# THEMIS-B

> satellite in the THEMIS constellation

**Wikidata**: [Q111497133](https://www.wikidata.org/wiki/Q111497133)  
**Source**: https://4ort.xyz/entity/themis-b

## Summary
THEMIS-B is a geomagnetic satellite in NASA's THEMIS constellation, built to study Earth's magnetosphere. It was launched from Cape Canaveral on 2007-02-17 aboard a Delta II (D-323) rocket and is operated by the National Aeronautics and Space Administration.

## Key Facts
- THEMIS-B is an instance of a geomagnetic satellite — a satellite class designed to monitor Earth's magnetosphere and related regions.
- Launch date: 2007-02-17 at 23:01:00 (UTC), launched from Cape Canaveral Space Launch Complex 17B.
- Launch vehicle: Delta II (flight configuration D-323); launch contractor: United Launch Alliance.
- Operator: National Aeronautics and Space Administration (NASA).
- Manufacturer: Swales Aerospace (general contractor); University of California, Berkeley (subcontractor for space instrument and system integration).
- Mass: dry mass 77 kilogram; launch mass 126 kilogram.
- Dimensions: height 51 centimetre; diameter 84 centimetre.
- Identifiers: SCN (satellite catalog number) 30581; COSPAR ID / NSSDCA ID 2007-004B.
- Part of: THEMIS constellation (listed as part_of THEMIS); aliases include Explorer 86, THEMIS-P1, MIDEX-5B, ARTEMIS-P1, Эксплорер-86.
- Power and propulsion (recorded values): spacecraft solar array (qualifier records amount "37" with unit identifier Q25236); reaction control system using hydrazine (qualifier records value "4").

## FAQs
### Q: What is THEMIS-B's mission?
A: THEMIS-B is a geomagnetic satellite in the THEMIS constellation, intended to observe and monitor Earth's magnetosphere and related regions.

### Q: When and where was THEMIS-B launched?
A: THEMIS-B was launched on 2007-02-17 at 23:01:00 (UTC) from Cape Canaveral Space Launch Complex 17B aboard a Delta II rocket (flight configuration D-323).

### Q: Who manufactured and operates THEMIS-B?
A: The spacecraft was manufactured by Swales Aerospace as the general contractor, with the University of California, Berkeley as a subcontractor for the space instrument and system integration. It is operated by NASA.

## Why It Matters
THEMIS-B is part of a coordinated constellation of geomagnetic satellites that provide in-situ measurements of Earth's magnetosphere. As a member of the THEMIS mission, it contributes to multi-point observations that help characterize large-scale and small-scale magnetic and plasma processes near Earth. The spacecraft's relatively compact dimensions and modest mass enabled deployment as part of a multi-spacecraft mission architecture. Operated by NASA and built by Swales Aerospace with UC Berkeley instrumentation, THEMIS-B represents a collaboration between industry and academia to deliver focused science capability. Its launch on a Delta II vehicle and cataloging under COSPAR ID 2007-004B/SATCAT 30581 make it a recorded and trackable asset in near-Earth space studies. For researchers and mission planners, THEMIS-B supplies targeted data on magnetospheric dynamics that complement ground-based observations and other spaceborne assets, improving understanding of space weather drivers that affect Earth's near-space environment.

## Notable For
- Being a flight element of NASA's THEMIS constellation of geomagnetic satellites.
- Small form factor: 51 cm height and 84 cm diameter, with a dry mass of 77 kg and launch mass of 126 kg.
- Multiple operational and historical aliases, including Explorer 86 and THEMIS-P1.
- Manufactured by Swales Aerospace with UC Berkeley as subcontractor for instruments and integration.
- Launched on 2007-02-17 by a Delta II (D-323) vehicle; cataloged as COSPAR 2007-004B and SCN 30581.

## Body

### Overview
- Name: THEMIS-B.
- Wikidata description: "satellite in the THEMIS constellation."
- Instance of: geomagnetic satellite (satellite class designed to monitor Earth's magnetosphere and related regions).
- Part of: THEMIS constellation (listed in source as part_of THEMIS).

### Identification & Catalog Numbers
- Satellite Catalog Number (SCN): 30581.
- COSPAR ID: 2007-004B.
- NSSDCA ID: 2007-004B.
- Aliases: Explorer 86; THEMIS-P1; MIDEX-5B; ARTEMIS-P1; Эксплорер-86.
- Wolfram Language entity code: Entity["Satellite","30581"].
- Image: https://commons.wikimedia.org/wiki/Special:FilePath/THEMIS_spacecraft_model.png

### Launch and Operations
- Launch date and time: 2007-02-17, 23:01:00 (qualifier recorded).
- Launch site: Cape Canaveral Space Launch Complex 17B.
- Launch vehicle: Delta II, flight configuration D-323.
- Launch contractor: United Launch Alliance.
- Operator: National Aeronautics and Space Administration (NASA).

### Manufacturers and Contributors
- General contractor / manufacturer: Swales Aerospace.
- Subcontractor: University of California, Berkeley — listed as subcontractor for space instrument and system integration.

### Physical Characteristics
- Dry mass: 77 kilogram (criterion used: dry weight).
- Launch mass: 126 kilogram (criterion used: launch weight).
- Height: 51 centimetre.
- Diameter: 84 centimetre.

### Power and Propulsion
- Power source listed as: spacecraft solar array (source records qualifier amount "37" with unit identifier Q25236).
- Propulsion / attitude control: reaction control system using hydrazine (source records qualifier value "4").

### Program Context and Relationships
- Part of the THEMIS mission/constellation.
- Related class: geomagnetic satellite (designed to monitor Earth's magnetosphere and related regions).
- Source entries also reference a separate "Themis" (European Space Agency reusable launcher prototype) in the provided part/parent listing; within this entry THEMIS-B is identified as part of the THEMIS constellation.

### References & Source Notes
- Core technical and manufacturing details referenced to Swales Aerospace and archived Swales pages noted in source material.
- Launch details referenced to mission launch record entries and Delta II launch reporting in the provided sources.
- Identification numbers and catalog entries provided as recorded in the structured properties.

## 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)