SCALE Nanotech, a digital startup from Estonia – and currently operating from ESA’s Business Incubator Center in Germany – has created an ultra-thin sail from graphene.
The tiny sail recently passed initial tests designed to show that it could be used as a viable material to make solar sails for spacecraft.
Light sails have been creating a lot of buzz within the space community for quite sometime now. They are one of the most promising existing space propulsion technologies that could enable us to reach other star systems within many decades.
Traditional spacecraft carry fuel to power their journeys and use complex orbital manoeuvres around other planets. The drawback with such craft is that the weight of the fuel makes them difficult to launch, and intricate flyby manoeuvres considerably lengthen the journey.
Solar sails on the other hand need no fuel. Spacecraft equipped with them are thus much lighter and easier to launch.
Two spacecraft flown over the past decade have already demonstrated the technology, but they used sails made of polyimide and of mylar, a polyester film.
And this where graphene comes into the picture; it is more lighter.
To test whether it could be used as a sail, the ESA-funded GrapheneSail team led by SCALE Nanotech director Santiago Cartamil-Bueno, used a scrap just 3 millimeters across.
They then dropped it from a 100-m tall tower in Bremen, Germany, to test whether it worked under vacuum and in microgravity.
Once the sail was in free-fall – effectively eliminating the effects of gravity – they shone a series of laser lights onto it, to see whether it would act as a solar sail.
Shining a 1 watt laser made the sail accelerate by up to 1 m/s2, similar to the acceleration of an office lift, but for solar sails the acceleration continues as long as sunlight keeps hitting the sails, taking spacecraft to higher and higher speeds.
Talking about the new solar sail, Astrid Orr from ESA’s Human Spaceflight Research Program, said that dropping graphene and shooting it with lasers is fascinating:
“To think that this research could help scientists to send instruments through the solar system and, if one dares to dream, to distant star systems in years to come is the icing on the cake.”
Image and content: ESA