LIGHTSAIL CRAFT PREPARES TO LAUNCH

- and it will use solar WIND to propel itself

Carl Sagan

40 years ago the late astronomer Carl Sagan proposed a spacecraft propelled only by the sun, is preparing to take flight - or rather, set sail .

The idea for a spacecraft to be equipped with a solar sail to use the solar wind for propulsion was described by the late Carl Sagan (left)

four decades ago in a 1976 broadcast of the Tonight Show with Jonny Carson

LightSail will be sent 447 miles (720km) above Earth to open its sail, with another spacecraft called Prox-1 taking images.

Here, it will unfurl its Mylar sail (illustrated)

Once unfurled, the Mylar sail - just 4.5 microns thick (a quarter the thickness of a bin bag) – will span more

than 345 square ft shown here in a test of the technology.

LightSail will be included on the first launch of SpaceX’s huge Falcon Heavy in 2016 along

with several other spacecraft.