An experimental satellite testing innovative solar sail propulsion has been launched to space today aiming to demonstrate technology that could open the possibilities of interstellar travel.
The LightSail satellite, funded by public donations, was developed by the Planetary Society, the world’s largest non-profit space advocacy group.
The spacecraft, about the size of a shoe box, launched on Wednesday aboard an Atlas V rocket from the Cape Canaveral Air Force Station in Florida, will reach only the low Earth orbit where atmospheric drag exceeds the energy available from the Sun and will not be able to demonstrate controlled solar sailing
However, the researchers say, it would enable them to test the sail deployment mechanism ahead of a more ambitious mission next year.
The spacecraft will deploy its 32 square meter sail about four weeks into its mission after an extensive period of technical checks. Once deployed, the solar sails will increase the atmospheric drag exerted on the spacecraft resulting in a speedy re-entry. The researchers will thus have only a limited window to study the actual behaviour of the solar sails.
Solar sail propulsion relies on large sails made of an extremely thin but sturdy material that is bombarded by light photons providing momentum.
In theory, solar sails could power spacecraft cheaply, without the need for extra propellant. In fact the speed of a solar-sail powered spacecraft would keep constantly increasing over time.
This ability would make solar sails suitable for many applications including deep space and interstellar travel. The technology could also provide convenient means of propulsion for cube sats, which are too small to carry other types of rockets.
However, the technology has not yet been successfully demonstrated.
“Over the next days, we will be monitoring our CubeSat as we prepare for the big show: the day LightSail deploys its super shiny Mylar sails for flight on sunlight,” said Bill Nye, CEO of the Planetary Society.
“As we await that stage, we just get more excited. After all, we've been working on this for 39 years.”
The LightSail demonstrator, launched today, will be followed by a more ambitious experiment next year, the Planetary Society hopes, that will reach a higher altitutde of 720km - enough to fully demonstrate solar sailing capabilities in Earth orbit.
More than 11,000 people have financially backed the project online, raising almost £380,000.