Artist illustration of the LightSail CubeSat, with Mylar sails unfolded. Image credit: The Planetary Society

May 21, 2015 LightSail launch is a success

Sen—If there is one thing I could happily write about all day, it is crowd-funded space projects. And successfully crowd-funded space projects are even more of a joy to write about.

To say that this project was a success is something of an understatement...the "LightSail" project reached its $200,000 USD target within 24 hours of going live on the Kickstarter website. Undoubtedly the target was reached with a little help from The Planetary Society's CEO Bill Nye who spearheaded the campaign.

The LightSail-1 CubeSat hitched a ride with the secretive X-37B military drone shuttle onboard the ULA Atlas 5 rocket on May 20.

This hitchhiking CubeSat is the first of two missions designed by The Planetary Society to demonstrate the functionality of a small solar sail propulsion system, which uses the force of the Sun's photons to gradually accelerate a sail attached to a CubeSat, in a way analogous to that of a traditional ocean-based sail boat.

This first test mission will demonstrate the deployment of the sails in a very Low Earth Orbit, allowing refinements to be made for the second mission (LightSail-2) slated for April 2016. If the first two missions are a success and funding can be secured, The Planetary Society state the possibility of another two missions dubbed LightSail-3 and 4 may be on the cards.

LightSail is not The Planetary Society’s first venture into solar sail technology—the Society has been toying with the idea for decades, since the founding days of Carl Sagan. In this video, Sagan can be seen with a mockup of a prototype solar sail, way back in 1976.

Effectively, LightSail is the spiritual successor to Cosmos-1, which if successful would have been the first solar sail satellite in history. However, due to the failure of the Russian Volna rocket in 2005, Cosmos-1 failed to reach orbit, and the honor of “first solar sail spacecraft ever” went to the Japanese, with the successful launch and completion of the IKAROS mission in 2010.

Solar sails are of particular interest to space agencies as they require no propellant and very little complicated machinery compared to traditional rockets, which require many tons worth of fuel and moving parts. Because solar sail spacecraft accelerate gradually but continuously, as opposed to rockets which accelerate rapidly and sporadically, solar sail spacecraft can reach much higher velocities than chemical rockets. It is envisioned that one day solar sails will help transport cargo across the Solar System, and maybe even to other stars.

Additionally, there has been talk of using solar sail technology for station keeping and orbit raising maneuvers on satellites. A satellite in an elliptical orbit around the Earth can gain speed by pointing its sail away from the Sun, therefore increasing its orbital altitude. Conversely, pointing the sail and spacecraft towards the Sun can slow the craft down, and lower the orbit.

Legendary engineer, physicist and science fiction writer Robert Forward proposed using solar sails to create static satellites, known as “statites”. The statite would loiter above the pole of the Earth having gained just enough acceleration to overcome the Earth’s gravitational field. 

The LightSail spacecraft launched on May 20 has already begun to send data back to Earth, confirming that the communications payload is functional. According to The Planetary Society website, the LightSail spacecraft will now deploy its sails and after the main phase is complete will begin to take some pretty pictures while keep an eye out on social media for those photos. 

Given the size of the solar sails, it should be possible to see the sunlight reflecting from Lightsail here on Earth. The position of the satellite can be monitored from The Planetary Society mission control website. So take a look on the site and point your eyes may just catch a glimpse of the spacecraft as it passes overhead!