Euclid, Mapping the geometry of the dark Universe


Euclid Surveys

Euclid's Wide Survey will cover > 1/3 of the sky at high galactic latitude. The Wide Survey will achieve galaxy shear measurements for 30-40 galaxies/arcmin2, and spectroscopic measurements for 3500-5000 galaxies/deg2 with a redshift accuracy of ?z< 0.001(1+z). Euclid's Deep Survey will be 2 magnitudes deeper than the Wide Survey, and cover a total of approximately 40 deg2 in patches of greater than 10 deg2.


The Euclid payload will consist of a 1.2-m Korsch telescope feeding two instruments via a dichroic beam splitter. The VIS (visible-band imager) instrument has one wavelength band from 550-900 nm. The VIS focal plane consists of 36 4kx4k CCDs, covering more than a 0.5 deg2 field of view with 100 milliarcsecond pixels. The NISP instrument provides both spectroscopy and imaging, with mode selection via a filter wheel. The NISP focal plane consists of 16 2kx2k infrared detectors, covering more than a 0.5 deg2 field of view with 300 milliarcsecond pixels. The NISP imaging photometer mode contains 3 filters: Y, J, H in the 1-2 micron wavelength range. The NISP slitless spectrometer mode contains 4 grisms, 2 with blue and 2 with red bandpass coatings, to provide spectra in two bands with two orthogonal directions. This mode has spectral resolution ~ 250 over two pixels.


Euclid will provide science data downlink with K-band telemetry and 4 hours ground station contact. Commanding and housekeeping data will be provided with X-band telemetry. The compressed science data rate is 850 Gbits/day. Mission operations will be conducted from the European Science Operations Center (ESOC), Darmstadt (Germany); science operations will be conducted from the European Space Astronomy Center (ESAC), Madrid (Spain).

Project Structure

The Euclid Consortium, led by Yannick Mellier, is a collaboration of over 100 universities and laboratories, and is tasked with building VIS and NISP for Euclid, as well as contributing to the Science Ground Segment. ESA has established a project structure for Euclid, with Giuseppe Racca as the Project Manager and René Laureijs as the Project Scientist. For its contribution, a NASA project office has been established at the Jet Propulsion Laboratory, with Ulf Israelsson as the Project Manager and Michael Seiffert as the Project Scientist. NASA's contribution includes the NISP detectors, along with cryogenic cables and cold readout electronics. Goddard Space Flight Center's Detector Characterization Lab (DCL) will characterize the flight detectors. The Infrared Processing and Analysis Center (IPAC) is conducting a study for the possibility of NASA contributing a US Euclid Science Data Center.
Launch: 2020 (Kourou)

Launch Vehicle: Soyuz ST2-1B

Launch Capability: 2160 kg

Orbit: Sun-Earth L2

Nominal mission: 6 years