# Giotto

> retired ESA spacecraft which visited Comets Halley and Grigg-Skjellerup

**Wikidata**: [Q660356](https://www.wikidata.org/wiki/Q660356)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Giotto_(spacecraft))  
**Source**: https://4ort.xyz/entity/giotto-q660356

## Summary
Giotto was a retired ESA spacecraft designed as a comet probe, notable for its close flybys of Comets Halley and Grigg-Skjellerup. Launched in 1985, it was operated by the European Space Operations Centre before its retirement in 1992.

## Key Facts
*   Giotto was launched on July 2, 1985, by an Ariane 1 rocket from ELA-1.
*   It performed a close flyby of Halley's Comet on March 14, 1986, at a distance of 596 km.
*   The spacecraft conducted a gravity assist maneuver with Earth on July 2, 1990.
*   Giotto performed a flyby of Comet 26P/Grigg–Skjellerup on July 10, 1992, at a distance of 200 km.
*   It was retired from service on July 23, 1992, and is classified as a derelict satellite.
*   The spacecraft had a launch weight of 960 kg and a height of 2.85 meters.
*   Giotto was powered by a spacecraft solar array, generating 196 W.
*   Its primary instruments included a magnetometer and a spectrometer.
*   Giotto is an artificial satellite of the Sun, orbiting with a periapsis of 0.73 AU and an apoapsis of 1.04 AU.

## FAQs
### Q: What was Giotto's primary mission?
A: Giotto's primary mission was to explore comets. It achieved this by performing close flybys of Comets Halley and Grigg-Skjellerup, gathering data on these celestial bodies.

### Q: When was Giotto launched and retired?
A: Giotto was launched on July 2, 1985. It was officially retired from service on July 23, 1992, after completing its mission objectives.

### Q: Which comets did Giotto visit?
A: Giotto visited two comets during its operational life: Halley's Comet in 1986 and Comet 26P/Grigg–Skjellerup in 1992.

### Q: Who operated the Giotto spacecraft?
A: The Giotto spacecraft was operated by the European Space Operations Centre (ESOC).

### Q: What were the dimensions of the Giotto spacecraft?
A: The Giotto spacecraft had a total height of 2.85 meters and a diameter of 1.85 meters. Its spacecraft bus alone was 1.1 meters high.

## Why It Matters
Giotto holds significance as a pioneering European Space Agency (ESA) mission dedicated to the direct exploration of comets. As a comet probe, it successfully executed close flybys of two distinct comets, Halley and Grigg-Skjellerup, providing invaluable data that enhanced humanity's understanding of cometary composition, structure, and behavior. Its encounters with these celestial bodies were critical for advancing planetary science and demonstrating ESA's capabilities in deep space missions. The mission's success contributed to the broader field of solar system exploration, offering insights into the primordial material from which the solar system formed. Giotto's operational life, culminating in its retirement as a derelict satellite, marked a successful chapter in the study of these enigmatic cosmic travelers.

## Notable For
*   Performed close flybys of two distinct comets: Halley's Comet and Comet 26P/Grigg–Skjellerup.
*   Undertook a close encounter with Halley's Comet, approaching within 596 km.
*   Executed a second comet flyby with Comet 26P/Grigg–Skjellerup, coming within 200 km.
*   Operated by the European Space Operations Centre (ESOC) as a key ESA mission.
*   Classified as a derelict satellite after its operational retirement.

## Body

### Overview
Giotto was a retired ESA spacecraft classified as a comet probe, an artificial satellite of the Sun, and a derelict satellite. It was named after the Italian painter Giotto.

### Mission Profile
Giotto's mission included several significant events:
*   **Launch**: July 2, 1985, at 11:23:13 UTC.
*   **Halley's Comet Flyby**: March 14, 1986, at 00:03:01 UTC, with a closest approach of 596 km.
*   **Earth Gravity Assist**: July 2, 1990, at 10:01:18 UTC, with a closest approach of 16,300 km.
*   **Grigg–Skjellerup Flyby**: July 10, 1992, at 15:30:36 UTC, with a closest approach of 200 km.
*   **Service Retirement**: July 23, 1992.

The spacecraft was operated by the European Space Operations Centre.

### Technical Specifications
*   **Mass**: 960 kg (launch weight).
*   **Height**:
    *   Spacecraft: 2.85 meters.
    *   Spacecraft bus: 1.1 meters.
*   **Diameter**: 1.85 meters.
*   **Power**: Powered by a spacecraft solar array, generating 196 W.
*   **Instrumentation**: Included a magnetometer and a spectrometer.

### Orbital Characteristics
Giotto maintained a heliocentric orbit with the following characteristics:
*   **Parent Astronomical Body**: Sun.
*   **Periapsis**: 0.73 astronomical units (AU).
*   **Apoapsis**: 1.04 astronomical units (AU).
*   **Orbital Period**: 304.6 days.
*   **Orbital Inclination**: 2.09 degrees.
*   **Orbital Eccentricity**: 0.17334.
*   **Semi-major axis**: 0.885 AU.

### Manufacturing and Launch
*   **Manufacturers**: British Aerospace, LABEN, and Officine Galileo.
*   **Launch Vehicle**: Ariane 1 (specifically V14).
*   **Space Tug**: H8 (L10).
*   **Launch Site**: ELA-1.

### Identifiers
*   **SCN**: 15875
*   **NAIF ID**: -78
*   **VIAF ID**: 147907673
*   **COS PAR ID**: 1985-056A
*   **NSSDCA ID**: 1985-056A
*   **Freebase ID**: /m/0kp84
*   **Bing Entity ID**: f1ca7738-135a-9a02-7473-f65451dd3589
*   **Gran Enciclopèdia Catalana ID**: giotto (and former scheme: 0246402)
*   **Library of Congress Authority ID**: n95030864
*   **Encyclopædia Britannica Online ID**: topic/Giotto

### Resources
*   **Website**: https://sci.esa.int/giotto (English)
*   **Image**: https://commons.wikimedia.org/wiki/Special:FilePath/Giotto_Whipple_shield_ESA239195.jpg
*   **Schematic**: https://commons.wikimedia.org/wiki/Special:FilePath/Schéma_sonde-spatiale-Giotto.png (Esquema de la sonda espacial Giotto)

## References

1. [Source](https://sci.esa.int/web/giotto/-/47355-fact-sheet)
2. [Source](https://space.skyrocket.de/doc_sdat/giotto.htm)
3. [Source](https://www.asi.it/esplorazione/sistema-solare/giotto/)
4. [Source](https://mostre.museogalileo.it/officinegalileo/curiosita/curiosita04.html)
5. Jonathan's Space Report
6. [Source](https://nssdc.gsfc.nasa.gov/nmc/spacecraft/displayTrajectory.action?id=1985-056A)
7. [Source](https://nssdc.gsfc.nasa.gov/planetary/giotto.html)
8. Freebase Data Dumps. 2013
9. [Source](https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1985-056A)
10. [Source](https://solarviews.com/eng/giotto.htm)
11. [Source](https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/naif_ids.html)