Minimize Space Segment

Overall configuration
Satellite budgets

Overall configuration

The major driver for the Polar Platform/Envisat satellite configuration has been the need to maximise the payload instrument mounting area and to meet the viewing requirements within the constraints of the Ariane 5 fairing and interfaces. Additionally, the configuration also has been driven by the reuse of the SPOT Mk II service module concept and the ERS payload accommodation experience (concept of instrument electronics in an internal enclosure with externally mounted antennas).

The Envisat satellite in flight

In flight, the major spacecraft longitudinal axis (the Xs-axis) is normal to the orbit plane, the Ys-axis is closely aligned to the velocity vector and the Zs-axis is Earth pointing. This configuration concept provides a large, modular, Earth-facing mounting surface for payload instruments and an anti-sun face for radiative coolers, free of occultation by satellite subsystem equipment.

For more information on Ariane 5 see: Ariane 5 Launch Vehicle
For more information on SPOT see: SPOT Mk II Service Module
For more information on ERS see: ERS Heritage


Satellite budgets


Launch configuration

  Dimensions (m)
length 10.5 m,
envelope diameter 4.57m
26m * 10m * 5m
Mass Budget
  Mass (kg)
Service Module  2673 
Payload Equipment Bay  1021 
Payload Carrier  2078 
Fuel  319 
Payload Instruments  2118 
Total 8211
Power Budget
  Average Power (W)
  Sunlight  Eclipse 
Payload  1841  1886 
Payload Module  860  527 
Service Module  859  684 
Total Load 3560 3097
System Capability 3847 3291