The Planetary Society’s LightSail 2 spacecraft has been demonstrating the viability of solar sailing for a little over two years now and the society recently debuted a retrospective video called Sailing the Light. Given these events, I thought it would be interesting to look back at the Planetary Society’s first attempt at launching a solar sail, the ill-fated Cosmos 1. The design ideas implemented in Cosmos 1 were ones I used when creating the Aristarchus for my novel, The Solar Sea.
Cosmos 1 was primarily developed in Russia with oversight from The Planetary Society in the United States. The Planetary Society also provided system design expertise along with subsystem development, such as designing the onboard radio system. The craft’s design involved eight triangular sails deployed on inflatable booms. Motors at the ends of the booms allowed the sails to turn in pairs. This allowed them to optimize the amount of sunlight collected. Solar sails are propelled by the momentum from sunlight, so a solar sail in orbit wants to catch as much sunlight as possible when moving away from the sun. When moving toward the sun, the blades turn sideways, so the solar sail doesn’t slow down. I incorporated the turning boom design into my fictional solar sail. By the way, if you would like to build a Cosmos 1 model, I discovered that the instructions are still online. The pattern and instructions are free at: http://spacecraftkits.com/cosmos1/
The Russians finished building Cosmos 1 in 2005. They planned to send it into space with a Volna Rocket launched from a nuclear submarine. The expectation was that the rocket could carry Cosmos 1 to an orbital distance of 820 kilometers above the Earth’s surface. Just as a comparison, LightSail 2 orbits at about 710 kilometers above the Earth’s surface. Unfortunately the June 21, 2005 launch of Cosmos 1 failed and the rocket crashed into the sea. As I mentioned, The Planetary Society debuted a video about the current LightSail 2 mission called Sailing the Light. I watched the YouTube premier as it happened. You can see it here.
In the video, they talk about upcoming NASA solar sail missions Solar Cruiser and NEA Scout. Solar Cruiser is a significantly larger solar sail than Lightsail 2. Solar Cruiser would be 1650 square meters compared to LightSail 2’s 32 square meters. NEA Scout will be 86 square meters and will have the mission of looking for potentially harmful asteroids.
LightSail 2 accomplishes the turning maneuvers I mentioned above, not by turning its sails, but by using momentum wheels inside the space craft. It takes a couple of minutes to turn the craft ninety degrees. With new NASA solar sails in the works, I wondered if anyone was considering a return to the Cosmos 1 design anytime in the near future. I was able to pose that question to LightSail 2’s project scientist Dr. Bruce Betts at the end of the video. In effect, he says that in the near term, most projects are now developing square sails with reaction wheels to turn the craft.
You can read about my fictional solar sail in my novel The Solar Sea. It imagines an entrepreneur building a manned solar sail spaceship and taking it to Titan to search for mysterious particles that appear to travel through time. Along the way, the crew visits Mars and Jupiter and they find clues that we may not be alone in the universe after all. Learn more about the book and watch the book trailer at: http://davidleesummers.com/solar_sea.html