In the late 1960s, astronauts training in an Apollo simulator have their session ended early. They grumble about it, but their commander, Chiz (Robert Duvall), knows the reason for the abort: the Pilgrim Program. The Russians will be sending a Moon landing mission up in four weeks. The Americans had a secret alternate plan to the Apollo program, the fictional program Pilgrim, in case this happened. One man would be sent to the Moon in a one-way rocket (depicted in the film as a Titan II), using a modified Project Gemini craft. He would stay on the Moon for a few months in a shelter pod launched and landed before him. Later, a manned Apollo mission would come to retrieve him.