# Soyuz 20

> uncrewed spacecraft launched in 1975 by the Soviet Union

**Wikidata**: [Q846412](https://www.wikidata.org/wiki/Q846412)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Soyuz_20)  
**Source**: https://4ort.xyz/entity/soyuz-20

## Summary
Soyuz 20 was an uncrewed Soviet spacecraft launched in 1975 as part of the Soyuz programme. It was based on the Soyuz 7K-T design and orbited Earth for over 90 days, completing 1,470 orbits. The mission demonstrated long-duration spaceflight capabilities without a crew.

## Key Facts
- Launched on November 17, 1975, from Baikonur Cosmodrome ("Gagarin's Start")
- Part of the Soyuz programme under the Soviet space program
- Spacecraft class: Soyuz 7K-T
- Launch vehicle: Soyuz-U rocket
- Mass at takeoff: 6,570 kilograms
- Orbital period: 89.1 minutes; inclination: 51.6 degrees
- Apoapsis: 251 km; periapsis: 177 km
- Total mission duration: 130,306 minutes (~90 days)
- Completed 1,470 orbits before landing in Kazakhstan
- COSPAR ID: 1975-106A

## FAQs
### Q: What was the purpose of the Soyuz 20 mission?
A: Soyuz 20 was an uncrewed test flight designed to validate long-term orbital operations using the Soyuz 7K-T spacecraft. It helped assess systems needed for extended missions without human occupants.

### Q: How long did Soyuz 20 stay in orbit?
A: The spacecraft remained in orbit for approximately 90 days, or 130,306 minutes, completing 1,470 revolutions around Earth.

### Q: Was anyone aboard Soyuz 20 during its mission?
A: No, Soyuz 20 was an uncrewed spacecraft used to test hardware and gather data on automated orbital operations.

## Why It Matters
Soyuz 20 played a critical role in advancing the Soviet Union’s understanding of long-duration spaceflight without human presence. As part of the broader Soyuz programme, it contributed to the development of reliable spacecraft systems that would later support both crewed missions and international collaborations like the Apollo–Soyuz Test Project. Its successful operation validated technologies essential for future space station resupply missions and autonomous orbital platforms. Additionally, by demonstrating robust performance over nearly three months in orbit, Soyuz 20 reinforced confidence in the reliability of the Soyuz design lineage.

## Notable For
- One of the longest uncrewed Soyuz missions in history
- Demonstrated endurance testing of the Soyuz 7K-T configuration
- Used the widely adopted Soyuz-U launch vehicle
- Provided valuable engineering data for subsequent Soyuz variants
- Operated entirely autonomously with no life-support or reentry requirements for humans

## Body
### Mission Overview
Soyuz 20 was launched on November 17, 1975, from Site 1/5 at the Baikonur Cosmodrome, known historically as "Gagarin's Start." The mission was conducted under the auspices of the Soviet space program and formed part of the larger Soyuz programme aimed at advancing orbital spaceflight technology.

### Technical Specifications
The spacecraft utilized the second-generation Soyuz 7K-T design, which had been modified following earlier crewed flights to improve structural integrity and operational flexibility. At launch, the total mass of the vehicle was recorded as 6,570 kilograms. During its time in orbit, Soyuz 20 followed an elliptical path with an apoapsis of 251 kilometers and a periapsis of 177 kilometers above Earth. The orbital inclination was set at 51.6 degrees relative to the equator.

### Flight Profile and Duration
Over the course of its mission, Soyuz 20 completed 1,470 full orbits around Earth. The total mission duration spanned 130,306 minutes—approximately 90 days—making it one of the longer uncrewed missions within the Soyuz family up to that point. This length allowed engineers to collect extensive telemetry and evaluate system degradation over prolonged exposure to the space environment.

### Launch Vehicle and Trajectory
The spacecraft was lofted into orbit using a Soyuz-U carrier rocket, a standardized variant developed specifically for launching Soyuz capsules. The launch occurred successfully on schedule, placing the craft into low Earth orbit where it remained throughout its operational lifetime.

### Landing and Recovery
Following completion of its objectives, Soyuz 20 safely landed in Kazakhstan. While exact coordinates are not specified in available sources, all historical Soyuz landings have taken place within designated recovery zones across central Kazakhstan.

### Legacy and Impact
As an uncrewed mission, Soyuz 20 served primarily as a technological demonstration rather than a scientific expedition. However, its success confirmed key aspects of spacecraft durability and automation necessary for supporting future logistical roles such as cargo delivery to space stations. By operating reliably for nearly three months without intervention, it also highlighted the maturity of the Soyuz platform even in non-standard configurations.

## References

1. Jonathan's Space Report
2. Freebase Data Dumps. 2013
3. BabelNet