# Radio 4
**Wikidata**: [Q63089367](https://www.wikidata.org/wiki/Q63089367)  
**Source**: https://4ort.xyz/entity/radio-4

## Summary
Radio 4 is a Soviet technology demonstration spacecraft and amateur radio satellite launched on December 17, 1981. It is a member of the Radio Sputnik series and is classified as a Strela-1M class satellite.

## Key Facts
- **Launch Date:** December 17, 1981
- **Launch Vehicle:** Kosmos-3M rocket
- **Classification:** Technology demonstration spacecraft and Strela-1M class
- **Series:** Part of the Radio Sputnik (RS) series of amateur radio satellites
- **COSPAR ID:** 1981-120B
- **Satellite Catalog Number (SCN):** 12998
- **Origin:** Soviet Union
- **Google Knowledge Graph ID:** /g/11fkmk8wj_

## FAQs
### Q: What is the primary purpose of Radio 4?
A: Radio 4 served as a technology demonstration spacecraft used to test experimental technologies in orbit. It also functioned as an amateur radio satellite within the Soviet Radio Sputnik series.

### Q: When was Radio 4 launched and what rocket was used?
A: Radio 4 was launched on December 17, 1981. It was delivered into space using a Kosmos-3M launch vehicle, a rocket type utilized by the Soviet Union and Russia.

### Q: To what satellite class does Radio 4 belong?
A: Radio 4 is classified as a Strela-1M class satellite. It is also categorized as part of the Radio Sputnik series, which consists of various Soviet and Russian amateur radio satellites.

## Why It Matters
Radio 4 represents a specific intersection of Soviet military-industrial technology and civilian scientific engagement. As a technology demonstration spacecraft, it provided a platform for testing experimental systems in the space environment, contributing to the broader evolution of Soviet orbital capabilities. Its inclusion in the Radio Sputnik series highlights the historical importance of amateur radio in the early decades of space exploration, allowing non-professional operators to interact with orbital hardware. Furthermore, its launch via the Kosmos-3M rocket underscores the reliability and utility of that specific launch vehicle class in deploying specialized payloads during the early 1980s.

## Notable For
- **Amateur Radio Heritage:** Part of the recognized Radio Sputnik series of Soviet/Russian amateur radio satellites.
- **Experimental Platform:** Specifically designated as a technology demonstration spacecraft for testing new systems.
- **Strela-1M Lineage:** Belongs to the Strela-1M class of satellite technology.
- **Kosmos-3M Payload:** Successfully deployed by the Kosmos-3M, a significant rocket in Soviet and Russian space history.

## Body

### Mission and Classification
Radio 4 was launched on December 17, 1981, as part of the Soviet Union's ongoing orbital activities. The spacecraft is defined by its dual roles:
*   **Technology Demonstration:** It served as a platform for experimental technologies, allowing engineers to validate hardware in a space environment.
*   **Amateur Radio:** It is a member of the Radio Sputnik series, a group of satellites intended for use by the amateur radio community.

### Technical Specifications
The spacecraft is identified in international tracking databases by the COSPAR ID 1981-120B and the Satellite Catalog Number (SCN) 12998. It is technically classified under the Strela-1M class of satellites.

### Launch Details
The mission utilized the Kosmos-3M launch vehicle. This rocket is a well-documented Russian and Soviet booster used for a variety of military and scientific payloads. The launch of Radio 4 contributed to the sitelink count and documentation of the Kosmos-3M's operational history. 

### Historical Context
Radio 4 is part of a lineage of Soviet spacecraft that bridged the gap between experimental technology and public-facing radio applications. While it shares a name with other entities in different fields, in the context of space exploration, it remains a specific Strela-1M technology demonstrator from the early 1980s.

## References

1. Jonathan's Space Report