A recent European Space Agency (ESA) parabolic flight has demonstrated that graphene aerogels can be efficiently propelled by laser light in microgravity, highlighting a promising route for fuel‑free space propulsion. In near‑weightlessness, ultralight graphene aerogel cubes (density around 0.01 g/cm³) accelerated “faster than a blink” when illuminated with a laser, while under normal Earth gravity the same samples showed only minimal motion.
During the microgravity phases, the aerogels travelled about 50 mm in a few hundredths of a second and reached peak velocities of around 1.7 m/s, with a short thrust pulse on the order of 0.6 mN. On the ground at 1 g, displacement was limited to roughly 15 mm, velocities stayed near 0.06 m/s, and the thrust dropped to only a few tens of µN. This clearly shows that gravity and surface friction had been hiding most of the material’s light‑driven performance in previous lab measurements.
The propulsion mechanism is thermal: the laser heats the illuminated face of the porous graphene network, creating a steep temperature gradient across the aerogel. Residual gas in the pores is driven by Knudsen pumping and photophoretic forces, which convert this gradient into a directed thrust along the beam. By tuning the aerogel’s density and pore structure, the researchers found that an intermediate architecture gives the strongest thrust, while the laser power acts as a convenient “throttle” to control the response.
Researchers at the Université Libre de Bruxelles (ULB) in Belgium and Khalifa University in the United Arab Emirates (UAE) led the study, carried out during ESA’s parabolic‑flight campaign. Their results suggest that carefully engineered graphene aerogels can turn light into useful mechanical work in space, without the need for conventional propellant, enabling future concepts such as laser‑driven micro‑propulsion, attitude‑control elements for small satellites, and ultralight graphene‑based solar sails.
