In this artist's concept, Giotto points its white high-gain antenna dish towards earth with the ring of solar cells facing the sun. The hidden face towards the bottom right collects information on comets.

Giotto was a European unmanned space mission from the European Space Agency, intended to fly by and study Halley's Comet. Giotto illustration (large). ... Giotto illustration (large). ... This article is about the continent. ... Unmanned space missions are those using remote-controlled spacecraft. ... The European Space Agency (ESA), established in 1975,is an inter-governmental organisation dedicated to exploration of space with currently 17 member states. ... Comet Halley, officially designated 1P/Halley, more generally known as Halleys Comet after Edmond Halley, is a comet that can be seen every 75-76 years. ...

Mission

On March 13, 1986, Giotto approached at a 596 kilometre distance from Halley's nucleus. March 13 is the 72nd day of the year in the Gregorian calendar (73rd in leap years). ... 1986 (MCMLXXXVI) was a common year starting on Wednesday of the Gregorian calendar. ... To help compare orders of magnitude; this page lists lengths between 100 and 1,000 km (105 and 106 m). ... A kilometre (American spelling: kilometer), symbol: km is a unit of length in the metric system equal to 1000 metres (from the Greek words χίλια (khilia) = thousand and μέτρο (metro) = count/measure). ...

The spaceprobe "Giotto" from the European Space Agency was designed to study Halley's Comet. The spacecraft was named after the medieval Italian painter Giotto di Bondone. He had observed Halley's Comet in 1301 and was inspired to depict it as the star of Bethlehem in his painting The Christmas Story. The European Space Agency (ESA), established in 1975,is an inter-governmental organisation dedicated to exploration of space with currently 17 member states. ... The Middle Ages formed the middle period in a traditional schematic division of European history into three ages: the classical civilization of Antiquity, the Middle Ages, and modern times. ... A painter is a person who paints woodwork, walls, etc. ... Statue of Giotto di Bondone, close to the Uffizi. ... Events February 7 - Edward of Caernarvon (later King Edward II of England) becomes the first Prince of Wales End of the reign of Emperor Go-Fushimi, emperor of Japan Emperor Go-Nijō ascends to the throne of Japan Dante was sent into Exile in Florence. ... The sky over Bethlehem at the time of Jesus. ...

Originally a United States partner probe was planned that would accompany Giotto, but this fell through due to budget cuts at NASA. There were plans to have observation equipment on-board a Space Shuttle in low-Earth orbit around the time of Giotto's fly-by, but they fell through with the Challenger disaster. NASA logo Listen to this article · (info) This audio file was created from an article revision dated 2005-09-01, and does not reflect subsequent edits to the article. ... The Space Shuttle Columbia seconds after engine ignition, 1981 (NASA). ... The launch of the Space Shuttle Challenger on mission 51L/STS-33, the 25th of the STS (Space Transportation System) program, began at an estimated time of 16:38:00. ...

The plan then became a cooperative armada of five spaceprobes including Giotto, two from the Soviet Union's Vega program and two from Japan: the Sakigake and Suisei probes. The idea was for Japanese probes and the pre-existing American probe International Cometary Explorer to make long distance measurements, followed by the Russian Vegas which would locate the nucleus, and the resulting information sent back would allow Giotto to precisely target very close to the nucleus. Because Giotto would pass so very close to the nucleus ESA was mostly convinced it would not survive the encounter due to bombardment from the many high speed cometary particles. The coordinated group of probes became known as the Halley Armada. The Vega mission was a Venus mission which also took advantage of the appearance of Comet Halley in 1986. ... Spacecraft Sakigake Sakigake (MS-T5), was Japans first interplanetary spacecraft and was lauched January 7, 1985 from Kagoshima Space Center. ... Suisei (the Japanese name meaning `Comet) was launched on August 18, 1985 into heliocentric orbit to fly by Comet P/Halley. ... The International Cometary Explorer (ICE) spacecraft was originally known as International Sun/Earth Explorer 3 (ISEE-3) satellite, launched August 12, 1978. ... The Halley Armada is a group of space probes sent to examine Comet Halley during its 1986 sojourn through the inner solar system. ...

The craft

The spacecraft is derived from the GEOS research satellite built by British Aerospace, and modified with the addition of a dust shield as proposed by Fred Whipple and comprising a thin aluminium sheet separated by a space and a thicker Kevlar sheet. Later the Stardust (spacecraft) would use a similar Whipple shield. Fred Lawrence Whipple (November 5, 1906–August 30, 2004) was an American astronomer. ... Kevlar (poly-paraphenylene terephthalamide) is the DuPont Company’s brand name for a synthetic material constructed of para-aramid fibers that the company claims is five times stronger than the same weight of steel, while being lightweight, flexible and comfortable. ... An artists rendering of Stardust (NASA image) The Stardust capsule with cometary and interstellar samples landed at the U.S. Air Force Utah Test and Training Range at 10:10 UTC (15 January 2006) in the Bonneville Salt Flats. ...

Timeline

Comet Halley as taken with the Halley Multicolour Camera on the ESA Giotto mission. The nucleus is sunlit from the left, and several bright jets of gas and dust are visible.

The mission was given the go-ahead by ESA in 1980, and launched on an Ariane 1 rocket (flight V14) on 1985 July 2 from Kourou. Halleys Comet as taken with the Halley Multicolor Camera on the ESA Giotto mission. ... Halleys Comet as taken with the Halley Multicolor Camera on the ESA Giotto mission. ... The European Space Agency (ESA), established in 1975,is an inter-governmental organisation dedicated to exploration of space with currently 17 member states. ... Ariane I is the first version of the Ariane launcher family. ... This article is about the year. ... July 2 is the 183rd day of the year (184th in leap years) in the Gregorian Calendar, with 182 days remaining. ... Kourou Kourou is a town and commune in French Guiana, some 40 km northwest of the capital Cayenne at the mouth of the Kourou river on the Atlantic coast. ...

The Russian Vega 1 starts returning images of Halley on 1986 March 4, and the first ever of its nucleus, and made its flyby on March 6, followed by Vega 2 making its flyby on March 9. 1986 (MCMLXXXVI) was a common year starting on Wednesday of the Gregorian calendar. ... March 4 is the 63rd day of the year in the Gregorian Calendar (64th in leap years). ...

Giotto passed Halley successfully on 1986 March 14 at 600 km distance, and surprisingly survived despite being hit by some small particles. One impact sent it spinning off its stablised spin axis so that its antenna no longer always pointed at the Earth, and importantly, its dust shield no longer protected its instruments. After 32 minutes Giotto re-stabilised itself and continued gathering science data. 1986 (MCMLXXXVI) was a common year starting on Wednesday of the Gregorian calendar. ... March 14 is the 73rd day of the year in the Gregorian Calendar (74th in Leap years) with 292 days remaining in the year. ... To help compare orders of magnitude; this page lists lengths between 100 and 1,000 km (105 and 106 m). ... A kilometre (American spelling: kilometer), symbol: km is a unit of length in the metric system equal to 1000 metres (from the Greek words χίλια (khilia) = thousand and μέτρο (metro) = count/measure). ...

Another impact destroyed the Halley Multicolor Camera, but not before it took spectacular pictures of the nucleus at closest approach.

Giotto's trajectory was adjusted for a return to Earth (flyby) and its science instruments were turned off on 1986 March 15 02:00 UT. 1986 (MCMLXXXVI) was a common year starting on Wednesday of the Gregorian calendar. ... March 15 is the 74th day of the year in the Gregorian Calendar (75th in Leap years). ...

In 1990 Giotto was commanded to wake up and on July 2 flew by the Earth in order to sling shot to its next cometary encounter. This article is about the year. ...

Giotto also flew by the Comet Grigg-Skjellerup in 1992 July 10, which it approached to a distance of ca. 200 kilometres. Afterwards, on 1992 July 23 Giotto was again switched off. Comet Grigg-Skjellerup (formally designated 26P/Grigg-Skjellerup) is a periodic comet. ... 1992 (MCMXCII) was a leap year starting on Wednesday. ... July 10 is the 191st day (192nd in leap years) of the year in the Gregorian Calendar, with 174 days remaining. ... 1992 (MCMXCII) was a leap year starting on Wednesday. ... July 23 is the 204th day (205th in leap years) of the year in the Gregorian Calendar, with 161 days remaining. ...

In 1999 Giotto made another Earth flyby but was not reactivated. 1999 (MCMXCIX) was a common year starting on Friday, and was designated the International Year of Older Persons by the United Nations. ...

Results

Images showed Halley's nucleus to be a dark peanut-shaped body, 15 km long, 7 to 10 km wide. Only 10% of the surface was active, with at least three outgassing jets seen on the sunlit side. Analysis showed the comet formed 4.5 billion years ago from volatiles (mainly ice) that had condensed onto interstellar dust particles. It had remained practically unaltered since its formation.

Of the volume of material ejected by Halley: 80% was water, 10% carbon monoxide, and 2.5% a mix of methane and ammonia. Other hydrocarbons, iron, and sodium were detected in trace amounts. Water (from the Old English word wæter; c. ... Carbon monoxide, chemical formula CO, is a colorless, odorless, tasteless, flammable and highly toxic gas. ... R-phrases S-phrases , , , Flash point −188 °C Autoignition temperature 537 °C Explosive limits 5–15% Supplementary data page Structure and properties Thermodynamic data Spectral data UV, IR, NMR, MS Related compounds Related alkanes Ethane Propane Related compounds Methanol Chloromethane Except where noted otherwise, data are given for materials in... Ammonia is a compound of nitrogen and hydrogen with the formula NH3. ... Hydrocarbons are refined at oil refineries and chemical plants In chemistry, a hydrocarbon is any chemical compound that consists only of the elements carbon (C) and hydrogen (H). ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number sodium, Na, 11 Chemical series alkali metals Group, Period, Block 1, 3, s Appearance silvery white Atomic mass 22. ...

Halley's nucleus was blacker than soot, which suggests there is proportionally more dust than ice.

The nucleus's surface was rough and of a porous quality, with the density of whole nucleus only 0.3 kg/m³.

The quantity of material ejected was found to be 3 tonnes per second for seven jets, and these caused the comet to wobble over long time periods.

The dust ejected was mostly only the size of cigarette smoke particles, the largest being 40 milligram. Although the one that sent Giotto spinning was not measured, from its effects its mass has been estimated to lie between 0.1 and 1 gram.

Two kinds of dust were seen: one with carbon, hydrogen, nitrogen and oxygen; the other with calcium, iron, magnesium, silicon and sodium.

The ratio of abundances of the comet's light elements excluding nitrogen (ie. hydrogen, carbon, oxygen) were the same as the Sun's. The implication is that the constituents of Halley are among the most primitive in the solar system.

The plasma and ion mass spectrometer instruments showed Halley has a carbon-rich surface.

External link

• Official site