Paul Calle (American, 1928 - 2010) and Chris Calle (American, B. 1961) "Space Exploration Captivates Millions" Signed lower right. Original Watercolor/ Mixed Media painting on Illustration Board. Provenance: Collection of James A. Helzer (1946-2008), Founder of Unicover Corporation. This painting is the original which was published on the Republic of the Marshall Islands The 20th Century Series 60c Space Exploration Captivates Millions stamp issued March 15, 2000. In the 1990s, people around the world were captivated by space exploration. On April 24, 1990, the space shuttle Discovery launched the Hubble Space Telescope. On September 11, 1997, NASA's Mars Global Surveyor began orbiting the red planet for a two year mapping survey of the entire Martian surface. On July 4, 1997, NASA's Pathfinder and its semi-autonomous rover Sojourner successfully landed on Mars. After Pathfinder's touchdown, Sojourner -- a microwave oven-size vehicle -- traveled down a ramp and began exploring its alien surroundings. For the first time in the history of America's space program, the Mars Pathfinder mission demonstrated the ability of engineers to deliver a semi-autonomous roving vehicle, capable of conducting science experiments, to the surface of another planet. Image Size: 9 x 13 in. Overall Size: 13 x 20 in. Unframed. (B16755 / B16756)