| Description | Enclosing some of the photographs that he thinks are relevant to the 'dust blowing problem' he referred to in his last letter. Says that 'I believe that the evidence of the dirty mirror on Surveyor III and these bits of evidence strongly indicate that all surfaces that are unshielded from the ground below the rocket exhaust will, in general, get a thin coating, which is difficult to see on white surfaces in the operation of the Surveyor, but which nevertheless is a serious problem for any optical surfaces, especially if they are in sunlight. An occasional patch has a thick glob adhering, but experimental evidence indicates that a thin film adheres almost everywhere. The lunar flying machine would present a serious and dangerous problem of that kind'. Goes on to discuss it in more detail. |