Minimize Sentinel 3

Sentinel-3 is primarily an ocean mission, however, the mission will also be able to provide atmospheric and land applications. The mission will provide data continuity for the ERS, Envisat and SPOT satellites.

Sentinel-3 will make use of multiple sensing instruments to accomplish its objectives; SLSTR (Sea and Land Surface Temperature Radiometer), OLCI (Ocean and Land Colour Instrument), SRAL (SAR Altimeter), DORIS, and MWR (Microwave Radiometer).

SLSTR and OLCI are optical instruments that will be used to provide data continuity for Envisat's MERIS and AATSR instruments and the swath's of the two instruments will overlap, allowing for new combined applications. OLCI is a  medium-resolution imaging spectrometer, and the instrument uses five cameras to provide a wide field of view.

SRAL, DORIS, MWR and LRR will be used for topographic measurements of the ocean and in-land water. The SRAL altimeter will be the main topographic instrument. The MWR radiometer will measure water vapour and cloud water content and the thermal radiation emitted by the Earth.

The observations acquired by the mission will be used to in conjunction with other ocean-observing missions to contribute to the Global Ocean Observing System (GOOS) which aims to create a permanent system of ocean observation.

In July 2009, ESA conducted an airborne campaign, Sen3Exp (Sentinel-3 Experiment) to test the land and ocean imaging applications of the Sentinel-3 mission using three instruments; AHS (Airborne Hyperspectral System), CASI-1500i (Compact Airborne Spectrographic Imager) and SASI-600 (Shortwave Infrared Airborne Spectrometer). Satellite observations were also made by Envisat's MERIS and AATSR instruments, which are similar to Sentinel-3's SLSTR and OLCI instruments, and the CHRIS instrument aboard Proba-1.

Mission Details:

Planned Launch Date:

  • Sentinel-3A - December 2015
  • Sentinel-3B - 18 months after Sentinel-3A
  • Sentinel-3C - Before 2020

Operational lifepsan:
7 years (With consumables for 12)

Mission objectives:

  • Measuring sea-surface topography, sea-surface height and significant wave height
  • Measuring ocean and land-surface temperature
  • Measuring ocean and land-surface colour
  • Monitoring sea and land ice topography
  • Sea-water quality and pollution monitoring
  • Inland water monitoring, including rivers and lakes
  • Aid ocean forecasts with acquired data
  • Climate monitoring and modelling
  • Land-use change monitoring
  • Forest cover mapping
  • Fire detection
  • Weather forecasting
  • Measuring Earth's thermal radiation for atmospheric applications

Mission Orbit:

Orbit Type: Sun-synchronous
Orbit Height: 814 km
Inclination: 98.6o
Repeat Cycle: 27 days


  • OLCI (Ocean and Land Colour Instrument)
  • SLSTR (Sea and Land Surface Temperature Radiometer)
  • SRAL (Synthetic Aperture Radar Altimeter)
  • MWR (Microwave Radiometer)
  • LRR (Laser Retroreflector)
  • GNSS (Global Navigation Satellite System)

Resolution and Swath Width:

  • OLCI - 1270 km
  • SLSTR - 1420 km


In addition to the observation instruments, the Sentinel-3 spacecraft will carry the GNSS (Global Navigation Satellite System) and LRR (Laser Retro Reflector) instruments. GNSS will provide precise orbit determination and can track multiple satellites simultaneously. LRR will be used to accurately locate the satellite in orbit using a laser ranging system.

The dimensions of the craft are: 3.7 x 2.2 x 2.2 m with a weight (at time of launch) of 1250 kg.

Launch vehicle:

  • Rockot vehicle (Sentinel-3A)
  • Vega rocket (Sentinel-3B)

Operator: EUMETSAT


Thales Alenia Space is the prime contractor, responsible for constructing the spacecraft and the SRAL instrument, as well as contributing to the supply of the SLSTR instrument.
Many European companies are involved in supplying the SLSTR instrument, including SELEX Galileo, RAL (Rutherford Appleton Laboratory), Jena-Optronik, Thales Alenia Space, ABSL and ESA-ESTEC.
EADS CASA Espacio is contracted to provide the MWR instrument.
CNES is contracted to provide the DORIS instrument.
Eurockot and Arianespace are contracted to launch the spacecraft.