Light‑Driven Propulsion of Graphene Aerogels in Microgravity

Ultralight graphene aerogels can convert light into mechanical work, yet their performance under reduced gravity remains largely unquantified. We investigated light-driven motion of macroscopic porous graphene networks during the 86th parabolic flight campaign of ESA, directly comparing their response in microgravity and at 1 g. In microgravity, optical excitation produced rapid translation: aerogels with a density of 0.01 g cm^{- 3} traversed 50 mm within 0.05 s and reached peak velocities of 1.7 m s^{- 1}, with peak accelerations ≳10² m s^{- 2} and an initial thrust pulse of 0.6 mN occurring within 0.03 s. Under 1 g, motion was strongly suppressed: displacement peaked near ≈15 mm by ≈0.16 s, with a modest velocity maximum ≈0.06 m s^{- 1} and a delayed thrust peak ≈11 µN at ≈0.08 s. Removing weight and normal-force friction, therefore, markedly amplifies optically induced forces in these ultralow-density networks. By directly quantifying distance, velocity, and transient thrust across gravitational regimes, our study establishes performance benchmarks for light-driven propulsion using graphene aerogels in microgravity environments.