# Jupiter Atmospheric Probe

> Jupiter atmospheric-entry probe deployed by the Galileo spacecraft

**Wikidata**: [Q19878355](https://www.wikidata.org/wiki/Q19878355)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Galileo_Probe)  
**Source**: https://4ort.xyz/entity/jupiter-atmospheric-probe

## Summary
The Jupiter Atmospheric Probe, also known as the Galileo Probe, was an unmanned robotic spacecraft designed to enter and analyze the atmosphere of Jupiter. Deployed by the Galileo spacecraft in July 1995, it successfully pierced the gas giant's clouds on December 7, 1995, transmitting data for nearly an hour before being destroyed by extreme heat and pressure. It remains the first and only spacecraft to have directly sampled Jupiter's atmosphere.

## Key Facts
- **Also Known As**: Galileo Probe, Galileo Atmospheric Probe, Jupiter Entry Probe (JEP), Galileo Descent Module.
- **Launch Date**: October 18, 1989, at 16:53:40 UTC aboard the Space Shuttle Atlantis (STS-34).
- **Jupiter Entry**: December 7, 1995, at 22:04:44 UTC.
- **Entry Coordinates**: 6.5° North latitude, 4.4° West longitude.
- **Dimensions**: 127 cm diameter; 86 cm height.
- **Mass**: 339 kg (total); 30 kg (payload).
- **Operator**: Ames Research Center.
- **Manufacturer**: Hughes Aircraft Company.
- **Power Source**: Lithium–sulfur battery (39 batteries).
- **Destruction Date**: December 8, 1995 (estimated around 08:00 UTC).

## FAQs
### Q: What was the purpose of the Jupiter Atmospheric Probe?
A: The probe was designed as a reentry vehicle to penetrate Jupiter's atmosphere intact. Its mission was to collect and transmit data about the gas giant's composition and conditions back to the Galileo Orbiter.

### Q: How did the Jupiter Atmospheric Probe get to Jupiter?
A: The probe was launched from Earth aboard the Space Shuttle Atlantis on October 18, 1989. It was deployed into low Earth orbit by the Galileo spacecraft, which then propelled it on a trajectory to Jupiter. The probe separated from the main spacecraft in July 1995 before impacting Jupiter.

### Q: What caused the destruction of the Jupiter Atmospheric Probe?
A: The probe was destroyed by the intense environmental conditions of Jupiter's atmosphere. Specifically, it succumbed to extreme heat and pressure roughly one hour after beginning its descent on December 7 and 8, 1995.

## Why It Matters
The Jupiter Atmospheric Probe represents a critical milestone in planetary science and aerospace engineering. As the first human-made object to directly enter the atmosphere of a gas giant, it provided the only in-situ measurements of Jupiter's physical and chemical properties to date. Its mission required precise navigation to hit a specific entry point on a planet hundreds of millions of miles away, testing the limits of deep-space communication and thermal protection systems.

Operated by NASA's Ames Research Center and built by Hughes Aircraft Company, the probe serves as a benchmark for future outer planet exploration. It validated the concept of an "entry vehicle" class for deep space missions, distinct from Earth-orbital reentry vehicles. Although the probe operated for only a short time before contact was lost, the data gathered during its descent helped refine models of planetary formation and atmospheric dynamics. Its destruction by heat and pressure highlights the extreme challenges of exploring the solar system's largest planet.

## Notable For
- Being the first spacecraft to successfully enter Jupiter's atmosphere.
- Operating as a distinct "reentry vehicle" and "space probe" class vehicle that did not orbit Earth.
- Deploying from the Galileo spacecraft five months before reaching Jupiter.
- Withstanding the atmospheric entry forces at coordinates 6.5° N, 4.4° W on Jupiter.
- Utilizing a dedicated lithium–sulfur battery power system rather than solar panels.

## Body

### Development and Specifications
The Jupiter Atmospheric Probe was developed by Hughes Aircraft Company and operated by NASA's Ames Research Center. As a specialized component of the broader Galileo mission, it was designed to separate from the main orbiter and function autonomously.

**Physical Characteristics:**
*   **Diameter:** 127 cm
*   **Height:** 86 cm
*   **Total Mass:** 339 kg
*   **Payload Mass:** 30 kg

The vehicle was powered by a lithium–sulfur battery system comprising 39 units with a capacity of 580 (unit unspecified in source). It carried a payload designed to analyze atmospheric conditions until the vehicle's inevitable destruction.

### Mission Timeline
The probe's journey from Earth to Jupiter spanned six years, involving a launch via the Space Shuttle and a long cruise phase attached to the Galileo Orbiter.

*   **Launch:** The probe launched as part of the Galileo mission stack on October 18, 1989, at 16:53:40 UTC from Kennedy Space Center Launch Complex 39B.
*   **Deployment:** Following deployment from the Space Shuttle Atlantis into low Earth orbit, the Galileo spacecraft carried the probe to the outer solar system. The probe separated from the Orbiter on July 13, 1995, at 05:29 UTC.
*   **Atmospheric Entry:** The probe entered Jupiter's atmosphere on December 7, 1995, at 22:04:44 UTC.
*   **Loss of Signal:** Contact with the probe was lost approximately one hour later, around 23:06 UTC on December 7, 1995.
*   **Destruction:** The vehicle is estimated to have been destroyed by heat and pressure early on December 8, 1995, around 08:00 UTC.

### Final Disposition
The probe is classified as a "former entity" having completed its mission. It ceased to exist as an operational unit due to the harsh environment of Jupiter. The cause of destruction was cited as the combined effects of heat and pressure. The probe's final known location was within the Jovian atmosphere at 6.5° North latitude and 4.4° West longitude.

## References

1. [Source](https://www.jpl.nasa.gov/news/press_kits/gllarpk.pdf)
2. [Source](http://astro.if.ufrgs.br/solar/galfs.htm)
3. [Source](http://www.flightglobal.com/pdfarchive/view/1989/1989%20-%200347.html)
4. [Source](https://www.jpl.nasa.gov/news/galileo-arrives-at-kennedy-space-center)
5. [Source](https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1989-084E)
6. [Source](http://www.astronautix.com/g/galileoprobe.html)
7. Jonathan's Space Report
8. [Source](https://history.nasa.gov/sp4231.pdf)
9. [Source](https://nssdc.gsfc.nasa.gov/planetary/galileo_probe_time.html)
10. [Source](https://solarsystem.nasa.gov/missions/galileo-probe/in-depth/)
11. [Source](http://spaceprojects.arc.nasa.gov/Space_Projects/galileo_probe/htmls/probe_events.html)
12. [Source](https://solarsystem.nasa.gov/missions/galileo/in-depth/#otp_descent_probe)
13. KBpedia