Back in 1976, late Carl Sagan in one of his interview put forth the concept of a new form of space propulsion that is called solar sailing. Solar sailing is a revolutionary concept of propelling spacecraft through space. A solar sail spacecraft consists of large reflective sails that captures momentum of light from the Sun. Then it uses that momentum to propel the spacecraft from the space. Now, around four decades later, Planetary Society validated this prospect in practice. After expending ten years of considerable hard work, and seven million dollars in funding, Planetary Society’s Light Sail 2 spacecraft is first of its kind spacecraft, that was able to raise its orbit only on the power of sunlight.
Light Sail program manager and also Society’s chief scientist Bruce Betts announces success for the mission “Light Sail 2″. He further announced that the criteria were to demonstrate controlled solar sailing in CubeSat, obtained by changing spacecraft’s orbit using light pressure from the Sun. It was revolutionary as it was something never achieved before. Light Sail 2 has been up into the orbit for a month now, and for the first time last week it opened its sail. After a week now, aircraft has raised its orbit by 1.7 km. It is being pushed along merely by Sun’s photons, which bounces off its reflective sails. After Japan’s “IKAROS” solar sail that launched in year 2010, Light Sail 2 is second successful attempt in the field of solar flying. But unlike IKAROS, Light Sail 2 uses this new form of propulsion actually to change its orbit.
An onboard algorithm autonomously controls Light Sail 2. This software alters aircraft’s orientation by twisting it 90o every 50 minutes. By this aircraft gets enough energy no matter where it is. This impressive algorithm is still being tweaked and updated. Until now one of the challenge has been refining the spacecraft’s momentum, controlled by a spinning wheel. This spinning wheel is used to change aircraft’s orientation and turns the thrusts from solar sailing on and off. When wheels arrive maximum speed, it needs to be slow down. This is now done using electromagnetic torque rod which orients the craft, using the Earth’s magnetic field. However, unfortunately, it takes the craft out of its actual orientation temporarily for solar sailing. Scientists are still figuring out how to lessen these saturation points to as much extent as possible. According to Bill Nye, CEO of Planetary Society, they are still learning a lot from Light Sail 2 right now.