As a kid, a favorite movie of mine was the 1994 live action The Jungle Book starring Jason Scott Lee and Lena Headey. In the movie, Mowgli escapes the British Soldiers by climbing up a rope that was mesmerized by a flute into stretching into the sky. Even at a young age, I understood the concept of gravity and knew that without tying the rope to an anchor point there was no way it holds a man’s weight. Even so, what an awesome escape! And it turns out, the idea is not completely incredulous.
Like the cosmic sling shots discussed in my last email, today’s topic, space elevators, have the potential to revolutionize the space industry. According to the International Space Elevator Consortium (ISEC), a space elevator is a vertical railroad using a cable tether extending 100,000 km to a counterweight in space. Along the tether, mechanical climbers would transport people and cargo from Earth’s surface to various orbital altitudes.
Sounds simple, right? Not quite. Let’s breakdown the design a little bit. In order to support payload weights as they move up and down, the tether has to remain taut. This is what the counterweight provides. However, at 100,000 km, the Earth’s rotation also becomes a factor. We can’t feel it down here, but this planet is rotating at 1,038 mph (check the math here). At the counterweight, that speed is noticeable. So a tether must be strong enough to carry heavy payloads with a high tensile strength (ability to withstand perpendicular pull). Steel cables just don’t make the grade.
According to this article by Interesting Engineering, however, space elevators could materialize in the next thirty years. In 2005, NASA sponsored the first Centennial Challenges, a program intended to encourage the development of the space elevator building blocks. The program included two challenges: the Tether Challenge and the Power Beaming Challenge. Since 2005, significant improvements in both areas underscore Interesting Engineering’s claim. The first is single crystal graphene (check out this article) boasting a tensile strength of 130 GPa, 236 times the tensile strength of steel and comfortably stronger than the 50 GPa requirement of the tether. The second improvement is in power beaming, a concept originating from Nikola Tesla. As reported in this article, the U.S. Defense Advanced Research Projects Agency (DARPA) and the U.S. Navy has successfully demonstrated microwave power beaming across one kilometer. When applied to the space elevator, power beaming would energize the payload to move along the tether.
NASA, the ISEC, and other space organizations recognize the development of the space elevator as the true opening of Earth’s Space Age. The elevator would allow NASA to sidestep the propulsion limitation of rockets as well as create a permanent reusable infrastructure. Space elevators are also not limited by most weather, could be used daily, and could carry large payloads (14 metric tons) from the beginning.
Projecting this into our science fiction future, space elevators suggest multiple transformations for Earth. I am always stuck by how massive spaceships are on TV shows like Star Trek. They are the size of small cities, and yet, those shows always depict the ships landing on planets. Personally, I am not a fan of giving up the wide, open spaces we still have to starship ports. Space elevators can provide travel to and from the surface without the hassle, cost, and potential pollution of landing a ship on the planet. The elevator would also act as a world wide harbor, providing transport and an Earth customs point.
This development also moves space from being the playground of the rich to being accessible to all. This creates possible science fiction history to weave into your story. With the enormous cost of getting into orbit, space development and colonization is currently in the purview of governments and corporations. The longer it stays like this, the longer those entities have to craft outer space to their specifications. In your story, do the elevators come early or late? Who holds the controlling stake in the orbital infrastructures? How/Does that affect Earth politics, government structures, or socieo-economic norms? Who achieves the first space elevator? Is it a single world power such as the U.S., China, or Russia or an international partnership such as the European Space Agency (ESA)? How does this effect the flavor of your space-faring society?
On a more personal level, the graphene and power beaming inventions change the interactions of your characters with the world around them. With its flexibility and tensile strength, graphene can be used to construct a wide variety of items, from space ships to personal protective clothing. Power beaming can provide remote recharging for many devices. Think back to my email about Holoportation. The exploration drone I conceptualized will need to get power from somewhere. Power beaming may be the answer.
Since the 1890s, the space elevator has inspired imaginations scientists and writers alike. Now, its reality is almost within reach. We may soon live in our own science fiction stories!