content 22-October-2017 15:51:53

Fact Sheet

 Fast Facts


Launch date: 14-May-2009 13:12 UT
Mission end: end 2011 (extended mission, HFI & LFI); mid-2013 (extended mission, LFI only); spacecraft turned off on 23 October 2013 at 12:10:27 UT
Launch vehicle: Ariane 5 ECA
Launch mass: about 1900 kg
Mission phase: Post-operations phase
Operational orbit: Lissajous orbit about the second Lagrange point of the Earth-Sun system (L2), with an average amplitude of about 400 000 km.
Objectives: The primary science goals of Planck include:
  • Mapping the Cosmic Microwave Background anisotropies with improved sensitivity and angular resolution
  • Testing inflationary models of the early Universe
  • Measuring the amplitude of structures in the Cosmic Microwave Background
  • Determination of Hubble constant
  • Perform measurements of Sunyaev-Zel'dovich effect


Planck is helping to provide answers to some of the most important questions in modern science: how did the Universe begin, how did it evolve to the state we observe today, and how will it continue to evolve in the future? Planck's objective is to analyse, with the highest accuracy ever achieved, the remnants of the radiation that filled the Universe immediately after the Big Bang - this we observe today as the Cosmic Microwave Background.


Mission Objectives 

  • Perform measurements of Cosmic Microwave Background anisotropies
  • Test inflationary models of the early Universe
  • Measure amplitude of structures in the Cosmic Microwave Background
  • Perform measurements of Sunyaev-Zeldovich effect

Mission Name

Planck, originally named COBRAS/SAMBA, was renamed on approval of the mission in 1996 in honour of the German scientist Max Planck (1858-1947) who won the Nobel Prize for Physics in 1918. J.C. Mather and G.F. Smoot have received the Nobel Prize for Physics in 2006 for their discovery of the blackbody nature of the Cosmic Microwave Background radiation and the small-scale deviations from the blackbody curve.



Mass About 1900 kg at launch
Dimensions 4.2 m high, 4.2 m maximum diameter
Launcher Ariane 5 ECA from Guiana Space Centre
Mission Lifetime (Nominal) 15 months from end of Calibration and Performance Verification Phase; (Actual) almost 4.5 years
Wavelength Microwave: 27 GHz to 1 Thz
Telescope 1.9m × 1.5m primary mirror (1.5m projected aperture)


Frequency Instrument
Description 83 GHz - 1 THz
Array of 52 bolometric detectors, operated at 0.1K
Principal Investigator Jean-Loup Puget,
Institut d'Astrophysique Spatiale (Orsay, France)
Deputy Principal Investigator François Bouchet,
Institut d'Astrophysique de Paris (Paris, France)
Frequency Instrument
Description 27 - 77 GHz
Array of 22 tuned radio receivers, operated at 20K
Principal Investigator Nazzareno Mandolesi,
Istituto di Tecnologie e Studio delle Radiazioni Extraterrestri (Bologna, Italy)
Deputy Principal Investigator Marco Bersanelli,
Universita' degli Studi di Milano (Milan, Italy)


Planck was launched on an Ariane 5 ECA rocket together with ESA's Herschel spacecraft on 14 May 2009, at 13:12 UTC.The two spacecraft separated after launch and were directly injected towards the second Lagrange point of the Sun-Earth system. On 3 July, following a few orbit correction manoeuvres, Planck reached its final operational orbit: a Lissajous orbit with an average amplitude of about 400 000 km around the L2 point at a distance of around 1.5 million km from Earth.


Operations Centre

The ground segment of Planck is composed of the Operations Ground Segment, comprising all the elements under the responsibility of the European Space Operations Centre (ESOC), which includes the Mission Operations Centre, the ground stations and the communications network, and the Scientific Ground Segment.

The Mission Operations Centre (MOC) was located at ESA's European Space Operations Centre (ESOC) in Darmstadt, Germany. For communication with the spacecraft ESA's 35-m deep-space antenna at New Norcia (close to Perth, Australia) was the prime ground station, and Cebreros (close to Avila, Spain) was the back-up.

The Scientific Ground Segment is distributed between the following centres: the Planck Science Office, which took care of the scheduling of the survey strategy, and the two instrument teams' Data Processing Centres and Instrument Operations Teams, responsible for each instrument to process the telemetry and monitor the instrument operations respectively.

Last Update: 13 May 2015

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