The U.S. Air Force are attempting to make Nikola Tesla's dream of power transmission from the atmosphere to the Earth a reality.

Illuminating a lightbulb isn't quite as dramatic as <a href="http://en.wikipedia.org/wiki/Wireless_energy_transfer" target="_blank">what Tesla envisaged</a> over a century ago, but it's a start...  

<em>The project as now blueprinted involves the building of two satellite systems concurrently, one “heavy” and one “light.” Each satellite would weigh some 400 pounds or less, with the desired launch dates in 2010.</em>

<em>The “heavy” satellite mission represents a more complicated set of tasks and greater expense than its counterpart. It involves placing on orbit a satellite that will collect power and broadcast it to Earth via laser, broadcasting it to a special ground receiving station where a lightbulb would be illuminated.</em>

<em>The “light” satellite mission would receive laser energy from the ground, lighting up a lightbulb. Visual observation of the light on the satellite being illuminated during the laser broadcast will indicate success.</em>

More info at the project's <a href="http://spacesolarpower.wordpress.com/" target="_self">web site</a>

Via <a href="http://www.livescience.com/blogs/2008/10/20/power-beaming-satellite-one-lightbulb-experiment/" target="_blank">Live Science</a>