Earth Observation and Science

Earth Observation Constellations

Small satellite constellations are financially viable, enable rapid revisit imaging, and provide flexibility for replenishing space assets for data continuity.

  • Two or more co-ordinated satelllites provide better revisit times than single satellite systems.  
  •  Multiple satellites operating as a constellation can deliver near-real time imagery.
  • Comprehensive capability can be achieved by combining satellites with different sensors.
  • Constellations increase operational utility and reduce operational risk. 

The Disaster Monitoring Constellation

Surrey conceived the innovative and unique Disaster Monitoring Constellation (DMC), the first Earth observation constellation of low-cost small satellites providing daily images for applications including global disaster monitoring.

The Disaster Monitoring Constellation is coordinated by DMC International Imaging Ltd (DMCii)  for both commercial imaging programs and to provide free satellite imagery for humanitarian use in the event of major international disasters within the International Charter: Space & Major Disasters ( The DMC is represented by the UK Space Agency on the Charter board and DMCii in the executive secretariat. The national civil protection authorities of Algeria, China, Nigeria, Turkey and UK are direct authorised users of the Charter.

Disaster Monitoring Constellation operational satellites


Disaster Monitoring Constellation retired satellites

The DMC3 Constellation


Launched in 2015, the DMC3 constellation provides daily revisit times—crucial for change detection, disaster monitoring, and response planning, and essential for acquiring cloud-free imagery. 21AT leases 100% of the imaging capacity of the three satellites.

More about the DMC3 Constellation

The FORMOSAT-7 Constellation

SSTL is supplying 6 satellite platforms to NOAA/Taiwan for the FORMOSAT-7 weather forecasting constellation.

More about the FORMOSAT-7 Constellation.

The RapidEye Constellation 

5 RapidEye platforms in SSTL's cleanroom

Surrey supplied the platforms for the 5-satellite RapidEye constellation, which launched in 2008. RapidEye is a commercial small satellite mission developed by MacDonald Dettwiler & Associates (MDA). The constellation is now owned and operated by BlackBridge. This unique system enables unprecedented global monitoring of  Earth’s surface. The mission provides rapid delivery of land information products and services to the agricultural industry for crop monitoring and mapping, yield predictions, and natural disaster assessment.

The constellation provides:

  • Daily revisit
  • Multispectral imagery
  • 6.5 m GSD resolution