For a number of years, we have followed the Planetary Society‘s efforts to launch a solar sail which would be propelled by light radiating from the sun. Yesterday, the society’s LightSail 2 deployed a 32-square-meter solar sail, about the size of a boxing ring, in Earth orbit.
LightSail 2 is the first spacecraft in Earth orbit to be propelled only by sunlight. The craft will orbit the earth powered by the momentum of solar photons striking the sail.
LightSail 2 is the Planetary Society’s second crowdfunded solar sail spacecraft. The Planetary Society is a non-government, nonprofit organization committed to advancing space science and exploration.
“We use the term boom just like on a sailboat, to hold the sails out, because we’re twisting relatively fast in Earth orbit,” explained Bill Nye, former host of Bill Nye the Science Guy and now CEO of the nonprofit Planetary Society, to the press before launch. “We go edge on toward the sun, twist 90 degrees, go face on and get a full push like a sailboat going downwind, building orbital energy. [We] then twist again on the night side of the Earth and twist on the day side, over and over.”
LightSail 2 is expected to remain in orbit for about the next year until atmospheric friction will cause it to fall back to Earth and burn up in the atmosphere.
The idea of solar sailing dates back to 1610, when Johannes Kepler observed that comet tails point away from the sun as if pushed by a celestial wind. In a letter to Galileo, he wrote, “Provide ships or sails adapted to the heavenly breezes, and there will be some who will brave even that void.”
If it doesnt go any where withe the suns energy. Will it finally be realised as a waste of time? Because if that wind existed, it should blow the sail far past the earth until another star blows it some where else. Or even that the sail will get shot around the earth until the sail comes out of the dark then gets shot in the other direction because the sail is now coming into the wind.
Plenty of ‘cans’ up there for it to tack around 🙂
It was back in the early 80s that the American Johnathan Eberhart a writer on space science and a lead singer with the folk group Boarding Party wrote a song about when sailors would sail and navigate their ships among the stars in his song `Solar Privateer’. It may yet come to pass as he then forecast. My fellow shanty singer Jonathan died of MS some years ago.
Very cool experiment. Could have a lot of practical applications.