The Spitzer Space Telescope whizzes in front of a brilliant, infrared view of the Milky Way galaxy's plane in this artistic depiction.

The mission marks the last of NASA's Great Observatories, a program that includes the Hubble Space Telescope, the Chandra X-Ray Observatory and the Compton Gamma-Ray Observatory.

In addition to studying many of the coldest, oldest and most dust-enshrouded objects and processes in the universe, the mission will also be an important part of NASA's Origins Program, which seeks to answer the questions: Where did we come from? Are we alone?