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Rosetta (spacecraft)

Rosetta (spacecraft)

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Rosetta is a robotic spacecraft
Robotic spacecraft
A robotic spacecraft is a spacecraft with no humans on board, that is usually under telerobotic control. A robotic spacecraft designed to make scientific research measurements is often called a space probe. Many space missions are more suited to telerobotic rather than crewed operation, due to...

 of the European Space Agency
European Space Agency
The European Space Agency , established in 1975, is an intergovernmental organisation dedicated to the exploration of space, currently with 18 member states...

 on a mission to study the comet 67P/Churyumov–Gerasimenko. Rosetta consists of two main elements: the Rosetta space probe and the Philae lander
Philae lander
Philae is the lander that accompanies the Rosetta spacecraft. It is designed to land on Comet 67P/Churyumov-Gerasimenko shortly after arrival...

. The spacecraft was launched on 2 March 2004 on an Ariane 5
Ariane 5
Ariane 5 is, as a part of Ariane rocket family, an expendable launch system used to deliver payloads into geostationary transfer orbit or low Earth orbit . Ariane 5 rockets are manufactured under the authority of the European Space Agency and the Centre National d'Etudes Spatiales...

 rocket and will reach the comet by mid 2014. The space probe is intended to orbit and perform long-term exploration of the comet at close quarters. On 10 November 2014 the Philae lander will attempt to land and perform detailed investigations on the comet's surface. Both the probe and the lander carry a large complement of scientific experiments designed to complete the most detailed study of a comet ever attempted.

The probe is named after the Rosetta Stone
Rosetta Stone
The Rosetta Stone is an ancient Egyptian granodiorite stele inscribed with a decree issued at Memphis in 196 BC on behalf of King Ptolemy V. The decree appears in three scripts: the upper text is Ancient Egyptian hieroglyphs, the middle portion Demotic script, and the lowest Ancient Greek...

, as it is hoped the mission will help form an idea of how the solar system
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...

 looked before planets formed. The lander is named after the Nile
Nile
The Nile is a major north-flowing river in North Africa, generally regarded as the longest river in the world. It is long. It runs through the ten countries of Sudan, South Sudan, Burundi, Rwanda, Democratic Republic of the Congo, Tanzania, Kenya, Ethiopia, Uganda and Egypt.The Nile has two major...

 island Philae
Philae
Philae is an island in the Nile River and the previous site of an Ancient Egyptian temple complex in southern Egypt...

 where an obelisk
Obelisk
An obelisk is a tall, four-sided, narrow tapering monument which ends in a pyramid-like shape at the top, and is said to resemble a petrified ray of the sun-disk. A pair of obelisks usually stood in front of a pylon...

 was found that helped decipher the Rosetta Stone
Rosetta Stone
The Rosetta Stone is an ancient Egyptian granodiorite stele inscribed with a decree issued at Memphis in 196 BC on behalf of King Ptolemy V. The decree appears in three scripts: the upper text is Ancient Egyptian hieroglyphs, the middle portion Demotic script, and the lowest Ancient Greek...

. The spacecraft has already performed two successful asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...

 flyby missions on its way to the comet. The craft completed its fly-by of asteroid 2867 Šteins
2867 Šteins
2867 Šteins is a small main-belt asteroid that was discovered in 1969 by N. S. Chernykh. It is named after Kārlis Šteins, a Latvian and Soviet astronomer...

 in September 2008 and of 21 Lutetia
21 Lutetia
21 Lutetia is a large main-belt asteroid of an unusual spectral type. It measures about 100 kilometers in diameter . It was discovered in 1852 by Hermann Goldschmidt, and is named after Lutetia, the Latin name for Paris....

 in July 2010, and is presently in hibernation
Hibernation
Hibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate. Hibernating animals conserve food, especially during winter when food supplies are limited, tapping energy reserves, body fat, at a slow rate...

 and on-target for its final destination as of June 2011.

Mission timeline



This is the planned timeline for the mission after its launch:
  • First Earth flyby (March 4, 2005)
  • Mars flyby (February 25, 2007)
  • Second Earth flyby (November 13, 2007 )
  • Flyby of asteroid 2867 Šteins
    2867 Šteins
    2867 Šteins is a small main-belt asteroid that was discovered in 1969 by N. S. Chernykh. It is named after Kārlis Šteins, a Latvian and Soviet astronomer...

     (September 5, 2008)
  • Third Earth flyby (November 13, 2009)
  • Flyby of asteroid 21 Lutetia
    21 Lutetia
    21 Lutetia is a large main-belt asteroid of an unusual spectral type. It measures about 100 kilometers in diameter . It was discovered in 1852 by Hermann Goldschmidt, and is named after Lutetia, the Latin name for Paris....

     (July 10, 2010)
  • Deep-space hibernation (June 2011 - January 2014)
  • Comet approach (January–May 2014)
  • Comet mapping / Characterisation (August 2014)
  • Landing on the comet (November 2014)
  • Escorting the comet around the Sun (November 2014 - December 2015)
  • End of mission (December 2015)


Rosettas current location can be found here: http://www.esa.int/SPECIALS/Rosetta/SEMRZF1PGQD_0.html

Overview


During the 1986 apparition of the Comet Halley
Comet Halley
Halley's Comet or Comet Halley is the best-known of the short-period comets, and is visible from Earth every 75 to 76 years. Halley is the only short-period comet that is clearly visible to the naked eye from Earth, and thus the only naked-eye comet that might appear twice in a human lifetime...

, a number of international space probes were sent to explore the cometary system, most prominent among them being ESA
European Space Agency
The European Space Agency , established in 1975, is an intergovernmental organisation dedicated to the exploration of space, currently with 18 member states...

's highly successful Giotto
Giotto mission
Giotto was a European robotic spacecraft mission from the European Space Agency, intended to fly by and study Halley's Comet. On 13 March 1986, the mission succeeded in approaching Halley's nucleus at a distance of 596 kilometers....

. After the probes returned a treasure-trove of valuable scientific information it was becoming obvious that follow-ons were needed that would shed more light on the complex cometary composition and resolve the newly opened questions.

Both NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

 and ESA started cooperatively developing new probes. The NASA project was the Comet Rendezvous Asteroid Flyby
Comet Rendezvous Asteroid Flyby
The Comet Rendezvous Asteroid Flyby was a cancelled plan for a NASA led exploratory mission designed by the Jet Propulsion Laboratory during the mid-to-late 1980s and early 1990s, that planned to send a spacecraft to encounter an asteroid, and then to rendezvous with a comet and fly alongside it...

 (CRAF) mission. The ESA project was the follow-on Comet Nucleus Sample Return (CNSR) mission. Both missions were to share the Mariner Mark II
Mariner Mark II
Mariner Mark II was NASA's planned family of unmanned spacecraft for the exploration of the outer solar system that were to be developed and operated by JPL between 1990 through the year 2010....

 spacecraft design, thus minimizing costs. In 1992, after NASA axed CRAF due to budgetary limitations, ESA decided to develop a CRAF-style project on its own. By 1993 it was evident that the ambitious sample return mission was unfeasible with the existing ESA budget, so the mission was redesigned, with the final flight plan resembling the canceled CRAF mission, an asteroid flyby followed by a comet rendezvous with in-situ examination, including a lander.

Rosetta was built in a clean room according to COSPAR
COSPAR
The Committee on Space Research was established by the International Council for Science in 1958.Among COSPAR's objectives are the promotion of scientific research in space on an international level, with emphasis on the free exchange of results, information, and opinions, and providing a forum,...

 rules, but "Sterilisation
Sterilization (microbiology)
Sterilization is a term referring to any process that eliminates or kills all forms of microbial life, including transmissible agents present on a surface, contained in a fluid, in medication, or in a compound such as biological culture media...

 [was] generally not crucial since comets are usually regarded as objects where you can find prebiotic molecules, that is, molecules that are precursors of life, but not living microorganisms, " according to Gerhard Schwehm
Gerhard Schwehm
Dr Gerhard Schwehm PhD is Head of Solar System Science Operations Division for the European Space Agency , and Mission Manager for the Rosetta mission.-Education and work:...

, Rosetta's Project Scientist.

It was set to be launched on January 12, 2003 to rendezvous with the comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...

 46P/Wirtanen
46P/Wirtanen
46P/Wirtanen is a small short-periodic comet with a current orbital period of 5.4 years. It was the original target for close investigation by the Rosetta spacecraft, planned by the European Space Agency. It belongs to the Jupiter family of comets, all of which have aphelia between 5 and 6 AU. Its...

 in 2011.
However, this plan was abandoned after a failure of the planned launch vehicle Ariane 5
Ariane 5
Ariane 5 is, as a part of Ariane rocket family, an expendable launch system used to deliver payloads into geostationary transfer orbit or low Earth orbit . Ariane 5 rockets are manufactured under the authority of the European Space Agency and the Centre National d'Etudes Spatiales...

 on December 11, 2002. A new plan was formed to target the comet Churyumov–Gerasimenko, with launch on February 26, 2004 and rendezvous in 2014. The larger mass and the resulting increased impact velocity made modification of the landing gear necessary. After two cancelled launch attempts, Rosetta was launched on March 2, 2004 at 7:17 GMT. Besides the changes made to launch time and target, the mission profile remains almost identical.

The first flyby of Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

 occurred on March 4, 2005.

On February 25, 2007, the craft was scheduled for a low-altitude bypass of Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

, to correct the trajectory after the first launch in 2003 was delayed by one year. This was not without risk, as the estimated altitude of the flyover manoeuvre was a mere 250 km (155 miles). During that encounter the solar panels could not be used since the craft was in the planet's shadow, where it would not receive any solar light for 15 minutes, causing a dangerous shortage of power. The craft was therefore put into standby mode, with no possibility to communicate, flying on batteries that were originally not designed for this task.
This Mars manœuvre was therefore nicknamed "The Billion Euro Gamble".
Fortunately, the flyby was successful and the mission continued as planned.

The second Earth flyby occurred on November 13, 2007.

The spacecraft performed a close flyby of asteroid 2867 Šteins
2867 Šteins
2867 Šteins is a small main-belt asteroid that was discovered in 1969 by N. S. Chernykh. It is named after Kārlis Šteins, a Latvian and Soviet astronomer...

 on September 5, 2008. Its onboard cameras were used to fine-tune the trajectory, achieving a minimum separation of less than 800 km (497 miles). Onboard instruments measured the asteroid from August 4 to September 10. Maximum relative speed between the 2 objects during the flyby was 8.6 km/s (19,240 mph).

The asteroid's orbit was known before Rosettas launch, from ground-based measurements, to an accuracy of approximately 100 km. Information gathered by the onboard cameras beginning at a distance of 24 million km will be processed at ESA's Operation Center to refine the asteroid's position in its orbit to a few km.

Rosettas third and final flyby of Earth happened on November 12, 2009.

In May 2014, the Rosetta craft will enter a slow orbit around the comet and gradually slow down in preparation for releasing a lander that will make contact with the comet itself. The lander, named "Philae
Philae lander
Philae is the lander that accompanies the Rosetta spacecraft. It is designed to land on Comet 67P/Churyumov-Gerasimenko shortly after arrival...

", will approach Churyumov–Gerasimenko at relative speed around 1 m/s and on contact with the surface, two harpoon
Harpoon
A harpoon is a long spear-like instrument used in fishing to catch fish or large marine mammals such as whales. It accomplishes this task by impaling the target animal, allowing the fishermen to use a rope or chain attached to the butt of the projectile to catch the animal...

s will be fired into the comet to prevent the lander from bouncing off. Additional drills are used to further secure the lander on the comet.

Once attached to the comet, expected to take place in November 2014, the lander will begin its science mission:
  • Characterisation of the nucleus
  • Determination of the chemical compounds present, including enantiomers

  • Study of comet activities and developments over time


The exact surface layout of the comet is currently unknown and the orbiter has been built to map this before detaching the lander. It is anticipated that a suitable landing site can be found, although few specific details exist regarding the surface.

Core


The spectroscopical investigation of the core is done by four instruments.
  • ALICE (an ultraviolet imaging spectrograph). The UV spectrograph
    Ultraviolet-visible spectroscopy
    Ultraviolet-visible spectroscopy or ultraviolet-visible spectrophotometry refers to absorption spectroscopy or reflectance spectroscopy in the ultraviolet-visible spectral region. This means it uses light in the visible and adjacent ranges...

     will search for the abundance of noble gas
    Noble gas
    The noble gases are a group of chemical elements with very similar properties: under standard conditions, they are all odorless, colorless, monatomic gases, with very low chemical reactivity...

     in the comet core, from which the temperature during the comet creation could be estimated. The detection is done by an array of potassium bromide
    Potassium bromide
    Potassium bromide is a salt, widely used as an anticonvulsant and a sedative in the late 19th and early 20th centuries, with over-the-counter use extending to 1975 in the United States. Its action is due to the bromide ion...

     and caesium iodide
    Caesium iodide
    Caesium iodide is an ionic compound often used as the input phosphor of an x-ray image intensifier tube found in fluoroscopy equipment....

     photocathode
    Photocathode
    A photocathode is a negatively charged electrode in a light detection device such as a photomultiplier or phototube that is coated with a photosensitive compound...

    s. The 3.1 kg instrument uses 2.9 watts and was produced in the USA, and an improved version is used in the New Horizons
    New Horizons
    New Horizons is a NASA robotic spacecraft mission currently en route to the dwarf planet Pluto. It is expected to be the first spacecraft to fly by and study Pluto and its moons, Charon, Nix, Hydra and S/2011 P 1. Its estimated arrival date at the Pluto-Charon system is July 14th, 2015...

    .
  • OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System). The camera system has a narrow angle
    Macro photography
    Macrophotography is close-up photography, usually of very small subjects. Classically a macrophotograph is one in which the size of the subject on the negative is greater than life size. However in modern use it refers to a finished photograph of a subject at greater than life size...

     lens (700 mm) and a wide angle
    Wide Angle
    Wide Angle is the debut studio album by British breakbeat trance producers Hybrid, and was re-released in 2000 as a double-CD edition entitled Wider Angle...

     lens (140 mm), with a 2048x2048 pixel CCD
    Charge-coupled device
    A charge-coupled device is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value. This is achieved by "shifting" the signals between stages within the device one at a time...

     chip. The instrument was constructed in Germany.
  • VIRTIS (Visible and Infrared Thermal Imaging Spectrometer). The Visible and IR spectrometer
    Infrared spectroscopy
    Infrared spectroscopy is the spectroscopy that deals with the infrared region of the electromagnetic spectrum, that is light with a longer wavelength and lower frequency than visible light. It covers a range of techniques, mostly based on absorption spectroscopy. As with all spectroscopic...

     is able to make pictures of the core in the IR and also search for IR spectra of molecules in the coma. The detection is done by a mercury cadmium teluride array for IR and with a CCD chip for the Visible range. The instrument was produced in Italy, and improved versions were used for Dawn and Venus express
    Venus Express
    Venus Express is the first Venus exploration mission of the European Space Agency. Launched in November 2005, it arrived at Venus in April 2006 and has been continuously sending back science data from its polar orbit around Venus. Equipped with seven science instruments, the main objective of the...

    .
  • MIRO (Microwave Instrument for the Rosetta Orbiter). The abundance and temperature of volatile substances like water, ammonia and carbon dioxide can be detected by MIRO via their microwave
    Microwave
    Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...

     emissions. The 30 cm radio antenna was constructed in Germany, while the rest of the 18.5 kg instrument was provided by the USA.


The interior of the comet is probed by the CONSERT instrument.
  • CONSERT
    CONSERT
    CONSERT is a scientific experiment on board the European Space Agency's Rosetta mission, launched in 2004, which will provide information about the deep interior of the comet 67P/Churyumov-Gerasimenko upon the probe's rendezvous with the comet in 2014.The CONSERT radar will perform a...

     (Comet Nucleus Sounding Experiment by Radiowave Transmission). The CONSERT experiment is the only experiment on board the ROSETTA mission which will provide information about the deep interior of the comet. The Consert radar
    Radar
    Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

     will perform tomography
    Tomography
    Tomography refers to imaging by sections or sectioning, through the use of any kind of penetrating wave. A device used in tomography is called a tomograph, while the image produced is a tomogram. The method is used in radiology, archaeology, biology, geophysics, oceanography, materials science,...

     of the nucleus by measuring electromagnetic wave propagation between the Philae lander
    Philae lander
    Philae is the lander that accompanies the Rosetta spacecraft. It is designed to land on Comet 67P/Churyumov-Gerasimenko shortly after arrival...

     and the Rosetta orbiter through the comet nucleus. This allows it to determine the comet's internal structure and deduce information on its composition. The lander and orbiter electronics were provided by France and both antennas were constructed in Germany.

Gas and particles

  • ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis). The instrument consists a double focus magnetic mass spectrometer
    Sector instrument
    A sector instrument is a general term for a class of mass spectrometer that uses a static electric or magnetic sector or some combination of the two as a mass analyzer. A popular combination of these sectors has been the BEB...

     DFMS and a reflectron
    Reflectron
    A reflectron is a type of time-of-flight mass spectrometer that comprises a pulsed ion source, field-free region, ion mirror, and ion detector and uses a static or time dependent electric field in the ion mirror to reverse the direction of travel of the ions entering it...

     type time of flight mass spectrometer
    Time-of-flight
    Time of flight describes a variety of methods that measure the time that it takes for an object, particle or acoustic, electromagnetic or other wave to travel a distance through a medium...

     RTOF. The DFMS has a high resolution (can resolve N2
    Nitrogen
    Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...

     from CO
    Carbon monoxide
    Carbon monoxide , also called carbonous oxide, is a colorless, odorless, and tasteless gas that is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal...

    ) for molecules up to 300 amu
    Atomic mass unit
    The unified atomic mass unit or dalton is a unit that is used for indicating mass on an atomic or molecular scale. It is defined as one twelfth of the rest mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state, and has a value of...

    . The RTOF is highly sensitive for neutral molecules and for ions.
  • MIDAS (Micro-Imaging Dust Analysis System). The high resolution atomic force microscope
    Atomic force microscope
    Atomic force microscopy or scanning force microscopy is a very high-resolution type of scanning probe microscopy, with demonstrated resolution on the order of fractions of a nanometer, more than 1000 times better than the optical diffraction limit...

     will investigate the dust particles which are deposited on a silicone plate.
  • COSIMA (Cometary Secondary Ion Mass Analyser). COSIMA analyses the composition of dust particles by secondary ion mass spectrometry
    Secondary ion mass spectrometry
    Secondary ion mass spectrometry is a technique used in materials science and surface science to analyze the composition of solid surfaces and thin films by sputtering the surface of the specimen with a focused primary ion beam and collecting and analyzing ejected secondary ions...

    , after the surface is cleaned by indium
    Indium
    Indium is a chemical element with the symbol In and atomic number 49. This rare, very soft, malleable and easily fusible post-transition metal is chemically similar to gallium and thallium, and shows the intermediate properties between these two...

     ions. It can analyse ions up to a mass of 4000 amu.

Solarwind interaction

  • GIADA (Grain Impact Analyser and Dust Accumulator)

  • RPC (Rosetta Plasma Consortium).

2004

  • March 2 – ESA's Rosetta mission was successfully launched at 07:17 UTC (08:17 Central European Time
    Central European Time
    Central European Time , used in most parts of the European Union, is a standard time that is 1 hour ahead of Coordinated Universal Time . The time offset from UTC can be written as +01:00...

    ). The launcher successfully placed its upper stage and payload into an eccentric coast orbit (200 x 4,000 km). About two hours later, at 09:14 UTC, the upper stage ignited its own engine to reach escape velocity
    Escape velocity
    In physics, escape velocity is the speed at which the kinetic energy plus the gravitational potential energy of an object is zero gravitational potential energy is negative since gravity is an attractive force and the potential is defined to be zero at infinity...

     in order to leave the Earth’s gravity field and enter heliocentric orbit. The Rosetta probe was released 18 minutes later. ESA’s Operations Centre (ESOC) in Darmstadt
    Darmstadt
    Darmstadt is a city in the Bundesland of Hesse in Germany, located in the southern part of the Rhine Main Area.The sandy soils in the Darmstadt area, ill-suited for agriculture in times before industrial fertilisation, prevented any larger settlement from developing, until the city became the seat...

    , Germany, established contact with the probe shortly after that.

  • May 10 – The first and most important deep space maneuver was successfully executed to adjust the course of the space craft, with a reported inaccuracy of 0.05%.

2005

  • March 4 – Rosetta executed its first planned close flyby of Earth. The Moon and the Earth's magnetic field were used to test and calibrate the instruments on board of the spacecraft. The minimum altitude above the Earth's surface was about 1,954.7 km at 22:09 UTC and images of the space probe passing by were captured by amateur astronomers.
  • July 4 – Imaging instruments on board observed the collision between the comet Tempel 1 and the impactor of the Deep Impact mission.

2007

  • February 25 – Mars swing-by. Philae's ROMAP (Rosetta Lander Magnetometer and Plasma Monitor) instrument measures the complex Martian magnetic environment
    Magnetism
    Magnetism is a property of materials that respond at an atomic or subatomic level to an applied magnetic field. Ferromagnetism is the strongest and most familiar type of magnetism. It is responsible for the behavior of permanent magnets, which produce their own persistent magnetic fields, as well...

    , while Rosetta's OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) took various images of the planet using different photographic filter
    Photographic filter
    In photography and videography, a filter is a camera accessory consisting of an optical filter that can be inserted in the optical path. The filter can be a square or oblong shape mounted in a holder accessory, or, more commonly, a glass or plastic disk with a metal or plastic ring frame, which...

    s. While in Mars' shadow most of the instruments were turned off the Philae lander was autonomously running on batteries. During this operation the ÇIVA instrument on the lander took pictures of Mars. Among others, both actions were meant to test the spacecraft's instruments. The space craft used the gravity of Mars to change course towards its second Earth flyby in November.
  • November 8 – Misidentification of Rosetta space craft as an asteroid (see below).

2008

  • September 5 – Flyby of asteroid 2867 Šteins
    2867 Šteins
    2867 Šteins is a small main-belt asteroid that was discovered in 1969 by N. S. Chernykh. It is named after Kārlis Šteins, a Latvian and Soviet astronomer...

    . The spacecraft passed the main-belt asteroid at a distance of 800 km and the relatively slow speed of 8.6 km/s.

2009

  • November 13 – Last swingby (gravity assist passage) of Earth. The spacecraft made its closest approach (perigee passage) at 2481 km altitude over 109°E and 8°S - just off the coast of the Indonesia
    Indonesia
    Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

    n island of Java
    Java
    Java is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java...

    , at 07:45 UTC.

2010

  • March 16 - Observation of the dust tail of the asteroid P/2010 A2
    P/2010 A2
    P/2010 A2 is a small Solar System body that displayed characteristics of both an asteroid and a comet, and thus, was initially given a cometary designation. Since it has the orbit of a main-belt asteroid and showed the tail of a comet, it was listed as a main-belt comet...

    . Together with observations of Hubble space telescope
    Hubble Space Telescope
    The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...

     it could be confirmed that the P/2010 A2 is not a comet but an asteroid and the tail most likely consists of particles from an impact of a smaller asteroid.
  • July 10 - Flew by and photographed the asteroid 21 Lutetia
    21 Lutetia
    21 Lutetia is a large main-belt asteroid of an unusual spectral type. It measures about 100 kilometers in diameter . It was discovered in 1852 by Hermann Goldschmidt, and is named after Lutetia, the Latin name for Paris....

    .

2011

  • June 8 - The space craft was transferred into a spin stabilized mode and all electronic except the onboard computer and the hibernation heaters were switched off.

Misidentification as an asteroid


In November, 2007, during its second flyby, the Rosetta spacecraft was mistaken for a dangerous near-Earth asteroid and given the designation 2007 VN84. Based upon images taken by a 0.68 meter telescope of the Catalina Sky Survey
Catalina Sky Survey
Catalina Sky Survey is a project to discover comets and asteroids, and to search for Near-Earth objects. More specifically, to search for potentially hazardous asteroids , that may pose a threat of impact.-Mission:...

, an astronomer 'discovered' the spacecraft and misidentified it as an asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...

 about 20 meters in diameter, and performed a trajectory calculation showing that it would make its closest flyby of the Earth at a distance of 5,700 kilometers on November 13, 2007. This extremely close approach (in astronomical terms) led to speculation that 2007 VN84 might be at risk of impacting the Earth. However, astronomer Denis Denisenko
Denis Denisenko
Denis Denisenko is a Russian astronomer and ironist of the late 20th – early 21st century.-Biography:Born in 1971 in Moscow, Denisenko graduated from Moscow Institute of Physics and Technology in 1993 with a Master of Science in Astrophysics and a Diploma: Spectral Properties of Gamma-Ray Bursts...

 recognized that the trajectory matched that of the Rosetta probe, which was performing a flyby of Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

 en route to its rendezvous with a comet. The Minor Planet Center
Minor Planet Center
The Minor Planet Center operates at the Smithsonian Astrophysical Observatory , which is part of the Center for Astrophysics along with the Harvard College Observatory ....

later confirmed in an editorial release that 2007 VN84 was actually the spacecraft.

External links