 This study uses coherent diffractive imaging and ultra-short soft x-ray free electron laser pulses to track the evolution of individual large gas-phase xenon clusters turned into a nanoplasma by a high-power infrared laser pulse, from femtoseconds up to nanoseconds after excitation. The analysis reveals a mean cluster size and length scale of internal density fluctuations, which are reproduced by scattering simulations that assume the cluster expands with pronounced internal density fluctuations hundreds of picoseconds after excitation. This article was authored by L. Fluckager, D. Rupp, M. Adolf, and others.