A group of engineers and technicians prepare to mate the rover (tucked inside its backshell and turned upside-down on the left) to its protective heatshield, the black disk on the right.
The Mars Science Laboratory's main "hub" was a cleanroom at Jet Propulsion Laboratory in Pasadena, Calif. Various partners built and tested individual instruments at other locations. Teams needed to ensure that they delivered the best possible instrument to be mated with the body of the spacecraft. Eventually, all of the instruments traveled to Jet Propulsion Laboratory to be installed.
A very vital stage for the mission is the assembly, test and launch operations phase. Following individual testing, instruments are shipped to the cleanroom and mated with the rover and spacecraft. As everything begins to take shape, the entire structure is put through rigorous environmental, electronics, software and systems testing.