A Boeing Delta II 7920-8 rocket launches the ASA Advanced Composition Explorer (ACE) observatory into orbit from Cape Canaveral Air Station. The Delta II second stage delivered the observatory into an elliptical transfer orbit. ACE then used its own propulsion system to establish an orbit between the Earth and the sun. Approximately one million miles from Earth, the ACE observatory conducted its mission to examine the composition of several different types of solar and galactic matter.