Letter from Thomas Gold to Dr Sebastian von Hoerner, National Radio Astronomy Observatory, Charlottesville, Virginia Says that there is opposition within the Washington Defense Department to having a non-US citizen as Director of Arecibo [Ionospheric Observatory]. Says that, for the moment, this appears to exclude Dr von Hoerner from being offered the directorship. However, it does not exclude closer cooperation between Dr von Hoerner and Arecibo. 15 April 1966