SPOT 1 to 5 – A prodigious programme!
SPOT 1, 2 and 3: the programme's beginnings
On February 22, 1986, Ariane placed the SPOT 1 satellite into orbit. Two days later, the instruments transmitted the first image, offering unparalleled performance, with a spatial resolution of 10 or 20 metres, and the capacity to map relief accurate to within ten metres. SPOT 2 joined SPOT 1 in orbit on January 22, 1990, followed by SPOT 3 on September 26, 1993.
SPOT 1’s orbit was lowered in 2003 so that it will gradually lose altitude and break up naturally in the atmosphere, without leaving a trail of debris in space. Likewise, SPOT 2 was moved to a reentry orbit on 29 July 2009 after 19 years in service. SPOT 3 became inoperable in 1996 due to a failure of its stabilization system.
Djebel Amour, one of the first images taken by SPOT. Crédits : CNES/distribution Spot Image
SPOT 4, a new-generation satellite
SPOT 4, launched on March 24, 1998, features significant improvements over its predecessors. Its design lifetime was increased from 3 to 5 years, and its telescopes and recording capacities were improved. Its enhanced observation capabilities give it the edge in an increasingly competitive market.
In addition, SPOT 4 is carrying the new Vegetation instrument. This radiometer, specially designed to provide daily coverage of the entire globe, is a tool designed to study how the Earth's vegetation affects the climate and its variations.
Africa viewed by VEGETATION. CNES/distribution Spot Image,2003
SPOT 5, the latest addition to the family
SPOT 5, launched on May 3, 2002, meets a dual objective: ensuring continuity of services for customers, and improving the quality of data and images by anticipating changes in market requirements.
While maintaining the main features that have built SPOT’s reputation, SPOT 5 offers enhanced resolution thanks to the Supermode imaging process, which makes it possible to resolve features of 2.5 metres in size. And with its new HRS instrument (High Resolution Stereoscopic), which acquires images simultaneously in front of and behind the satellite, SPOT 5 is also able to measure relief and view the landscape in 3D.
SPOT series (except for SPOT 3 which is inoperable). CNES/ill.D.Ducros, 2002
Orfeo, SPOT's successor
programme is intended to replace SPOT. Pleiades is the result of studies begun several years ago on the possibility of using smaller, cheaper satellites which are more agile, and above all, offer better performance.
Different kind of sensor have been identified to meet virtually all optical and radar imaging needs . The system will be made up of several satellite constellations, each furnishing specific data. The first high-resolution satellites of this programme will be launched in 2010. They will complement the Italian radar satellite constellation within the French-Italian Orfeo system, which has both civil and military applications.
Pleiades satellites constellation. Crédits : CNES/Ill.P.Carril