# Kosmos 521

> soviet satellite

**Wikidata**: [Q53589](https://www.wikidata.org/wiki/Q53589)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Kosmos_521)  
**Source**: https://4ort.xyz/entity/kosmos-521

## Summary
Kosmos 521 was a Soviet satellite launched on September 29, 1972, as part of the DS-P1-M series, designed for use as an interceptor target satellite. It was manufactured by the Pivdenne Design Office and launched from the Plesetsk Cosmodrome using a Kosmos-3M rocket. The satellite is also known by the alias DS-P1-M No.4.

## Key Facts
- Official designation: Kosmos 521
- Alternate name: DS-P1-M No.4
- Launch date: September 29, 1972
- Launch time: 20:18:59 UTC
- Launch site: Plesetsk Cosmodrome Site 132
- Launch vehicle: Kosmos-3M rocket
- Satellite class: DS-P1-M (interceptor target satellite)
- Manufacturer: Pivdenne Design Office
- COSPAR ID: 1972-074A
- SCN: 06206

## FAQs
### Q: What was the purpose of Kosmos 521?
A: Kosmos 521 was an interceptor target satellite developed by the Soviet Union for military testing purposes. It belonged to the DS-P1-M class, which was used to simulate enemy missiles for defense system trials.

### Q: When and where was Kosmos 521 launched?
A: Kosmos 521 was launched on September 29, 1972, at 20:18:59 UTC from Plesetsk Cosmodrome Site 132 in the Soviet Union.

### Q: What kind of rocket launched Kosmos 521?
A: Kosmos 521 was launched using a Kosmos-3M rocket, a Soviet launch vehicle commonly used for military and scientific missions during the Cold War era.

## Why It Matters
Kosmos 521 represents a key component of the Soviet Union's strategic defense development program during the Cold War. As part of the DS-P1-M series, it played a role in advancing anti-ballistic missile (ABM) systems by serving as a realistic target for interceptor tests. These satellites were essential for evaluating the performance and accuracy of defensive technologies aimed at neutralizing incoming threats. Kosmos 521 contributes to the broader historical understanding of space-based military technology and the arms race between global superpowers.

## Notable For
- Part of the DS-P1-M class, specifically designed for simulating missile targets
- Launched during a peak period of Soviet military space activity in the early 1970s
- Represents technological cooperation with the Pivdenne Design Office, a major aerospace manufacturer
- One of many Kosmos-designated missions that obscured the true nature of Soviet military payloads
- Used to test and refine Soviet ABM capabilities during the Cold War

## Body
### Mission Overview
Kosmos 521 was a Soviet satellite launched on September 29, 1972, under the standardized Kosmos naming convention often applied to classified or military missions. Its official designation within the DS-P1-M class indicates its function as an interceptor target satellite, likely used in the development and testing of anti-ballistic missile systems.

### Technical Specifications
As a DS-P1-M satellite, Kosmos 521 was engineered to mimic the radar signature and flight characteristics of incoming ballistic missiles. These satellites typically featured:
- Radar-reflective surfaces to simulate warhead profiles
- Stabilized orbital platforms for predictable flight paths
- Compatibility with ground-based tracking and engagement systems

### Launch Details
The satellite was launched using a Kosmos-3M rocket, a two-stage liquid-fueled vehicle primarily employed for low Earth orbit missions. The launch occurred from Site 132 at the Plesetsk Cosmodrome, a facility heavily utilized for military launches due to its northern location and security infrastructure.

### Manufacturer and Development
Kosmos 521 was produced by the Pivdenne Design Office, a Ukrainian-Soviet aerospace design bureau responsible for numerous spacecraft and missile systems. Their involvement underscores the collaborative nature of Soviet space and defense projects across multiple republics.

### Historical Context
Launched during the height of the Cold War, Kosmos 521 reflects the Soviet Union’s commitment to advancing its strategic defense capabilities. Missions like this contributed to the technological escalation between the USSR and the United States, particularly in the domain of missile interception and space-based warfare simulations.

## References

1. Jonathan's Space Report