It's the scourge of futurists everywhere: The space elevator can't seem to shake its image as something that's just ridiculous, laughed off as the stuff of sci-fi novels and overactive imaginations. But there are plenty of scientists who take the idea quite seriously, and they’re trying to buck that perception.
To that end, a diverse group of experts at the behest of the International Academy of Astronautics completed an impressively thorough study this month on whether building a space elevator is doable. Their resulting report, "Space Elevators: An Assessment of the Technological Feasibility and the Way Forward," found that, in a nutshell, such a contraption is both totally feasible and a really smart idea. And they laid out a 300-page roadmap detailing how to make it happen.
The "why build a space elevator?" part is easy. First up, it's because rockets aren't cutting it. Rocket technology is such that 80 percent of the mass is fuel and 14 percent is structure, leaving just 6 percent for the payload. Then the rocket takes off, spews a bunch of chemicals into the atmosphere, and never comes back. A cable-based transportation system, by comparison, would have no constraints on the size or shape of the payload, and at a fraction of the energy and cost, the study explains.
Moreover, once the elevator's cargo can safely switch from large payloads to transporting people into orbit, that could usher in a new era of space exploration that would lead to a "renaissance" that would transform the Earth, researchers write:
The facility to provide power to any location on the surface [space solar power satellites] will enable development across the world. Several examples are that Africa could skip the 20th century of wires while the outback of countries like India or China would not have to burn coal and the Amazon region could retain more of its rain forests. In addition, the increase in communications and Earth resource satellites will remake the emergency warning systems of the world. Some intractable problems on the Earth’s surface would also have solutions, such as the safe and secure delivery—and thus disposal—of nuclear waste to solar orbit.
Naturally, how to build a space elevator is more difficult to answer. The gist of the idea is this: A long, strong tether is anchored at the equator and extends into geosynchronous orbit some 62,000 miles above the Earth. At the other end is a counterweight far enough away to keep the center of mass in orbit with the Earth so the cable stays over the same point above the equator as the planet rotates. The rotation keeps the cable taut, to counter the gravitational pull as robotic, electric "climbers" ride the line up into space carrying the payload. Boom.
This basic concept hasn't changed much since Arthur C. Clark's 1979 novel The Fountains of Paradise first popularized the idea of an elevator to space—though no one took it seriously. Decades later, in 2003, Clarke stated, "The space elevator will be built ten years after they stop laughing … and they have stopped laughing."
What made people stop laughing? Nanotech. Carbon nanotubes were developed in the 90s and promised to be the uber-strong, light, flexible supermaterial needed to build the kind of 62,000-mile cable that could transport humans into space. By the end of the 90s, NASA had released its report on the technological progress: "Space Elevators: An Advanced Earth-Space Infrastructure for the New Millennium."
This month's IAA report gives something of an update. "The materials currently being tested in the laboratory have surpassed that level and promise a tether that can withstand the environmental and operational stresses necessary," it states. "Will it end up being carbon nanotubes, or boron nitrite materials, or something else?"
Nanomaterials are strong and light enough, but the rub is that scientists can't get them to scale yet. Luckily, billions of dollars are being poured into this area of research. The report predicts a suitable material will be ready by the 2020s.
As material engineering research continues, experts are feeling increasingly comfortable putting an ETA on the long-imagined space elevator. A couple years ago Japan predicted it could create the machine "by 2050". Rumors that the secretive Google X lab was building a space elevator sparked at least one prediction that it would “replace rockets in 50 years.”
Google has since denied any such project, but plenty of other attempts to make the journey into space easier and cheaper are still on the table. There is the research out of the International Space Elevator Consortium, the ambitious Kickstarter project to build a vehicle that travels from the Earth to the Moon, the Japanese space elevator that runs on solar power cells attached to the ISS, Elon Musk’s reusable rockets, NASA’s plan to launch objects into space with rail guns and magnetic levitation, and acclaimed sci-fi author Neil Stephenson’s moonshot project to build a tower so tall it reaches to the stars.
LiftPort raised $100,000 on Kickstarter for its plan to build an elevator to the moon
The IAA report, for its part, is ready to put the rubber to the road. It lays out everything from the technological infrastructure of the machine and the physics of defying gravity, to the funding profiles of the future space markets it would open up, and when investors should expect a return on investment from the elevator. "No doubt all the space agencies of the world will welcome such a definitive study that investigates new ways of transportation with major changes associated with inexpensive routine access to GEO and beyond," IAA president Gopalan Madhavan Nair writes in the report.
Be it 20, 50, or 100 years from now, if the elevator/bridge/gun/train/tower next-gen celestial transport system comes to fruition, it could be rockets that people are laughing about in the future.