SJAA Ephemeris November 2005 | SJAA Home | Contents | Previous | Next

November General Meeting

November 12 Speaker: Ben Shelef to talk on Space Elevators

David Smith


Spacecraft have contributed significant advances to our astronomical knowledge. The Hubble, Compton, Spitzer, and Chandra observatories among others in Earth orbit have expanded our spectral and resolution horizons. From Mariner 2, through the Voyagers, to Cassini and the Mars rovers, Interplanetary spacecraft have revolutionized knowledge of the solar system. But these, and other applications of space flight remain rare and expensive, to a large degree because of launch costs. It costs around $10,000 to put a kilogram of payload into orbit with current rockets.

Yet, the amount of energy required to orbit that kilogram is surprisingly small: 9 kilowatt-hours. That is, half a kilowatt-hour worth of gravitational energy to reach an altitude of 200 km, and another 8.5 kwh in kinetic energy to reach a speed of 17,500 mph. That is about 90 cents worth of electricity.

Our Nov, 12 speaker will be Ben Shelef, founder of the Spaceward Foundation. Ben will describe research on space elevators, a method to achieve cheap access to space using electricity instead of rockets. Space elevators (or "beanstalks") have long been considered outlandish science fiction. But advances in materials science are pushing them into the realm of the plausible. Space elevators are the cover story of the August IEEE Spectrum, published by the no-nonsense Institute of Electrical and Electronics Engineers.

This year, Mr. Shelef's foundation has won a grant from NASA to administer as prize money for developments needed to enable elevator construction.

The Spaceward Foundation will sponsor the first Space Elevator Games on October 21, 2005. Ben is helping to raise the curtain on the new Age of Space Exploration.


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