes $22,000 to send 1 kilogram of material into space with a rocket. With a space elevator, it only takes $200 to send 1 kilogram into space.

When compared to a rocket that has to start up going straight and immediately has to turn to go into Earth’s orbit, therefore making space elevators are a more energy-efficient solution.

How it Works

A space elevator works by using energy to go directly up. Once it reaches Earth’s orbit the elevator would then rely on the rotation of the Earth to travel in Earth’s orbit. Traveling in Earth’s orbit requires no energy since if you are moving sideways fast enough, the curvature of the earth makes the ground fall beneath you while at the same time gravity pulls you towards it. They balance each other out.

A space elevator is comprised of 4 parts, the tether, climber, counterweight, and anchor.

• The tether would be connected from an anchor on Earth and would be stretched out to meet a counterweight in space. The tether would have to be lightweight, affordable, and strong.
• The counterweight would have to be higher than the geosynchronous orbit. Geosynchronous orbit is when something is roughly above the equator while in orbit. The center of mass would have to be in this orbit. This would make the elevator orbit around the Earth.
• The elevator would rely on tension between the counterweight and anchor on the tether, allowing for the climber to go up and down. The climber would be fully robotic and use a ribbon to guide it. Traction-tread rollers would be used to allow the climber to go up by grabbing the ribbon and constantly running it through.
• The platform would have to be located somewhere near the equator and would anchor the ribbon. This is because right above the equator would be perfectly in line with the geostationary orbit. The counterweight would have to be 100,000 kilometers above in space.

The space elevator would also require something to power it. There are many proposed ideas for this. One idea is a free-electron laser system that would have to be located at the anchor on Earth.

Limitations

Some problems have occurred though. One of the problems is the material of the tether. As I said earlier, the tether needs to be strong, lightweight, and affordable, and there is not any material that fits in all the categories. The tether needs to be strong enough to hold up to certain conditions such as space debris, radiation, weather, etc. Adding to the problem of the tether, it is going to be hard to find/create all that raw material to create the tether.

Some scientists are looking into carbon nanotubes that fit all the requirements. A brief overview, carbon nanotubes are a type of nanotechnology, meaning they are a piece of tech that works on the nanoscale, 10^-9. By working on such a small scale, carbon molecules gain new properties by working on this size scale. For example, carbon nanotubes are known for their strength. Carbon nanotubes are 117x stronger than steel. The carbon nanotube's strength is credited due to its structure. They are made up of hexagonal rings of carbon atoms that are double bonded. These hexagonal rings of carbon join to form a tube-shaped molecule.

The problem with carbon nanotubes today is that they’re hard to grow, based on the actual process and manufacturing costs.

Progress

The idea of a space elevator is purely a concept right now but many companies are working towards this idea.

1. Obayashi Corporation: Obayashi Corporation, located in Tokyo, has made plans for a space elevator and plans to build it by 2050. On their website, you can find designs for their space and earth ports. They also go into detail about the logistics of this and how they plan on using carbon nanotubes for the tether.
2. China: China plans on building a space elevator by 2045. They have been conducting tests in space although specific details have not been disclosed on what the test is about. They claim to have created the strongest fiber that could potentially be used as a tether for a space elevator.

Possible next steps for building a space elevator on Earth, may be taking it to the moon. By creating a space elevator, there are many risks that may permanently destabilize the planet. The thought behind taking it to the moon, allows for more leeway in making mistakes early.

Overall, a space elevator would completely change our thinking of space exploration. Our society is fueled by what is the cheapest option, making space exploration seem far-fetched. Reducing fuel costs by maximizing how we use our fuel, space exploration will no longer seem as far fetched. Space elevators would act as hubs allowing rockets to refuel and travel further away. While space elevators do seem like a far-fetched idea, putting a man on the moon used to seem far-fetched too. Space elevators will be a stepping stone of a future where we are a multiplanetary society.