Mikhail Kotov — about the interplanetary missions of Russia and other countries to the second planet from the Sun
The Venera-7 automatic interplanetary station set off from the Baikonur cosmodrome to Venus 55 years ago, on August 17, 1970. Less than four months later, the Venus-7 lander carried out the first ever data transfer after a soft landing on the surface of another planet.
The exploration of Venus is one of the most glorious pages of Russian cosmonautics. What about now? And when will the new assault on this planet begin?
Not on the first try
Back in the 1950s, science fiction writers considered Venus to be one of the most "convenient" planets for landing, exploring and colonizing. They perceived the celestial body almost as a younger "twin" of the Earth, boldly assuming that under a dense layer of clouds there is a prehistoric version of our world: huge fern forests, dinosaurs... Later, the concept changed a bit, but also for the Strugatsky brothers in "The Land of Crimson Clouds" (1959) and in Pavel Klushantsev's film "Planet of Storms" (1961) Venus was a suitable landing site for manned missions.
However, studying with the help of spacecraft gradually killed all optimism. After the Soviet Venera-1 flew at a distance of 100,000 km in 1961. A year later, the American Mariner-2 spacecraft received information about the planet's extremely hot atmosphere. But this information did not stop the scientists — just five years later, Soviet specialists sent the Venera-4 interplanetary automatic station to the target. Its lander was supposed to operate at a temperature of 425 ° C and a pressure of up to 10 atmospheres. The specialists were overly cautious, the device could actually carry twice as much load.
Alas, even this was not enough — at an altitude of 28 km during the parachute descent, the hull, made of aluminum-magnesium alloy AMg6 and capable of operating at a depth of 200 m, crumpled like a tin can. However, the data transmitted by him made it possible to clarify the real situation — the pressure near the surface of Venus was about 90-100 atmospheres. On Earth, such conditions are in the ocean at a depth of about a kilometer.
Experience, son of mistakes is difficult
Venera 7 took into account everything that scientists already knew about the inhospitable atmosphere of Venus.
It was assumed that the atmosphere consists of carbon dioxide, warms up to 500 °C, clouds are made of sulfuric acid, constantly mixed by winds blowing at speeds up to 100 m/s. The descent vehicle, created at the Lavochkin Scientific Research Institute, was supposed to pass through this hell and land gently on the surface of the planet, transmit the results.
The automatic interplanetary station consisted of a titanium case with fiberglass insulation of the lower hemisphere and glass wool packed in a cellular structure — in the upper one, a small parachute with an area of only 3 square meters. m. Of course, there were special devices capable of operating even in the conditions of Venus, a more powerful lead-zinc battery. We even had to change the design of the upper stage tanks of the Molniya-M launch vehicle in order to deliver the heavily weighted descent vehicle into the orbit of the planet. Each of these solutions is a huge work done by engineers from various space enterprises of the Soviet Union.
On December 15, 1970— 120 days after launch— the Venera-7 station reached the vicinity of the planet. Reducing the speed by means of aerodynamic braking, the device passed through the dense layers of the atmosphere (the speed relative to the surface of the planet decreased by 50 times — from 11.5 km/s to 200 m/s). Naturally, such braking was accompanied by severe overloads reaching 350g. But the instruments and the design of the device have borne such a load.
At an altitude of 55 km above the surface of the planet, the Venus-7 parachute system was activated, and half an hour later the device made the first landing on the surface of another planet in the history of mankind. For another 20 minutes, the structure resisted the enormous pressure, the devices regularly transmitted information. So Soviet scientists were able to accurately determine the pressure and temperature on the surface of the second planet from the Sun — 90 atmospheres and 475 ° C.
Waiting for the "Venus-D"
Even after 55 years, these events are perceived almost as a fantastic story. Meanwhile, the needs are growing — new data needs to be installed, which means that other interplanetary missions need to be created and launched. But the world's cosmonautics is not capable of this right now.: Each of the missions is an extremely expensive and time—consuming project. It is no longer enough for scientists and space engineers to launch three instruments — the GS-4 gamma spectrometer and temperature and pressure sensors. Current missions require months and years of development and testing, and sometimes collaboration between different countries to manufacture devices.
The era of "planetary assault" has passed. Now every interplanetary project is an even more serious event than at the dawn of cosmonautics, when our country was ahead of the rest of the planet. In addition, it is extremely difficult to obtain funding for such missions, which can provide data mainly for basic science. These are not spacecraft, which are needed in a whole range of areas, including the military.
A project for the Venera-D interplanetary automatic station is being created in Russia (although it has been quite a long time and so far without much activity). The mission will consist of an orbiter and a lander for a comprehensive study of the atmosphere of Venus, its surface, internal structure and surrounding plasma. It is assumed that the orbiter will operate in orbit and be used as a repeater, while a balloon module will be lowered into the dense layers of the atmosphere. Due to this choice of altitude, it will be able to survive for several weeks, transmitting data on the composition of the atmosphere.
In addition to the balloon module, it is planned to send a descent vehicle to the surface of the planet. His main task is to work in the most difficult conditions for at least three hours. During this time, the instruments will have to take soil samples and place them in a spectrometer, which will transmit the composition of the Venusian earth to Earth. Each of the instruments — the ground collector, the spectrometer and the transmitting station must survive these 180 minutes in order to deliver such important and interesting data to Earth.
So far, it is difficult to say when exactly the Venus-D will go on its mission. Everything will depend on the financing, which, I think, will become somewhat known from the National Space Project.
In March, Lev Zeleny, Scientific director of the Space Research Institute of the Russian Academy of Sciences, noted : "Scientists insist on launching Venera-D in 2031 or 2032, in the same window along with other missions that will be sent by our foreign colleagues to Venus. Given the recent history of our previous missions, we are afraid and do not want to rush NPO Lavochkin, so the launch is highly likely to shift to 2034-2035."
So all that remains is to be patient and wait for a new space mission to go to the Morning Star. I really want to make sure that it turns out to be no less successful than Venus-7.
The main thing in this situation is not to relax and not to let the launch date go too far. Foreign competitors are not asleep, in recent years several missions to Venus have been announced at once. Among them, the most promising and interesting are the Indian Shukrayan-1 and the American DAVINCI+ and VERITAS.
The Indian mission is an orbiter that can carry up to 100 kg of payload on board. His tasks include determining the geological composition of the surface of Venus, as well as studying atmospheric chemistry. So far, its shipment is planned for 2029.
The American devices are the finalists of the NASA Discovery competition. The task of DAVINCI+ is to descend into the atmosphere of Venus in order to study its composition, VERITAS is an orbiter equipped with a radar to make a topographic map of the planet. Both missions are expected to launch in the early 2030s. Let's see if these projects will be able to survive the reduction in space funding conducted by US President Donald Trump in 2025.
