Assembly began April 1, 2010, for NASA's Juno spacecraft in the high-bay cleanroom at Lockheed Martin Space Systems in Denver, Colo. In this picture, workers are readying the spacecraft's propulsion module.

Juno aims to understand the origin and evolution of Jupiter.

Juno's principal investigator is Scott Bolton of Southwest Research Institute in San Antonio, Texas. NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the mission. Lockheed Martin Space Systems of Denver, Colo., is building the spacecraft. The Italian Space Agency, Rome, is contributing an infrared spectrometer instrument and a portion of the radio science experiment.

For more information about Juno, visit http://www.nasa.gov/juno.