# Envisat

> former Earth observation satellite of the European Space Agency

**Wikidata**: [Q49692](https://www.wikidata.org/wiki/Q49692)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Envisat)  
**Source**: https://4ort.xyz/entity/envisat

## Summary
Envisat was a former Earth observation satellite operated by the European Space Agency, launched in 2002 and decommissioned in 2012. It was designed to monitor environmental changes on Earth from its polar orbit, carrying a suite of scientific instruments for various Earth observation purposes.

## Key Facts
- Envisat was a former Earth observation satellite of the European Space Agency
- It was launched on March 1, 2002, using an Ariane 5G rocket from the Guiana Space Centre
- The satellite had a mass of 8,211 kg at takeoff and nominal power output of 6,500 watts
- Envisat operated in a polar orbit with an orbital period of 100.6 minutes and orbital inclination of 98.6 degrees
- It carried multiple scientific instruments including Advanced Synthetic Aperture Radar and MEdium Resolution Imaging Spectrometer
- The satellite ended its operations on April 8, 2012, when contact was lost
- Envisat was built by Astrium and launched by Arianespace

## FAQs
### Q: What was the primary mission of Envisat?
A: Envisat's primary mission was to monitor environmental changes on Earth from orbit. The satellite carried multiple scientific instruments to observe Earth's atmosphere, oceans, land, and ice to study phenomena like climate change, natural disasters, and pollution.

### Q: How long did Envisat remain operational?
A: Envisat was launched on March 1, 2002, and remained operational for more than 10 years until April 8, 2012, when contact was unexpectedly lost. The satellite was designed for a 5-year mission but exceeded its operational lifetime by several years.

### Q: What made Envisat different from other Earth observation satellites?
A: Envisat was distinguished by its comprehensive suite of 10 scientific instruments that could monitor various aspects of Earth's environment simultaneously. It was one of the largest Earth observation satellites ever built, with a mass of over 8,000 kg, and provided continuous data collection for over a decade.

## Why It Matters
Envisat played a crucial role in advancing Earth observation science and environmental monitoring. The satellite's decade-long operation provided unprecedented data on climate change, natural disasters, and environmental degradation, supporting scientific research and policy decisions. Its comprehensive instrument suite allowed simultaneous monitoring of atmospheric composition, ocean temperatures, ice cover, and vegetation changes, which was instrumental in understanding global environmental processes. Envisat data has been used in thousands of studies, helping to predict and track events like volcanic eruptions, floods, and oil spills. Despite its sudden loss of contact in 2012, Envisat's legacy continues through the extensive archive of data it collected, which remains a valuable resource for researchers studying Earth's changing environment.

## Notable For
- Longevity: Envisat operated for more than 10 years, far exceeding its designed 5-year mission lifespan
- Comprehensive instrument suite: Carried 10 different scientific instruments that could simultaneously monitor various aspects of Earth's environment
- Large scale: One of the largest Earth observation satellites ever built, with a mass of 8,211 kg
- Polar orbit: Operated in a highly inclined polar orbit (98.6°) allowing near-complete Earth coverage

## Body
### Basic Information
Envisat was a former Earth observation satellite operated by the European Space Agency. It was launched on March 1, 2002, using an Ariane 5G rocket from the ELA-3 launch pad at the Guiana Space Centre. The satellite ended its operations on April 8, 2012, when contact was unexpectedly lost.

### Technical Specifications
- Mass: 8,211 kg at takeoff
- Orbital parameters: Polar orbit with 98.6° inclination
- Orbital period: 100.6 minutes
- Apoapsis: 791 km
- Periapsis: 785 km
- Semi-major axis: 7,144.9 km
- Orbital eccentricity: 0.00042
- Power output: 6,500 watts
- Manufacturer: Astrium
- Launch contractor: Arianespace

### Scientific Payload
Envisat carried 10 scientific instruments:
1. Laser Retro-Reflector (LRR)
2. Advanced Along Track Scanning Radiometer (AATSR)
3. MEdium Resolution Imaging Spectrometer (MERIS)
4. Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY)
5. Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS)
6. Global Ozone Monitoring by Occultation of Stars (GOMOS)
7. Michelson Interferometer for Passive Atmospheric Sounding (MIPAS)
8. Advanced Synthetic Aperture Radar (ASAR)
9. Radar Altimeter 2 (RA-2)
10. Microwave Radiometer (MWR)

## References

1. Jonathan's Space Report
2. [Source](https://earth.esa.int/web/guest/news/-/asset_publisher/G2mU/content/good-bye-envisat-and-thank-you)
3. Freebase Data Dumps. 2013