During its mission, the device made 293 revolutions around Saturn, among which it performed 162 passes near its satellites and discovered 7 new ones, transmitted 453,048 photographs to Earth as part of 635 GB of scientific data and became a source for 3,948 scientific publications. He discovered the ocean on Enceladus, as well as the ocean, 3 seas and hundreds of small lakes on Titan. About 5 thousand people from 27 countries participated in this project, and its total cost was $3.9 billion, in which the initial shares were distributed as follows: $2.6 billion from NASA, $500 million from the European ESA and $160 million from Italian ASI.
Cassini design
Cassini-Huygens apparatus in the process of testing. The round orange part in the foreground is Huygens landing on Titan, the white part is the 4m Cassini antenna/radar
Diagram of the device from different angles:
The probe, named after Giovanno Cassini (who discovered the 2nd to 5th satellites of Saturn), is as much as 6.8 m high and 4 m wide with a dry weight of 2150 kg (it was the third largest interplanetary probe after a pair of Soviet "Phobosov"). Saturn reaches only 1.1% of the solar energy available to us in Earth orbit, so the probe is powered by 3 RTGs of the same huge size as the device itself - they have 32.7 kg of plutonium-238 (this is 3.6 times more than it was both Voyagers at the start, 6.8 times more than Curiosity has and apparently the most plutonium available to NASA at the moment:,). The device has 1630 separate electronic components and 22 thousand wired connections with a total cable length of 14 km, and is controlled by duplicated 1750A 16-bit computers (another one controlled the Titan IV launch vehicle that put the device into orbit). Scientific equipment includes 12 instruments grouped into three groups, which are designed for 27 separate scientific studies:
Optical range sensors:
1) Composite infrared spectrometer, including cameras of 3 ranges (CIRS); 2) wide-angle and narrow-angle (33 cm in diameter) cameras of the visible range with a set of several filters for different colors and CCD matrices with a resolution of 1024x1024 pixels. (ISS); 3) ultraviolet spectrometer, including 4 telescopes (UVIS); 4) a mapping spectrometer of the visible and infrared range, which breaks the light it sees into 352 spectral sections (VIMS);
Sensors of magnetic fields and charged particles:
Radio wave sensors:
11) a 4-meter diameter radar designed for mapping satellites of Saturn (Radar); 12) scientific radio subsystem, which consists in using the main 4-meter antenna to observe Saturn, its rings and satellites through radio waves (RSS). The signal delay at Saturn is 68-84 minutes one way.
Through thorns to Saturn
The weight of the orbital and landing probes was too large to be directly launched to Saturn (with 350 kg of Huygens, the total weight of the apparatus was 2.5 tons) - even taking into account the fact that the Titan IV on which Cassini-Huygens flew had a 40% greater useful load than the Titan IIIE on which the Voyagers flew. Therefore, the vehicles had to wander a lot around the solar system, picking up speed with gravitational maneuvers to meet Saturn: after the launch on October 15, 1997, a 5.7-ton bundle of two vehicles filled with 2978 kg of fuel went to meet Venus. Having performed 2 gravitational maneuvers on April 26, 1998 and June 24, 1999 (in which they flew only 234 and 600 km from the planet, respectively), on August 18, 1999 they returned briefly to Earth (flying 1171 km from us) after which went to Jupiter.
A picture of the Moon taken by the narrow-angle camera of the device in the near ultraviolet, from a distance of about 377 thousand km and a shutter speed of 80 μs.
Flying through the asteroid belt, the device met on January 23 with the asteroid Mazursky: unfortunately, the distance was 1.6 million km, and the asteroid itself was only 15x20 km in size, so the photo was less than 10 by 10 pixels. On December 30, 2000, Cassini-Huygens met with Jupiter and his brother - Galileo, whose mission was already approaching the final (he completed his mission almost 14 years ago with the same selfless feat that Cassini is now going to accomplish). This 4th gravity assist finally gave the two spacecraft enough speed to meet Saturn on July 1, 2004, by which time it had already traveled 3.4 billion km.
In order not to waste time, the mission team used the radio antennas of the apparatus to clarify the Shapiro effect (slowing down the propagation of a radio signal when it moves in the gravitational field of a heavy object). The measurement accuracy has been increased from previous results of 1/1000 for the Vikings and Voyagers to 1/51000. Published on October 10, 2003, the results completely coincided with the predictions of the general theory of relativity.
The graph clearly shows the peaks of encounters with planets (after which the apparatus increases speed), a long descent with a slight break at Jupiter (when the apparatus flew to meet Saturn, gradually exchanging kinetic energy for potential, getting out of the "gravitational well" of the Sun), and a series waves at the end (when the device entered the orbit of Saturn, and began to rotate in its orbit).
The long-awaited meeting and the main mission
On May 27, 2004, for the first time since December 1998, Cassini turned on its main engine to give the device an impulse of 34.7 m / s, which was needed to correct the trajectory that took it on June 11 at 2068 km from Phoebe, a very distant satellite of Saturn, which presumably formed in the Kuiper belt and was subsequently captured by the gravitational pull of Saturn. Due to the huge radius of the orbit of this satellite (averaging about 12.5 million km), this was the only meeting of Cassini with this satellite.On July 1, the main engine of the device was turned on again (for 96 minutes) to drop 626 m / s of speed to enter Saturn's orbit. On the same day, Methone was discovered and Pallena was rediscovered, which was discovered on another of the Voyager-2 images, but since it was not on the other images, the orbit of the celestial body could not be established and for 25 years it received the designation S / 1981 S 14. The very next day, Cassini completed the first flyby of Titan, on October 24 another satellite (Polideucus) was discovered, and on December 24 the Huygens landing probe was dropped.
On January 14, 2005, Cassini acted as a repeater for the landing probe (which will be discussed below), and the next day the device got as close as possible to Titan and, using its radar, discovered a 440-kilometer crater on its surface. On May 6, the satellite Daphnis was discovered, which lives on the edge of the Keeler gap:
At the edges of the 42-kilometer gap, waves were detected caused by the very weak attraction of Daphnis (whose weight is only 77 billion tons, which creates an attraction 25-100 thousand times lower than the earth):
Saturn's equator and the plane of its rings are tilted 27° relative to the ecliptic, so that we can observe both poles of Saturn as well as observe its rings from above and below. But since they are observed at a large angle and from great distances (1.2-1.66 billion km, depending on the relative position of the Earth and Saturn) - it was simply impossible to see anything there, so let's say Saturn's hexagon - only passing Voyagers.
Natural color photograph of Saturn, consisting of 36 Cassini images taken on January 19, 2007 with three filters (red, green and blue). The exposure of the images was made with the expectation that the dark areas of the rings would be visible, so the surface of Saturn turned out to be very overexposed.
In 2005, it was found that about 250 kg of water vapor leaves it every second through the geysers of Enceladus at a speed of up to 600 m / s. In 2006, scientists managed to establish that they are the source of material for the penultimate and widest - the E ring.
On July 22, 2006, the spacecraft flew over the northern latitudes of Titan, and for the first time dark areas were detected on the radar map made by the spacecraft, indicating that methane lakes are located on the surface in these places. During the 127 flybys of this satellite, many sections of its surface were studied in detail, on some of which dynamic changes were observed. Among these was the Ligeia Sea, which has dimensions of 420x350 km and an average depth of about 50 m with a maximum of more than 200 m (the maximum depth recorded by the radar):
Waves, solids below or above the surface, or bubbles in the liquid column (which affect the reflectivity of the surface) are considered the most likely cause of such measurements.
On May 30, 2007, the 2-kilometer Anfa satellite was discovered, and on September 10, the device passed only 1600 km from Iapetus, but already when transmitting images, a cosmic ray particle got into the computer of the device, which caused it to switch to safe mode. Luckily, no pictures were lost. Shortly before this event, Arthur Clarke received a video congratulation on this event (according to one of his most famous novels - "2001: A Space Odyssey" - one of the monoliths was on the surface of Iapetus).
Video greeting and its translation
Hello! This is Arthur Clark joining you from my home in Colombo, Sri Lanka.
I am delighted to be a part of this Cassini flyby of Iapetus.
I send my greetings to all the friends - famous and unknown - who have gathered for this important occasion.
I am sorry that I cannot be with you as I am wheelchair bound with polio and do not plan to leave Sri Lanka again.
Thanks to the World Wide Web, I have been able to follow the progress of the Cassini-Huygens mission since its launch a few years ago. As you know, I have more than just an interest in Saturn.
And I was really scared in early 2005 when the Huygens probe transmitted sound recordings from the surface of Titan. This is exactly what I described in my 1975 novel Earth Empire, where my character listens to the winds blow over the desert plains.
Perhaps it was a foretaste of the future! On September 10, if all goes according to plan, Cassini will take our closest look at Iapetus, one of Saturn's most interesting moons.
Half of Iapetus is dark as asphalt, while the other half is light as snow. When Giovanni Cassini discovered Iapetus in 1671, he could only see the bright side. We took our best glimpse when Voyager 2 flew past it in August 1981 - but that was almost a million kilometers away.
On the other hand, Cassini is about to pass a little more than a thousand kilometers from Iapetus.
This is a particularly exciting moment for fans of 2001: A Space Odyssey - because the monolith of Saturn discovered by lone astronaut David Bowman has become a gateway to the stars.
The 35th chapter of the novel, titled "The Eye of Iapetus", contains the following passage:
The Discovery approached Iapetus so slowly that movement was hardly felt and it was impossible to notice the moment when a subtle change took place and the cosmic body suddenly became a landscape some eighty kilometers below the ship. Reliable verniers gave the last correcting shocks and fell silent forever. The ship entered its last orbit: the turnaround time is three hours, the speed is only one thousand three hundred kilometers per hour. Greater speed in this weak gravitational field was not required. "Discovery" became a satellite of the satellite.Over 40 years later, I can't remember why I placed the Saturn monolith on Iapetus. In those days of the beginning of the Space Age, ground-based telescopes could not see the details of this celestial body. But I have always had a strange fascination with Saturn and its family of moons. By the way, this “family” grew at a very impressive pace: when Cassini was launched, we only knew about 18 of them. I understand that there are now 60 of them, and their number continues to increase. I can't resist the temptation to say:
My God, it's full of satellites!
However, in the film, Stanley Kubrick decided to place all the action in the Jupiter system, not Saturn. Why such a change? Well, on the one hand, it made the plot more straightforward. More importantly, the special effects department was unable to produce a model of Saturn that Stanley found convincing.
It was done right, because otherwise the film would have become obsolete with the flyby of the Voyager mission, which presented the rings of Saturn in a way that no one could even imagine.
I have seen many examples of Neptune depicted in art, so I will keep my fingers crossed as Cassini flies past Iapetus.
I want to thank everyone involved with the mission and the whole project. It may lack the glamor of manned spaceflight, but the science project is vital to our understanding of the solar system. And who knows - maybe one day our survival on Earth will depend on what we find there.
This is Arthur Clarke, I wish you a successful flight.
Map of Iapetus with a resolution of 400 m per pixel (original 5 MB):
Approximately 40% of the surface of this satellite is occupied by dark regions with an albedo 10 times smaller than light regions. Now the source of such a big difference is considered to be the effect of the separation of dust and ice, when ice evaporates from dark areas and is deposited on light areas, thereby light areas become even lighter and dark areas darker. The reason that the rest of the satellites behave "normally" is that they have a shorter day, during which the surface does not have time to warm up enough.
Extension and mission "Cassini - Equinox"
On July 1, 2008, an extended 27-month Cassini mission began, which included 21 additional flybys of Titan, 8 Tethys, 7 Enceladus, 6 Mimas and one each of Dione, Rhea and Helena.On August 15, 2008, Aegeon was discovered, which, although it was named after a monster with 100 arms and 50 heads, was an almost harmless "pebble" 500 m in diameter (it was so small that its dimensions had to be set in brightness, so the exact we do not know the shape of this satellite). And on October 9, Cassini performed his most dangerous maneuver - flying just 25 km from Enceladus (and this at a speed of 17.7 km / s!). The mission team took such a risky step for the sake of direct analysis of the composition of the water vapor of its geysers.
During its 23 flybys of Enceladus during the entire mission (in 10 of which the device approached at a distance of less than 100 km), it was found that the subsurface ocean is 11-12 units (which is unsuitable for terrestrial life forms), but in secretions of geysers were also found nitrogen (4±1%), carbon dioxide (3.2±0.6%), methane (1.6±0.6%) as well as traces of ammonia, acetylene, hydrocyanic acid and propane (which speaks of the active formation of organic substances under the surface of Enceladus). Unfortunately, the device does not contain special instruments for registering complex organics (since it was not even possible to assume that the device was found during the mission planning), so the answer to the question “is it possible that life exists under the surface of Enceladus?” Cassini left for his followers.
By July 26, 2009, the last of the satellites discovered by Cassini was discovered - the 300-meter S / 2009 S 1, which was discovered due to the 36-kilometer shadow that it casts on the far edge of the B ring along which its orbit lies:
Second extension and Cassini Solstice mission
In February 2010, a decision was made on an additional extension of the mission, which began already in September, and was supposed to last until May 2017, when the final fate of the device was to be decided. It included 54 more flybys of Titan and 11 flybys of Enceladus.The efforts of Cassini and his team, who managed to obtain an additional allocation of about $ 400 million for the next 7 years of the mission (brought the cost of the program to almost $ 4 billion) were not in vain: already in December 2010, during the passage of Enceladus, the apparatus established the presence of an ocean under the north pole (later it was found that the ocean is not limited to the polar region). In the same year, the Great White Spot reappeared on the surface of Saturn - a huge storm that appears in the atmosphere of Saturn approximately every 30 years (Cassini was very lucky with this, and he managed to register such storms twice - in 2006 and 2010). On October 25, 2012, the device recorded a powerful discharge inside it, which raised the temperature of the stratospheric layers of the atmosphere by 83 ° C above normal. Thus, this vortex became the hottest among the storms in the solar system, bypassing even the Great Red Spot of Jupiter.
"The Day the Earth Smiled"- a project organized on July 19, 2013 by the head of the Cassini imaging team, during which Cassini took a picture of the entire Saturn system, which also included the Earth, Moon, Venus and Mars. A total of 323 photographs were taken, of which 141 were further used to compile the mosaic:
The earth is in the lower right corner, and the original without signatures is (4.77 MB).
At the same time, NASA launched a campaign "Wave to Saturn" during which 1,600 photographs were collected, from which a mosaic was assembled on November 12, which appeared on the cover of the New York Times on the same day (carefully, the original weighs 25.6 MB):
From 2012 to 2016, the device recorded changes in the color of the Saturn hexagon (photos from 2013 and 2017, original 6 MB):
"Huygens"
The landing probe, named after Christian Huygens (discoverer of Titan in 1655, on which the probe landed), is a 318-kilogram apparatus with a diameter of 2.7 meters with 6 sets of instruments:
1) a constant frequency transmitter designed to measure wind speed using the Doppler effect (Doppler Wind Experiment - DWE);
2) sensors of the physical properties of the atmosphere that measure the density, pressure and electrical resistance of the atmosphere, as well as acceleration sensors in all three axes, which, together with the previous device, set the density of the atmosphere (Huygens Atmospheric Structure Instrument - HASI);
3) cameras of the visible and infrared spectra, in parallel with obtaining images, measuring the spectrum and illumination at the current altitude of the device (Descent Imager / Spectral Radiometer - DISR);
4) an aerosol particle pyrolyzer that heats samples taken from two different heights and redirects them to the next device (Aerosol Collector and Pyrolyser - ACP);
5) gas chromatography-mass spectrometer measuring the composition and concentration of individual components of the atmosphere of Titan, and at the last stage - also the upper layer of soil evaporated by the heater (Gas Chromatograph Mass Spectrometer - GCMS);
6) a set of instruments for measuring surface properties, which include an acoustic sensor that measures the density / temperature of the atmosphere in the last 100 m of descent according to the properties of the sound reflected by the surface (Surface-Science Package - SSP).
Huygens separated from Cassini on December 24, 2004, and by January 14 had reached Titan's atmosphere. The descent in the atmosphere took 2 hours and 27 minutes, during which the thermal protection of the apparatus and its three parachutes came into action sequentially, and after landing, it transmitted data from the surface for another 72 minutes (until the Cassini probe, which acted as a signal repeater, went beyond the horizon).
International cooperation of the Huygens probe
"Grand Finale"
In May 2017, the further fate of the device was decided: by the end of the second extended mission, it had very little fuel left, and 19 possible options for completing the mission were considered, among which were a collision with Saturn, its main rings or icy satellites, removal from Saturn's orbit to a heliocentric an orbit or a stable orbit around Titan/Phoebe (and even the possibility of a collision with Mercury). As a result, it was decided to send the apparatus into the atmosphere of Saturn in order to protect Saturn's satellites from their possible biological contamination. To accomplish this task, the device performed a maneuver near Titan on April 22, which redirected it into a 2000-kilometer gap between Saturn and its nearest ring.Since then, it has made 21 orbits at a distance of only 1600-4000 km from the Saturian clouds, all the while approaching the atmosphere of Saturn, and is currently on its last 22nd orbit. The spacecraft will take its last pictures before re-entry, after which it will turn its 4-meter antenna towards Earth, and will transmit data on the composition of the Saturnian atmosphere from its spectrometers until it can fend off atmospheric disturbances. Soon after the loss of communication with it, it will collapse and burn out in the dense layers of the atmosphere of Saturn - somewhere there, in the constellation Ophiuchus, 1.4 billion km from us.
Mankind has always sought to find out what is there, beyond the unknown. To study Saturn and its satellites, the Cassini spacecraft was built and launched on October 15, 1997, which had the Huygens descent probe on board ( Huygens). It was a joint brainchild of NASA, the European and Italian space agencies. The main mission of the device was: to reach the Saturn system, go into orbit, calculate the optimal trajectory for rendezvous with Titan. The Huygens descent probe was then to make a soft landing on Titan.
Cassini successfully completed its mission, arriving in the Saturn system on July 1, 2004, and on December 25 of the same year shot Huygens, who passed through the atmosphere of Titan, transmitting a lot of interesting scientific data along the way and landed on the surface of the satellite. From the surface of Titan, Huygens transmitted a large amount of interesting scientific data, photographs in various ranges, and analyzed the substance of the satellite.
(Shot from Cassini: Saturn's large moon Titan against the background of the planet, the rings of the giant planet are especially clearly visible)
The apparatus itself is used by scientists to study Saturn, its magnetosphere, rings, and the distribution of matter in them. Initially, the device was planned to operate for about four years, then its service life was extended twice. By decision of NASA, the work of the space probe was extended until 2017, during which time it will study both Saturn and Titan itself with its sensors and sensors, and will pass near Enceladus, famous for its amazing ice geysers.
(Cassini filmed the transit of Saturn's moon Enceladus in front of the larger moon Dione, showing the amazing beauty of Saturn's outer ring in the foreground)
The work of the probe will allow us to examine the rings of the planet from different angles, more accurately determine their mass, and thoroughly study the structure of the gas giant, its magnetosphere. According to Jim Green, Cassini transmitted so much information to Earth that it revolutionized the human understanding of Saturn, its satellites, and the gas giants in general.
(Unique video transmitted by Cassini: depiction of a thunderstorm on the surface of the planet Saturn, the sounds of lightning flashes transmitted by radio frequencies are also heard. Unlike terrestrial thunderstorms, on Saturn they do not occur simultaneously and only once a year, while their strength is much more significant than on Earth, and duration up to several months)
The work of the probe until 2017 will allow scientists to get a complete picture of seasonal changes in the structure of the planet. The probe will then self-destruct, plunging into Saturn's dense atmosphere by September 2017.
For the past 13 years, the Cassini spacecraft has been silently changing our understanding of the solar system. The Cassini mission, a $3.62 billion joint project between NASA and the European Space Agency, was to study the gas giant Saturn and its many moons. But tomorrow this mission will come to its literally burning end. On Friday at 7:55 pm ET, the Earth will stop receiving data from Cassini as the device will fall at the speed of a meteor into Saturn's atmosphere and will be purposefully destroyed. Astronomers have been preparing for this moment for many years.
All of the spacecraft's instruments are still working fine, but the long mission has used up nearly all of the propellant needed to correct the probe's orbital path around Saturn. But instead of just letting the craft get out of control and possibly crash somewhere else, the mission control team programmed the probe's computer to re-enter Saturn's atmosphere in order to save the planet's moons and any likely life forms on them.
Despite all the merits of this spacecraft, Cassini, so to speak, has always been an outsider. Its mission has not been as spectacular as the New Horizons mission that flew past Pluto, or any other Mars-related mission, where the US agency has sent more than one lander and rover over the past couple of decades. Saturn-related topics rarely made headlines. However, the lack of hype in no way diminished the degree of scientific importance of the discoveries made by Cassini.
If we discard the formalities, then it began on October 15, 1997, when Cassini was launched into Earth orbit aboard the Titan IVB / Centaur launch vehicle. The launch was joint - the launch vehicle also put into orbit the Huygens probe, built by the European Space Agency. This vehicle was designed to land on Saturn's largest moon Titan, from where it could transmit scientific data to researchers on Earth.
The launch was not without incident. There were people who protested against the launch of Cassini for fear of contamination of the environment by plutonium fuel, on the basis of which the spacecraft is powered. Before the launch of Cassini, physicist Michio Kaku stated that if the launch fails and the rocket explodes, radioactive material will rain down on people near the launch complex. NASA and government agencies were quick to assure everyone that such a situation was simply impossible. Fortunately, in the end, the launch did indeed pass without any problems.
Two spacecraft arrived at Saturn 7 years after they were launched from the launch complex at Cape Canaveral. Huygens landed on Titan on January 14, 2005. Since then, Cassini has made many orbits around the planet and its moons. Thanks to him, we got the opportunity to take a fresh look at this system, to understand the features of the rings of the planet.
satellites
From the giant Titan to the tiny moon Daphnis, Cassini's observations have revealed a lot about the moons of this giant ring planet. Saturn and its moons can literally be viewed as a miniature solar system.
Epimetheus
Elena
Hyperion
Mimas, a moon similar to the Death Star
Pandora
Titan and Tethys (foreground)
Daphnis creating waves inside Saturn's rings
Pan (similar to a dumpling)
Top 5 Cassini discoveries
It is difficult to enumerate all the contribution to planetary science that Cassini has made over the 13 years of its mission, but it is not at all difficult to understand how much this mission means to scientists on Earth. Below are just a few of the most important discoveries made by this probe in more than a decade of its operation.
Geysers on Enceladus
Cassini not only spotted, but flew through the ejecta of liquid water shot into space from the subsurface ocean of Enceladus. The discovery was amazing. The moon's ocean may well have the right chemistry for life, making it one of the most desirable targets for finding extraterrestrial life inside the solar system.
Titan's "Earth-Like" Environment
By watching Titan, we were able to learn more about ourselves. Exploration of one of Saturn's largest moons has revealed to us the complex world of lakes of liquid methane and dunes of hydrocarbons. To the untrained observer, Titan may appear similar to Earth, but it is clearly an alien planet, providing a perfect example of the diversity among planetary bodies.
Many moons of Saturn
Until Cassini was sent to Saturn in 1997, scientists only knew about the existence of 18 moons orbiting the ring giant. While the spacecraft has been moving towards this planet for seven years, the researchers have discovered 13 more satellites. However, today, thanks to Cassini, we were able to find out that Saturn is the "father" of as many as 53 satellites.
Saturn Hexagonal Storm
Cassini has captured some truly impressive images of Saturn over the course of its history, but perhaps the most impressive yet unique are the photographs of the planet's poles. We were able to see in detail the hexagonal flow of atmospheric currents surrounding a powerful storm raging at the north pole of Saturn. According to NASA, the area of this hurricane is 50 times larger than the area of the average hurricane on Earth.
Empty space between the rings of Saturn
Before the climax of the mission, Cassini took a position between the planet's rings and Saturn itself. And as it turned out, it is incredibly calm here. Instead of the expected swirls of dust darting between the planet and the rings, Cassini has found absolutely empty space as part of its latest orbital flybys.
A mission to be missed
Although, as noted above, the Cassini mission was not as bright as the Martian ones, it proved to be very useful for modern astronomy. Each month, the probe sent truly unique, never-before-seen images and new scientific data back to Earth. Many aspiring astronomers have built their careers around this data.
Completion of the mission will be a real loss for the scientific and pseudo-scientific community. Especially given the fact that, apart from the probe that will study Jupiter's moon Europa, NASA and other space agencies have no plans, at least in the visible future, to continue studying the horizons of the distant worlds of the solar system like Saturn, Neptune and Uranus.
Saturn, one of Cassini's last "masterpieces"
A number of studies of Saturn were started by Pioneer 11, an American-made interplanetary station, in 1973, and continued by two Voyagers.
Thanks to these expeditions, a lot of things were found out about Saturn, its rings and satellites, but the main thing did not work out: to see what it is like, the surface of this mysterious planet. Despite the many photographs and new data received, it was soon decided that it was necessary to start a new project that would allow us to look at this space object from a new perspective. Such a project was the mission of two vehicles - Cassini and Huygens.
Exploring Saturn: The Cassini-Huygens mission cost America a pretty tidy sum of about three billion dollars, but it was worth it. Its construction, development and equipment were carried out by very well-known organizations in the circles of space explorers.
As a result, a device was obtained with a height of 10 meters and a starting weight of 6 tons with 12 scientific instruments on board, a rod of 11 meters for a magnetometer and wiring, whose total length is about fourteen kilometers.
To communicate with the Earth, the Italians created a special antenna four meters long. The device, however, does not use solar panels, which is understandable: for Saturn it is meaningless. Instead, the role of energy tanks is performed by three thermoelectric and radioisotope generators, which contain 33 kilograms of extremely radioactive plutonium, thanks to which the apparatus can operate for about two hundred years.
It's also worth noting that half of Cassini's launch weight is nothing more than fuel, which is needed for deceleration, Saturn orbit, and many other special maneuvers.
Huygens
This device is nothing more than a probe, whose task was to land on Saturn's moon - Titan. Its equipment includes as many as six instruments that allow the most detailed study of the surface of the satellite, and a landing camera, which should capture as many landscapes as possible of a little-studied object. This probe weighs about 350 kilograms and is an addition to the Cassini: their destinations are very close to each other.
Views of Saturn and its moons from Cassini
Flight
The launch of Cassini and the Huygens attached to it took place in 1997 on October 15. To launch the device into space, a special, special launch vehicle "Titan-4B" and an additional booster unit called "Centaur" were needed. For many reasons (there is no direct road to any of the galaxies), Venus became Cassini's original direction.
In order to accelerate, the device used the gravitational fields of three planets for two years. However, before meeting with the planet - the destination - he was in a kind of suspended animation: all his systems were used only a couple of percent. And so, in the winter of 2000, Cassini finally passed Saturn, activated and took its first pictures depicting the Giant in a similar lunar first quarter, which is almost impossible to see from Earth.
True, before getting as close as possible to the majestic Saturn, Cassini passed by its no less mysterious satellite, Phoebus, whose images were transmitted to Earth. They turned out to be a real sensation: for the first time this object was considered so well. The photographs showed that Phoebus is very similar to an asteroid, that it has an irregular shape, that its dimensions are about two hundred kilometers. It has also been found that this moon is mostly made of ice, which strongly resembles Charon, which means that Phoebus is much closer in structure to comets than to asteroids. This discovery definitely brings humanity closer to unraveling most of the mysteries of the Saturn system.
The most important milestone for Cassini was, of course, the entry into orbit of the Giant. It took place with the help of a special braking maneuver on July 1, 2004. At that time, he even managed to pass between two rings (F and G). Having encountered obstacles several times, but remaining without significant damage, the device approached Saturn as close as possible and ended up in its orbit. After this achievement, Cassini had to make 74 revolutions around the planet over the course of four years, overcoming a huge distance equal to 1.7 billion kilometers, and studying both the surface of Saturn and its moons. Among the latter, special attention is definitely paid to Titan - it was decided to make 45 revolutions around it.
Achievements
Among all the achievements that have been achieved thanks to Cassini and Huygens, one can highlight not only a fairly detailed survey of the surface of Saturn, but also of its many satellites: Mimas, Rhea, Phoebe, Titan, Tethys, Dione and Hyperion, as well as Epimetheus . But this is not the end: the Cassini expedition will continue until 2017, which will allow us to learn much more about the Saturn system.
