Light-induced Propulsion of Graphene-on-grid Sails in Microgravity

ESA-backed researchers demonstrate the laser-propulsion of graphene sails in microgravity. In an article recently published in Acta Astronautica, they report a scalable design that minimizes the overall sail mass and hence increases their thrust upon light irradiation. In addition, they prove the new sail concept by accelerating prototypes in a free-fall facility with 1W-lasers, reaching up to 1 m/s2. This milestone paves the way for lightweight ultralarge sails and eventually may help us to reach other star systems in a human lifespan.

Above – Graphene light sail of 3mm in diameter with a mass of 0.25 mg ‘sets sail’ when pointed with a 1W laser. The prototype has a graphene micromembrane design that reduces the overall mass while keeping functional the complete area of the sail.
Credit Dr. Santiago Jose Cartamil-Bueno

“Graphene is part of the solution”, says Dr. Santiago J. Cartamil-Bueno, SCALE Nanotech’s director and leader of GrapheneSail team. “We demonstrate a novel sail design that reduces the overall sail mass by using perforated films. By covering the holes with CVD graphene, the full area of the sail is again available for optical performance at minimal mass cost. The fabrication is relatively simple and could be easily scaled up to squared kilometers, although the in-space deployment of such a giant sail will be a serious challenge”.

researchers gained access to the ZARM Drop Tower in Bremen (Germany), in order to test the graphene sails in space-like conditions. Here, experiments are performed in a free-fall capsule that ensures a high-quality microgravity environment (<10-6 g) for few seconds. When the sail prototypes of small sizes were weightlessly floating, they were irradiated by 1W lasers and started to move with accelerations up to 1 m/s2.


• Light sails based on graphene have a reduced mass density that boosts their thrust.
• Graphene sails were accelerated with a laser in vacuum and microgravity.
• Microgravity enables sail release with reduced clamping effects during take off.
• Delays on the light-induced displacement may be caused by material desorption.
• 2D sails pave the way for reaching other star systems in a human lifespan.