Skip to main content

The space elevator

Thumbnail
An illustration for a space elevator as seen from the geo-stationary transfer station looking down the length of the elevator structure towards Earth. Electromagnetic vehicles travel the length of the elevator to transfer passengers and cargo between space and the Earth. (Photo: NASA)

The concept of a space elevator is Biblical; Jacob's dream of a ladder extending into the heavens, upon which the angels of the Lord travel, is recorded in Genesis 28:12.  The dream was revived in the nineteenth and twentieth centuries by a two Russian scientists. Inspired by the Eiffel Tower, Konstantin Tsiolkovky advanced the idea of a 'Celestial Castle' in geosynchronous orbit, sitting atop an enormous structure reaching miles into space. 

In 1959, two years after the first Sputnik satellite went into orbit, Yuri Artsutanov conceived the idea of lowering a tapered tether with from an orbiting satellite down to Earth.  The tether could then be employed in an elevator to carry things into space.   A few years later, John Isaacs and colleagues published a paper in Science describing a "Sky Hook" in which masses could be launched into orbit along a tether using the rotation of the Earth to generate a large portion of the requisite energy.  The space elevator became part of pop culture after Arthur C. Clarke described a fictional version in his 1979 science fiction novel Fountains of Paradise.  The idea has been elaborated further in fiction by Robert H. Heinlein (Friday), Charles Scheffield (Web Between the Worlds), Kim Stanley Robinson (Red Mars), and David Gerrold (Jumping Off the Planet).

The tether of the elevator must contend with enormous forces -- gravity in one direction, and centripetal force in the other.  Heat generated by the friction of the lifter against the tether is another problem; heat is hard to dissipate in the vacuum of space.  The discovery of the carbon nanotube, with its enormous tensile strength and heat and electrical conductivity, brought the idea of a space elevator out of the realm of science fiction and into that of the technically challenging, but possible.

With support from NASA's Institute of Advanced Concepts, aeronautical engineer Brad Edwards conducted a feasibility study.  In his final report, published in 2003, Edwards concludes that a space elevator could be built in 15 years at a cost of $15 billion.  In a 2005 interview, Edwards estimated that the space elevator could carry payloads into space for 1/100th of the cost per pound of the shuttle missions. When NASA didn't immediately jump on the idea, Edwards formed his own company, Carbon Designs, to make the space elevator a reality.  A former associate, Michael Laine, started a competing company called Liftport Group. 

Michael Laine has envisioned the tether of the space elevator as a flat carbon nanotube ribbon extending 62,000 miles out into space.   Lifters would largely be powered by the centripetal force of the Earth's rotation, as cargos are whipped out into space.  One need only to step off at the altitude of one's choosing. 

The International Space Elevator Consortium sponsors an annual conference, as well as Climb, The Space Elevator Journal, which publishes scientific and engineering papers related to the concept of the space elevator.  There are space elevator games that challenge people to come up with innovative ideas to make the elevator a reality.  The European Space Elevator Challenge is being held in Munich in October of this year, and the fourth annual Japan Space Elevator Technical and Engineering Competition will be held August 1st.

So far, space elevator fans have an abundance of energy, enthusiasm and ingenuity but a shortage of funding.  What is needed, given the dismal state of government finances, is a young Internet billionaire or two seeking new challenges.  A hopeful sign is a recent New York Times report that Google's secretive X-lab is interested in the space elevator.