Sky-high hopes for the future of space travel
Ontario company gets patent to develop 20-km tall inflatable elevator to the sky
A Canadian-made, inflatable space elevator stretching 20 kilometres into the sky could one day provide an alternative launch pad into space.
Thoth Technology, based in Pembroke, west of Ottawa, secured a U.S. patent for the space elevator technology in July, The Canadian Press has reported.
The self-supporting tower could deliver equipment and personnel to a platform above the Earth’s surface for the purposes of scientific research, communications or tourism, the patent states. The technology would function something like an airport on the edge of space.
“From the top of the structure you would be able to launch using a single-stage space plane directly into low Earth orbit,” Thoth co-founder and chief technical officer Brendan Quine told The Canadian Press from the Algonquin Radio Observatory in Pembroke. “The whole thing would be like a passenger jet.”
The idea for elevators into the sky is a science fiction staple which arguably dates back as far as the fable Jack and the Beanstalk. But in recent decades concepts to build real ones have taken root as a technically feasible and more efficient means to launch and retrieve spacecraft.
This particular concept is promising but huge challenges remain, according to one Canadian observer, Ishwar Puri, dean of engineering at McMaster University in Hamilton.
“The engineering challenge is to maintain the structural integrity of this tower and make sure that it doesn’t snap into two,” Puri told the Star in a telephone interview Tuesday.
“The space elevator concept has been sort of science fiction for a while. It’s been embedded in our psyche . . . The concept is quite simple whereas the reality is not.”
Specifically, three giant questions continue to stalk the idea of the space elevator. They pertain to:
1. Material
Traditionally, most space elevator designs have involved the use of a tether, extending between the Earth and space, along which elevators cars and other climbers will ascend and descend.
In practice, this would mean sending a satellite into orbit, which then releases a “string” back to Earth, according to Bradley Edwards, author of a 2003 report for NASA called The Space Elevator.
A mechanical climber then goes up the string to attach a second string and solidify the first one. This process gets repeated “until the ‘string’ has been thickened to a cable, our space elevator.”
The main problem with this system has been finding a material that is both tensile and lightweight enough to build the tether cable.
2. Stability
Quine told The Canadian Press the company intends to use pneumatic cells composed of materials such as polyethylene and Kevlar and leverage the power of gas pressure to create a strong, rigid structure capable of holding up the immense mass.
Space elevators must also withstand a variety of environmental hazards, including hurricanes and lightning on Earth, and meteors, space debris, radiation and electromagnetic fields in space, the IAA says.
3. Energy
Puri said another big challenge will be supplying energy to the inflatable tower. “When you go up and down an elevator in a hotel, it utilizes electricity . . . So how are they going to provide electricity across these long distances? What happens if there’s an electricity blackout?” he said.
“You would also have to supply a hospitable environment within your elevator which would be an oxygen-containing environment.”
Quine said the advantages of launching into space from the elevator are numerous.
Most significantly, launching into space vertically would not be necessary, saving more than 30 per cent of the fuel of a conventional rocket.
Quine says the project will cost between $5 billion and $10 billion (U.S.), and could take three to five years to complete the demonstration tower, and another three years to finish the full version.