# PARASOL

> French Earth observation satellite

**Wikidata**: [Q1465904](https://www.wikidata.org/wiki/Q1465904)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Parasol_(satellite))  
**Source**: https://4ort.xyz/entity/parasol

## Summary
PARASOL (Polarization & Anisotropy of Reflectances for Atmospheric Sciences coupled with Observations from a Lidar) is a French Earth observation microsatellite launched in 2004 to study atmospheric aerosols and cloud properties. Operated by CNES, the French space agency, it was part of the A-Train satellite constellation and carried the POLDER instrument for polarization and directional reflectance measurements.

## Key Facts
- **Launch Date**: December 18, 2004, at 16:26 UTC from ELA-3 launch site.
- **Mass**: 120 kg (launch weight), 115 kg (dry weight).
- **Operator**: CNES (French space agency), which also manufactured the satellite.
- **Spacecraft Bus**: Myriade, a microsatellite platform (under 200 kg).
- **Launch Vehicle**: Ariane 5G+ (flight V165/520g).
- **Power System**: Gallium arsenide solar array (1.7 m², 180 W) and a lithium-ion battery (15 Ah).
- **Instrument**: POLDER (Polarization and Directionality of the Earth's Reflectances).
- **Service Retirement**: December 18, 2013, after nearly 9 years of operation.
- **Orbit**: Part of the A-Train satellite constellation for coordinated Earth observations.

## FAQs
### Q: What does PARASOL stand for?
A: PARASOL stands for *Polarization & Anisotropy of Reflectances for Atmospheric Sciences coupled with Observations from a Lidar*. It refers to its mission to study atmospheric properties using polarized light measurements.

### Q: Who operated PARASOL?
A: PARASOL was operated by CNES, the French space agency, which also manufactured the satellite with subcontractor Latécoère handling assembly and system integration.

### Q: What was PARASOL's primary instrument?
A: The satellite carried the **POLDER** instrument, designed to measure polarization and directional reflectance of sunlight to analyze aerosols, clouds, and surface properties.

### Q: When was PARASOL launched and decommissioned?
A: PARASOL was launched on **December 18, 2004**, and retired from service on **December 18, 2013**, after completing its mission.

### Q: What type of satellite is PARASOL?
A: PARASOL is a **microsatellite** (under 200 kg) classified as an **Earth observation satellite**, specifically designed for atmospheric and climate research.

## Why It Matters
PARASOL played a critical role in advancing our understanding of Earth's atmosphere by providing high-resolution data on aerosols, clouds, and radiative properties. As part of the A-Train constellation, it worked alongside other satellites like Aqua and Aura to create a comprehensive dataset for climate modeling and air quality studies. Its POLDER instrument uniquely measured polarized light, offering insights into particle size, shape, and composition—key factors in climate change and pollution tracking. The mission’s nearly decade-long operation contributed significantly to global climate research, helping scientists refine models of atmospheric behavior and solar radiation interactions.

## Notable For
- **First microsatellite in the A-Train constellation**, demonstrating the viability of small satellites for high-impact Earth science.
- **POLDER instrument**: One of the few space-based instruments capable of measuring **polarized light** to study aerosols and clouds.
- **Long operational lifespan**: Functioned for **9 years**, exceeding typical microsatellite mission durations.
- **Collaborative science**: Coordinated observations with NASA’s A-Train satellites, enhancing data accuracy for climate studies.
- **Lightweight design**: Built on the **Myriade bus**, a cost-effective platform for scientific microsatellites.

## Body
### Overview
PARASOL was a French Earth observation microsatellite designed to study atmospheric aerosols, clouds, and surface reflectance using polarized light measurements. Operated by CNES, it was launched as part of the **A-Train**, a constellation of satellites flying in close formation to enable synchronized Earth observations.

### Technical Specifications
- **Mass**:
  - Launch weight: **120 kg**
  - Dry weight: **115 kg**
- **Dimensions**: Based on the **Myriade spacecraft bus**, a modular platform for small satellites.
- **Power System**:
  - **Solar array**: Gallium arsenide panels (1.7 m², 180 W output).
  - **Battery**: Lithium-ion (15 Ah capacity).
- **Orbit**: Sun-synchronous, aligned with the A-Train constellation at an altitude of approximately **705 km**.

### Mission and Instruments
- **Primary Instrument**: **POLDER (Polarization and Directionality of the Earth's Reflectances)**
  - Measured **polarized light** in multiple spectral bands to analyze aerosol properties, cloud microphysics, and surface reflectance.
  - Provided data on particle size, shape, and optical thickness, critical for climate modeling.
- **Science Objectives**:
  - Improve understanding of aerosol-climate interactions.
  - Enhance cloud property retrievals for weather and climate models.
  - Support studies of Earth’s radiative budget.

### Launch and Operations
- **Launch Date**: December 18, 2004, aboard an **Ariane 5G+** rocket (flight V165/520g) from **ELA-3** in Kourou, French Guiana.
- **Operational Period**: December 2004 to December 2013 (9 years).
- **Decommissioning**: Officially retired on **December 18, 2013**, after completing its mission objectives.

### Collaborations and Legacy
- **A-Train Constellation**: PARASOL flew in formation with satellites like **Aqua, Aura, and CALIPSO**, enabling multi-angle observations of the same atmospheric phenomena.
- **Data Contributions**: Its measurements were integrated into global climate datasets, improving models of aerosol impacts on climate and air quality.
- **Follow-on Missions**: POLDER’s success influenced later instruments, such as those on the **EarthCARE** satellite.

### Manufacturer and Technology
- **Primary Contractor**: CNES (design and manufacturing).
- **Subcontractor**: **Latécoère** (assembly and system integration).
- **Spacecraft Bus**: **Myriade**, a CNES-developed platform for cost-effective microsatellites, reused in other missions like **DEMETER** and **TARANIS**.

## Schema Markup
```json
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  "@type": "Thing",
  "name": "PARASOL",
  "description": "French Earth observation microsatellite launched in 2004 to study atmospheric aerosols and clouds using polarized light measurements.",
  "url": "https://parasol.cnes.fr/en/",
  "sameAs": [
    "https://www.wikidata.org/wiki/Q6272367",
    "https://en.wikipedia.org/wiki/Parasol_(satellite)"
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  "manufacturer": {
    "@type": "Organization",
    "name": "CNES"
  },
  "dateCreated": "2004-12-18",
  "dateDeleted": "2013-12-18",
  "weight": {
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    "value": 120,
    "unitCode": "KGM"
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}

## References

1. [Source](https://space.skyrocket.de/doc_sdat/parasol.htm)
2. [Source](https://directory.eoportal.org/web/eoportal/satellite-missions/content/-/article/parasol)
3. Jonathan's Space Report
4. Freebase Data Dumps. 2013
5. [Source](https://parasol.cnes.fr/en/PARASOL/GP_actualites.htm)
6. [Source](https://space.oscar.wmo.int/satellites/view/parasol)