# Apollo 13 SIVB

> The Apollo Saturn V SIVB was the third stage of the Saturn V booster.

**Wikidata**: [Q111912934](https://www.wikidata.org/wiki/Q111912934)  
**Source**: https://4ort.xyz/entity/apollo-13-sivb

## Summary
The Apollo 13 SIVB (Saturn V Instrument Unit/Third Stage) was the third stage of the Saturn V rocket used in the Apollo 13 mission, serving as the critical propulsion unit for trans-lunar injection. Identified by COSPAR ID 1970-029B and NSSDCA ID 1970-029B, it played a pivotal role in the mission despite the lunar landing abort. After completing its burn, it was intentionally deorbited and destroyed in the Pacific Ocean.

## Key Facts
- **Aliases**: Apollo 13 Saturn V third stage, 04372, Apollo13SIVB  
- **COSPAR ID**: 1970-029B  
- **NSSDCA ID**: 1970-029B  
- **Instance of**: Spacecraft  
- **Wikidata Description**: The Apollo Saturn V SIVB was the third stage of the Saturn V booster.  
- **Mission Role**: Provided propulsion for trans-lunar injection during the Apollo 13 mission.  
- **Post-Mission Status**: Deorbited and impacted the Pacific Ocean on April 15, 1970.  

## FAQs
- **What does "SIVB" stand for?**  
  SIVB stands for Saturn V Instrument Unit/Third Stage, denoting its role as the third stage of the Saturn V rocket.  

- **What happened to the Apollo 13 SIVB after its mission?**  
  After propelling the Apollo 13 spacecraft toward the Moon, the SIVB was intentionally deorbited and destroyed in the Pacific Ocean to prevent space debris.  

- **Was the SIVB reused in other missions?**  
  No, the SIVB was mission-specific and not designed for reuse. Each Saturn V launch utilized a unique third stage.  

## Why It Matters
The Apollo 13 SIVB was essential for achieving the mission's lunar trajectory, demonstrating the Saturn V's reliability even during the aborted landing. Its successful operation underscored the precision of NASA's propulsion systems, ensuring crew safety and mission continuity. The stage's intentional deorbiting also highlighted early efforts to mitigate space debris, a critical consideration in spaceflight operations.

## Notable For
- **Critical Propulsion Role**: Enabled trans-lunar injection for the Apollo 13 mission.  
- **Historic Mission Affiliation**: Part of the first lunar mission to safely return astronauts after an in-flight abort.  
- **Unique Identifiers**: Designated COSPAR ID 1970-029B and NSSDCA ID 1970-029B for tracking and cataloging.  
- **Controlled Deorbit**: Intentionally destroyed post-mission to avoid contributing to orbital debris.  

## Body

### Mission Overview
The Apollo 13 SIVB was the third stage of the Saturn V rocket (SA-508) that launched on April 11, 1970. Its primary function was to propel the Apollo 13 spacecraft into a trans-lunar trajectory after the second stage (S-II) completed its burn. Despite the mission's lunar landing abort due to an oxygen tank explosion, the SIVB successfully executed its critical propulsion role.

### Technical Specifications
- **Propellant**: Liquid hydrogen and liquid oxygen (LH2/LOX).  
- **Engine**: Single J-2 engine producing 200,000 lbf (890 kN) of thrust.  
- **Burn Duration**: Approximately 2 minutes and 30 seconds for trans-lunar injection.  
- **Mass**: ~123,000 kg (271,000 lbs) at liftoff, including propellant.  

### Post-Mission Disposal
After completing its mission, the SIVB was separated from the Apollo spacecraft and intentionally deorbited. NASA directed the stage to re-enter Earth's atmosphere, resulting in its destruction over the Pacific Ocean on April 15, 1970. This procedure adhered to early spaceflight protocols aimed at minimizing orbital debris risks.

### Historical Context
As part of the Saturn V rocket family, the SIVB was a cornerstone of NASA's Apollo program, enabling lunar missions through its high-efficiency propulsion. The Apollo 13 SIVB's performance, even amid the mission's challenges, reinforced the Saturn V's reputation as a reliable heavy-lift launch vehicle. Its identifiers (COSPAR/NSSDCA IDs) remain cataloged in international space databases, preserving its record in space exploration history.