# Cluster 3

> one of four identical magnetospheric research satellites in the Cluster II constellation

**Wikidata**: [Q111658942](https://www.wikidata.org/wiki/Q111658942)  
**Source**: https://4ort.xyz/entity/cluster-3

## Summary
Cluster 3 is one of four identical magnetospheric research satellites in the European Space Agency's Cluster II constellation, designed to study Earth's magnetosphere and its interaction with solar wind. Launched in 2000, it operates alongside its sister satellites to provide simultaneous, multi-point observations of space plasma. Nicknamed "Samba," it remains operational far beyond its planned 5-year mission lifespan.

## Key Facts
- **Launch Date**: July 16, 2000, at 12:39:34 UTC from Baikonur Cosmodrome Site 31.
- **Part of**: Cluster II constellation, a quartet of satellites for 3D magnetospheric research.
- **Manufacturer**: Astrium (now Airbus Defence and Space).
- **Dimensions**: 1.3 meters in height, 2.9 meters in diameter.
- **Mass**: 1,200 kg at launch (550 kg dry weight).
- **Power**: 224 solar cells and S400 batteries.
- **Operator**: European Space Operations Centre (ESOC).
- **Mission Longevity**: Designed for 5 years but remains operational as of 2023.
- **Identifiers**: COSPAR ID 2000-041A, NAIF ID -194.

## FAQs
### Q: What is Cluster 3's primary mission?
A: Cluster 3 investigates Earth's magnetosphere and its interaction with solar wind as part of the Cluster II mission, providing critical data on space plasma dynamics.

### Q: How long was Cluster 3 designed to operate?
A: It was designed for a 5-year mission but has far exceeded this, continuing operations into its third decade.

### Q: What launch vehicle deployed Cluster 3?
A: It was launched aboard a Soyuz-U rocket (serial number A 15000-069) with a Fregat upper stage.

## Why It Matters
Cluster 3 plays a pivotal role in advancing our understanding of Earth's magnetosphere, a shield protecting the planet from solar radiation. As part of the Cluster II constellation, it enables unprecedented 3D mapping of space weather phenomena, such as geomagnetic storms, which impact satellite operations and ground infrastructure. Its long-term operation has provided continuous datasets, helping scientists model solar-terrestrial interactions and mitigate risks to technology. The mission's success underscores the value of international collaboration in space science, particularly between ESA and its partners.

## Notable For
- **3D Magnetospheric Mapping**: First mission to use a constellation for simultaneous, multi-point observations of space plasma.
- **Operational Longevity**: Exceeded its 5-year design life by over 15 years, demonstrating robust spacecraft engineering.
- **Identical Design**: One of four functionally identical satellites (Samba, Tango, Rumba, Salsa) ensuring coordinated data collection.
- **Solar Wind Insights**: Contributed to discoveries about bow shock formation and magnetotail dynamics.

## Body
### Mission Overview
Cluster 3 is a geomagnetic satellite launched to investigate Earth's magnetosphere, a region influenced by solar wind. Its instruments analyze plasma density, magnetic fields, and electric fields, with data used to model space weather events.

### Design and Specifications
- **Structure**: Cylindrical body with 1.3 m height and 2.9 m diameter.
- **Power System**: 224 solar cells generating 1,100 W (1,500 W at launch) and S400 batteries for eclipse phases.
- **Propulsion**: Used for orbital adjustments, though primary positioning relies on the Fregat upper stage.

### Launch and Operations
- **Launch Vehicle**: Soyuz-U (Soyuz Universal) rocket, a Soviet-designed carrier with over 700 launches.
- **Deployment**: Reached a highly elliptical polar orbit (perigee: 4,000 km, apogee: 19,000 km) for optimal magnetospheric sampling.
- **Ground Control**: Operated by ESOC in Darmstadt, Germany, with data archived by ESA's science portal.

### Legacy
Cluster 3's extended mission has supported over 2,000 scientific publications, addressing phenomena like auroral acceleration and magnetopause crossings. Its synergy with other ESA missions (e.g., Swarm) enhances Earth system science, while its design informs future satellite constellations.

## References

1. [Source](https://space.skyrocket.de/doc_sdat/cluster.htm)
2. [Source](https://sci.esa.int/web/cluster/-/47348-fact-sheet)
3. Jonathan's Space Report