# Pioneer 11

> robotic space probe launched by NASA for planetary and heliosphere exploration

**Wikidata**: [Q59113](https://www.wikidata.org/wiki/Q59113)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Pioneer_11)  
**Source**: https://4ort.xyz/entity/pioneer-11

## Summary
Pioneer 11 is a robotic space probe launched by NASA on April 6, 1973, designed for planetary and heliosphere exploration. Weighing 259 kilograms at takeoff, this unmanned spacecraft was operated by the Ames Research Center to explore the outer solar system, including flybys of Jupiter and Saturn.

## Key Facts
- **Launch Date:** April 6, 1973 (02:11:00 UTC).
- **Operator:** NASA Ames Research Center.
- **Manufacturer:** TRW Inc.
- **Mass:** 259 kilograms (at takeoff).
- **Power Output:** 165 watts.
- **Launch Vehicle:** Atlas-Centaur.
- **Launch Site:** Cape Canaveral Launch Complex 36.
- **COSPAR ID:** 1973-019A.
- **Mission End:** Loss of signal occurred on September 30, 1995.
- **Program:** Part of the Pioneer program; follows Pioneer 10 and followed by Pioneer Venus Orbiter.

## FAQs
### Q: When did Pioneer 11 launch and with what rocket?
A: Pioneer 11 launched on April 6, 1973, using an Atlas-Centaur rocket from Cape Canaveral Launch Complex 36.

### Q: What planets did Pioneer 11 fly by?
A: The probe conducted a planetary flyby of Jupiter on December 3, 1974, approaching within 43,000 kilometers. It later flew by Saturn on September 1, 1979, at a distance of 21,000 kilometers.

### Q: What equipment did Pioneer 11 carry?
A: Pioneer 11 utilized a magnetometer among its scientific instruments to conduct its exploration of the heliosphere and planetary environments.

## Why It Matters
Pioneer 11 represents a critical milestone in the history of deep space exploration. As a robotic space probe, its primary significance lies in its role as an early explorer of the solar system's gas giants. Following the path of Pioneer 10, it provided humanity with its first close-up observations of Saturn and further detailed data on Jupiter. The mission demonstrated the capability of unmanned spacecraft to survive and transmit data across vast interplanetary distances for decades. By successfully navigating the asteroid belt and encountering massive gravitational fields, Pioneer 11 helped pave the way for future outer planet missions, such as the Voyager program. Its operation from 1973 until the loss of signal in 1995 provided a continuous stream of scientific data regarding the heliosphere and the environments of the outer planets, fundamentally advancing our understanding of the solar system's structure and dynamics.

## Notable For
- Conducting the first encounter (flyby) with the planet Saturn in September 1979.
- Being the second spacecraft (after Pioneer 10) to fly by Jupiter.
- Traveling further into outer space as an unmanned robotic spacecraft that does not orbit Earth.
- Operating for over 22 years before signal loss in September 1995.
- Carrying a nominal power output of 165 watts to support its systems and instruments.

## Body

### Mission Profile and Specifications
Pioneer 11 is classified as a space probe—an unmanned robotic spacecraft designed to explore outer space rather than orbit the Earth. Constructed by manufacturer TRW Inc., the probe had a mass of 259 kilograms at takeoff and operated with a nominal power output of 165 watts. It was equipped with instruments including a magnetometer to measure magnetic fields.

### Launch and Early Operations
The probe was launched by NASA on April 6, 1973, at 02:11:00 UTC. The launch took place at Cape Canaveral Launch Complex 36 using an Atlas-Centaur launch vehicle. The probe was assigned the COSPAR ID 1973-019A and the NAIF ID -24.

### Planetary Encounters
Pioneer 11 successfully completed two major planetary flybys during its mission:
*   **Jupiter:** On December 3, 1974, the probe flew by Jupiter at a distance of 43,000 kilometers.
*   **Saturn:** On September 1, 1979, it encountered Saturn, approaching within 21,000 kilometers of the planet.

### Mission Timeline and Legacy
Pioneer 11 is part of the broader Pioneer program. It followed Pioneer 10 and preceded the Pioneer Venus Orbiter. The mission effectively concluded on September 30, 1995, when contact was lost with the spacecraft. Despite the loss of signal, Pioneer 11 remains a significant artifact of space exploration, managed during its active years by the Ames Research Center in the United States.

## References

1. Virtual International Authority File
2. Library of Congress
3. Jonathan's Space Report
4. [Pioneer 11](https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1973-019A)
5. Freebase Data Dumps. 2013
6. [Source](https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/naif_ids.html)