# SPOT-4

> Earth observation satellite (1998-2013)

**Wikidata**: [Q106366942](https://www.wikidata.org/wiki/Q106366942)  
**Source**: https://4ort.xyz/entity/spot-4

## Summary  
SPOT-4 is an Earth observation satellite launched by France in 1998 and operated until 2013. It was part of the SPOT satellite program, designed to capture high-resolution imagery of Earth’s surface for environmental monitoring, land use planning, and disaster management. Built by Matra Marconi Space, it significantly contributed to global remote sensing efforts during its extended operational lifetime.

## Key Facts  
- Launched on March 24, 1998, at 01:46 UTC from ELA-2 using an Ariane 40 rocket.  
- Weighed 2,755 kg at launch (launch weight).  
- Operated in a Sun-synchronous orbit as part of the SPOT satellite program.  
- Designed for a 5-year mission but exceeded expectations with over 15 years of service.  
- Officially retired on June 29, 2013.  
- Succeeded SPOT-3 and preceded SPOT-5 in the SPOT constellation.  
- Manufactured by Matra Marconi Space (now Airbus DS Geo).  
- Equipped with a single spacecraft solar array for power generation.  

## FAQs  
### Q: What was the purpose of SPOT-4?  
A: SPOT-4 was designed for Earth observation, capturing detailed images of the planet's surface for applications such as agriculture, forestry, urban planning, and environmental monitoring.

### Q: How long was SPOT-4 operational?  
A: Although designed for a 5-year lifespan, SPOT-4 remained operational for over 15 years, retiring on June 29, 2013.

### Q: Who built and operated SPOT-4?  
A: The satellite was manufactured by Matra Marconi Space and operated by Airbus DS Geo under the French national space program.

## Why It Matters  
SPOT-4 played a crucial role in advancing Earth observation capabilities through the late 1990s and early 2000s. As part of the SPOT program—one of the earliest civilian Earth observation systems—it provided consistent, high-quality multispectral imagery used globally for scientific research and policy-making. Its longevity beyond design parameters demonstrated robust engineering and helped bridge coverage gaps between successive missions. SPOT-4 also supported international cooperation in climate studies, land-use mapping, and emergency response coordination, making it a foundational asset in the evolution of modern remote sensing infrastructure.

## Notable For  
- Extended operational life—over three times longer than its intended 5-year design life.  
- Successful integration into the SPOT constellation, ensuring continuity of Earth observation data.  
- Use of the proven SPOT spacecraft bus architecture, which enabled cost-effective development.  
- Launch via the reliable Ariane 40 rocket, marking continued European self-reliance in space access.  
- Contribution to long-term datasets used in environmental science and geographic information systems (GIS).

## Body  
### Mission Overview  
SPOT-4 was developed as part of the SPOT (Système Probatoire d'Observation de la Terre) program initiated by CNES, the French space agency. It followed SPOT-3 and preceded SPOT-5, maintaining observational consistency across decades.

### Technical Specifications  
- **Launch Mass**: 2,755 kilograms (launch weight)  
- **Power Source**: Single spacecraft solar array  
- **Orbit Type**: Sun-synchronous orbit  
- **Service Life**:  
  - Design Life: 5 years  
  - Actual Service Duration: ~15.3 years  
- **Spacecraft Bus**: Based on the SPOT standard platform  

### Launch Details  
- **Date**: March 24, 1998  
- **Time**: 01:46 UTC  
- **Location**: ELA-2, Kourou, French Guiana  
- **Launch Vehicle**: Ariane 40 (flight V107)  
- **Payload Assist Module**: H10-3 upper stage (serial number L477b)

### Operational History  
- Began operations shortly after reaching orbit in 1998.  
- Provided continuous Earth imagery used in both commercial and governmental sectors.  
- Retired on June 29, 2013, following successful completion of its extended mission.

### Manufacturer & Operator  
- **Manufacturer**: Matra Marconi Space (later part of Airbus Defence and Space)  
- **Operator**: Initially CNES; later managed by Airbus DS Geo  

### Legacy  
SPOT-4 ensured seamless transition of Earth observation services within the SPOT program. Its data remains valuable for historical analysis and contributes to multi-decadal climate and land-cover change studies.

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  "description": "Earth observation satellite (1998-2013)",
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## References

1. Jonathan's Space Report
2. [Source](https://space.skyrocket.de/doc_sdat/spot-4.htm)
3. [Source](https://space.skyrocket.de/doc_sat/astrium_spot.htm)