# Cosmos 851
**Wikidata**: [Q13566927](https://www.wikidata.org/wiki/Q13566927)  
**Source**: https://4ort.xyz/entity/cosmos-851

## Summary
Cosmos 851 was a Soviet signals intelligence satellite launched on August 27, 1976, as part of the Tselina-D satellite program. It was deployed into orbit using a Vostok-2M carrier rocket from the Plesetsk Cosmodrome.

## Key Facts
- Official designation: Kosmos 851 (alternate spelling)
- COSPAR identifier: 1976-085A
- Serial number (SCN): 09389
- Satellite class: Tselina-D (Soviet signals intelligence satellite)
- Launch date: August 27, 1976
- Launch vehicle: Vostok-2M (expendable carrier rocket)
- Launch site: Plesetsk Cosmodrome Site 43/4
- Launch time: 14:34:58
- Available in multiple Wikipedia languages (Hungarian, Macedonian, Serbo-Croatian, Serbian)

## FAQs
### Q: What was the purpose of Cosmos 851?
A: Cosmos 851 was a signals intelligence satellite, designed to gather electronic intelligence for Soviet military operations as part of the Tselina-D program.

### Q: How was Cosmos 851 launched?
A: The satellite was deployed into orbit using a Vostok-2M carrier rocket launched from Plesetsk Cosmodrome Site 43/4 on August 27, 1976.

### Q: What was the significance of the Tselina-D satellite program?
A: The Tselina-D program represented a class of Soviet satellites specifically designed for signals intelligence, enabling the USSR to monitor and collect electronic intelligence from various sources.

## Why It Matters
Cosmos 851 represents an important component in Cold War-era space-based intelligence operations. As a Tselina-D signals intelligence satellite, it contributed to Soviet capabilities in electronic warfare, communications monitoring, and strategic intelligence gathering. These satellites played a crucial role in maintaining the USSR's surveillance capabilities during a period of heightened tensions between superpowers. The Vostok-2M launch vehicle used for this mission was a workhorse of the Soviet space program, having been used for numerous military and scientific satellites throughout the 1970s and 1980s.

## Notable For
- Part of the Tselina-D signals intelligence satellite class, specialized in electronic intelligence gathering
- Launched from the less frequently used Site 43/4 at Plesetsk Cosmodrome
- Assigned the serial number 09389 in the Soviet satellite catalog system
- One of multiple Cosmos satellites launched with the same mission profile in 1976
- Demonstrates the Soviet Union's continuing investment in space-based intelligence capabilities during the Cold War

## Body
### Mission Overview
Cosmos 851 was a military satellite launched under the Soviet space program's Cosmos series designation. The satellite was specifically designed for signals intelligence purposes, belonging to the Tselina-D class that focused on electronic intelligence collection.

### Technical Specifications
- Satellite class: Tselina-D
- COSPAR ID: 1976-085A
- Serial number: 09389
- Alternative designation: Kosmos 851
- Primary function: Signals intelligence (SIGINT)

### Launch Details
- Launch vehicle: Vostok-2M (8A92M)
- Launch date: August 27, 1976
- Launch time: 14:34:58
- Launch site: Plesetsk Cosmodrome, Site 43/4
- Mission type: Rocket launch
- Mission status: Successfully deployed

### Program Context
The Tselina-D program represented a specialized class of Soviet satellites dedicated to electronic intelligence. Cosmos 851 was part of a series of similar missions that formed the backbone of Soviet space-based surveillance capabilities during the Cold War era. These satellites were critical for monitoring military communications, radar signals, and other electronic transmissions.

## References

1. Jonathan's Space Report