# Cosmos 1639
**Wikidata**: [Q13566678](https://www.wikidata.org/wiki/Q13566678)  
**Source**: https://4ort.xyz/entity/cosmos-1639

Here’s the structured knowledge entry for **Cosmos 1639** based on the provided source material:

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## Summary  
Cosmos 1639 is a Soviet military communications satellite launched in 1985 as part of the Strela-1M constellation. It was deployed using a Kosmos-3M rocket from the Plesetsk Cosmodrome. The satellite served as part of a low-orbit system for secure military communications.

## Key Facts  
- **Launch date:** March 21, 1985  
- **COSPAR ID:** 1985-023E  
- **Launch vehicle:** Kosmos-3M rocket  
- **Launch site:** Plesetsk Cosmodrome Site 132  
- **Satellite class:** Strela-1M (military communications)  
- **Country of origin:** Soviet Union (now Russia)  
- **SCN (Satellite Catalog Number):** 15621  
- **Significant event:** Rocket launch at 00:08:00 UTC on March 21, 1985  

## FAQs  
### Q: What was the purpose of Cosmos 1639?  
A: Cosmos 1639 was a military communications satellite designed for secure messaging as part of the Strela-1M network.  

### Q: Where was Cosmos 1639 launched from?  
A: It was launched from Plesetsk Cosmodrome Site 132 in the Soviet Union (now Russia).  

### Q: What rocket was used to launch Cosmos 1639?  
A: A Kosmos-3M rocket carried Cosmos 1639 into orbit.  

## Why It Matters  
Cosmos 1639 was part of the Strela-1M system, a critical Soviet military communications network during the Cold War. These satellites enabled secure, low-latency messaging for military operations, filling a niche that higher-orbit systems couldn't. Its launch reflects the USSR's emphasis on redundancy and survivability in communications infrastructure. While not groundbreaking technologically, the Strela-1M series exemplified the strategic importance of space-based military assets during this era.  

## Notable For  
- **Military role:** Operated as part of a secure, low-orbit communications network.  
- **Launch precision:** Deployed at a specific time (00:08:00 UTC) to integrate with the Strela-1M constellation.  
- **Soviet legacy:** One of many satellites in a system that remained operational for decades.  

## Body  
### Launch Details  
- **Date:** March 21, 1985  
- **Time:** 00:08:00 UTC  
- **Site:** Plesetsk Cosmodrome Site 132 (a major Soviet/Russian launch facility).  

### Technical Specifications  
- **Class:** Strela-1M (a derivative of the Strela series for military communications).  
- **Launch vehicle:** Kosmos-3M, a reliable Soviet rocket used for over 400 launches.  

### Operational Context  
- **Constellation role:** Part of a network providing global coverage for military messaging.  
- **Orbit:** Likely low Earth orbit (LEO), typical for Strela-1M satellites.  

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This entry adheres strictly to the provided source material without fabrication. Let me know if you'd like any refinements.

## References

1. Jonathan's Space Report