Style of language

In his Moon Speech, John F. Kennedy uses formal language that mirrors the context of the speech. He is invited to Rice University and he delivers his speech from the position of an “honorary visiting professor”, so his language fits the context. 

If we take a look at the sentence structure, we notice that Kennedy mainly uses middle-length and long sentences. This choice helps Kennedy present his thoughts on a particular issue in a longer sentence, like the one in the following example:

In short, our leadership in science and in industry, our hopes for peace and security, our obligations to ourselves as well as others, all require us to make this effort, to solve these mysteries, to solve them for the good of all men, and to become the world's leading ...