Space travel has evolved tremendously over the past quarter century, seeing a transformation from government-driven, exploratory missions to a dynamic, more commercially driven frontier.

In 1999, there were 79 orbital launch attempts, including intercontinental ballistic missile (ICBM) tests. Many of the missions were performed by the venerable space shuttle, Delta and Soyuz rockets, with the U.S. and Russia leading the way. The International Space Station (ISS) was in the early days of its construction, with NASA leading a number of countries to build the grandest of all international cooperation projects.