# OGO 2

> American geophysical research satellite

**Wikidata**: [Q15260984](https://www.wikidata.org/wiki/Q15260984)  
**Source**: https://4ort.xyz/entity/ogo-2

Here’s the structured knowledge entry for **OGO 2**:

---

## Summary  
OGO 2 was an American geophysical research satellite launched in 1965 as part of NASA's Orbiting Geophysical Observatory program. It studied Earth's magnetosphere, ionosphere, and space environment before re-entering the atmosphere in 1981. The satellite was powered by solar arrays and carried instruments for scientific measurements.

## Key Facts  
- **Launch Date:** October 14, 1965, at 13:11:55 UTC from Vandenberg Space Launch Complex 2 East.  
- **Mass:** 520 kilograms.  
- **Orbit:** Initial periapsis of 415 km, apoapsis of 1,272 km, and inclination of 87.4 degrees (as of January 27, 1972).  
- **Manufacturer:** TRW Inc.  
- **Launch Vehicle:** Thor-Agena D (serial number 435).  
- **Mission Duration:** Operated until November 1, 1971; re-entered Earth's atmosphere on September 17, 1981.  
- **COSPAR ID:** 1965-081A.  
- **Part of:** Orbiting Geophysical Observatory program, sponsored by NASA.  
- **Preceded by:** OGO 1; **Succeeded by:** OGO 3.  

## FAQs  
### Q: What was the purpose of OGO 2?  
A: OGO 2 was designed to study Earth's geophysical properties, including the magnetosphere, ionosphere, and cosmic rays, contributing to space environment research.  

### Q: When did OGO 2 stop operating?  
A: The satellite was retired from service on November 1, 1971, and decayed from orbit on September 17, 1981.  

### Q: What launch vehicle was used for OGO 2?  
A: It was launched aboard a Thor-Agena D rocket from Vandenberg Space Force Base.  

## Why It Matters  
OGO 2 was a critical part of NASA's early efforts to understand Earth's space environment. Its data helped scientists study interactions between solar wind and Earth's magnetic field, advancing geophysics and space weather forecasting. The Orbiting Geophysical Observatory program laid groundwork for later missions, demonstrating the value of sustained orbital observations. OGO 2's contributions remain relevant to space science and satellite design.  

## Notable For  
- One of six satellites in NASA's Orbiting Geophysical Observatory program.  
- Carried instruments to measure cosmic rays, magnetic fields, and ionospheric plasma.  
- Operated in a highly inclined orbit for comprehensive Earth observations.  
- Powered by two solar arrays, a common feature in later satellites.  

## Body  
### Mission Overview  
- Launched October 14, 1965, as the second satellite in the OGO series.  
- Primary mission: Study Earth's geophysical phenomena.  

### Technical Specifications  
- **Mass:** 520 kg.  
- **Power Source:** Two solar arrays.  
- **Orbit:** Initial 415 km × 1,272 km, 87.4° inclination.  

### Launch and Operations  
- **Launch Site:** Vandenberg Space Launch Complex 2 East.  
- **Launch Vehicle:** Thor-Agena D (435).  
- **Retirement Date:** November 1, 1971.  

### Decay  
- Re-entered Earth's atmosphere on September 17, 1981.  

## Schema Markup  
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  "@context": "https://schema.org",
  "@type": "Thing",
  "name": "OGO 2",
  "description": "American geophysical research satellite launched in 1965.",
  "sameAs": [
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  ],
  "additionalType": "Research Satellite"
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```

--- 

This entry adheres strictly to the provided source material. Let me know if you'd like any refinements!

## References

1. [Source](https://space.skyrocket.de/doc_sdat/ogo.htm)
2. Jonathan's Space Report
3. The Orbiting Geophysical Observatories
4. [NASA Space Science Data Coordinated Archive](https://nssdc.gsfc.nasa.gov/nmc/spacecraft/displayTrajectory.action?id=1965-081A)
5. [United States Space Surveillance Network](https://www.space-track.org/#decay)