Laser Communications Gets a Zap(pa) from Moon Unit

Photo by ESO Photo Ambassador Yuri Beletsky. Unrelated to the NASA experiment but cool nonetheless.

Lasers rank among the most vital and widespread technologies in the industrialized world, but for years they were considered a solution looking for a problem. One possible application lay in communications: Lasers, being of higher frequency and energy than radio, held the potential to communicate more information per second.

Fast-forward to October 2013, when NASA pulled off one of the most impressive proofs-of-concept in history. That month, a spacecraft orbiting the moon sent data 239,000 miles to Earth via a pulsed laser beam at a download rate of 622 megabits per second (by comparison, high-speed consumer data plans are usually measured in the tens of megabits). Everyone from cryptographers to high-speed Wall Street traders sat up and took notice. Sound cool? Read on as I explain…

How Laser Communication Works

Like a Bridge Under Troubled Waters

A partially disassembled tunnel boring machine (TBM)
A partially disassembled tunnel boring machine (TBM). Photo by Mike.

Between the years of 1825 and 1843 , through floods and financial failures, Marc Isambard Brunel and his son dug a tunnel under London’s Thames River. Our ambitions have grown since then, but the technology we use still bears a striking resemblance to Brunel’s shipworm-inspired device.

In this article, I look at some of the worlds most breathtaking underwater tunnels and delve into how they were constructed.

How do you build an underwater tunnel?