Pembroke, Ont.-based Thoth Technology has patented an inflatable tower that could carry a "space elevator" higher than passenger jets fly – and eventually into low-Earth orbit.

The patent, which has been granted in the U.K. and the U.S. so far, describes a tower with a space launch platform on top that would initially be built to a height of around 20 kilometres high, but could theoretically be built to more than 200 kilometres high, and reach into low Earth orbit.

It would be made of stacked rings of Kevlar cells inflated with hydrogen or helium to an extremely high pressure. An elevator could ride up the tower, carrying spacecraft, satellites and other goods to be launched into space – along with tourists looking for an extraordinary view.

Carrying space cargo partway with an electric elevator would drastically reduce the amount of fuel needed to send such loads into space, says Brendan (Ben) Quine, the inventor behind the patent and Thoth Technology's chief technical officer.

Right now, rockets carry extra fuel in containers called "stages" that drop off and fall into the ocean as the rocket gains altitude.

Brendan Quine

Ben Quine, inventor of the space elevator tower, is chief technology officer at Thoth Technology and an associate professor of space engineering at York University in Toronto. (Thoth Technology)

Launching from a 20-kilometre-high tower would cut the amount of fuel needed by a third and make the first stage of the rocket unnecessary, Quine said, making fully reusable spacecraft, including rockets and space planes, more practical.

Caroline Roberts, president and CEO of the company, which is also working on getting a Canadian patent, says the tower could work well with the reusable rocket technology that SpaceX is developing.

She also believe the 20-kilometre-high tower would be an attractive tourist destination.

"From the top of the tower looking out, you would be able to see the bright blue rim of the Earth and a view stretching 1,000 kilometres."

The tower could also support massive wind turbines for power generation and be an alternative to satellites as a place to attach communications equipment.

Quine has already built a seven-metre-high scale model, which he unveiled in 2009 at York University in Toronto, where he is an associate professor.

Roberts says the company hopes to build a 1.5-kilometre-high prototype within five years – a height that would make it significantly higher than the current world's tallest building, the 830-metre-tall Burj Khalifa in Dubai.

Roberts thinks a version that could reach 20 kilometres above sea level, starting from the top of a five-kilometre-high mountain, could be built with 10 years at a cost of about $5 billion US.

Burj Khalifa

The Burj Khalifa in Dubai is the world's tallest manmade structure, at 828 metres. Thoth Technology hopes to build a protoype of its space elevator tower that is almost twice as tall within five years.

She added that Thoth is interested in partnering with companies that could help with construction of the prototype, including the developers of the world's largest buildings.

Quine's invention isn't a traditional space elevator, an idea that has been kicking around since the late 19th century. The traditional concept consists of a fine cable with one end attached to weight in space, orbiting the Earth, and the other end tethered to the ground. The cable would be used as a track for attaching "climbers" carrying goods from one end to the other.

There are two challenges with that concept, Quine said:

  • It needs to be built in space.
  • The cable would be degraded by meteor and lightning strikes, and would have to be replaced every six months.

Thoth Technology's elevator tower could be built from the ground up, and easily withstand not just lightning and meteors, but even category five hurricanes, Quine says.

In fact, the design includes gyroscopes to control the tower's movement and actively stabilize it during major storms.

Self-climbing elevator

Quine envisions several possible ways to get the elevator up the tower.

The traditional cable used to raise most elevators wouldn't be possible, since existing elevator cable materials couldn't support 1.5 kilometres worth of their own weight. Scientists have proposed making space elevator cables out of a new, ultra-strong, high-tech material called carbon nanotubes, but "you can't make cables out of carbon nanotubes that are rated for people yet," Quine says.

One possibility is a "self-climbing" elevator attached to claws that reach three-quarters of the way around the tower and wheels underneath the claws to allow the elevator to spiral around the outside.

"My preference would definitely be to have them on outside because then you'd get the view," Quine said. "The safety engineers are going to want it on the inside."

While the company works on the Canadian patent, it is interested in talking to anyone around the world who is interested in licensing its technology and building the prototype, Quine says.