The idea of climbing up an artificial structure into the heavens apparently goes back at least 4000 years as recorded by Moses in Genesis, Chapter 11; it was called the Tower of Babel. Tsiolkovski brought it up again in 1895, but the first technical paper did not appear until 1975. NASA has had tether and space elevator technology workshops since the 1980s and in 2000 published Space Elevators (NASA/CP-2000-210429), compiled by MSFC’s David Smitherman.

NASA’s Space Elevator concept consists of a tether structure in a GEO orbit (24 hour period) that hangs down 35,786 km to an ocean-based tall tower (e.g., 50 km high) at the equator. Then, like any other elevator, you simply climb up and down the cable!

If you lust for outer space — and who doesn’t?! — this is potentially an ebullient dream come true. Because this technique would dramatically lower launch costs (how’s $10/kg?), NASA believes a Space Elevator would, “… open up near-Earth space to miners, explorers, settlers, and adventurers, which will give us a frontier society once again….and alleviate any perception of overcrowding and scarcity of resources.”

NASA suggests that a typical Space Elevator would rank in weight somewhere between a North Sea oil platform and the Great Pyramid of Giza, although in length it’s only 1/3 of the U.S. interstate highway system. Interestingly, NASA compares the construction of a GEO Space Elevator to the 2nd greatest MEP of the last 200 years: the Panama Canal.

In 2000, NASA suggested that Space Elevator technology appears “within reach” during perhaps, “the next few decades,” which would put it smack in the middle of the next Maslow Window.

But there are many challenges — costs, materials, power — in the path of 21st Century Space Elevators, and technologists and entrepreneurs met recently at the 2008 Space Elevator Conference at Microsoft in Redmond, WA to chat about them. Participants hope that laser beamed power systems and ultra-strong carbon nanotube fibers are becoming more practical and economical, and are pushing Space Elevators a little closer to reality. To provide incentives, NASA is sponsoring the Space Elevator Games — an X-Prize-style competition — featuring cash prizes for technology demos in power beaming (climbing the cable), and tether strength (for a robust cable).

Another speed bump relates to Maslow Windows. Any complex, high-tech project — like a Space Elevator — that requires more than 20 years development time is potentially jeopardized not only by technology uncertainties, but also by the fact that in the last 200 years, Maslow Windows rarely linger longer than a decade.

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