Man Who Sold the Moon / Orphans of the Sky
From the back cover:

***The Man Who Sold The Moon***

D.D. Harriman is a billionaire with a dream: the dream of Space for All Mankind.  The method?  Anything that works.  Maybe, in fact, Harriman goes too far.

But he will give us the stars...

***Orphans of the Sky***

Hugh had been taught that, according to the sacred writings, the Ship was on a voyage to faraway Centaurus.  But he also understood that this was allegory for a voyage to spiritual perfection.  Indeed, how *could* the Ship move, since its miles and miles of metal corridors were all there was of creation.  But then he discovered the truth....
American Science fiction, FICTION / Science Fiction / General, FICTION / Science Fiction / Adventure, FICTION / Science Fiction / Space Opera, Fiction, science fiction, general
Robert A. Heinlein
Robert Anson Heinlein was an American science fiction writer. Often called "the dean of science fiction writers", he was one of the most popular, influential, and controversial authors of the genre. He set a high standard for science and engineering plausibility and helped to raise the genre's standards of literary quality. He was one of the first writers to break into mainstream, general magazines such as The Saturday Evening Post, in the late 1940s, with unvarnished science fiction. He was among the first authors of bestselling, novel-length science fiction in the modern, mass-market era. For many years, Heinlein, Isaac Asimov, and Arthur C. Clarke were known as the "Big Three" of science fiction. ([Source](http://en.wikipedia.org/wiki/Robert_A._Heinlein).)