We’ve been keeping readers informed about the Planetary Society’s project known as LightSail. This is our third update.
LightSail is an experiment to test the feasibility of solar sailing. Solar sailing entails capturing the pressure from the photons in the sun’s rays for propulsion. It uses large reflective sheets that work like wind sails. LightSail2 has now been in orbit for one month so its time for an update.
It has raised the apogee (high point) of its orbit by 7 km. Scientists have confirmed that the reason for this is that LightSail’s solar sails are working. The perigee (low point) of its orbit has declined by 9 km. This is normal because LightSail2 is in low earth orbit and so experiences some atmospheric drag at this altitude.
LightSail is the first spacecraft to use solar sailing for propulsion in Earth orbit. It’s also the first small spacecraft to show how solar sailing works. Only one other spacecraft has used solar sailing; Japan’s IKAROS in 2010. LightSail 2 is a fully crowdfunded spacecraft, and is the first such project to successfully demonstrate a new form of propulsion.
“this moment has been decades in the making”
“For The Planetary Society, this moment has been decades in the making,” said Planetary Society CEO Bill Nye. “Carl Sagan talked about solar sailing when I was in his class in 1977. But the idea goes back at least to 1607, when Johannes Kepler noticed that comet tails must be created by energy from the Sun. The LightSail2 mission is a game-changer for spaceflight and advancing space exploration.”
Three cheers for the Planetary Society, the LightSail missions team, its members and its sponsors!
There is always more to learn if we dare to know.