In a 2010 Space Foundation survey, Shepard was ranked as the ninth most popular space hero (tied with astronauts Buzz Aldrin and Gus Grissom). In 2011, NASA honored Shepard with an Ambassador of Exploration Award, consisting of a Moon rock encased in Lucite, for his contributions to the U.S. space program. His family members accepted the award on his behalf during a ceremony on April 28 at the U.S. Naval Academy Museum in Annapolis, Maryland, where it is on permanent display. On May 4, 2011, the U.S. Postal Service issued a first-class stamp in Shepard's honor, the first U.S. stamp to depict a specific astronaut. The first day of issue ceremony was held at NASA's Kennedy Space Center Visitor Complex.