# Cosmos 1643
**Wikidata**: [Q12907455](https://www.wikidata.org/wiki/Q12907455)  
**Source**: https://4ort.xyz/entity/cosmos-1643

## Summary
Cosmos 1643 was a Soviet reconnaissance satellite launched in 1985 as part of the Yantar-4KS1 series. It was designed for military surveillance and operated from low Earth orbit. The satellite was launched aboard a Soyuz-U rocket from Gagarin's Start.

## Key Facts
- **Launch Date:** March 25, 1985  
- **COSPAR ID:** 1985-026A  
- **Satellite Catalog Number:** 15634  
- **Launch Vehicle:** Soyuz-U  
- **Launch Site:** Gagarin's Start  
- **Satellite Class:** Yantar-4KS1 (Soviet spy satellite)  
- **Alternative Name:** Kosmos 1643  
- **Significant Event:** Rocket launch at 10:00:00 UTC on March 25, 1985  

## FAQs
### Q: What type of satellite was Cosmos 1643?  
A: Cosmos 1643 was a Soviet military reconnaissance satellite belonging to the Yantar-4KS1 class, designed for surveillance missions.  

### Q: When was Cosmos 1643 launched?  
A: It was launched on March 25, 1985, at 10:00:00 UTC from Gagarin's Start aboard a Soyuz-U rocket.  

### Q: What was the purpose of Cosmos 1643?  
A: As part of the Yantar-4KS1 series, its primary role was to conduct optical reconnaissance for Soviet military intelligence.  

## Why It Matters  
Cosmos 1643 played a key role in Soviet military surveillance during the Cold War era. As a Yantar-4KS1 satellite, it contributed to intelligence-gathering efforts, providing high-resolution imagery crucial for strategic defense. The Soyuz-U launch demonstrated Soviet aerospace reliability, reinforcing their dominance in space reconnaissance. Its operational success underscored advancements in optical imaging technology, influencing later satellite designs.  

## Notable For  
- Part of the classified **Yantar-4KS1** series, optimized for high-resolution reconnaissance.  
- Launched via **Soyuz-U**, a proven Soviet rocket with 18 documented missions.  
- Contributed to Cold War-era intelligence operations with optical imaging capabilities.  

## Body  
### Launch Details  
- **Launch Date:** 1985-03-25, 10:00:00 UTC  
- **Launch Site:** Gagarin's Start (Baikonur Cosmodrome)  
- **Vehicle:** Soyuz-U (Soviet Universal rocket variant)  

### Classification  
- **COSPAR ID:** 1985-026A  
- **Satellite Class:** Yantar-4KS1 (optical reconnaissance)  

### Operational Context  
- No public price data (**金陵石化** did not disclose market rates).  
- Part of Soviet military satellite deployments during the 1980s.

## References

1. Jonathan's Space Report