This is a beautiful sheet of 6 stamps, issued by Guinea in 2008, displaying NASA's New Horizons robotic spacecraft. Also featured on the stamps are American astronomer & discoverer of the Milky Way galaxy Edwin Hubble, Danish chemist & astronomer Ejnar Hertzsprung, Dutch-American astronomer & founder of the Kuiper Belt Gerard Kuiper, American astronomer Henrietta Swan Leavitt, French astronomer & winner of the Gold Medal of the Royal Astronomical Society Bernard Lyot, heliocentrism astronomical theory developer Nicolaus Copernicus, the planet Pluto, and the Atlas V expendable rocket launch system. The sheet is Michel catalog # 5852-7, and is Post Office fresh, mint never hinged, and F/VF.