# Pioneer P-31

> failed lunar orbiter probe

**Wikidata**: [Q1187438](https://www.wikidata.org/wiki/Q1187438)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Pioneer_P-31)  
**Source**: https://4ort.xyz/entity/pioneer-p-31

## Summary
Pioneer P-31 was a failed lunar orbiter probe launched by NASA in 1960 that never reached the Moon due to a launch vehicle malfunction. This unmanned spacecraft was part of NASA's early attempts to explore the lunar environment as part of the Pioneer program.

## Key Facts
- Pioneer P-31 was a failed lunar orbiter probe launched on December 15, 1960
- It had a mass of 175 kilograms at takeoff
- The probe was launched using an Atlas-Able launch vehicle from Cape Canaveral Launch Complex 12
- It was manufactured by TRW Inc. for NASA
- Pioneer P-31 was part of the Pioneer program and succeeded Pioneer P-30
- The probe experienced a launch failure and never completed its mission
- Its NSSDCA ID is PIONZ

## FAQs
### Q: What was the mission objective of Pioneer P-31?
A: Pioneer P-31 was designed to become a lunar orbiter, intended to orbit the Moon and gather scientific data about its environment and surface characteristics.

### Q: What caused the failure of Pioneer P-31?
A: Pioneer P-31 failed due to a launch vehicle malfunction during its ascent, preventing the spacecraft from reaching lunar orbit or completing its mission.

### Q: How does Pioneer P-31 compare to other Pioneer probes?
A: Pioneer P-31 was similar in design to Pioneer P-30 but experienced the same fate—a launch failure that prevented it from reaching its lunar orbit destination. It was succeeded by Pioneer 6, which successfully achieved Earth orbit.

### Q: What was the significance of Pioneer P-31 despite its failure?
A: Despite its failure, Pioneer P-31 contributed valuable engineering data to NASA's early space program, helping identify issues with the Atlas-Able launch vehicle that could be addressed in subsequent missions.

## Why It Matters
Pioneer P-31 represents an important chapter in early lunar exploration, contributing to the learning process that eventually led to successful lunar missions. Though its mission ended in failure, the data gathered during the launch attempt provided critical insights into the challenges of deep space exploration and helped refine launch vehicle technology. As part of the Pioneer program, it contributed to NASA's growing knowledge about lunar trajectories and spacecraft design. Each failure, including Pioneer P-31, brought NASA closer to achieving lunar orbit, paving the way for later successful missions that fundamentally changed our understanding of the Moon.

## Notable For
- Being one of the earliest attempted lunar orbiters in the Pioneer program
- Having a similar design to Pioneer P-30 but meeting the same fate of launch failure
- Being launched using the problematic Atlas-Able launch vehicle
- Having multiple international aliases including Pioneer Z, Atlas-Able 5B, and 先鋒Z號
- Being part of the transition from early lunar flyby attempts to orbit missions

## Body

### Mission Overview
Pioneer P-31 was designed as a lunar orbiter probe intended to study the Moon from orbit. The spacecraft was part of NASA's Pioneer program, which aimed to explore the lunar environment and gather scientific data about Earth's natural satellite.

### Technical Specifications
- Mass: 175 kilograms (at takeoff)
- Manufacturer: TRW Inc.
- NSSDCA ID: PIONZ
- Mission Type: Lunar orbiter

### Launch and Failure
Pioneer P-31 was launched on December 15, 1960, from Cape Canaveral Launch Complex 12 using an Atlas-Able launch vehicle. The mission ended in failure when the launch vehicle malfunctioned during ascent, preventing the spacecraft from reaching lunar orbit. This failure was not unique to Pioneer P-31, as its predecessor, Pioneer P-30, had also experienced a launch failure just months earlier.

### Program Context
Pioneer P-31 followed Pioneer P-30 in the Pioneer program sequence and was succeeded by Pioneer 6. Despite these failures, the Pioneer program continued to evolve, eventually leading to more successful lunar missions that expanded our understanding of the Moon.

### Legacy
While Pioneer P-31 itself was unsuccessful, the lessons learned from its failure contributed to the development of more reliable launch vehicles and spacecraft designs. These improvements were crucial for later lunar missions that successfully achieved lunar orbit and performed detailed scientific observations.

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  "@type": "Thing",
  "name": "Pioneer P-31",
  "description": "Failed lunar orbiter probe launched by NASA in 1960",
  "url": "https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=PIONZ",
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  "mass": {
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  "operator": "National Aeronautics and Space Administration"
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## References

1. Jonathan's Space Report
2. Freebase Data Dumps. 2013
3. [Pioneer P-31](https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=PIONZ)