It is a big honour to be invited to give this lecture in memory of that great engineer, Sir Henry Royce, but particularly so for anyone who happens to work in the Company of which he was co-founder and which of course represents the best memorial for which he could have wished.

I am very conscious of all this tonight but also, and with a distinct unease, that the Grand Old Man might be something less than sympathetic to my theme. The traditions of quality, craftsmanship and meticulous attention to detail design for which Royce is rightly famous, find, of course, their extreme justification in the construction of complex space vehicles, with their critical dependence on reliability. (There were about 15 million parts which had to work in the whole Apollo system, nearly half in the vehicle itself.) There is no doubt that he could have made immense contributions to space propulsion, as he did for land and air.