Sentinel 3 is a future space mission from ESA

European Space Agency

The European Space Agency , established in 1975, is an intergovernmental organisation dedicated to the exploration of space, currently with 18 member states...

, the third in the GMES

GMES

Global Monitoring for Environment and Security is a joint initiative of the European Commission and European Space Agency, which aims at achieving an autonomous and operational Earth observation capacity....

 program.
It will provide medium resolution optical and radar

Radar

Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

 altimetry Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

 observation data. It is designed for data continuity of ERS

ERS

ERS can refer to:* The Electoral Reform Society* Elektroprivreda Republike Srpske* Elevator Repair Service, a New York-based theater ensemble* Ellipsoidal reflector spotlight* ERS10, a share index of the Banja Luka Stock Exchange...

 and Envisat

Envisat

Envisat is an Earth-observing satellite. It was launched on 1 March 2002 aboard an Ariane 5 from the Guyana Space Centre in Kourou, French Guyana into a Sun synchronous polar orbit at an altitude of...

 missions, with coverage and instrument performance improvements.

On the 14th of April 2008, The European Space Agency and Thales Alenia Space

Thales Alenia Space

Thales Alenia Space is an aerospace company born after the Thales Group bought the participation of Alcatel in the two joint-ventures between Alcatel and Finmeccanica, Alcatel Alenia Space and Telespazio.-History:...

 signed a €305 million contract to build the first GMES Sentinel-3.

A launch date around 2013 is foreseen.

Mission characteristics

• Role: Earth Observation
• Launch date: 2013
• Launch mass: ~1250 kg
• Launcher: Vega
  Vega
  Vega is the brightest star in the constellation Lyra, the fifth brightest star in the night sky and the second brightest star in the northern celestial hemisphere, after Arcturus...
  
   or Soyuz
  Soyuz (rocket)
  The Soyuz was a Soviet expendable carrier rocket designed by OKB-1 and manufactured by State Aviation Plant No. 1 in Samara, Russia. It was used to launch Soyuz spacecraft as part of the Soyuz programme, initially on unmanned test flights, followed by the first 19 manned launches of the...
  
  /Kourou
  Kourou
  Kourou is a commune in French Guiana, an overseas region and department of France located in South America.Kourou is the location of the Guiana Space Centre, France and ESA's main spaceport.-Geography:...
  
  
• Launch location: French Guiana
  French Guiana
  French Guiana is an overseas region of France, consisting of a single overseas department located on the northern Atlantic coast of South America. It has borders with two nations, Brazil to the east and south, and Suriname to the west...
  
  
• Orbit: Sun
  Sun
  The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
  
  -synchronous
• Altitude: 800 km
• Orbit cycle: ~100 minutes
• Nominal duration: 7.25 years

Instruments

• Ocean and Land Colour Instrument
• Sea and Land Surface Temperature Instrument (SLSTR)
• Radar Altimeter
• Microwave Radiometer
• GNSS receiver
• Laser retroflector

Applications

• Sea and land colour data
• Sea and land surface temperature
• Sea surface topography data