The probe floats in an icy void. Three years have passed since its launch at Baikonur and a long road stretches behind for a billion kilometers. The asteroid belt has been safely crossed, the fragile instruments have withstood the severe cold of world space. And ahead? Terrible electromagnetic storms in the orbit of Jupiter, deadly radiation and a difficult landing on the surface of Ganymede - the largest of the satellites of the gigantic planet.
According to modern hypothesis, under the surface of Ganymede lies a huge warm ocean, which is possibly inhabited by the simplest forms of life. Ganymede is five times farther from the Earth, the 100-kilometer layer of ice reliably shelters the "cradle" from the cosmic cold, and the monstrous gravitational field of Jupiter continuously "shakes" the core of the satellite, creating an inexhaustible source of thermal energy.
The Russian probe is to make a soft landing in one of the canyons on the icy surface of Ganymede. In a month, he will drill ice to a depth of several meters and analyze samples - scientists hope to establish the exact chemical composition of ice impurities, which will give some idea of the internal structure of the satellite. Some believe that it will be possible to find traces of extraterrestrial life. An interesting interplanetary expedition - Ganymede will become the seventh celestial body *, on the surface of which earth probes will visit!
"Europe-P" or the technical side of the project
If the words of Deputy Prime Minister Rogozin about the "lunar landing" of the International Space Station can be regarded as a joke, then last year's statement by the head of Roscosmos Vladimir Popovkin about the upcoming mission to Jupiter looks like a serious decision. Popovkin's words completely coincide with the opinion of the director of the Institute of Space Research of the Russian Academy of Sciences, Academician Lev Zeleny, who back in 2008 announced his intention to send a scientific expedition to Jupiter's icy moons - Europa or Ganymede.
Four years ago, in February 2009, an international agreement was signed to start the Europa Jupiter System Mission comprehensive study program, in which, in addition to the Russian interplanetary station, the American JEO, the European JGO and the Japanese JMO station will go to Jupiter. It is noteworthy that Roskosmos chose for itself the most expensive, complex and most important part of the program - unlike other participants who are preparing only orbiters for the study of four "large" satellites of Jupiter (Europa, Ganymede, Callisto, Io) from space, the Russian station should make the most difficult maneuver and gently "land" on the surface of one of the selected satellites.
Russian cosmonautics is heading for the outer regions of the solar system. It is too early to put an exclamation mark here, but the mood itself is encouraging. The reports from the depths of space look much more interesting than the reports from the French Riviera, where some Russian officials frolic on vacation.
As in any ambitious project, in the case of the Russian probe for studying Ganymede, there is a lot of skepticism, the degree of which ranges from competent and justified warnings to outright sarcasm in the style of "replenishment of the Russian orbital group at the bottom of the Pacific Ocean."
The first and, perhaps, the simplest question: why does Russia need this super-expedition? Answer: if we were always guided by such questions, humanity still sat in caves. Cognition and mastery of the Universe - this, perhaps, is the main meaning of our existence.
It is too early to expect any concrete results and practical benefits from interplanetary expeditions - just as it is to demand that a three-year-old child earn his own living independently. But sooner or later a breakthrough will happen and the accumulated knowledge about distant cosmic worlds will definitely come in handy. Perhaps tomorrow the space "gold rush" will begin (adjusted for some Iridium or Helium-3) and we will have a powerful incentive to master the solar system. Or maybe we will stay on Earth for another 10,000 years, unable to step into outer space. Nobody knows when this will happen. But this is inevitable, judging by the fury and indomitable energy with which a person changes new, previously uninhabited territories on our planet.
The second question, related to the flight to Ganymede, sounds more harsh: is Roscosmos capable of conducting an expedition of this magnitude? After all, neither Russian nor Soviet interplanetary stations have ever operated in the outer regions of the solar system. Domestic cosmonautics was limited to the study of the nearest celestial bodies. Unlike the four small "inner planets" with a solid surface - Mercury, Venus, Earth and Mars, the "outer planets" are gas giants, with completely inadequate sizes and conditions on their surfaces (and in general, do they have any then the "surface"? According to modern concepts, the "surface" of Yuriter is a monstrous layer of liquid hydrogen in the depths of the planet under pressure in hundreds of thousands of terrestrial atmospheres).
But the internal structure of gas giants is a trifle compared to the difficulties that arise in preparation for a flight to the "outer regions" of the solar system. One of the key problems is associated with the colossal remoteness of these regions from the Sun - the only source of energy on board the interplanetary station is its own RTG (radioisotope thermoelectric generator), fueled with tens of kilograms of plutonium. If such a “toy” were on board the Phobos-Grunt, the epic with the fall of the station to the Earth would have turned into a worldwide “Russian roulette” … Who would have got the “main prize”?
However, unlike the even more distant Saturn, solar radiation in Jupiter's orbit is still very sensitive - by the beginning of the 21st century, the Americans managed to create a highly efficient solar battery, which was equipped with the new interplanetary station Juno (launched to Jupiter in 2011). We managed to get rid of the expensive and dangerous RTG, but the dimensions of the three solar panels "Juno" are simply enormous - each 9 meters long and 3 meters wide. Complex and cumbersome system. So far, no official comments have followed what decision Roscosmos will make.
The distance to Jupiter is 10 times greater than the distance to Venus or Mars - therefore, the question arises about the duration of the flight and ensuring the reliability of equipment for many years of operation in open space.
Currently, research is being carried out in the field of creating highly efficient ion engines for long-distance interplanetary flights - despite their fantastic name, these are completely banal and rather simple devices that were used in the attitude control systems of Soviet satellites of the Meteor series. Principle of operation - a stream of ionized gas flows out of the working chamber. The thrust of the "super-motor" is tenths of Newton … If you put the "ion engine" on the small car "Oka", the car "Oka" will remain in place.
The secret is that, unlike conventional chemical jet engines, which develop enormous powers for a short time, the ion engine works quietly in open space during the entire flight to a distant planet. A tank of liquefied xenon weighing 100 kg is enough for tens of years of operation. As a result, after a few years the device develops a fairly solid speed, and given the fact that the speed of the outflow of the working medium from the nozzle of the "ion engine" is many times higher than the speed of the outflow of the working medium from the nozzle of a conventional liquid-propellant rocket engine, the prospects for the acceleration of spaceships open up before the engineers up to speeds of hundreds of kilometers per second! The whole question is with the presence on board a sufficiently powerful and capacious source of electrical energy to create a magnetic field in the engine chamber.
In 1998, NASA was already experimenting with an ion propulsion system aboard Deep Space-1. In 2003, the Japanese probe Hayabusa, also equipped with an ion engine, went to the asteroid Itokawa. Time will tell whether the future Russian probe will receive a similar engine. In principle, the distance to Jupiter is not as great as, for example, to Pluto, therefore, the main problem lies in ensuring the reliability of the probe equipment and its protection from cold and streams of cosmic particles. Let's hope Russian science will cope with this difficult task.
The third key problem on the way to distant worlds sounds short and concise: Connectivity
Ensuring a stable connection with an interplanetary station - this issue is not inferior in complexity to the construction of the "Tower of Babel". For example, the Voyager 2 interplanetary probe, which in August 2012 the probe left the solar system and is now floating in interstellar space, is heading towards Sirius, which it will reach in 296,000 Earth years. At the moment, Voyager 2 is located 15 billion kilometers from Earth, the transmitter power of the interplanetary probe is 23 W (like a light bulb in your refrigerator). Many of you will shake your head in disbelief - to see the dim light of a 23-watt light bulb from a distance of 15 billion kilometers … it's impossible.
However, NASA engineers regularly receive telemetry data from the probe at 160 bps. After a 14-hour delay, the Voyager 2 transmitter signal reaches Earth with an energy of 0.3 billionths of a trillionth of a Watt! And this is quite enough - the 70-meter antennas of NASA's long-range space communications centers in the USA, Australia and Spain confidently receive and decode the signals of space wanderers. Another frightening comparison: the energy of radio emission from stars, adopted for the entire existence of space radio astronomy, is not enough to heat a glass of water by at least a millionth of a degree! The sensitivity of these devices is simply amazing. And if a distant interplanetary probe chooses the right frequency and orients its antenna towards the Earth, it will certainly be heard.
Unfortunately, there is no ground infrastructure for long-distance space communications in Russia. The ADU-1000 "Pluto" complex (built in 1960, Evpatoria, Crimea) is capable of providing stable communication with spacecraft at a distance of no more than 300 million kilometers - this is enough for communication with Venus and Mars, but too little for flights to "external planets ".
However, the lack of the necessary ground equipment should not become an obstacle for Roscosmos - powerful NASA antennas will be used to communicate with the device in Jupiter's orbit. Still, the international status of the project obliges …
Finally, why was Ganymede chosen for the study, and not Europe, more promising in terms of searching for the subglacial ocean? Moreover, the project was originally designated as "Europe-P". What made Russian scientists reconsider their intentions?
The answer is simple and somewhat unpleasant. Indeed, it was originally intended to land on the surface of Europa.
In this case, one of the key conditions was the protection of the spacecraft from the impact of the radiation belts of Jupiter. And this is not a far-fetched warning - the Galileo interplanetary station, which entered Jupiter's orbit in 1995, received 25 lethal doses of radiation on its first orbit. The station was saved only by effective radiation protection.
At the moment, NASA has the necessary technologies for radiation protection and shielding of spacecraft equipment, but, alas, the Pentagon has banned the transfer of technical secrets to the Russian side.
We had to urgently change the route - instead of Europe, Ganymede was chosen, located at a distance of 1 million km from Jupiter. Getting closer to the planet would be dangerous.
