Dr. Marc Mauer, president of the National Federation of the Blind, left, accepts two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009 from NASA Associate Administrator Chris Scolese, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)