# SL-1 rocket body

> defunct Soviet upper stage which orbited the Sputnik-3 satellite

**Wikidata**: [Q110576801](https://www.wikidata.org/wiki/Q110576801)  
**Source**: https://4ort.xyz/entity/sl-1-rocket-body

## Summary
The SL-1 rocket body was a defunct Soviet upper stage that orbited the Sputnik-3 satellite in 1958, later becoming space debris. Launched on May 15, 1958, it operated as part of the Sputnik 8A91 rocket and decayed in Earth's atmosphere later that year. It is classified as both a historic space tug and orbital debris.

## Key Facts
- **COSPAR ID**: 1958-004A (cataloged as satellite 00007).
- **Launch Date**: May 15, 1958, from Gagarin's Start (Baikonur Cosmodrome).
- **Launch Vehicle**: Sputnik 8A91 (serial number B1-1), a Soviet space launch vehicle.
- **Country of Origin**: Soviet Union.
- **Mission Role**: Upper stage for deploying Sputnik-3, the third Soviet artificial satellite.
- **Decay Date**: Re-entered Earth's atmosphere on December 3, 1958.
- **Classifications**: Space tug, space debris, and former orbital entity.

## FAQs
### Q: What was the SL-1 rocket body used for?
A: The SL-1 rocket body served as the upper stage for launching Sputnik-3, the Soviet Union's third artificial satellite, into orbit on May 15, 1958.

### Q: How long did the SL-1 rocket body remain in orbit?
A: It decayed and re-entered Earth's atmosphere on December 3, 1958, approximately 6 months after launch.

### Q: Is the SL-1 rocket body still in space?
A: No, it disintegrated during atmospheric re-entry in 1958 and is no longer in orbit.

## Why It Matters
The SL-1 rocket body represents an early milestone in space exploration as part of the Sputnik program, which demonstrated Soviet technological prowess during the Space Race. As the upper stage for Sputnik-3—a satellite designed to study Earth's upper atmosphere and ionosphere—it contributed to foundational scientific research. Its rapid decay also highlighted the transient nature of early orbital technology and the growing issue of space debris, making it a notable example of both achievement and challenge in early spaceflight.

## Notable For
- **Firsts**: Supported the launch of Sputnik-3, which carried more advanced scientific instruments than its predecessors.
- **Space Debris Legacy**: One of the earliest tracked orbital decay events, illustrating the finite lifespan of early satellites.
- **Soviet Space Tug**: Demonstrated the use of upper stages for payload deployment, a critical capability for spaceflight.

## Body
### Launch and Mission
- **Launch Vehicle**: The SL-1 was part of the Sputnik 8A91 rocket (serial B1-1), launched from Gagarin's Start at Baikonur Cosmodrome.
- **Payload**: Carried Sputnik-3, a 1,327 kg satellite equipped with instruments to measure radiation, temperature, and micrometeoroid impacts.
- **Date**: Launched on May 15, 1958, at 20:15:00 UTC.

### Orbital Decay
- **Re-entry**: The rocket body decayed on December 3, 1958, due to atmospheric drag, disintegrating over Earth.
- **Tracking**: Cataloged by COSPAR as 1958-004A and tracked until its demise.

### Classifications
- **Space Tug**: Functioned to transfer Sputnik-3 from launch orbit to its operational trajectory.
- **Space Debris**: Post-mission, it became inert orbital debris, a status confirmed by its decay date.

### Historical Context
- **Sputnik Program**: Part of the Soviet Union's early satellite efforts, following Sputnik-1 and Sputnik-2.
- **Technical Significance**: Demonstrated the capability to deploy scientific payloads into orbit, advancing space research.

## References

1. [Source](https://space.skyrocket.de/doc_lau_det/sputnik-2.htm)
2. [Source](https://www.n2yo.com/satellite/?s=00007)