- 07.02.85 Launch (11:23:16 UT)
- 03.14.86 Comet Halley Flyby (00:03:02 UT)
- 07.02.90 Earth Gravity Assist
- 07.10.92 Comet Grigg-Skjellerup Flyby
- Status: Mission Complete
- Narrow-angle camera
- Three mass spectrometers for neutrals, ions and dust
- Various dust detectors
- Set of plasma experiments
- Giotto was hammered by an average of 100 dust particles as second as it flew past comet Halley.
- The spacecraft was named in honor of 14th century Italian artist Giotto di Bondone. His Adoration of the Magi is the first time the Star of Bethlehem was represented as a comet.
- Giotto was the first spacecraft to use Earth's gravity to assist it on its journey.
The major objectives of the mission were to:
- Obtain color photographs of the nucleus
- Determine the elemental and isotopic composition of volatile components in the cometary coma, particularly parent molecules
- Characterize the physical and chemical processes that occur in the cometary atmosphere and ionosphere
- Determine the elemental and isotopic composition of dust particles
- Measure the total gas-production rate and dust flux and size/mass distribution and derive the dust-to-gas ratio
- Investigate the macroscopic systems of plasma flows resulting from the cometary-solar wind interaction.
After the Mission:
After formal termination of the encounter on 23 July 1992, Giotto was put in hibernation. In September 1999, ESA scientists revealed that a second comet or cometary fragment may have been accompanying Grigg-Skjellerup during the encounter in 1992. The spacecraft repeated a flyby of Earth at 02:40 UT on 1 July 1999 at a range of 219,000 kilometers.
According to the ESA, Giotto had a number of very impressive ‘firsts’ and achievements to its credit:
- It was Europe's first deep-space mission.
- It photographed the first close-up images of a comet nucleus (Halley). It discovered the size and shape of Halley's nucleus and discovered that the surface is very dark and that bright jets of gas and dust spring out of its nucleus.
- It was the first deep-space mission to change orbit by returning to Earth for a gravity-assist manoeuvre.
- Giotto made the closest comet fly-by to date by any spacecraft (about 200 kilometres from Comet Grigg-Skjellerup) and studied the interaction between the solar wind, the interplanetary magnetic field, and the comet itself.
- It was the first spacecraft to encounter two comets and in doing so measured the size, composition, and velocity of dust particles and measured the composition of those two comets.