# THEMIS-C

> satellite in the THEMIS constellation

**Wikidata**: [Q111497134](https://www.wikidata.org/wiki/Q111497134)  
**Source**: https://4ort.xyz/entity/themis-c

## Summary
THEMIS-C is a geomagnetic satellite launched as part of NASA's THEMIS constellation in 2007. It was designed to study Earth's magnetosphere and related regions, contributing to our understanding of space weather and its effects on Earth.

## Key Facts
- **Class**: Geomagnetic satellite (designed to monitor Earth's magnetosphere)
- **Launch date**: February 17, 2007, at 23:01 UTC
- **Launch site**: Cape Canaveral Space Launch Complex 17B
- **Launch vehicle**: Delta II (model D-323)
- **Operator**: National Aeronautics and Space Administration (NASA)
- **Manufacturer**: Swales Aerospace (general contractor), University of California, Berkeley (subcontractor)
- **Mass**: 77 kg (dry weight), 126 kg (launch weight)
- **Dimensions**: 51 cm height, 84 cm diameter
- **Power system**: Solar array (37 W), reaction control system (hydrazine, 4 thrusters)
- **Part of**: THEMIS constellation
- **Aliases**: Explorer 87, THEMIS-P2, MIDEX-5C, ARTEMIS-P2, Эксплорер-87
- **COSPAR ID**: 2007-004C
- **NSSDCA ID**: 2007-004C

## FAQs
### Q: What was THEMIS-C's primary mission?
A: THEMIS-C was part of NASA's THEMIS constellation, which aimed to study Earth's magnetosphere and the processes leading to geomagnetic substorms.

### Q: Who built THEMIS-C?
A: THEMIS-C was built by Swales Aerospace as the general contractor, with the University of California, Berkeley serving as a subcontractor for space instruments and system integration.

### Q: What type of propulsion did THEMIS-C use?
A: THEMIS-C was equipped with a reaction control system using hydrazine fuel and had four thrusters.

### Q: How much did THEMIS-C weigh at launch?
A: THEMIS-C had a launch weight of 126 kg.

### Q: What was THEMIS-C's role in the THEMIS mission?
A: THEMIS-C was one of five identical satellites launched to observe the aurora and magnetic reconnection events in Earth's magnetosphere.

## Why It Matters
THEMIS-C played a crucial role in NASA's THEMIS mission, which sought to unravel the mysteries of geomagnetic substorms—sudden releases of energy in Earth's magnetosphere. By studying these phenomena, the mission aimed to improve our understanding of space weather and its potential impacts on satellites, power grids, and communication systems. The constellation of satellites, including THEMIS-C, provided valuable data on magnetic reconnection, auroral activity, and the dynamics of Earth's magnetosphere. This research has broader implications for space weather forecasting and the protection of critical infrastructure from solar storms.

## Notable For
- **Part of a constellation**: THEMIS-C was one of five identical satellites in the THEMIS mission, working together to observe Earth's magnetosphere.
- **Geomagnetic focus**: Unlike general Earth-observing satellites, THEMIS-C was specifically designed to study Earth's magnetic field and its interactions with solar wind.
- **Hydrazine propulsion**: The satellite used a reaction control system with hydrazine, a common but precise propulsion method for small satellites.
- **Multi-agency collaboration**: THEMIS-C was a product of collaboration between NASA, Swales Aerospace, and the University of California, Berkeley.
- **Legacy mission**: The THEMIS mission, including THEMIS-C, provided foundational data on geomagnetic substorms, influencing future space weather research.

## Body
### Mission Overview
THEMIS-C was launched as part of NASA's Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission, which consisted of five identical satellites. The primary goal was to investigate geomagnetic substorms—large disturbances in Earth's magnetosphere—by studying auroral activity and magnetic reconnection events.

### Technical Specifications
- **Mass**: THEMIS-C had a dry weight of 77 kg and a launch weight of 126 kg.
- **Dimensions**: The satellite measured 51 cm in height and 84 cm in diameter.
- **Power**: It was powered by a solar array generating 37 W and a reaction control system with four hydrazine-fueled thrusters.

### Launch Details
- **Launch date**: February 17, 2007, at 23:01 UTC.
- **Launch site**: Cape Canaveral Space Launch Complex 17B.
- **Launch vehicle**: Delta II (model D-323), operated by United Launch Alliance.

### Construction and Collaboration
- **Manufacturer**: Swales Aerospace served as the general contractor, while the University of California, Berkeley handled space instruments and system integration.
- **Operator**: NASA managed the mission and data collection.

### Scientific Contributions
THEMIS-C contributed to the broader understanding of space weather by observing magnetic reconnection and auroral phenomena. The mission's findings have been referenced in academic studies on geomagnetic substorms and their impacts on Earth's upper atmosphere.

## References

1. [Source](http://www.swales.com/spacecraft/themis.html)
2. [Source](https://www.nasaspaceflight.com/2007/02/ulas-delta-ii-launches-with-themis/)
3. Jonathan's Space Report
4. [Source](https://directory.eoportal.org/web/eoportal/satellite-missions/t/themis#spacecraft)
5. [Source](https://directory.eoportal.org/web/eoportal/satellite-missions/t/themis)