The LightSail spacecraft launched to test solar sail technology has ended its mission, burning up as the vehicle re-entered the Earth's atmosphere. The spacecraft broke from orbit and began to fall to our home planet at 1:23 p.m. on June 14.
Planetary Society President Bill Nye wrote of his experience seeing LightSail zip across the sky before the end of the week-long flight.
"Tonight, for the first time, I glimpsed our spacecraft with my own eyes. It was just the faintest pinprick against the bright lights of the big city. But there it was, right on time and exactly per the coordinates. I've tried to see it a few times before, but clouds and lights obscured my view," Nye said.
LightSail was launched on May 20 in an effort to test solar sails as a means of propulsion. These act like sails on ships, except they harvest sunlight instead of wind. The sails aboard this vessel, made of Mylar, stretched out over 344 square feet. The spacecraft launched into space aboard an Atlas 5 rocket, together with an X-37 space plane. The first days of the mission were plagued by trouble, but on June 7, engineers finally extended the sail on the craft.
"After completing the download of a sails-out photograph on Tuesday, the team started working to get an image from the spacecraft's opposite-side camera. LightSail sent home what was supposed to be a picture, but the file did not compile into a viewable image. Preparations began to capture a fresh set of images," Jason Davis wrote for The Planetary Society near the end of the mission.
Mission planners knew, even before the start of the mission, that the vehicle would fall to Earth within days of unfurling its sail.
The LightSail-A mission achieved its main goal of extending its sail. A second mission, LightSail-B, will be launched into a higher orbit, where it will be able to reflect enough sunlight to propel the vehicle. The force of the light particles, known as photons, pushes the LightSail similar to the way wind pushes a sailboat along in the water.
The cost of the LightSail project is estimated at $5.3 million. Most of this is coming from private donations, including a Kickstarter campaign. The idea of solar-powered spacecraft was first popularized three decades ago by the famed astronomer Carl Sagan. This technology would allow spacecraft to travel around the inner solar system without the need for fuel, greatly reducing the cost of missions.