"[Christopher Frayling:] The moon buggy picked up on the real on we'd recently seen on television from the moon shot – as ever, reflecting things that were in the news and extending them.
[Ken Adam:] That was not my idea. Guy Hamilton decided that it should look grotesque so I extended the mechanical arms. I copied the fibreglass conical wheels of the real moon buggy but they kept breaking at high speed on the rough terrain of the moonscape we based on NASA photographs, so eventually Sony gave me balloon tyres and we completed the sequence with them."
Christopher Frayling: Ken Adam and the Art of Production Design. London 2005, S. 174.