Mercury Seven a team and solo. Grissom, Cooper, and Slayton were Air Force pilots; Shepard, Carpenter, and Schirra were Navy pilots, and Glenn was a Marine Corps pilot. All seven had attended a variety of postsecondary institutions in the 1940s. Of the five astronauts who had completed undergraduate degrees before being selected, two (Shepard and Schirra) were graduates of the United States Naval Academy. Having earned a Master of Arts degree in 1957 at the Naval War College, Shepard was the only selectee who held an advanced degree. Following a decade of intermittent studies, Cooper completed his degree as a mid-career student
The Seven Stars Inn for indicating the direction North. "The Plough" is also a common pub name. The reference to "seven stars in the sky" in the famous Green Grow the Rushes O! Teaching Song or Dilly Song gives further, if mystical, insights. The Seven Stars could be the Seven Stars referred to in Revelations as representing the seven angels of the Seven churches of Asia; or the Pleiades, or Ursa Major. The song is replete with Christian and Pre-Christian symbolism, and dates to medieval times, if not earlier. Shakespeare refers to the "seven stars" in King Lear Act 1, v The Seven Stars