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Planck (spacecraft)

space observatory

Planck was a space observatory operated by the European Space Agency (ESA) from 2009 to 2013.

Mission typeSpace telescope
COSPAR ID2009-026B
SATCAT no.34938
Mission durationPlanned: >15 months
Final: 4 years, 5 months, 8 days
Spacecraft properties
ManufacturerThales Alenia Space
Launch mass1,950 kg (4,300 lb)[1]
Payload mass205 kg (452 lb)
DimensionsBody: 4.20 m × 4.22 m (13.8 ft × 13.8 ft)
Start of mission
Launch date14 May 2009, 13:12:02 (2009-05-14UTC13:12:02) UTC
RocketAriane 5 ECA
Launch siteGuiana Space Centre,
French Guiana
Entered service3 July 2009
End of mission
Deactivated23 October 2013, 12:10:27 (2013-10-23UTC12:10:28) UTC
Orbital parameters
Reference systemTemplate:L2
(1,500,000 km / 930,000 mi)
Main telescope
Diameter1.9 m × 1.5 m (6.2 ft × 4.9 ft)
Wavelengths300 µm – 11.1 mm (frequencies between 27 GHz and 1 THz)
Horizon 2000

It mapped the anisotropies of the cosmic microwave background (CMB) at microwave and infra-red frequencies, with high sensitivity and small angular resolution.

The mission improved on observations made by the NASA Wilkinson Microwave Anisotropy Probe (WMAP). Planck provided a major source of information about cosmology and astrophysics. It tested theories of the early Universe and the origin of cosmic structure.

Since the end of its mission, Planck has made the most precise measurements of several key numbers. These include the average density of ordinary matter and dark matter in the Universe, and the age of the universe. Planck is now switched off.


  1. "The Planck space observatory is integrated on Ariane 5 for Arianespace's upcoming launch". Arianespace. 24 April 2009. Retrieved 31 December 2013.