"The Childe...More restless than the swallow in the skies..." -Lord Byron, Childe Harold's Pilgrimage

Tuesday, August 31, 2010

Harnessing "The Wind From the Sun"

Look closely at the photo below and you will see people walking around what appears to be the mother of all TV dinners. In truth, the triangular sheets are not a TV dinner. They are something better. Perhaps for the first time, but almost certainly not for the last, you are looking at a solar sail.

Photo Credit: NASA

The above solar sail measures 66 feet on a side. Click here for the full caption provided by NASA. In part it reads, "Much like the wind pushing a sailboat through water, solar sails rely on sunlight to propel vehicles through space. The sail captures constantly streaming solar particles..." To be clear, solar wind is real. And for the first time, it has been utilized in actual spaceflight. Given this is an election year, I take some wry glee in pointing out that the first country to have successfully incorporated solar sail technology into space flight is neither the U.S. nor Russia. It is Japan. They did it earlier this summer.

My first exposure to solar sails came via a delightful short story by Arthur C. Clarke: "The Wind From the Sun." My memory is patchy, but I likely found the story in a bound collection borrowed from the public library when I was in junior high school. Perhaps I read it in this volume. (The short story was originally published in Boy's Life in 1964.) Regardless, Clarke's story enchanted me then, and enchants me even more today.

What I love about "The Wind from the Sun" is its sense of scale. The protagonist, John Merton, pilots a two-square-mile solar sail in a yacht race to the Moon. He competes against international rivals and faces the threat of a devastating solar flare during the race. It's exciting fiction and holds up very well over four decades later. Plus, you don't need to be a sci-fi geek to enjoy it. You only need to know that Clarke, in 1964, imagined a technology and space culture that is now becoming reality. "The Wind From the Sun" presciently depicts a global space race and the rise of space tourism.

Still, it is a bit deflating to know that while Clarke's story is even more relevant today, most of the research is still being done on the ground. However, I am excited to say that the United States may soon join Japan in testing solar sail technology in space. We are one rocket launch away. And the organization spearheading the mission is not NASA. It is The Planetary Society, co-founded by Carl Sagan.

Like many other enthusiasts, I'm not content with the tiny portion of my tax dollars allocated for space exploration. (Trust me, the portion of your personal tax contribution to NASA is tiny.) So I regularly make tax-deductible donations to projects like LightSail. Click this next link to see a wonderful artist's depiction of the solar sail our Society is helping build. By starting small, the Planetary Society can piggyback LightSail-1 on a rocket launch by NASA or another space agency in the near future. Call it cosmic carpooling.

In the meantime, there is Clarke's wonderful story "The Wind from the Sun" to enjoy. Without giving away the ending, I'd like to share a short excerpt. It describes the poignant moment when John Merton exits his solar wind-borne craft "Diana" for the last time. By opening the air lock, he uses the release of air to nudge the sail forward.

"The thrust he gave her then was his last gift to Diana. She dwindled away from him, sail glittering splendidly in the sunlight..."

Has Merton won the race? Has he lost? Will he or his solar sail even survive? You'll have to read the story to find out. In any case, the greater real-life tale is only beginning.


  1. I just got to go the Rose Center for Earth and Space/Hayden Planetarium in NYC. I watched the Hubble IMAX and the planetarium show. Amazing!
    The sail looks awesome.

  2. I was enthralled by the Hayden Planetarium. As you say, "Amazing!" Hopefully I'll get to go again someday. And Hubble might be the best IMAX film I've yet seen.