Encyclopedia Astronautica
SPOT-4


French earth land resources satellite. One launch, 1998.03.24, SPOT 4. SPOT was the French government-sponsored civil earth observation program. A single SPOT satellite provides complete coverage of the Earth every 26 days.

Image products from SPOT were sold by a commercial entity, SPOT-Image Corp.

The SPOT-4 spacecraft was 3-axis stabilized, and used a single 5-panel solar array, each panel being 2.6 x 1.9 m. A hydrazine propulsion system provided orbit maintenance.

Two HRVIR (High Resolution Visible - Infrared) push-broom imaging instruments were carried. HRVIR was derived from the HRV instruments on SPOT 1-3. This system provided 10 m resolution in the panchromatic band and 20 m resolution in the multispectral bands. HRVIR included a new medium IR channel to support vegetation analysis and harvest forecasting. The HRVIRs were steerable to within 27 deg off-nadir. Each HRVIR had a swath width of 60 km. The Vegetation Monitoring instrument had 1 km resolution in the same bands as the HRVIR. SPOT-4 also carried the PASTEL optical link terminal supported laser crosslink experiments and DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite) precision orbit determination system. The $ 110 million Silex - semiconductor laser intersatellite link experiment. provided data relay for Artemis.

AKA: Satellite Probatoire d'Observation de la Terre.
Gross mass: 2,755 kg (6,073 lb).
Height: 5.40 m (17.70 ft).
First Launch: 1998.03.24.
Number: 1 .

More... - Chronology...


Associated Countries
See also
  • Ariane First successful European commercial launch vehicle, developed from L3S Europa launch vehicle replacement design. Development of the Ariane 1 was authorised in July 1973, took eight years, and cost 2 billion 1986 Euros. More...

Associated Launch Vehicles
  • Ariane French orbital launch vehicle. First successful European commercial launch vehicle, developed from L3S Europa launch vehicle replacement design. Development of the Ariane 1 was authorised in July 1973, took eight years, and cost 2 billion 1986 Euros. More...
  • Ariane 4 French orbital launch vehicle. The ultimate Ariane development. Compared with the Ariane 2/3, the Ariane 4 featured stretched first (61%) and third stages, a strengthened structure, new propulsion bay layouts, new avionics, and the Spelda dual-payload carrier. The basic 40 version used no strap-on motors, while the Ariane 42L, 44L, 42P, 44P, and 44LP versions used varous combinations of solid and liquid propellant strap-on motors). Development was authorised in January 1982, with the objective of increasing payload by 90%. Total development cost 476 million 1986 ECU's. More...
  • Ariane 40 French orbital launch vehicle. 3 stage core vehicle with original Ariane H10 upper stage. A fully fueled Ariane core cannot lift off the ground without strap-on liquid or solid motors. When Ariane 4 is launched in this configuration, the propellant tanks of the first and second stages are not completely filled. More...

Associated Manufacturers and Agencies
  • CNES French agency overseeing development of spacecraft. Centre National d'Etudes Spatiales, Paris, France. More...

Associated Programs
  • SPOT Systeme Probatoire pour l'Observation de la Terre - French remote sensing satellite network. More...

Bibliography
  • McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: here.
  • JPL Mission and Spacecraft Library, Jet Propulsion Laboratory, 1997. Web Address when accessed: here.

Associated Launch Sites
  • Kourou After the agreement with newly independent Algeria for France to evacuate their launch sites in that country, a location near Biscarosse was selected for French missile testing. However since only launches westwards across the Bay of Biscay could be made from this site, it was unsuitable for France's Diamant orbital launch vehicle. After reviewing 14 potential sites, a location in the South American French colony of Guiana was selected. This would allow over-water launches to a tremendous range of possible orbital inclinations -- from -100.5 deg to 1.5 deg. Being near the equator, it would provide the maximum assist from the earth's rotation for launches into equatorial orbits. The decision was formalized in April 1964 and in July 1966 ELDO chose the site for future launches of the Europa II launch vehicle. More...

SPOT-4 Chronology


1998 March 24 - . 01:46 GMT - . Launch Site: Kourou. Launch Complex: Kourou ELA2. LV Family: Ariane. Launch Vehicle: Ariane 40. LV Configuration: Ariane 40-3 V107.
  • SPOT 4 - . Mass: 2,755 kg (6,073 lb). Nation: France. Agency: CNES. Manufacturer: Toulouse. Program: SPOT. Class: Earth. Type: Earth resources satellite. Spacecraft: SPOT-4. USAF Sat Cat: 25260 . COSPAR: 1998-017A. Apogee: 826 km (513 mi). Perigee: 824 km (512 mi). Inclination: 98.7000 deg. Period: 101.40 min. Developed by Matra Marconi Space/Toulouse for CNES, the satellite provided 10-m resolution images with a wide field of view. SPOT 4 also carried a wide field 'vegetation' imager and a laser communications experiment. Launch was by an Arianespace Ariane 40 rocket, the base Ariane 4 model with no strap-on boosters. The liquid hydrogen fuelled third stage of the Ariane 40 entered an 800 km sun-synchronous orbit together with SPOT 4.

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