# Satellite Concept

The satellite concept is based on the re-utilisation of the Multi-mission Platform, developed within the French SPOT programme. This platform provides the major services for the satellite and payload operation, in particular attitude and orbit control, power supply, monitoring and control of payload status, telecommunications with the ground segment.

To meets its mission objectives, ERS-1 has been placed in a near-polar orbit at a mean altitude of about 780 km with an instrument payload comprising active and passive microwave sensors and a thermal infra-red radiometer. The satellite (see the figure) is large, weighing 2400 kg and measuring 12 m x 12 m x 2.5 m, making it the largest and most sophisticated free-flying satellite built so far in Europe.

## ERS-1 Overview

  Satellite Concept
  ERS-1 Orbit
  Payload Summary
  Operational Capabilities
  ERS-1 Specification Table

ESA Earth Observation