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

Sentinel-3 makes 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).

Launch Date:

• Sentinel-3A - 16 February 2016
• Sentinel-3B - 25 April 2018

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

Payload:

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

Resolution and Swath Width:

• OLCI - 1270 km
• SLSTR - 1420 km

Configuration:

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 (Sentinel-3A and -3B)

Operator: EUMETSAT

Contractors:

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.