Planck pre-launch status: The Planck mission

The European Space Agency’s Planck satellite, launched on 14 May 2009, is the third-generation space experiment in the field of cosmic microwave
background (CMB) research. It will image the anisotropies of the CMB over the whole sky, with unprecedented sensitivity ( ΔT
T
∼ 2 ×
10−6) and angular resolution (∼5 arcmin). Planck will provide a major source of information relevant to many fundamental cosmological problems
and will test current theories of the early evolution of the Universe and the origin of structure. It will also address a wide range of areas of
astrophysical research related to the Milky Way as well as external galaxies and clusters of galaxies. The ability of Planck to measure polarization
across a wide frequency range (30−350 GHz), with high precision and accuracy, and over the whole sky, will provide unique insight, not only
into specific cosmological questions, but also into the properties of the interstellar medium. This paper is part of a series which describes the
technical capabilities of the Planck scientific payload. It is based on the knowledge gathered during the on-ground calibration campaigns of the
major subsystems, principally its telescope and its two scientific instruments, and of tests at fully integrated satellite level. It represents the best
estimate before launch of the technical performance that the satellite and its payload will achieve in flight. In this paper, we summarise the main
elements of the payload performance, which is described in detail in the accompanying papers. In addition, we describe the satellite performance
elements which are most relevant for science, and provide an overview of the plans for scientific operations and data analysis.