# Cosmos 2157
**Wikidata**: [Q12907592](https://www.wikidata.org/wiki/Q12907592)  
**Source**: https://4ort.xyz/entity/cosmos-2157

## Summary  
Cosmos 2157 is a Ukrainian military communications satellite of the Strela-3 class, launched on September 28, 1991. It was deployed from the Plesetsk Cosmodrome using a Tsyklon-3 launch vehicle. The satellite supports secure military communication capabilities and is part of Ukraine's space-based defense infrastructure.

## Key Facts  
- Official designation: Cosmos 2157 (alias: Kosmos 2157)  
- COSPAR ID: 1991-068A  
- Satellite class: Strela-3 (military communications satellite)  
- Launch date: September 28, 1991  
- Launch time: 07:05:55 UTC  
- Launch site: Plesetsk Cosmodrome Site 32  
- Launch vehicle: Tsyklon-3  
- SCN (Satellite Catalog Number): 21728  
- Wikipedia coverage: Available in Croatian (hr), Macedonian (mk), Serbo-Croatian (sh), and Serbian (sr)  
- Wolfram Language entity code: Entity["Satellite", "21728"]  

## FAQs  
### Q: What is Cosmos 2157 used for?  
A: Cosmos 2157 is a military communications satellite designed to support secure communication for the Ukrainian armed forces. It belongs to the Strela-3 class, which specializes in tactical data relay.

### Q: When was Cosmos 2157 launched?  
A: Cosmos 2157 was launched on September 28, 1991, at 07:05:55 UTC from the Plesetsk Cosmodrome in Russia.

### Q: Which rocket was used to launch Cosmos 2157?  
A: The satellite was launched using a Tsyklon-3 expendable launch vehicle, a Soviet-designed rocket later operated by Ukraine.

## Why It Matters  
Cosmos 2157 represents a key component of Ukraine’s early post-Soviet military space program. As part of the Strela-3 constellation, it contributes to strategic communication capabilities essential for national defense. Its launch marked continued Ukrainian reliance on legacy Soviet infrastructure and launch systems during the transitional period following the dissolution of the USSR. The satellite underscores the role of space assets in modern military operations and illustrates how former Soviet states repurposed existing technologies for independent defense needs.

## Notable For  
- Being a Strela-3 class satellite, optimized for secure military communications  
- Launching aboard the Tsyklon-3, one of the last missions of this Soviet-era launch system  
- Representing Ukraine’s continuation of military satellite deployment after gaining independence  
- Having international recognition through multiple-language Wikipedia entries  
- Assigned SCN 21728, tracked globally in satellite databases  

## Body  
### Classification and Purpose  
Cosmos 2157 is classified as a Strela-3 satellite, a series developed for secure military communications. These satellites are typically used for relaying encrypted tactical data between ground stations and mobile units, particularly within military contexts.

### Launch Details  
The satellite was successfully launched on **September 28, 1991**, at **07:05:55 UTC**. The launch occurred from **Plesetsk Cosmodrome Site 32**, a historically significant launch facility used extensively by the Soviet Union and later by Russia and Ukraine.

It was carried into orbit by a **Tsyklon-3** launch vehicle, a three-stage liquid-fueled rocket originally developed by the Soviet Union. The Tsyklon-3 had a long operational history and was frequently used for launching military payloads.

### Identification and Tracking  
Cosmos 2157 is catalogued under several identifiers:
- **COSPAR ID**: 1991-068A  
- **SCN (Satellite Catalog Number)**: 21728  

These identifiers are used by global tracking organizations and databases such as the Wolfram Language, which recognizes it via the code `Entity["Satellite", "21728"]`.

### International Recognition  
Despite being a military satellite, Cosmos 2157 has received attention in public knowledge bases, with dedicated articles in several Slavic language Wikipedias:
- Croatian (hr)
- Macedonian (mk)
- Serbo-Croatian (sh)
- Serbian (sr)

This multilingual documentation reflects regional interest in post-Soviet space activities and Ukrainian military advancements.

## References

1. Jonathan's Space Report