The Space Shuttle Discovery's Cargo Bay and Crew Module, and the Earth's horizon are reflected in the helmet visor of one of the space walking astronauts on STS-103. Astronauts Steven L. Smith, John M. Grunsfeld, C. Michael Foale and Claude Nicollier participated in three days of extravehicular activity on the NASA's third servicing visit to the Hubble Space Telescope (HST).