Planck was selected as the third Medium-Sized Mission (M3) of ESA's Horizon 2000 Scientific Programme, and is today part of its Cosmic Vision Programme. It is designed to image the anisotropies of the Cosmic Background Radiation Field over the whole sky, with unprecedented sensitivity and angular resolution. Planck will provide a major source of information relevant to several cosmological and astrophysical issues, such as testing theories of the early universe and the origin of cosmic structure. The scientific development of the mission is directed by the Planck Science Team.

Planck was formerly called COBRAS/SAMBA. After the mission was selected and approved (in late 1996), it was renamed in honor of the German scientist Max Planck (1858-1947), Nobel Prize for Physics in 1918.

It is planned to launch Planck in the first quarter of 2007 together with the Herschel satellite. After launch, Planck and FIRST will separate and will be placed in different orbits around the second Lagrangian point of the Earth-Sun System.