# Injun 4

> NASA satellite of the Explorer program and Injun series

**Wikidata**: [Q9257134](https://www.wikidata.org/wiki/Q9257134)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Explorer_25)  
**Source**: https://4ort.xyz/entity/injun-4

## Summary
Injun 4 was a NASA research satellite launched in 1964 as part of both the Explorer program and the Injun series of geophysical research satellites. It was designed to study Earth's magnetosphere and cosmic rays using instruments developed by the University of Iowa. The satellite failed in December 1966 after successfully operating for over two years.

## Key Facts
- Launched on November 21, 1964 at 17:09:39 UTC from Vandenberg Space Launch Complex 5
- Weighed 40 kilograms and was powered by solar arrays
- Operated by NASA with funding from the National Aeronautics and Space Administration
- Failed in December 1966 after approximately 2 years of operation
- Also known as Explorer 25 or IE B
- Part of the Injun series (specifically Injun 4) and the Explorers Program (Explorer 25)
- Launched using a Scout X-4 rocket (S135R configuration)
- Studied Earth's magnetosphere and cosmic rays
- Had a COSPAR ID of 1964-076B and NSSDCA ID of 1964-076B

## FAQs
### Q: What was Injun 4's primary mission?
A: Injun 4 was designed to study Earth's magnetosphere and measure cosmic rays using scientific instruments developed by the University of Iowa. It was part of NASA's broader effort to understand space weather and radiation environments around Earth.

### Q: How long did Injun 4 operate in space?
A: Injun 4 operated successfully for approximately two years before failing in December 1966. It was launched on November 21, 1964 and provided valuable scientific data during its operational lifetime.

### Q: What type of rocket launched Injun 4?
A: Injun 4 was launched using a Scout X-4 rocket, specifically the S135R configuration, from Vandenberg Space Launch Complex 5 in California.

## Why It Matters
Injun 4 represented an important collaboration between NASA and academic institutions, specifically the University of Iowa, in advancing our understanding of space physics. As part of the Explorer program, it contributed to the systematic study of Earth's space environment during the early Space Age. The satellite's measurements of cosmic rays and magnetospheric phenomena helped scientists better understand the radiation environment that would affect both human spaceflight and satellite operations. Its relatively long operational lifetime for the era demonstrated the maturing capabilities of small scientific satellites. The Injun series, of which this was the fourth mission, showed how university-developed instruments could be successfully integrated into NASA's broader research program, establishing a model for academic-industrial partnerships in space science that continues today.

## Notable For
- Fourth mission in the University of Iowa's Injun series of geophysical research satellites
- Successfully operated for over two years, providing extended data collection
- Studied both cosmic rays and Earth's magnetosphere simultaneously
- Demonstrated successful university-NASA collaboration in satellite development
- Part of the historic Explorer program that pioneered American space science

## Body
### Technical Specifications
Injun 4 was a 40-kilogram research satellite equipped with solar arrays for power generation. The satellite carried scientific instruments designed to study cosmic rays and Earth's magnetosphere, building on the successful Injun series developed by the University of Iowa.

### Launch and Operations
The satellite launched on November 21, 1964 at 17:09:39 UTC aboard a Scout X-4 rocket (S135R configuration) from Vandenberg Space Launch Complex 5 in California. It operated successfully for approximately two years before experiencing a failure in December 1966.

### Scientific Mission
As part of both the Injun series and the Explorers Program, Injun 4 focused on measuring cosmic rays and studying Earth's magnetosphere. These measurements were crucial for understanding the space environment around Earth, which was important for both scientific knowledge and the safety of future space missions.

### Program Context
Injun 4 was the fourth satellite in the Injun series developed by the University of Iowa, following Injun 3 and preceding Injun 5. It was also designated as Explorer 25 in NASA's broader Explorer program, which included numerous small scientific satellites launched throughout the 1960s.

## Schema Markup
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  "@context": "https://schema.org",
  "@type": "Thing",
  "name": "Injun 4",
  "description": "NASA research satellite launched in 1964 as part of the Explorer program and Injun series to study Earth's magnetosphere and cosmic rays",
  "url": "https://en.wikipedia.org/wiki/Explorer_25",
  "sameAs": [
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## References

1. Jonathan's Space Report
2. [Source](https://space.skyrocket.de/doc_sdat/explorer_ie-b.htm)
3. [Source](https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1964-076B)