Dispatches from the world of research
Successful deployment realises a 40-year dream.
A small non-profit organisation has achieved a space-travel feat dreamed about for more than 40 years: proving that it is possible to manoeuvre a spacecraft in Earth orbit using only the power of sunbeams.
In late June, The Planetary
Society, which has 50,000 members in 109 countries, launched a tiny, fivekilogram spacecraft into orbit, aboard a SpaceX Heavy Falcon rocket that also carried two dozen spacecraft for the US Air Force.
From there, the spacecraft, called LightSail 2, was delivered to an orbit about 720 kilometres above the Earth.
Seven weeks later, after preliminary tests, it deployed a boxing-ring-sized sheet of reflective Mylar film, which it used to “sail” on the pressure of sunlight.
The spacecraft’s small size makes it easy to manoeuvre, which is important because its operations require the orientation of its lightsail to be changed rapidly as it circles the Earth, like a sailboat tacking in changing winds.
LightSail 2 wasn’t designed to do anything other than test the ability to use lightsails to manoeuvre, but its success has important applications.
NASA has a six-CubeSat near-Earth asteroid mission, called NEA Scout, scheduled for launch sometime in 2020, which will also use lightsail propulsion.
“We’ve got an agreement to share technologies and findings,” says project manager David Spencer. “We really look forward to them carrying solar sailing technology to the next level.”