The two sentences from the passage that provide relevant evidence supporting the author's claim are:
- "Specifically, after the Soviet Union successfully launched Sputnik I, the world's first artificial satellite, America responded by developing and launching a satellite known as Explorer I."
- "More land was found on the western frontier for settlement and new resources were discovered for use, leading to the nation's growth."
These sentences illustrate the benefits and advancements that have historically resulted from exploration, reinforcing the author's argument about the importance of space exploration in fostering progress and innovation in society.