 Which of these is a reason that Mary would have wanted Sammy to replace Phil?
If anything could go wrong, they wouldn't be sending me; you know that. But I don't think I ever really believed it was possible—not until this morning when you said tonight was the take-off. Its future as a town rested with the ship, and the town seemed to feel the uncertainty of its future, seemed ready to stop existing as a town and to give itself back to the desert, if such was its destiny. Phil turned the car off the highway onto the rutted dirt road that led across the sand to the field where the ship waited. He read Phil's pass, shined his flashlight in their faces, and then saluted.
 She thought she could protect herself if someone else went.
 She knows that Sammy is more careful, and would have a greater chance at mission success.  She thought she could protect herself if someone else went.  She thought that Sammy was more qualified.  She thought but his lack of family showed his dedication to his job.