The surface area of the Red Planet is approximately 145 million square kilometers. Therefore, it is not difficult to imagine how difficult it is for scientists to determine the place for landing the next research vehicle on Mars. In the event that the main goal of the Martian expedition is to search for traces of the past, and possibly life existing on another planet, then the success of the entire expedition may depend on the choice of the landing site. This is precisely the task currently facing Roscosmos and the European Space Agency (ESA). In 2018, a joint project of specialists from two leading space agencies is to go to Mars - a rover called ExoMars.
It is reported that the rover will be equipped with a drill that will help it lift samples of Martian soil from a depth of 2 meters. Scientists hope that with the help of this apparatus they will be able to detect the presence of traces of microbial activity on the fourth planet from the Sun. Within the framework of the implementation of the joint Russian-European project for the exploration of Mars, it is planned both to carry out previously planned scientific research and to solve fundamentally new scientific problems. Important aspects of this project are the development, together with ESA, of a ground-based complex for receiving data and controlling interplanetary missions, as well as achieving the consolidation of the experience of European and Russian specialists in creating technologies for carrying out interplanetary missions. At the same time, the parties have the right to count on the ExoMars project as an important stage on the way to preparing the development of the Red Planet.
Back in 2012, Roskosmos became the main partner of the European Space Agency in the implementation of the ExoMars mission. One of the conditions for this cooperation was the full-fledged technical participation of the Russian side in the second stage of this mission. According to the agreements reached between Roscosmos and ESA, the Russian Federation will provide not only launch vehicles for both missions, but also some scientific instruments for them, and will also create a lander for the implementation of the second mission - ExoMars-2018. Engineers of the Lavochkin Scientific and Production Association will be engaged in the creation of the Mars landing module. At the same time, the Space Research Institute of the Russian Academy of Sciences (IKI RAS) became the main executor for the scientific component of this project on the part of Russia.
The first stage of the joint project called "ExoMars-2016" includes an orbital module being created by ESA, as well as a demonstration landing module. The orbital spacecraft TGO (Trace Gas Orbiter) is designed to study small gas impurities in the atmosphere and the distribution of water ice in the soil of the Red Planet. For this apparatus in Russia, the IKI RAS creates 2 scientific instruments: the FREND neutron spectrometer and the ACS spectrometric complex.
As part of the second stage of the project, the ExoMars-2018 mission, a landing platform (Russian development) and the ESA rover, weighing about 300 kilograms, will be delivered to the Martian surface with the help of a landing module created by Russian specialists from the Lavochkin Scientific and Production Association.
As a result, Russia will provide for this project:
1. Two launch vehicles "Proton-M".
2. A system for entering the atmosphere of the red planet, descent and landing of the rover on the surface in 2018. To minimize possible risks, Russia will be engaged in the development and construction of the "iron" part (that is, mechanical structures), and the electronic filling of the landing platform will be supplied mainly from Europe.
3. An orbital spacecraft called TGO will receive Russian scientific instruments, including those that were created for the failed Russian mission "Phobos-Grunt".
4. All scientific results of the joint expedition to Mars will become the intellectual property of Roscosmos and ESA.
A number of requirements were initially put forward for a potential landing site on the surface of Mars. For example, it was supposed to be an area of the Red Planet with a set of different geological characteristics, including the presence of ancient rocks, whose age exceeds 3.4 billion years. In addition, scientists are only interested in those areas in which the presence of large reserves of water in the past was previously confirmed by satellites. At the same time, much attention is paid to the safety of the landing process, since the future of the entire program may depend on this stage of the mission.
It should also take into account the fact that the Martian atmosphere is unstable, and it will not be possible to lower the device to a certain point. The landing platform will enter the Martian atmosphere at a speed of 20,000 km / h. The heat shield will have to decelerate the module to a speed 2 times the speed of sound. After that, 2 braking parachutes will slow down the descent module to subsonic speed. At the final stage of the flight, electronics will control the speed and distance to the Martian surface in order to turn off the rocket engines at the right time and put the descent vehicle into a controlled landing mode. At the same time, it is reported that the "Sky Crane" system, which was used for the arrival of the famous "Curiosity" on Mars, will not be used for landing.
The changing conditions at each stage of the descent lead to the fact that the zone of possible landing should represent an ellipse measuring 104 by 19 km. This circumstance almost immediately excludes from the list a number of potentially interesting locations for scientists, for example, Gale Crater, in which the NASA rover is currently operating. Since November 2013, leading scientists in the geography and geology of the Red Planet have been proposing their options for potential areas for landing.
Of these areas, only 8 were left, which preliminarily meet the strict requirements of scientists. At the same time, after a thorough analysis of these places, 4 of them were eliminated. As a result, the final list of landing sites for the rover included the Hypanis Vallis, Mawrth Vallis, Oxia Planum, and Aram Dorsum. All four locations are in the equatorial region of Mars.
In a press release from Jorge Vago, a participant in the ExoMars project, it is said that the modern Martian surface is hostile to living organisms, but primitive life forms could exist on Mars when the climate there was more humid and warmer - in the interval between 3, 5 and 4 billion years ago. Therefore, the landing site for the rover should be in an area with ancient rocks, where once it was possible to find liquid water in abundance. Four scientist-designated landing sites are best suited for mission purposes.
So, on the territory of the Morse Valley and the nearby Oksia Plateau, some of the oldest rocks emerge on the surface of Mars, whose age is 3.8 billion years, and the high clay content in this place indicates the presence of water here in the past. At the same time, the Morse Valley lies on the border of lowland and highlands. It is assumed that in the distant past, large water streams ran through this valley to lower areas. In addition, the results of the analyzes carried out have shown that the rock in these regions of the Red Planet has been eroded by oxidation and radiation for only the last several hundred million years. Until that time, the materials had been protected from the effects of a destructive environment for a long time and had to keep their bowels in good condition.
The Hypanis Valley may have once hosted the delta of a large Martian river. In the area, layers of fine-grained sedimentary rocks cover materials that have been stored here for 3.45 billion years. And the fourth place, the Aram ridge, got its name from the winding channel of the same name; along the banks of this channel, sedimentary rocks could reliably hide evidence of past Martian life. The final decision on the choice of the landing site for the rover will be made only in 2017.
