At Launch Pad 39B, Space Shuttle Discovery towers against the hazy blue sky after a seven-hour trek from the Vehicle Assembly Building. The orbiter, external tank and solid rocket boosters will undergo final preparations for the STS-103 launch. The mission is a "call-up" due to the need to replace and repair portions of the Hubble Space Telescope. Although Hubble is operating normally and conducting its scientific observations, only three of its six gyroscopes are working properly. Four EVA's are planned to make the necessary repairs and replacements on the telescope. The STS-103 crew members are Commander Curtis L. Brown Jr., Pilot Scott J. Kelly, Steven L. Smith, C. Michael Foale (Ph.D.), John M. Grunsfeld (Ph.D.), and Claude Nicollier of Switzerland and Jean-François Clervoy of France, both with the European Space Agency. The mission is targeted for launch Dec. 6 at 2:37 a.m. EST