Planck

Description

Planck is the third Medium-Sized Mission (M3) in ESA's Horizon 2000 Scientific Programme. A successor to the Differential Microwave Anisotropy experiment on NASA's Cosmic Background Explorer (COBE) mission and NASA's Microwave Anisotropy Probe (WMAP) mission, it will map the whole sky and measure temperature fluctuations in the Cosmic Microwave Background (CMB) with a precision of about two parts in a million at an angular resolution of ~10 arc-minutes. Thus, Planck will further constrain and test theories of the early universe and the origin of cosmic structure. Secondary science goals include measurement of the Sunyaev-Zeldovich effect and studies of the interstellar medium.

Planck will carry two scientific instruments. The Low-Frequency Instrument (LFI) contains an array of 56 radio receivers sensitive to 30-100 GHz emission. It operates at ~20K and provides angular resolution ~10 arcmin and 12 microKelvin sensitivity. The High-Frequency Instrument (HFI) contains 56 bolometers sensitive to 100-850 GHz emission. HFI is actively cooled to 0.1 K and provides angular resolution about 5 arc-min and approximately 5 microKelvin sensitivity. The Planck telescope is 1.5 m in diameter.

Planck was launched May 14, 2009 on an Ariane 5 along with the Herschel Space Observatory. The two satellites will separate shortly after launch, but both will go into operational orbits around the Sun-Earth L2 point, an optimal vantage point for far-infrared and submillimeter observing. This location is well isolated from the Earth's strong far-IR emission and provides good sky visibility because the Sun and Earth both lie in approximately the same direction.