# Shijian-1
**Wikidata**: [Q4524667](https://www.wikidata.org/wiki/Q4524667)  
**Source**: https://4ort.xyz/entity/shijian-1

## Summary  
Shijian‑1 (SJ‑1) was China’s first satellite in the Shijian experimental series, launched on 3 March 1971 from the Jiuquan Satellite Launch Center aboard a Long March 1 rocket. The artificial satellite remained in orbit for just over three months before re‑entering the atmosphere on 17 June 1971.

## Key Facts  
- **Launch date:** 3 March 1971.  
- **Launch site:** Jiuquan Satellite Launch Center, China.  
- **Launch vehicle:** Long March 1, the inaugural member of China’s Long March rocket family.  
- **COSPAR ID:** 1971‑018A.  
- **Satellite classification:** Artificial satellite (part of the Shijian series, designated “1”).  
- **Orbit decay:** The satellite’s orbit decayed and it re‑entered the atmosphere on 17 June 1971.  
- **Aliases:** SJ‑1, Shijian 1, Shi Jian 1, 实践一号卫星, Ши Цзянь‑1.  
- **Wikidata identifier:** 05007 (Wolfram Language entity code).  
- **Image reference:** Test of SJ‑1 (available via Wikimedia Commons).  

## FAQs  
### Q: When was Shijian‑1 launched?  
A: Shijian‑1 was launched on 3 March 1971 from the Jiuquan Satellite Launch Center.  

### Q: What launch vehicle carried Shijian‑1 into orbit?  
A: The satellite was placed into orbit by a Long March 1 rocket, the first member of China’s Long March family.  

### Q: How long did Shijian‑1 stay in orbit?  
A: Shijian‑1 remained in orbit for about three and a half months, decaying on 17 June 1971.  

### Q: What series does Shijian‑1 belong to?  
A: It is the first satellite (designated “1”) in China’s Shijian experimental satellite series.  

### Q: What is the COSPAR identifier for Shijian‑1?  
A: The COSPAR ID for Shijian‑1 is 1971‑018A.  

## Why It Matters  
Shijian‑1 marked a pivotal step in China’s early space program, demonstrating the nation’s ability to design, build, and launch an experimental satellite using domestically developed launch technology. By successfully deploying the satellite on a Long March 1 rocket—the first of its family—China validated the reliability of its launch vehicle, laying the groundwork for subsequent scientific, communications, and navigation missions. Although Shijian‑1’s operational life was brief, its atmospheric re‑entry after just over three months provided valuable data on orbital decay and re‑entry dynamics, informing future satellite design and mission planning. As the inaugural member of the Shijian series, the satellite set a precedent for a line of experimental platforms that would support research in Earth observation, technology testing, and space environment studies, contributing to China’s emergence as a major spacefaring nation.  

## Notable For  
- First satellite in the Shijian experimental series.  
- First payload launched on a Long March 1 rocket, establishing China’s indigenous launch capability.  
- Served as an early testbed for satellite technology and orbital decay analysis.  
- Demonstrated rapid development of China’s space infrastructure within a decade of its first successful launch.  

## Body  

### Launch Details  
- **Date & Time:** 3 March 1971.  
- **Location:** Jiuquan Satellite Launch Center, Gansu Province, China.  
- **Vehicle:** Long March 1, a two‑stage, liquid‑propellant launch rocket.  

### Satellite Classification & Identifiers  
- **Instance of:** Artificial satellite.  
- **Series:** Shijian (experimental series), designated as the first unit (P1545 = “1”).  
- **COSPAR ID:** 1971‑018A, used for international tracking and cataloguing.  
- **Wikidata / Wolfram Code:** 05007 (Entity["Satellite", "05007"]).  

### Operational Life & Decay  
- **Orbit Duration:** Approximately 106 days.  
- **Decay Event:** Atmospheric re‑entry on 17 June 1971, recorded as a significant event.  

### Visual & Reference Materials  
- **Image:** “Test of SJ‑1” available on Wikimedia Commons (link provided).  
- **Commons Category:** Shi Jian 1, containing media related to the satellite.  

### Context within Chinese Space Efforts  
- **Related Class:** Artificial satellite – a human‑made object placed into orbit.  
- **Related Launch Vehicle:** Long March 1 – the first member of China’s Long March rocket family, highlighting the early stage of domestic launch capabilities.  

These details collectively outline Shijian‑1’s role as a foundational mission that helped establish China’s capacity for independent satellite development and launch operations.

## References

1. Jonathan's Space Report