Why have the Americans developed space shuttle according to the passage?

Ever since the Apollo moon landings, the idea of human expeditions to the Mars has come up repeatedly as the kind of grand adventures that would give focus, purpose, and inspirational lift to the space program. But confronted with the cost — estimated at $ 150 billion last week — presidents starting with Richard Nixon and others have flinched and resorted to halfway measures like the shuttle.

Meditation is being recommended by more and more physicians as a way to prevent, slow or at least control the pain of chronic diseases like heart conditions, AIDS, cancer, and infertility. It is also being used to restore balance in the face of such psychiatric disturbances as depression, hyperactivity, and attention-deficit disorder(ADD). In a confluence of Eastern mysticism and western science, doctors are embracing meditation not because they think it’s hip or cool but because scientific studies are beginning to show that it works, particularly for stress-related conditions.