The Space Shuttle will be a critical element in the future of space exploration and utilization well into the next century. The Shuttle is now playing an important role[1] in the assembly of the International Space Station and will provide the tools, technology and human ingenuity to operate the Space Station in the challenging environment of Earth's orbit.

　　Among the Shuttle's greatest strengths, in addition to its amazing array[2] of capabilities, is its ability to adapt and evolve to meet new mission requirements. Whether it means installing a spare part or sending astronauts on a spacewalk to retrieve[3] an errant satellite, the Shuttle is unique in its ability to adapt real-time to get the job done.

　　As we enter routine operation of the International Space Station, the nation is also looking to the future of human space exploration, including a possible return to the Moon and the exploration of Mars. The Shuttle will continue to play a major role in human space exploration for years to come, including on-orbit assembly of new vehicles, and will become more capable and reliable with continued upgrades and development.