# ERS-2

> European Earth observation satellite (1995-2011)

**Wikidata**: [Q2874243](https://www.wikidata.org/wiki/Q2874243)  
**Source**: https://4ort.xyz/entity/ers-2

## Summary
ERS-2 was a European Earth observation satellite operational from 1995 to 2011, launched to monitor environmental and climate changes using instruments like synthetic aperture radar. Operated by the European Space Agency (ESA), it provided critical data for scientific research until its decommissioning in 2011 and eventual atmospheric reentry in 2024.

## Key Facts
- **Launch Date**: April 21, 1995, at 01:44:02 UTC.
- **Operator**: European Space Operations Centre (ESOC) and ESA Centre for Earth Observation.
- **Primary Instrument**: Synthetic aperture radar (SAR) for high-resolution imaging.
- **Mission Duration**: Designed for 3 years, operational for 16 years until retirement on September 5, 2011.
- **Launch Vehicle**: Ariane 40 (flight V72) from ELA-2, Guiana Space Centre.
- **Mass**: 2,516 kg at launch.
- **Orbit**: Sun-synchronous orbit at 785 km altitude.
- **Reentry**: Disintegrated over the North Pacific Ocean on February 21, 2024.
- **Preceded By**: ERS-1 (1991–2000).

## FAQs
### Q: When was ERS-2 launched and retired?
A: ERS-2 launched on April 21, 1995, and was retired on September 5, 2011, after 16 years of service.

### Q: What was the primary purpose of ERS-2?
A: ERS-2 monitored Earth’s environment, tracking ocean currents, ice coverage, and land use changes to support climate research and disaster management.

### Q: How did ERS-2’s mission end?
A: After decommissioning in 2011, ERS-2 remained in orbit until reentering Earth’s atmosphere on February 21, 2024, disintegrating safely over the Pacific Ocean.

## Why It Matters
ERS-2 played a pivotal role in advancing Earth observation science, delivering unprecedented data on oceanography, cryosphere dynamics, and land ecology. Its long-term operation provided continuous datasets critical for understanding climate patterns and environmental changes, supporting international research initiatives like the World Climate Research Programme. As part of the ERS series, it demonstrated the viability of synthetic aperture radar in space-based remote sensing, paving the way for future missions like Envisat and Sentinel. Its extended 16-year service life—far exceeding its 3-year design—highlighted ESA’s engineering prowess and the satellite’s adaptability to evolving scientific needs.

## Notable For
- **Longevity**: Operated 5x longer than its designed 3-year lifespan.
- **SAR Technology**: Utilized advanced synthetic aperture radar for all-weather, day/night imaging.
- **Data Continuity**: Bridged the gap between ERS-1 and Envisat, ensuring uninterrupted Earth observation.
- **Safe Reentry**: Successfully decommissioned with controlled orbital decay, posing no risk to populated areas.

## Body
### Mission Overview
ERS-2 was the second satellite in ESA’s European Remote-Sensing Satellite (ERS) programme, succeeding ERS-1. Its mission focused on global environmental monitoring, emphasizing oceanographic and polar ice research. The satellite carried a suite of instruments, including a C-band synthetic aperture radar, an along-track scanning radiometer (ATSR-2), and a microwave radiometer.

### Technical Specifications
- **Spacecraft Bus**: Derived from the SPOT satellite platform.
- **Power**: 2,600 W via two solar arrays.
- **Manufacturers**: DASA (prime contractor) and Matra Marconi Space (bus provider).
- **Orbit**: 98° inclination, 785 km altitude, 96-minute orbital period.

### Launch and Operations
- **Launch Vehicle**: Ariane 40 (V72) with an H10+ upper stage.
- **Commissioning**: Operational from August 17, 1995, after a calibration phase.
- **Data Transmission**: Relayed via ESA’s Kiruna (Sweden) and Villafranca (Spain) ground stations.

### Retirement and Reentry
- **Decommissioning**: Gyroscopes failed in 2011, ending scientific operations.
- **Orbit Decay**: Passively deorbited, with reentry occurring on February 21, 2024, at 17:17 UTC over the North Pacific (37.4° N, 151.9° W).
- **Legacy**: Archived data remains accessible via ESA’s Earth Observation Gateway.

## Schema Markup
```json
{
  "@context": "https://schema.org",
  "@type": "Thing",
  "name": "ERS-2",
  "description": "European Earth observation satellite (1995-2011)",
  "url": "https://earth.esa.int/eogateway/missions/ers",
  "sameAs": [
    "https://www.wikidata.org/wiki/Q6272367",
    "https://en.wikipedia.org/wiki/ERS-2"
  ],
  "additionalType": "Earth observation satellite",
  "manufacturer": "DASA, Matra Marconi Space",
  "launchDate": "1995-04-21",
  "operatingOrganisation": "European Space Agency",
  "satelliteOf": "Sun-synchronous orbit"
}

## References

1. [Source](https://space.skyrocket.de/doc_sdat/ers-1.htm)
2. [Source](https://earth.esa.int/eogateway/missions/ers/description)
3. Jonathan's Space Report
4. [Source](https://www.bbc.com/news/science-environment-68318273)
5. [Source](https://www.esa.int/Space_Safety/Space_Debris/ERS-2_reenters_Earth_s_atmosphere_over_Pacific_Ocean)
6. [Source](https://space.skyrocket.de/doc_sat/astrium_spot.htm)
7. [Source](https://www.esa.int/Enabling_Support/Operations/ERS_satellite_missions_complete_after_20_years)
8. [Source](https://earth.esa.int/eogateway/missions/ers)