# Kosmos 520

> Russian military early warning satellite

**Wikidata**: [Q3400824](https://www.wikidata.org/wiki/Q3400824)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Kosmos_520)  
**Source**: https://4ort.xyz/entity/kosmos-520

## Summary
Kosmos 520 was a Russian military early warning satellite launched on September 19, 1972. It belonged to the US-K class of Soviet satellites designed to detect missile launches. The satellite was deployed into orbit using a Molniya-M rocket from the Plesetsk Cosmodrome.

## Key Facts
- **Classification:** Kosmos 520 is an instance of the **US-K** class of satellites, a series used for Soviet and Russian early warning systems.
- **Launch Date:** The satellite was launched on **September 19, 1972**.
- **Launch Vehicle:** It was carried into space by a **Molniya-M** rocket, a Soviet space launcher.
- **Launch Site:** The launch originated from **Plesetsk Cosmodrome Site 41**.
- **COSPAR ID:** Its international satellite identifier is **1972-072A**.
- **Satellite Catalog Number:** It holds the SCN **06192**.
- **Launch Time:** The significant launch event occurred at **19:19:03** UTC.
- **Aliases:** The satellite is also known as **Cosmos 520**.

## FAQs
### Q: What type of satellite was Kosmos 520?
A: Kosmos 520 was a Russian military early warning satellite. It was part of the US-K series, which was designed to detect missile launches.

### Q: When was Kosmos 520 launched?
A: Kosmos 520 was launched on September 19, 1972. The launch took place at 19:19:03 UTC.

### Q: What rocket was used to launch Kosmos 520?
A: The satellite was launched using a Molniya-M rocket. This was a standard Soviet space launch vehicle used for this class of satellite.

## Why It Matters
Kosmos 520 serves as a historical example of the Soviet Union's strategic space-based infrastructure during the Cold War. As a component of the US-K (Oko) system, this satellite represented a critical technological capability for providing early warning of intercontinental ballistic missile (ICBM) attacks. The deployment of such satellites allowed for the monitoring of potential adversary launch sites, acting as a space-based sentinel to validate or deny threats.

The launch of Kosmos 520 specifically demonstrates the operational tempo and reliability of the Soviet space program in the early 1970s. Utilizing the workhorse Molniya-M launcher and launching from the domestic Plesetsk Cosmodrome, the mission highlights the established logistics and aerospace capabilities of the era. The satellite is a data point in the broader history of space-based reconnaissance and the militarization of space, illustrating how nations extended their defensive sensor networks beyond the Earth's atmosphere to ensure national security and strategic stability.

## Notable For
- Being a specific operational unit within the **US-K** early warning satellite network.
- Launching aboard the **Molniya-M**, a prominent Soviet rocket used for military and scientific payloads.
- Utilizing **Plesetsk Cosmodrome Site 41** as its departure point for orbit.
- Maintaining a distinct record in international catalogs via its COSPAR ID (1972-072A) and Satellite Catalog Number (06192).

## Body

### Classification and Function
Kosmos 520 is officially designated as a Russian military early warning satellite. Structurally and functionally, it is an instance of the **US-K** class (also known by the GRAU index 73D6). The US-K series comprised the first generation of Soviet early warning satellites, designed to detect the thermal radiation from rocket engine exhaust plumes against the background of the Earth.

### Launch Operations
The satellite was successfully launched on **September 19, 1972**. The mission was executed from the **Plesetsk Cosmodrome**, specifically from **Site 41**. The launch vehicle used to propel Kosmos 520 into its required trajectory was the **Molniya-M**. This rocket was a four-stage derivative of the R-7 Semyorka, frequently employed for military and lunar/planetary missions requiring high-energy orbits.

The specific moment of the rocket launch—the significant event marking the start of the mission—was recorded at **19:19:03** UTC.

### Identification and Records
In international tracking systems, Kosmos 520 is identified by the **COSPAR ID** `1972-072A`. This ID indicates it was the primary payload (denoted by the 'A') for the 72nd launch of 1972. Additionally, it is tracked under **Satellite Catalog Number (SCN)** `06192`. The satellite is referenced in multiple languages across Wikipedia, including English, Macedonian, Portuguese, and Serbian, reflecting its recognition in global space history databases.

## References

1. Jonathan's Space Report