Satellite: SENTINEL-3

SENTINEL-3 Overview

SENTINEL-3, launched in 2016 as part of ESA’s Copernicus Program,  main objective is to measure the land and sea temperatures and colors, sea-surface topography, and provide climate monitoring.

SENTINEL-3 currently has three mission, S-3A, S-3B, and S3C, but will be expanding to four with the addition of SENTINEL-3D in 2021.

The mission provides data continuity for the ERSENVISAT, and SPOT satellites.


SENTINEL-3 Instruments

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 (Doppler Orbitography and Radiopositioning Integrated by Satellite)
  • MWR (Microwave Radiometer).

SLSTR and OLCI are optical instruments that are used to provide data continuity for ENVISAT’s AATSR and MERIS instruments and the swaths of the two instruments overlap, allowing for new combined applications. OLCI is a medium-resolution imaging spectrometer, using five cameras to provide a wide field of view.

SRAL, DORIS, MWR and LRR are used for topographic measurements of the ocean and inland water. The SRAL altimeter is the main topographic instrument. The MWR radiometer measures water vapour, cloud water content and thermal radiation emitted by the Earth.

ESA Sentinel-3



ESA SENTINEL-3 – Animation

Video of S-3 deploying its solar array after moving into orbit.


SENTINEL 3 – Technical Details





First launch




Orbit type

SSO (Sun-synchronous Orbit) 12 day repeat cycle LTAN = 18:00 hours

SSO 10 day repeat cycle LTDN = 10:30 hours

SSO 27 day repeat cycle LTDN = 10:00 hours

Orbital altitude

693 km

786 km

800 km

Sensor complement

C-SAR (C-band Synthetic Aperture Radar)

MSI (Multi-Spectral Instrument)

SRAL (Sentinel-3 Radar Altimeter) MWR (Microwave Radiometer) OLCI (Ocean and Land Color Instrument) SLSTR (Sea and Land Surface Temperature Radiometer)

Spacecraft mass Spacecraft size Spacecraft power

2300 kg 3.4 m x 1.3 m x 1.3 m 4.8 kW (EOL)

1100 kg 3.0 m x 1.7 m x 2.2 m 1.7 kW (EOL)

1250 kg 3.9 m x 2.2 m x 2.2 m 2.05 kW (EOL)

Downlink X-band data rate

520 Mbit/s

520 Mbit/s

520 Mbit/s

TT&C S-band

64 kbit/s uplink 128 kbit/s or 2 Mbit/s downlink

64 kbit/s uplink 128 kbit/s or 2 Mbit/s downlink

64 kbit/s uplink 128 kbit/s or 2 Mbit/s downlink

Science data storage

1.4 Tbit (EOL)

2 Tbit (EOL)

300 Gbit (EOL)

Required data quality

BER (Bit Error Rate): < 10-9

FER (Frame Error Rate): < 10-8

FER (Frame Error Rate): < 10-7

Operational autonomy

8 days

14 days

27 days

Prime contractor

TAS-I (Thales Alenia Space-Italy)

EADS Astrium GmbH, Germany

TAS-F (Thales Alenia Space-France)

Baseline launcher

Soyuz (Kourou)

Vega (Kourou)

Vega (Kourou)