Space probe "Rosetta": description of the satellite and photo. What do we know about the Rosetta mission? What's wrong with the satellite on the comet?

Launching a spacecraft from Earth, which in ten years at a distance of 0.5 billion km from our planet will catch up with a tiny block 5 km in size, enter its orbit, gently land its mobile module on its surface and study the structure of this comet - that’s what something fantastic. After this experiment, flights to the Moon and Mars seem like simple tasks. However, this happened and on November 12, 2014, the Philai lander landed on comet 67P/Churyumov-Gerasimenko and transmitted its image and a lot of scientific data to Earth from a distance of 500,000,000 km. There is a lot of talk and writing about this event now. We, too, could not ignore this achievement of our century. We hope that in this material, prepared using material from the official websites of the flight organizers, you will find answers to questions that interest many.

What kind of comet is it and why is it called that? Comet 67P/Churyumov-Gerasimenko was named after its discoverers, Klim Churyumov and Svetlana Gerasimenko, who spotted and photographed the comet in 1969 while observing the starry sky from the observatory of the Astrophysical Institute in Almaty. The comet approached the Sun several times and was visible from Earth: in 1969, 1976, 1982, 1989, 1996, 2002 and 2009. In 2003, an image of the comet was obtained using the Hubble telescope, which made it possible to estimate the size of the comet - approximately 3 x 5 km.

Why was the space station called Rosetta? Rosetta is named after the famous Rosetta Stone, weighing 762 kg, consisting of volcanic basalt and now kept in the British Museum in London. The stone served as the key to deciphering ancient Egyptian writings. The stone was discovered by French soldiers who were preparing to demolish an old wall near the village of Rashid (Rosetta) in the Nile Delta in 1799. The inscriptions carved on the stone contained Egyptian hieroglyphs and at the same time Greek words that could be easily understood. By examining the inscriptions on the stone, historians were able to begin to decipher the mystical ancient drawings and recreate the history of ancient Egypt. Just as the Rosetta Stone was the key to an ancient civilization, the Rosetta spacecraft must unlock the mystery of the oldest building blocks of the solar system - comets.

Why was the lander called Philai? Philae - the Rosetta lander is also named after the discovery that made it possible to decipher ancient Egyptian inscriptions. Philae obelisk is one of two obelisks found in 1815 on the island of Philae (in Russian usually translated as Philae) in southern Egypt. Hieroglyphs and ancient Greek words were also found on the obelisk; scientists were able to recognize the names “Ptolemy” and “Cleopatra” written in hieroglyphs on the obelisk. In Russian, the Philae lander is sometimes pronounced as Philae, after the name of the Egyptian island. But foreigners don't say that. If you listen to Europeans, the pronunciation depends on the accent. The English say something between Philai and Phila, the Italians are very close to Phila.

What is the complete flight path? The trajectory is indeed very complex. Rosetta was launched in 2004 from the French Cosmodrome and in the first stage occupied a “parking orbit”. It then accelerated like a cosmic billiard ball within the solar system, making nearly four orbits around the Sun over a decade in a complex trajectory, using the gravity of Earth and Mars. Interesting space flight schedule:

Preparation for approach to the comet (maneuvering) May-August 2014

How was communication with Earth carried out? All scientific data from the instruments on board the station were transmitted to Earth via radio communications. The same communication channel was used to control devices on board. The mission control center is located at the European Space Operations Center (ESOC) in Darmstadt, Germany.

How big is Rosetta? There are a lot of pictures, sometimes it is difficult to estimate the real size of the ship from them. The Rosetta is actually an aluminum box measuring 2.8 x 2.1 x 2.0 meters. On one side of the device there is a two-meter rotating location dish - antenna. A descent module is attached to the opposite side. Huge wings extend on the other two sides. The area of each wing is 32 sq.m. The wingspan is 32 m. Each wing consists of five panels. Both wings can freely rotate ±180° to catch maximum sunlight. The total mass of the apparatus is about 3 tons, of which the mass of scientific instruments is 165 kg. The Philai lander weighs 100 kg and contains 10 scientific instruments weighing 21 kg.

Who manufactured and launched the spacecraft, how much did it cost? More than 50 companies from 14 European countries and the USA were involved in the project. The main developer is Astrium Germany with contractors: Astrium UK (ship platform), Astrium France (aviation equipment), Alenia Spazio (assembly, integration of parts, control). The cost of the space project is estimated at 1.4 billion euros.

What did Philai transmit to Earth? On November 12, the Philae lander was lowered from the Rosetta space station to the comet's surface. Scientists encountered an unexpected problem - the harpoons designed to immediately catch on to the surface did not work, as a result the device jumped twice before securing itself on the surface. The exact location of Philai became unknown. However, communication with the device was maintained, information and images from the surface were transmitted to Earth. This included information about temperature measurements. The thermal imaging device included in MUPUS (MUlti-PUrpose Sensors for Surface and Sub-Surface), located on the Philai body, operated throughout the entire landing and three contacts with the surface. During the final landing, MUPUS recorded a temperature of -153°C near the bottom of the vehicle's outer balcony just before it deployed to the surface. After landing and deployment, the sensors near the top of the vehicle cooled by another 10 °C for about half an hour. Scientists speculate that the cooling occurred due to radiative heat transfer to a nearby wall (a bump on the comet's surface) visible in the images, or due to the sensor being immersed in cold dust on the comet's surface. As planned, the surface was drilled with a special CD2 drill, which then transferred the samples taken to the COSAC analyzer. However, scientists are not sure that the drill actually transferred deep samples, and not gas and dust from the surface, because Philai was not sufficiently anchored to the surface and could rise during drilling. Analysis of materials continues. It is already obvious that the COSAC system, during the landing of the lander module, received valuable data that the gas on the surface of the comet contains organic molecules. The Ptolemy system has also successfully collected the gases and their spectra are currently being analyzed and molecular identifications are being made.

Unfortunately, three days after the comet landed on the surface, the solar batteries of the Philai lander were completely discharged and further communication with it was lost.

Can Philai “wake up” and continue working?

Scientists do not exclude this possibility. Mario Salatti (Philae Program Manager) hopes that Philae will come to his senses and continue measurements on the surface of the comet. Although the place where Philae is now located receives very little solar radiation, this, on the other hand, opens up new perspectives. At the moment, the device is in the shadow of boulders, the local temperature on it is lower than planned. And when Philai awakens, he will be able to work longer than expected, perhaps until his closest approach to the Sun.

How long will Rosetta fly near the comet? Rosetta will be close to the comet for the entire time the comet is flying towards the Sun and even longer - until December 2015. Its closest approach to the Sun will occur on August 13, 2015. Scientists hope to obtain interesting data about the changes occurring in the comet as it heats up.

Constantly updated images transmitted by Rosetta can be viewed on the website of the European Space Agency (ESA) http://sci.esa.int/rosetta/

Philosophizing on the topic:

The Rosetta space project is very impressive. In my opinion, what is important is not even the main mission (the study of the comet), but the implementation of the entire flight and landing on the comet. This speaks about the enormous capabilities of modern technology for converting radio signals and transmitting over vast distances, about the invention and testing of new, simply fantastic solar energy devices, about the possibility of planning flights using gravitational accelerations, etc. One of the most important achievements is the unification of scientists from different countries to implement a single project.

At the same time, I can’t help but make a few philosophical reflections about the possibilities of humanity. Over the past decade, a lot has been achieved in the field of information technology. People can almost instantly communicate with each other and with devices using mobile devices connected to the World Wide Web - the Internet. However, as far as the actual speed of movement of humans and other material objects is concerned, we have not achieved much here. The speed of movement still lags far behind the speed of information transfer. The signal from comet 67P/Churyumov-Gerasimenko now travels for 28 minutes, but the rocket took 10 years to reach the comet. Our capabilities for space exploration are very limited by the method and speed of movement. Can a person even get close to 300,000 km/s? Will teleportation ever be available? This is fantastic, but only for our time. Don't forget that the video phone was also a fantasy in the early 20th century.

Illustration copyright E.K.A. Image caption The picture was taken 10 seconds before the collision with the comet

The Rosetta space probe collided with comet Churyumov-Gerasimenko, which it followed for 12 years.

As it approached the comet's surface - a 4 km-diameter sphere of ice and dust - the probe was still transmitting photographs to Earth.

The European Space Agency's (ESA) mission control center in the German city of Darmstadt gave the command to change course on Thursday afternoon.

Final confirmation that a controlled collision had finally occurred came from Darmstadt after radio contact with the probe was suddenly lost.

"Goodbye, Rosetta! You've done your job. This is space science at its best," mission director Patrick Martin said.

Project Rosetta lasted 30 years. Some of the scientists who followed Rosetta's comet collision in Darmstadt devoted significant portions of their careers to the mission.

The speed of approach of the probe with the comet was extremely low, only 0.5 meters per second, the distance was about 19 kilometers.

According to ESA representatives, Rosetta was not designed to land on the surface and could not continue to function after the collision.

That's why the probe was pre-programmed to shut down completely automatically upon contact with a celestial body.

Comet 67 R (Churyumova-Gerasimenko)

Comet rotation cycle: 12.4 hours.
Weight: 10 billion tons.
Density: 400 kg per cubic meter (about the same as some types of wood).
Volume: 25 cu. km.
Color: Charcoal - judging by its albedo (reflectivity of the body surface).

Illustration copyright ESA Image caption This is what the surface of the comet looked like from a height of 5.8 km

Rosetta followed the comet for 6 billion kilometers. The probe was in its orbit for more than two years.

It became the first spacecraft to enter orbit around a comet.

Over the course of 25 months, the probe sent back to Earth over 100 thousand photographs and readings from measuring instruments.

The probe collected previously unavailable data about the celestial body, in particular, about its behavior, structure and chemical composition.

In November 2014, Rosetta lowered a small robot called Philae to the comet's surface to collect soil samples, the world's first of its kind.

Comets, as scientists suggest, have been preserved since the formation of the solar system in almost their original form, so the data transmitted by the probe to Earth will help to better understand the cosmic processes that took place 4.5 billion years ago.

“The data transmitted by Rosetta will be used for decades,” says flight director Andrea Accomazzo.

Last Stand

The probe was located at a distance of 573 million km from the Sun and was moving further and further away from it, approaching the boundaries of the Solar system.

The spacecraft was powered by solar panels, which could no longer be recharged effectively.

In addition, the data transfer speed has become extremely low: only 40 kb per second, which is comparable to the speed of accessing the Internet through a telephone line.

Overall, Rosetta, launched into space in 2004, has recently been in poor technical condition, having been exposed to radiation and extreme temperatures for many years.

According to project coordinator Matt Taylor, the team discussed the idea of putting the probe into standby mode and reactivating it the next time Comet Churyumov-Gerasimenko enters the inner Solar System.

However, scientists had no confidence that Rosetta would then work as before.

Therefore, the researchers decided to give Rosetta a chance to prove itself in the “last battle” and “exit life with brilliance,” no matter how bitter it may sound.

The collision with the surface of comet Churyumov-Gerasimenko ended the program of its exploration by the Rosetta probe.

On September 30 at 13:39 Moscow time, the European Space Agency's Rosetta probe completed its mission, having been exploring comet Churyumov-Gerasimenko for more than two years. This happened as planned, with a controlled fall of the spacecraft onto the surface of the comet from an altitude of about 19 km. It was the result of several weeks of complex maneuvers.

The Rosetta crash site is shown on the right. The other two arrows indicate the start and end positions of the lander (image ESA/Rosetta/Philae/CIVA)

The region where the probe fell. (Image: ESA/Rosetta/MPS)

The last photograph taken by the probe from a height of 20 m. It has a resolution of 5 mm per pixel and covers an area of about 2.4 m in diameter. (Image: ESA/Rosetta/MPS)

The probe's trajectory was aimed at an area of active pits in the so-called Ma'at region. These pits are of particular interest because they play an important role in the comet's activity and are where many of the recorded plasma jets originate. They also provide a unique window into the comet's interior. On the walls of the pits, lumpy meter-long structures are visible - “goosebumps”, which, according to researchers, may be traces of cometesimals that, sticking together, formed comets in the early stages of the formation of the Solar System.

The nearly 14-hour descent provided the opportunity to study the comet's gas, dust and plasma very close to its surface, and to take very high-resolution images of it. The probe managed to transmit the received information to Earth even before the impact.

The decision to end the mission in such a dramatic way was made after the comet again left the orbit of Jupiter and began to move so far away from the Sun that the energy generated by the solar panels would soon not be enough to operate the equipment. In addition, the month-long period was approaching when the Sun would be close to the line of sight between the Earth and the probe, making communication with it difficult. It was a fitting finale to Rosetta's incredible adventures.

Since its launch in 2004, the Rosetta probe has completed more than 5 orbits around the Sun, traveling nearly 8 billion kilometers. During this time, he flew near the Earth three times and once near Mars and two asteroids. The spacecraft survived 31 months of hibernation in deep space at the farthest point of its journey, where there was not enough energy to keep it fully functioning. After a successful awakening in January 2014, the probe finally arrived at the comet in August 2014. Then, for 786 days, he followed next to the comet, monitoring its evolution as it approached and moved away from the Sun, including at the moment of its closest approach to the Sun.

Rosetta became the first spacecraft in history to not only travel alongside a comet, but also to launch a research probe onto it in November 2014.

Several important discoveries were made during the mission. In particular, a higher content of heavy water was discovered in the ice of the comet, which contradicts the hypothesis about the cometary origin of water on Earth. The totality of the results of studying the structure of the comet and its gas and dust composition indicate the birth of the comet in a very cold region of the protoplanetary cloud at a time when the Solar system was still forming, more than 4.5 billion years ago. Of great interest is the discovery of the amino acid glycine, found in proteins, phosphorus, a key component of DNA, and other organic compounds.

The mission of the Probe itself is over, but the data obtained will be studied on Earth for several more decades. The name of the mission was given in honor of the famous Rosetta Stone, which played a decisive role in the understanding of the ancient Egyptian language. Researchers believe Rosetta will play a similar role in understanding the nature of comets.

And Lutetia

The spacecraft was launched on March 2, 2004 to the comet 67P/Churyumov - Gerasimenko. The choice of the comet was made for reasons of convenience of the flight trajectory (see). Rosetta is the first spacecraft to orbit a comet. As part of the program, on November 12, 2014, the world's first soft landing of a descent vehicle on the surface of a comet took place. The main Rosetta probe completed its flight on September 30, 2016, making a hard landing on comet 67P/Churyumov-Gerasimenko.

Origin of names

The name of the probe comes from the famous Rosetta Stone - a stone slab with three identical texts carved into it, two of which are written in ancient Egyptian (one in hieroglyphs, the other in demotic script), and the third is written in ancient Greek. By comparing the texts of the Rosetta Stone, Jean-François Champollion was able to decipher ancient Egyptian hieroglyphs; Using the Rosetta spacecraft, scientists hope to discover what the solar system looked like before the planets formed.

The name of the lander is also associated with the deciphering of ancient Egyptian inscriptions. An obelisk with a hieroglyphic inscription mentioning King Ptolemy VIII and Queens Cleopatra II and Cleopatra III was found on the island of Philae on the Nile River. The inscription, in which scientists recognized the names “Ptolemy” and “Cleopatra,” helped decipher ancient Egyptian hieroglyphs.

Prerequisites for creating the device

In 1986, a significant event occurred in the history of space exploration: Halley's comet approached the Earth at its minimum distance. It was studied by spacecraft from different countries: the Soviet Vega-1 and Vega-2, the Japanese Suisei and Sakigake, and the European Giotto probe. Scientists have received valuable information about the composition and origin of comets.

However, many questions remained unanswered, so NASA and ESA began working together on new space exploration. NASA has focused its efforts on asteroid flyby and comet encounter program(English) Comet Rendezvous Asteroid Flyby abbreviated CRAF). ESA was developing a comet nuclear sample return program (Comet Nucleus Sample Return - CNSR), which was to be carried out after the CRAF program. The new spacecraft were planned to be made on a standard platform Mariner Mark II, which greatly reduced costs. In 1992, however, NASA discontinued development of the CRAF due to budget constraints. ESA continued to develop the spacecraft independently. By 1993, it became clear that with the existing ESA budget, a flight to the comet with the subsequent return of soil samples was impossible, so the program of the device was subjected to major changes. Finally, it looked like this: the vehicle’s approach, first with asteroids, and then with a comet, and then - research of the comet, including a soft landing of the Philae descent module. The mission was planned to end with a controlled collision of the Rosetta probe with a comet.

Purpose and flight program

Rosetta's launch was originally scheduled for January 12, 2003. The target of the research was comet 46P/Wirtanen.

However, in December 2002, the Vulcan-2 engine failed during the launch of the Ariane 5 launch vehicle. Due to the need to improve the engine, the launch of the Rosetta spacecraft was postponed, after which a new flight program was developed for it.

The new plan included a flight to comet 67P/Churyumov - Gerasimenko, with a launch on February 26, 2004 and a meeting with the comet in 2014. The launch delay caused additional costs of about 70 million euros for spacecraft storage and other needs. Rosetta was launched on March 2, 2004 at 7:17 UTC from Kourou in French Guiana. The discoverers of the comet, Professor of Kyiv University Klim Churyumov and researcher at the Institute of Astrophysics of the Academy of Sciences of Tajikistan Svetlana Gerasimenko were present at the launch as honored guests. Apart from the change in time and purpose, the flight program remained virtually unchanged. As before, Rosetta was supposed to approach the comet and launch the Philae lander towards it.

“Philae” had to approach the comet with a relative speed of about 1 m/s and, upon contact with the surface, release two harpoons, since the weak gravity of the comet is not able to hold the device, and it could simply bounce off. After the landing of the Philae module, the start of the scientific program was planned:

determining the parameters of the comet's nucleus;
chemical composition research;
study of changes in comet activity over time.

Trajectory

In accordance with the purpose of the flight, the device needed not only to meet comet 67P, but also to remain with it the entire time the comet was approaching the Sun, continuously conducting observations; it was also necessary to drop Philae onto the surface of the comet's nucleus. To do this, the device had to be practically motionless in relation to him. Taking into account the fact that the comet will be located 300 million km from the Earth and move at a speed of 55 thousand km/hour. Therefore, the device had to be launched into exactly the orbit that the comet followed, and at the same time accelerated to exactly the same speed. From these considerations, both the flight path of the apparatus and the comet itself to which it should fly were chosen.

The Rosetta flight trajectory was based on the principle of “gravitational maneuver” ( On ill.). First, the device moved towards the Sun and, having gone around it, returned to the Earth again, from where it moved towards Mars. Having circled Mars, the device again approached the Earth and then again went beyond the orbit of Mars. At this point, the comet was behind the Sun and closer to it than Rosetta. The new approach to the Earth sent the device in the direction of the comet, which at that moment was heading from the Sun outside the solar system. Rosetta eventually approached the comet at the required speed. Such a complex trajectory made it possible to reduce fuel consumption by using the gravitational fields of the Sun, Earth and Mars.

The main propulsion system consists of 24 two-component engines with a thrust of 10. At the start, the device had 1670 kg of two-component fuel, consisting of monomethylhydrazine (fuel) and nitrogen tetroxide (oxidizer).

The case made of cellular aluminum and the electrical power distribution on board were manufactured by the Finnish company Patria. (English) Russian manufactured probe and lander instruments: COSIMA, MIP (Mutual Impedance Probe), LAP (Langmuir Probe), ICA (Ion Composition Analyzer), water search device (Permittivity Probe) and memory modules (CDMS/MEM).

Scientific equipment of the lander

The total mass of the descent vehicle consists of ten scientific instruments. The lander is designed for a total of 10 experiments to study the structural, morphological, microbiological and other properties of the comet's nucleus. The basis of the analytical laboratory of the descent module consists of pyrolyzers, a gas chromatograph and a mass spectrometer.

Pyrolyzers

To study the chemical and isotopic composition of the comet's nucleus, Philae is equipped with two platinum pyrolyzers. The first can heat samples to a temperature of 180 °C, and the second - up to 800 °C. Samples can be heated at a controlled rate. At each step, as the temperature increases, the total volume of released gases is analyzed.

Gas chromatograph

The main tool for separating pyrolysis products is a gas chromatograph. Helium is used as the carrier gas. The apparatus uses several different chromatography columns capable of analyzing various mixtures of organic and inorganic substances.

Mass spectrometer

To analyze and identify gaseous pyrolysis products, a mass spectrometer with a time of flight (TOF) detector is used.

List of research instruments by purpose

Core

ALICE(An Ultraviolet Imaging Spectrometer).
OSIRIS(Optical, Spectroscopic, and Infrared Remote Imaging System).
VIRTIS(Visible and Infrared Thermal Imaging Spectrometer).
MIRO(Microwave Instrument for the Rosetta Orbiter).

Gas and dust

ROSINA(Rosetta Orbiter Spectrometer for Ion and Neutral Analysis).
MIDAS(Micro-Imaging Dust Analysis System).
COSIMA(Cometary Secondary Ion Mass Analyzer).

Influence of the Sun

GIADA(Grain Impact Analyzer and Dust Accumulator).
RPC(Rosetta Plasma Consortium).

On January 23, 2015, Science magazine published a special issue of scientific research related to the comet. The researchers found that the bulk of the gases emitted by the comet occurred in the “neck” - the area where the two parts of the comet meet: here OSIRIS cameras constantly recorded the flow of gas and debris. OSIRIS imaging team members found that the Hapi region, located in the bridge between the comet's two major lobes and highly active as a source of gas and dust plumes, reflects red light less efficiently than other regions, which may indicate the presence of frozen water on the comet's surface. or shallow below its surface.

Notes

ESA Science & Technology: Rosetta(English) . - Rosetta on the ESA website. Archived from the original on August 23, 2011.
"Rosetta" went to comet Churyumov - Gerasimenko (undefined) (unavailable link). Grani.ru (March 2, 2004). Archived from the original on August 23, 2011.
Rosetta completed its 12-year mission (undefined) . TASS (September 30, 2016).
Nikolay Nikitin We are waiting for landing on the comet // Science and life. - 2014. - No. 8. - URL: http://www.nkj.ru/archive/articles/24739/
Tatyana Zimina Kiss of two comets // Science and life. - 2015. - No. 12. - URL: http://www.nkj.ru/archive/articles/27537/
The Ariane 5 rocket with two satellites fell into the ocean immediately after launch (undefined) (unavailable link). Grani.ru. Archived from the original on August 23, 2011.
Rosetta's flight to Comet Wirtanen was disrupted (undefined) (unavailable link). Grani.ru. Archived from the original on August 23, 2011.
The new target for Rosetta will be a comet discovered by Soviet astronomers (undefined) (unavailable link). Grani.ru (March 12, 2003). Archived from the original on August 23, 2011.
Burba((nbsp1))G. How to land on the tail of a comet? // Around the World, 2005, No. 12 (popular science article).
, With. 245.
The Rosetta spacecraft said goodbye to the Earth (undefined) (inaccessible link - story) . Compulenta (November 13, 2009).
No bugs please, this is a clean planet! (undefined) (inaccessible link - story) . European Space Agency (30 July 2002). Retrieved March 7, 2007.
The Rosetta orbiter (undefined) . European Space Agency (16 January 2014). Retrieved August 13, 2014.
Stage, Mie. "Terma-elektronik vækker rumsonde fra årelang dvale" Ingeniøren, 19 January 2014.

Over the past decades, autonomous spacecraft have made many landings on the planets of the Solar System and some of their satellites. And soon the leg... that is, the landing leg of a man-made spacecraft will leave its mark for the first time on the icy path of the nucleus of comet 67P/Churyumov-Gerasimenko.

Rosetta, ESA, 2004: Rosetta is the first mission whose program includes not only remote sensing, but also a landing in 2014 on the study comet Churyumov–Gerasimenko.

Dmitry Mamontov

There was neither the famous “Let's go!” nor “One small step for a man...” - on the screen, the countdown numbers simply passed zero, and the countdown changed sign from minus to plus. There were no other visible effects, but engineers at the European Space Agency's (ESA) mission control center were visibly tense. At that moment, the braking maneuver of the Rosetta spacecraft, located more than 400 million kilometers from us, began, but it took 22 minutes for the radio signal to reach Earth. And seven minutes later, Sylvan Laudue, the spacecraft operator, looking at the display with telemetry data, stood up and solemnly said: “Ladies and gentlemen, I can officially confirm: we have arrived at the comet!”

International Cometary Explorer (ICE) NASA/ESA, 1978. The American-European ICE flew through the tail of Comet Giacobini-Zinner in 1985, and later, in 1986, flew through the tail of Comet Halley at a distance of 28 million km from the nucleus.

Vega-1, Vega-2 USSR, 1984. Soviet vehicles, after a visit to Venus, headed to Halley’s comet to fly at a distance of 9 thousand km from the nucleus (Vega-1) and 8 thousand km (Vega-2) in March 1986 ).

Sakigake, Suisei ISAS, 1985. Japanese spacecraft were sent to Halley's comet. In 1986, Suisei passed 150 thousand km from the nucleus, studying the interaction of the comet with the solar wind, Sakigake flew at a distance of 7 million km from the nucleus.

Giotto ESA, 1985. The European apparatus in 1986 photographed the nucleus of Comet Halley from a distance of only 600 km, and later, in 1992, passed at a distance of 200 km from Comet Grigg-Skjellerup.

Deep Space 1 NASA, 1998. In 1999, this device approached asteroid 9969 Braille at a distance of 26 km. In September 2001, it flew at a distance of 2200 km from Comet Borrelli.

Stardust NASA, 1999. The first mission, the goal of which was not just to get within 150 km of the nucleus of comet Wild-2 in 2004, but also to deliver a sample of cometary material to Earth (in 2006). Later, in 2011, it came close to comet Tempel-1.

Contour (Comet Nucleus Tour) NASA, 2002. It was planned that Contour would fly near the nuclei of two comets - Encke and Schwassmann-Wachmann-3, after which it would be directed to the third (Comet D'Arrest was considered as the most likely target). But during the transition to the trajectory leading to the first target, contact with the device was lost.

Deep Impact NASA, 2005. In 2005, the Deep Impact apparatus approached the nucleus of comet Tempel-1 and “shot” at it with a special impactor. The composition of the substance knocked out by the impact was analyzed using onboard scientific instruments. The device was later sent to comet Hartley 2, from whose nucleus it passed at a distance of 700 km in 2010.

From antiquity to the present day

Comets are among the celestial objects that can be seen with the naked eye, and therefore they have always aroused special interest. These celestial bodies are described in many historical sources, often in very colorful language. “It shone with the light of day and dragged behind it a tail like the sting of a scorpion,” the ancient Babylonians wrote about the comet of 1140 BC. At different times they were considered either signs or harbingers of misfortune. Now scientists, based on the scientific data accumulated during the study of comets, believe that comets played a key role in the emergence of life on Earth, delivering water and, possibly, simple organic molecules to our planet.

The first data on the composition of cometary matter were obtained using spectroscopic instruments back in the 19th century, and with the beginning of the space age, humanity had the opportunity to directly see and “touch” (if not with our own eyes and hands, then with scientific instruments) the tails of comets and samples of cometary matter . Since the late 1970s, several spacecraft have been launched to study comets in a variety of ways - from photographing from small (by cosmic standards) distances to collecting samples and delivering samples of cometary material to Earth. But in 1993, the European Space Agency decided to aim for a much more ambitious goal - instead of delivering samples to a laboratory on Earth, engineers proposed delivering the laboratory to a comet. In other words, as part of the Rosetta space mission, the Philae lander was supposed to land on the surface of a miniature icy world - the nucleus of a comet.

10 years of flight

Mission development took ten years, and by 2003 the Rosetta spacecraft was ready for launch. It was planned to be launched into space using the Ariane??5 launch vehicle in January 2003, but in December 2002 the same rocket exploded during launch. The event had to be postponed until the causes of the malfunction were clarified, and the three-ton spacecraft was launched into a parking orbit only in March 2004. From here he began his journey to his goal - comet 67P/Churyumov-Gerasimenko, but in a very roundabout way. “There are no rockets powerful enough to directly launch a spacecraft into the path of a comet,” explains Andrea Accomazzo, flight director of the Rosetta mission. — Therefore, the device had to perform four gravitational maneuvers in the gravitational field of the Earth (2005, 2007, 2009) and Mars (2007). Such maneuvers make it possible to transfer part of the planet’s energy to the spacecraft, accelerating it. Twice the device crossed the asteroid belt, and so that this part of the flight would not be wasted, it was decided at the same time to explore some objects in the belt - the asteroids Lutetia and Stynes.”

To study the comet's nucleus: ALICE UV video spectrometer for searching for noble gases in the cometary material. OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) Visible and IR camera with two lenses (700 and 140 mm), with a 2048x2048 pixel matrix. VIRTIS (Visible and Infrared Thermal Imaging Spectrometer) Low-resolution multispectral camera and high-resolution spectrometer for thermal imaging of the nucleus and studying the IR spectrum of coma molecules. MIRO (Microwave Instrument for the Rosetta Orbiter) 3-cm radio telescope for detecting microwave radiation characteristic of water molecules, ammonia and carbon dioxide. CONSERT (Comet Nucleus Sounding Experiment by Radiowave Transmission) Radar for “scanning” and obtaining a tomogram of the comet’s nucleus. The emitter is installed on the Philae lander, and the receiver is installed on the orbiting satellite. RSI (Radio Science Investigation) Use of the apparatus' communication system to study the nucleus and coma. To study gas and dust clouds: ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) Magnetic mass spectrometer and time-of-flight mass spectrometer for studying the molecular and ionic composition of gases. MIDAS (Micro-Imaging Dust Analysis System) High-resolution atomic force microscope for studying dust particles. COSIMA (Cometary Secondary Ion Mass Analyzer) Secondary ion mass analyzer for studying the composition of dust particles. GIADA (Grain Impact Analyzer and Dust Accumulator) Impact analyzer and accumulator of dust particles for measuring their optical properties, speed and mass. RPC (Rosetta Plasma Consortium) Instrument for studying interactions with the solar wind.

Rosetta became the first spacecraft to travel to the outer solar system using solar panels as a power source rather than a radioisotope thermoelectric generator. At a distance of 800 million km from the Sun (this is the farthest point of the mission), the illumination does not exceed 4% of the earth's, so the batteries have a large area (64 m2). In addition, these are not ordinary batteries, but specially designed to operate in low-intensity and low-temperature conditions (Low-intensity Low Temperature Cells). But even despite this, to save energy in May 2011, when Rosetta reached the finish line to the comet, the device was put into hibernation mode for 957 days: all systems were turned off except for the command receiving system, the control computer and the power supply system.

First satellite

In January 2014, Rosetta was “awakened”, preparations began for a series of rendezvous maneuvers - braking and equalizing speeds, as well as the planned inclusion of scientific instruments. Meanwhile, the final goal of the journey became visible only a few months later: in the image taken by the OSIRIS camera on June 16, the comet occupied only 1 pixel. And a month later it barely fit into 20 pixels.

APXS (Alpha X-ray Spectrometer) Alpha and X-ray spectrometer for studying the chemical composition of the soil under the device (immerses 4 cm). COSAC (COmetary SAmpling and Composition) Gas chromatograph and time-of-flight spectrometer for the detection and analysis of complex organic molecules. PTOLEMY Gas analyzer for measuring isotope composition. CIVA (Comet Nucleus Infrared and Visible Analyzer) Six micro-cameras for surface panning, a spectrometer for studying the composition, texture and albedo of samples. ROLIS (Rosetta Lander Imaging System) High-resolution camera for descent and stereo imaging of sampling sites. CONSERT (COmet Nucleus Sounding Experiment by Radiowave Transmission) Radar for “scanning” and obtaining a tomogram of the comet’s nucleus. The emitter is installed on the Philae lander, and the receiver is installed on the orbiting satellite. MUPUS (MUlti-PUrpose Sensors for Surface and Sub-Surface Science) A set of sensors on the supports, sampler and external surfaces of the apparatus for measuring the density, mechanical and thermal properties of soil. ROMAP (Rosetta Lander Magnetometer and Plasma Monitor) A magnetometer and plasma monitor for studying the magnetic field and the interaction of a comet with the solar wind. SESAME (Surface Electric Sounding and Acoustic Monitoring Experiment) A set of three instruments for studying soil properties: Cometary Acoustic Sounding Surface Experiment (CASSE) - using sound waves, Permittivity Probe (PP) - using electric current, Dust Impact Monitor (DIM) Measures dust falling onto a surface. SD2 (Drill, Sample, and Distribution subsystem) A drill-sampler capable of taking samples from a depth of up to 20 cm and delivering them to ovens for heating and to various devices for further analysis.

On August 6, the device performed a braking maneuver, equalized the speed of the comet and became its “honorary escort.” “Rosetta creates curved triangles while positioned approximately 100 km from the comet on the solar side to capture all the details of its illuminated surface,” explains Frank Budnik, the mission’s flight dynamics specialist. “On each side of this triangle, the device drifts for three to four days, then the flight direction changes with the help of engines. The trajectory is slightly bent by the comet's gravity, and thanks to this we can calculate its mass in order to later transfer the device to a stable low orbit. At the same time, Rosetta will become the first artificial satellite of a comet in history.”

Key in your pocket

Mission Rosetta is named after the Rosetta Stone, a stone tablet found in 1799 by a French officer in Egypt. The same text is engraved on the tablet - in the well-known ancient Greek language, ancient Egyptian hieroglyphs and Egyptian demotic script. The Rosetta Stone served as the key through which linguists were able to decipher ancient Egyptian hieroglyphs. Since 1802, the Rosetta Stone has been kept in the British Museum. The Philae lander was named after the Egyptian island of Philae, where a surviving obelisk with inscriptions in ancient Greek and ancient Egyptian was found in 1815, which (along with the Rosetta Stone) helped linguists in deciphering. Just as the Rosetta Stone provided the key to understanding the languages of ancient civilizations, which made it possible to reconstruct events thousands of years ago, its cosmic namesake, scientists hope, will provide the key to understanding comets, the ancient “building blocks” of the solar system, which began 4.6 billion years ago.

Reconnaissance from orbit

But entering the comet's orbit is only the first stage, preceding the most important part of the mission. According to the plan, until November, Rosetta will study the comet from its orbit and also map its surface in preparation for landing. “Before arriving at the comet, we knew quite little about it, even its shape - a “double potato” - became known only after getting to know it closely,” Stefan Ulamek, head of the Philae landing team, tells Popular Mechanics. — When choosing a landing site, we are guided by a set of requirements. Firstly, it is necessary that the surface is, in principle, reachable from the orbit in which the device will be located. Secondly, you need a relatively flat area within a radius of several hundred meters: due to currents in the gas cloud, the device can be blown to the side during a rather long (up to several hours) descent. Thirdly, it is desirable that the lighting at the landing site changes and day gives way to night. This is important because we want to study how the comet's surface behaves under this change. However, we are also considering options for purely “daytime” places. We are lucky in that the comet’s nucleus rotates stably around one axis, this makes the task much easier.”

Very soft landing

Once the landing site is selected, the main event will take place in November - the 100-kg Philae module will separate from the vehicle and, releasing three legs, will make the first-ever landing on the nucleus of a comet. “When we started this project, we had absolutely no idea about many of the details of the process,” says Stefan Ulamek. “No one has landed on a comet before, and we still don’t know what its surface is like: whether it’s hard like ice, or loose like freshly fallen snow, or something in between.” Therefore, the lander is designed to stick to almost any surface. After separating from the Rosetta spacecraft and reducing its orbital speed, the Philae module will begin its descent to the comet under the influence of its low gravity, after which it will land at a speed of approximately 1 m/s.

An image of comet 67P/Churyumov-Gerasimenko taken on August 16 by the OSIRIS camera with a long lens from a distance of 100 km. The size of the comet's nucleus is 4 km, so the image resolution is approximately 2 m per pixel. Using a series of images of the comet, scientists have already identified five possible landing sites. The final choice will be made later.

At this point, it is very important to prevent the device from “bouncing” and to secure it to the surface of the comet, and several different systems are provided for this. The shock when touching the landing supports will be dampened by the central electrodynamic shock absorber, at the same moment the nozzle on the upper end of Philae will start working, the jet thrust from the release of compressed gas will press the device to the surface for several seconds while it throws two harpoons - the size of a pencil - on cables. The length of the cables (about 2 m) should be enough to hold the harpoons securely, even if the surface is covered with a layer of loose snow or dust. On three landing supports there are ice screws, which will also be screwed into the ice during landing. All these systems have been tested on the German Space Agency's (DLR) landing simulator in Bremen on both hard and soft surfaces, and we hope that they will not fail in real conditions.”

But that will come a little later, but for now, as Mark McCaurian, senior scientist at the ESA Directorate for Automated Research, says, “We are like children who have been in a car for ten years and now have finally arrived at Science Disneyland, where in November we The most exciting attraction awaits."

Editor's note: up-to-date information about landing is available here.