# Cosmos 1666

> Soviet signals intelligence satellite

**Wikidata**: [Q13566682](https://www.wikidata.org/wiki/Q13566682)  
**Source**: https://4ort.xyz/entity/cosmos-1666

## Summary
Cosmos 1666 was a Soviet signals intelligence satellite launched on July 8, 1985. It belonged to the Tselina-D class of spacecraft and was deployed into orbit using a Tsyklon-3 rocket from the Plesetsk Cosmodrome. Designated under the international COSPAR ID 1985-058A, it formed part of the Soviet Union's extensive efforts to gather electronic and signals intelligence from space.

## Key Facts
*   **Classification:** Cosmos 1666 is an instance of the **Tselina-D**, a specific model of Soviet signals intelligence satellite.
*   **Launch Date:** The satellite was launched on **July 8, 1985**.
*   **Launch Vehicle:** It was delivered to orbit by a **Tsyklon-3** expendable launch vehicle.
*   **Launch Site:** The launch originated from **Plesetsk Cosmodrome Site 32** in Russia.
*   **COSPAR ID:** Its international satellite designation is **1985-058A**.
*   **Satellite Catalog Number:** It is tracked under the Satellite Catalog Number (SCN) **15889**.
*   **Launch Event:** The specific rocket launch occurred at **23:40:00** UTC on the date of launch.
*   **Alternative Name:** The satellite is also known as **Kosmos 1666**.

## FAQs
### Q: What was the primary mission of Cosmos 1666?
A: Cosmos 1666 was a signals intelligence satellite designed to intercept electronic signals and communications. It was part of the Tselina-D series, which specialized in this type of military reconnaissance.

### Q: What rocket was used to launch Cosmos 1666?
A: The satellite was launched aboard a Tsyklon-3 rocket, a Soviet/Ukrainian expendable launch vehicle frequently used for placing military and scientific payloads into orbit.

### Q: Where and when was Cosmos 1666 launched?
A: The launch took place on July 8, 1985, from the Plesetsk Cosmodrome Site 32, a major spaceport used historically for Russian military satellite launches.

## Why It Matters
Cosmos 1666 represents a critical component of the Soviet Union's Cold War space strategy, specifically within the domain of signals intelligence (SIGINT). As a Tselina-D satellite, it illustrates the operational deployment of specialized technology designed to monitor the electronic activities of foreign powers. The use of the Tsyklon-3 launch vehicle and the launch from Plesetsk Cosmodrome Site 32 highlights the integrated military-industrial infrastructure supporting these missions.

These satellites were essential for providing the Soviet military with strategic intelligence regarding radar systems, communications, and other electronic emissions globally. The "Cosmos" designation itself was a standard Soviet practice used to obscure the military nature of reconnaissance satellites, and Cosmos 1666 served as a specific node in this vast, secretive network. Its launch in the mid-1980s occurred during a period of intensified technological competition in space capabilities, underscoring the continued reliance on orbital assets for national security assessment.

## Notable For
*   **SIGINT Specialization:** Being a dedicated platform for signals intelligence via the Tselina-D framework.
*   **Launch Infrastructure:** Utilizing the Tsyklon-3 rocket, a prominent launch vehicle of the era.
*   **Specific Launch Timing:** Deployment executed with precision at 23:40:00 UTC.
*   **Military Designation:** Operating under the ubiquitous "Cosmos" cover name for Soviet military satellites.

## Body
### Mission Profile
Cosmos 1666 functioned as a signals intelligence satellite operating under the Soviet space program. As an instance of the **Tselina-D** class, its role was to facilitate the collection of intelligence via the interception of signals. The "Cosmos" moniker was standard for Soviet military satellites, serving to standardize their public identification while masking specific military objectives.

### Launch Specifications
The satellite was successfully launched on **July 8, 1985**. The mission utilized a **Tsyklon-3** rocket, an expendable launch system known for its reliability in deploying multiple types of satellites. The launch event is recorded as a "rocket launch" significant event, initiating from **Plesetsk Cosmodrome Site 32**.

### Identification and Tracking
The international community tracked Cosmos 1666 under the **COSPAR ID 1985-058A**. This ID indicates it was the primary object (denoted by "A") launched in the 58th launch of 1985. Additionally, it was assigned the Satellite Catalog Number (SCN) **15889**. In the Wolfram Language knowledgebase, the entity is represented as `Entity["Satellite", "15889"]`.

### Associated Technologies
*   **Tselina-D:** The satellite class to which Cosmos 1666 belongs. These satellites were integral to the Soviet Union's electronic intelligence gathering.
*   **Tsyklon-3:** The launch vehicle used, characterized by its three-stage design and use of storable propellants, allowing for rapid launch capabilities.

## References

1. Jonathan's Space Report