LightSail 2 – One Year After Launch

This past Thursday marked the one-year anniversary of LightSail 2’s launch into orbit. LightSail 2 is a crowdfunded solar sail project managed by the Planetary Society and it’s the first craft propelled entirely by sunlight. The Planetary Society hosted a webinar to celebrate the event. Planetary Society CEO Bill Nye, Chief Operating Officer Jennifer Vaughn, Program Manager Dave Spencer, and Project Manager Bruce Betts all spoke. The presentation was moderated by Planetary Radio host Mat Kaplan. I am pleased to have been one of the mission funders and I was delighted to have had an opportunity to attend the webinar live. I gather the presentation will be viewable soon at https://www.planetary.org/multimedia/planetary-tv/. I found the presentation fascinating and I took three pages of notes. I’ll touch on a few highlights below and in Tuesday’s blog post, but if you’re interested in this project, be sure to check out the full video at the link above. You can learn more about the Planetary Society by visiting http://www.planetary.org.

Screen shot of the live webinar featuring Bill Nye, Dave Spencer, Mat Kaplan, Jennifer Vaughn, and Bruce Betts

The most exciting news from the webinar is that LightSail 2 is still flying one year after launch. It was placed into an orbit about 720 kilometers above the Earth’s surface, which is still low enough to have a very small amount of atmospheric drag. Despite that, the spacecraft has only lost about 10 km of altitude over the course of a year. It’s not certain how long it will be before it de-orbits, but current estimates say LightSail 2 could continue its mission for another year.

Bill Nye opened the presentation by noting it was 17th century astronomer Johannes Kepler who first speculated on the possibility of solar sails after observing the comet that would ultimately be known as Comet Halley. He reasoned that whatever force from the sun could produce the comet’s tail could propel a sailing vessel to other planets. The specific particle that can be used to propel a solar sail is the humble photon. Light has momentum and that momentum can be transferred to the sail for motion.

LightSail 2 has been able to perform so well because it can be turned like a sailboat’s sail. In this case, the craft is turned by momentum wheels aboard the ship. Momentum wheels are just gyroscopes, but tradition suggests that the word “gyroscope” is used principally when applied to navigation. When LightSail 2 is in a position to get a boost from sunlight, it turns so the sail catches all the light. When the light pressure would work against the sail, the craft turns 90 degrees so it presents the sun with the least amount of surface to push against.

Many great photos were shared during the webinar. My favorite was this one showing LightSail 2 over the Nile and the Red Sea. As you’ll notice, there’s a thin blue line at the Earth’s left edge. That’s our atmosphere, which looks very thin and fragile. I also imagine measuring the spectrum of that thin film on a planet in some distant stellar system from a telescope in our solar system. It’s a real technical challenge, but it looks like we may be getting close to a point where we could do that. This is something we’ll need to do in order to determine whether or not an exoplanet is potentially habitable.

LightSail 2 over the Nile and Red Sea. Image from The Planetary Society.
The Solar Sea

One of the things that makes all of this personally exciting is that I first joined the Planetary Society when I was in high school as a result of a letter sent to Star Trek fan clubs by Gene Roddenberry. I first learned of the Society’s interest to make solar sails a reality in the society’s newsletter, The Planetary Report. The idea caught my imagination and in high school, I started to write a novel called The Solar Sea. I didn’t complete it then, but the idea stayed with me and I made several attempts until I wrote a version that pleased me. That version was published in 2008 and you can learn more about it at: http://davidleesummers.com/solar_sea.html

Of Comic Cons and Solar Sails

I spent last weekend at Las Cruces Comic Con. Las Cruces is a relatively small town with a modest-sized convention center, so this was a much smaller event than say Phoenix Comicon, Emerald City Comicon, or the granddaddy of the them all: San Diego Comicon. Still, it was a great event with media panels featuring such people as David Zayas who played Sal Moroni in Gotham and Wendy Schaal who voices Francine Smith in American Dad. Lots of people turned out in some really inventive costumes and I was impressed with the photo area the convention organizers set up, which just allowed people to play. Here you see my youngest daughter and a friend having a light saber battle on Tatooine.

Tatooine

For me, it was an unusual convention in that I was the only writer in attendance. The organizers surprised me by giving me a “special appearance” credit in the program guide which was wonderful. Even though I was the only writer in attendance, I still managed quite a bit of networking. I got to speak to several of the artists in Artist’s Alley, had a productive chat with a film production team about possible book trailers, and of course, I got to speak with several friends and fans, some of which I knew from events in Phoenix and Tucson.

Unfortunately, at some point on Saturday I ate something that really disagreed with me. I didn’t sleep well Saturday night and I spent Sunday at the booth with my stomach churning. Still, I managed to have several nice conversations with people and by Monday morning I finally felt better.

Another feature of the weekend was that the DSL line to my house went dead on Friday, so even though I was at a local convention, I had limited internet contact. Fortunately, I still had access to wireless through the Convention Center, but it always amazes me how helpless I suddenly feel when instant communication—something that has come into existence during my adult life—has gone away. Still, I find these experiences helpful because I can channel them into my steampunk novels such as The Brazen Shark where my characters get to discover the novelty of instant, international communication, or my horror novel The Astronomer’s Crypt where my characters are literally and figuratively in the dark through the night and can’t even communicate with each other reliably through a building or across a mountaintop.

The Solar Sea

On Monday night, my older daughter called to say she got to hear Bill Nye the Science Guy give a talk in New Orleans. She said the talk was very inspirational and came right when she needed some encouragement about her recent decision to pursue a mathematics major. In addition to generally encouraging interest in STEM fields, Nye mentioned the Planetary Society’s recent success raising money for their LightSail Project.

In some fun synchronicity, the next day, Lachesis Publishing shared a guest blog post I wrote about creating a reading guide for my novel The Solar Sea. The novel imagines the first voyage to Jupiter and Saturn aboard a solar sail spacecraft. The reading guide presents activities and questions for any classrooms or book clubs who might be interested in reading the novel.

You can read my post at:
http://lachesispublishing.com/?p=6042.

You can learn more about The Solar Sea and download the reading guide at:
http://TheSolarSea.com