Euclid (spacecraft)

Euclid

Artist's impression of Euclid
Names	Dark Universe Explorer Spectroscopic All Sky Cosmic Explorer
Mission type	Astronomy
Operator	ESA
Website	sci.esa.int/euclid www.euclid-ec.org
Mission duration	6.25 years (planned)
Spacecraft properties
Manufacturer	Thales Alenia Space (main) Astrium SAS (payload module)
Launch mass	2,160 kg (4,760 lb)
Payload mass	855 kg (1,885 lb)
Dimensions	4.5 m × 3.1 m (15 ft × 10 ft)
Start of mission
Launch date	Q4 2020
Rocket	Soyuz-2.1b/Fregat-MT
Launch site	Kourou ELS
Contractor	Arianespace
Orbital parameters
Reference system	Sun–Earth L2
Regime	Halo orbit
Periapsis	1,000,000 km (620,000 mi)
Apoapsis	1,500,000 km (930,000 mi)
Epoch	planned
Main telescope
Type	Korsch telescope
Diameter	1.2 m (3 ft 11 in)
Focal length	24.5 m (80 ft)
Wavelengths	from 550 nm) (green) to 2 µm (near-infrared)
Transponders
Band	X band (TT&C support) K band (data acquisition)
Frequency	8.0-8.4 GHz (X band) 25.5-27 GHz (K band)
Bandwidth	few kbit/s down & up (S band) 55 Mbit/s (K band)
Instruments VIS Visible CCD imager NISP Near IR photometer
ESA astrophysics insignia for the Euclid mission Cosmic Vision ← Solar Orbiter SMILE →

ESA astrophysics insignia for the Euclid mission

Euclid (named after the ancient Greek mathematician Euclid of Alexandria, the "Father of Geometry"), is a space mission currently under development by the European Space Agency (ESA). The objective of Euclid is to better understand dark energy and dark matter by accurately measuring the acceleration of the universe. To achieve this, the spacecraft will measure the redshift of galaxies at varying distances from Earth and investigate the relationship between distance and redshift. Dark energy is generally accepted as contributing to the increased acceleration of the expanding universe, so understanding this relationship will help to refine how physicists and astrophysicists understand it. Euclid's mission advances and complements ESA's Planck mission, and other contemporary space missions.

Euclid is a medium-class ("M-class") mission and is part of ESA's "Cosmic Vision" (2015–2025) scientific program. This class of missions have an ESA budget cap at around €500 million. Euclid was chosen in October 2011 together with Solar Orbiter, out of several competing missions. The launch date is planned for 2020.

Euclid will probe the history of the expansion of the universe and the formation of cosmic structures by measuring the redshift of galaxies out to a factor of 2, which is equivalent to seeing back 10 billion years in the past. The link between galactic shapes and their corresponding redshift will give a look into how dark energy contributes to the increased acceleration of the universe. The methods employed exploit the phenomenon of gravitational lensing, measurement of Baryon acoustic oscillations, and measurement of galactic distances by spectroscopy.