An elevator ride to space

Imagine riding a space elevator to the edge of space. That is the premise of a new concept (and patent) by a Canadian company named Thoth Technology Inc, which plans to erect a free standing tower that will rise an astonishing 20 Km from the ground to enable astronauts and tourists to reach space. The tower, which will be inflated and supported by a series of gas-pressurized cells, will also act as the docking platform for space planes that will carry satellites, cargo and tourists into lower orbit. Astronauts would ascend to 20 km elevator and from the top of the tower, space planes will launch in a single stage to orbit, returning to the top of the tower for refueling and re-flight.

Tallest

This is indeed a ‘tall’ order, considering that even the tallest free standing tower or building constructed so far (Burj Khalifa) measures only 830 metres - less than one kilometre. The engineering challenge is to maintain the structural integrity of this tower and make sure that it does not basically snap into two. The structure will be affected not only by the gravitational attraction of the Earth and by the ‘centrifugal force’ but also by the attraction of the Sun and the Moon, by the detailed shape of the Earth, and by the presence of space debris among other things. But nothing is impossible given the advanced construction techniques and new materials available today. Thus, the space tower could be a reality after all.

It is not even a new idea. Arthur C Clarke, a visionary who was always decades ahead of his time, predicted just such a structure in his famous novel Fountains of Paradise set on the fictional island of Taprobane. No prizes for guessing the inspiration for this fictional island - Taprobane is a dead ringer for Sri Lanka, where Clarke lived most of his life right until his death.

Novel

The Fountains of Paradise is a Hugo and Nebula Award-winning 1979 novel set in the 22nd century. It describes the construction of an “orbital tower”, a giant structure rising from the ground and linking with a satellite at the height of approximately 36,000 kilometers. Such a structure would be used to raise payloads to orbit without having to use rockets, making it much more cost effective.

In this novel, Dr Vannevar Morgan is a famous structural engineer who hopes to develop the ‘space elevator’ from a theoretical concept to reality and enlists the resources of his employers to carry out experiments. But the only suitable starting point (Earth station) for the elevator lies at the summit of a mountain in Taprobane occupied by an ancient order of Buddhist monks, who oppose the plan.

Clarke himself said the fictional equatorial island country of Taprobane is “about ninety percent congruent with the island of Ceylon”, south of its real world location. The ruins of the palace at Yakkagala as described in the book very closely match the real-life ruins at Sigiriya (Lion Rock). The mountain on which the space elevator is built is called Sri Kanda in the book, and bears a strong resemblance to the real mountain Sri Pada. There is a real possibility that an equatorial island such as Sri Lanka is ideally suited for the new structure as well. Lest you think that the whole idea is from science fiction, NASA itself commissioned a report titled “Space Elevator” in 2003.

Elevator

The Canadian space company has received a U.S. patent for a free-standing space elevator that could one day take astronauts aloft where they could take space planes into Earth’s orbit. Caroline Roberts, president and CEO of Thoth says the space tower, (tentatively named ThothX Tower) coupled with self-landing spacecraft, would soon bring about a new era of space transportation, making space flight more like riding in a passenger jet. The tower also is expected to be used for tourism, as well as communications and to generate wind energy. It could house hotels and restaurants that would provide the experience of being in space without the potential discomfort of zero gravity. The company plans to build a wind farm on the tower with 50 turbines that would generate one gigawatt of continuous energy which can power about 700,000 homes in addition to powering the tower itself.

These are exciting possibilities on paper, but whether the structure can actually be built and used in the real world is a question worth pondering. Question marks also hang over possible damage to the environment through such a gigantic project though the company insists that only recyclable materials will be used for the construction.

Thoth first plans to build a nearly 1.6 Km high tower within three to five years as a demonstration of their design and building capacity. The final 20 Km structure is likely to cost nearly US$ 5 billion, which critics say can be channelled to other avenues of space exploration. Ideally, there could be some saving from reduced rocket and fuel costs to offset this cost. According to the company, use of the space elevator might save up to 30 percent of fuel used by a conventional rocket.

Experience

The company says the elevator will enable millions of people to experience the view from near space (at US$ 1,000 per 30 minute ride to the top by high speed elevator) and reduce dramatically the cost of space exploration, enabling humanity to explore the solar system. Elevator cars - each of them capable of carrying up to 10 tons of cargo - would travel either on the outer surface of the tower or through the core - much like a pneumatic tube message system.

A salient feature of the proposal is that the company plans to license the technology to design and construction partners around the world. There should be some technology transfer in case companies (and a base) in emerging economies are selected. In any case, with the advances made in materials and construction technology, it should be possible to build this tower at least in the next decade.