Microchannel plates bearing a 60 nm thick aluminum film have been exposed to the external International Space Station (ISS) environment for 756 days. Postretrieval analysis has revealed holes in the aluminum film, which may have resulted from impacts by dust particles as small as a few tens of nanometers in diameter. Such particles have been undetectable by previously flown, much thicker foils. The flux of such particles appears to be consistent with the extrapolation, to this particle size regime, of current models for the near-Earth dust and debris environment and data from previously flown foils.