Successful Solar Sailing

The Planetary Society’s LightSail 2 spacecraft launched into orbit on June 25, 2019 and deployed its 32-square meter sails almost a month later on July 23. In the time since sail deployment, it raised its orbit some seven kilometers. Here we see a great shot of the LightSail 2 over Australia.

LightSail 2 image courtesy The Planetary Society

In 1619, astronomer Johannes Kepler noticed that comet tails always point away from the sun and realized that some solar force must produce that effect. Two centuries later, in 1862, James Clerk Maxwell suggested that light has momentum and it was finally demonstrated in 1900. The goal of the LightSail 2 mission was to show that momentum from light could propel a spacecraft. The process of solar sailing is not unlike sailing on the water, only in space, gravity acts like water currents while light acts like wind. As with a sail at sea, the sails must be turned in flight to take the best advantage of the “wind” while the ship moves on the “current.” LightSail 2 accomplishes this via internal reaction wheels. The gif below shows how the sail is turned to take the best advantage of sunlight and raise its orbit.

Josh Spradling / The Planetary Society

The following graph shows the elevation of LightSail2 over the course of the mission. The apogee is the highest point in orbit, the perigee is the lowest point. At LightSail2’s elevation, there are two forces working on the sail besides gravity. The first is light pressure from the sun. The other is atmospheric drag from the Earth. Even though LightSail 2 is in a relatively high orbit, it’s still in the most tenuous parts of the upper atmosphere. The upshot is that the apogee increases because of light pressure, but the perigee decreases because of atmospheric drag. That noted, LightSail 2 has accomplished the mission it set out to do, demonstrate that light can propel a spacecraft.

Image from the LightSail Mission Control Page supported by the Planetary Society

You can keep up to date with the LightSail mission and visit their mission control page by going to http://www.planetary.org/explore/projects/lightsail-solar-sailing/#the-lightsail-2-mission.

It’s worth noting this is a technology in its infancy. That said, with the lessons learned from this mission, there’s promise that solar sails could be used for small unmanned probes in the not-too-distant future, or perhaps they could be used to deflect dangerous asteroids, especially if caught early enough that they only need a small nudge.

In the long run, with much more development and technical innovation, I would like to think solar sails could be used to propel humans across the solar system as I imagine in my novel The Solar Sea. In a little under a week, on Friday October 11, Lynn Moorer will interview me about the novel on her radio show from 12:30-1:00 pm mountain daylight time. If you’re in Las Cruces, you can tune in to 101.5 FM on your radio dial. If you aren’t in Las Cruces, or just don’t listen to shows on the radio, you can stream the show at  https://www.lccommunityradio.org/stream.html. It looks like KTAL Community Radio is building up their archive of past shows, so I’m hoping I can share these interviews with you soon. If you want to read the book before the interview, you can find all the places it’s available by visiting http://www.davidleesummers.com/solar_sea.html.

Taboo Tech

This past week, I had the opportunity to read Joy V. Smith’s latest novel, Taboo Tech. It tells the story of a young woman named Lacie Leigh Collier. Her parents seek out and try to understand old, dangerous, and forbidden technologies. As the novel opens, Lacie is graduating from primary school and preparing to move on to secondary school. Meanwhile, her parents have just found a lead on such a cache of taboo tech and leave her in the care of her uncle. If anything her uncle has an even greater interest in taboo tech and is soon tempted to explore yet another cache. He takes Lacie along with him, but they soon find the Interstellar Guard on their tail. Lacie’s uncle devises an intricate escape for his niece, but she soon finds herself alone in the galaxy with only the companionship of a fledgling AI called Embers.

At this point, Lacie’s adventures really begin. She completes school, then meets and befriends a group of professors who worked with her parents and they take her to a cache of taboo tech where she’s given command of a spaceship left to her by her parents. The professors and Lacie then hatch a plot to build a school on the site of the cache to allow the professors to investigate the cache while not arousing suspicion. To further allay suspicion, Lacie moves on to the resort world of Rainbow’s End where she befriends two members of the security staff and a diplomat’s daughter. All together, they help to thwart a plot against a princess. Lacie then must rescue her friends, the professors, from a plot to take over the school she helped to create. All the while, Lacie hopes to find clues to her parents’ and uncle’s whereabouts.

Taboo Tech is a rollicking fast story that propels Lacie from one adventure to another as she meets new friends, new adversaries, AIs and aliens. We’re never really told why old tech is taboo in this world other than it’s “dangerous.” However, I did wonder if the author gave us some sly clues. Her characters are often as carefully analytical as computers and the deepest emotions are sometimes expressed by the AIs in this world. It makes me wonder if the powers that be in this universe don’t want the humans to know something about their connection to the AIs. If Joy V. Smith ever writes a sequel, maybe this is something that can be explored. Taboo Tech is available at: https://www.amazon.com/Taboo-Tech-Joy-V-Smith/dp/0359516572/

I have had the pleasure of publishing another of Joy V. Smith’s books. Her short story collection Sugar Time is available as an audio book, a print collection, and an ebook from Hadrosaur Productions. The book tells the story of Sugar Sweet who inherits her Uncle Max’s old Victorian mansion where he conducted his research. She soon finds his collaborators—or what’s left of them—along with an angry Neanderthal. She also finds her uncle’s research project, a working time machine. Sugar must act quickly to unlock the secret of time travel so she can set things right and protect her uncle’s research. You can learn more about Sugar Time and order a copy at http://hadrosaur.com/SugarTime.php

The Solar Sea on Clearance

This past week, I’ve been reading the fine steampunk adventure Arabella on Mars by David D. Levine. It’s a fine novel that won the 2017 Andre Norton Award for best young adult novel. One of this fantasy novel’s conceits is that it imagines an atmosphere in interplanetary space that allows ships to sail between planets in the 1800s.

When I read the novel, I couldn’t help but think that while sailing between the planets without an atmosphere would have been beyond nineteenth century technology, it’s not beyond our current technology. In fact, I wrote a futuristic science fiction novel about such a journey called The Solar Sea. Solar sails don’t work by harnessing wind, or even the so-called solar wind, but they move by light pressure. About three years ago, I wrote a post that goes into some detail about how it works. You can read more here: https://davidleesummers.wordpress.com/2014/02/01/solar-sailing/

In my novel, I imagine a future where humans got as far as building lunar factories, but the will to go farther out into space died. While I know there’s still a strong interest in exploring space, I fear many of the people who control this country’s money don’t see the value in investing real money in all aspects of space exploration. As an example, the Trump administration routinely touts it’s support of space exploration, yet proposed significant cuts to astronomy funding in its initial budget.

I sometimes wonder if it will take a major discovery to give us the impetus to push out into space again as we did in the 1960s and 1970s. In the novel, a technician from the Very Large Array radio telescope in New Mexico discovers powerful particles orbiting Saturn’s moon, Titan, which could be a new energy source. When the discovery is announced, whales around the world changed their songs.

This chain of events encourages the owner of the powerful Quinn Corporation to build a solar sail to find the source of these particles in Titan’s orbit. He gathers the best and brightest team to pilot his craft: Jonathan Jefferson, an aging astronaut known as the last man on Mars; Natalie Freeman, a distinguished Navy captain; Myra Lee, a biologist specializing in whale communication; and John O’Connell, the technician who first discovered the particles. All together they make a grand tour of the solar system and discover not only wonders but dangers beyond their imagination.

Earlier this year, my publisher and I decided to take The Solar Sea out of print. There were several reasons for this. Partly, science and technology have caught up with the novel and I thought I worthwhile to revise it to make it more accurate. Partly the ebook was created ages ago and wasn’t up to the standards of newer ebooks, so I want to address this aspect as well. Once I finish work on my steampunk novel Owl Riders, I will turn my attention to some of my out of print titles.

In the meantime, I have a few copies of the first edition of The Solar Sea left in my stock and I’m even offering them at half off the cover price. You can order copies at http://www.hadrosaur.com/bookstore.html#solarsea. I would be delighted to sign any copies you buy. Just email me at hadrosaur [at] zianet [dot] com (replacing the info between the brackets with the relevant characters) and let me know that you would like it signed. If you would like them personalized, just tell me so and let me know who to sign the book to.