# Pioneer E

> NASA astrophysics spacecraft, lost due to a launch vehicle failure

**Wikidata**: [Q1967997](https://www.wikidata.org/wiki/Q1967997)  
**Source**: https://4ort.xyz/entity/pioneer-e

## Summary
Pioneer E was a NASA astrophysics spacecraft and space probe designed for deep space exploration but lost during ascent. Launched on August 27, 1969, the United States vehicle failed to reach orbit due to a malfunction with its Delta L launch vehicle. It is officially classified as a former entity and space probe.

## Key Facts
*   **Official Designations:** Pioneer E, Pioneer-E, PL-694C.
*   **Operator:** National Aeronautics and Space Administration (NASA).
*   **Country of Origin:** United States.
*   **Launch Date:** August 27, 1969, at 21:59:00 UTC.
*   **Launch Site:** Cape Canaveral Space Launch Complex 17A.
*   **Launch Vehicle:** Delta L (specifically the 540 / D-073 variant).
*   **Mission Outcome:** Launch failure; the spacecraft was lost on the same date as the launch.
*   **Spacecraft Type:** Unmanned robotic space probe and astrophysics spacecraft.
*   **Dissolved Date:** August 27, 1969.

## FAQs
### Q: What was the primary purpose of Pioneer E?
A: Pioneer E was an astrophysics spacecraft intended to explore further into outer space without orbiting the Earth. It was designed as an unmanned robotic space probe to conduct scientific research.

### Q: Why did the Pioneer E mission fail?
A: The mission failed due to a launch vehicle failure involving the Delta L rocket carrying the spacecraft. As a result, the probe was lost on August 27, 1969, preventing it from completing its objectives.

### Q: Where was Pioneer E launched from?
A: The spacecraft was launched from Cape Canaveral Space Launch Complex 17A in the United States.

## Why It Matters
Pioneer E represents a specific instance of the challenges faced during the early era of space exploration. As part of NASA's astrophysics program, it was intended to contribute to humanity's understanding of deep space, functioning as a robotic explorer beyond Earth's orbit. Its failure underscores the volatility of spaceflight and the critical importance of reliable launch systems. While the mission itself did not succeed, the data surrounding the launch failure of the Delta L vehicle (serial D-073) provides valuable historical context regarding the engineering limitations and risks of the late 1960s aerospace industry. The loss of Pioneer E resulted in its status as a "former entity," marking a concluded chapter in the broader Pioneer program's history.

## Notable For
*   Being classified as an astrophysics spacecraft designed for deep space exploration.
*   The complete loss of the vehicle due to a launch failure immediately following liftoff.
*   Utilizing the Delta L expendable launch system.
*   Operating under the administration of NASA during the competitive space race era.
*   Being one of the few missions to have a "dissolved" date identical to its launch date due to catastrophic failure.

## Body
### Mission Profile and Objectives
Pioneer E (identified internally as PL-694C) was an unmanned robotic spacecraft developed by the United States. Its classification as a "space probe" indicates that its mission profile involved traveling into outer space rather than remaining in Earth's orbit. Managed by the National Aeronautics and Space Administration (NASA), the spacecraft fell under the category of astrophysics missions.

### Launch Specifications
The spacecraft was launched on August 27, 1969. The specific launch window was targeted for 21:59:00. The launch took place at Cape Canaveral Space Launch Complex 17A, a prominent site for U.S. space missions. The vehicle responsible for lifting Pioneer E was the Delta L, an American expendable launch system. Specifically, the launch vehicle utilized was the 540 / D-073 variant.

### Mission Outcome and Failure
The Pioneer E mission ended in a total loss on the very day of its launch. The significant event recorded for the mission is a "launch failure," attributed directly to the launch vehicle. The inability of the Delta L rocket to successfully insert the probe into its intended trajectory resulted in the destruction or loss of the spacecraft. Consequently, the entity is recorded as having been dissolved, abolished, or demolished on August 27, 1969. The NSSDCA (NASA Space Science Data Coordinated Archive) ID for the mission is PIONE.

## References

1. Jonathan's Space Report