- What is the minimum information at the maximum cost?
- These are the launches of space stations to Mars.
On November 18, 2013, an Atlas-V launch vehicle was launched from Cape Canaveral with an automatic interplanetary station MAVEN, designed to study the atmosphere of Mars.
All systems of the SLC-4 launch pad worked perfectly - at 13:18 local time, the vicinity of the cosmodrome shuddered from the powerful roar of the RD-180 (Russian-made engines are used in both stages of the Atlas-V launch vehicle). A 300-ton fire-breathing team broke away from the launch pad and, sharply increasing its speed, rushed up to meet the stars. In 27 minutes after entering the reference low-earth orbit, the engines of the upper stage "Centaur" were launched: MAVEN gained the second space speed and entered the departure trajectory to Mars.
The first corrective maneuver is scheduled for December 3. In 10 months, on September 22, 2014, the station, having flown in the icy blackness of 300 million kilometers, should enter the Martian orbit. A scientific mission with an estimated duration of 1 Earth year will begin.
The launch under the MAVEN program became one of the main intrigues in the field of space launches in 2013 - the complete or partial suspension of the work of US government agencies from October 1, 2013 put the planned expedition to the Red Planet at risk, despite the full readiness of all technical systems of the rocket and space system. and also a good "time window" for the launch to Mars. There was a real threat of disruption of all the planned dates and the postponement of the launch of MAVEN to 2016.
And this despite the fact that the spacecraft itself had already been at Cape Canaveral since August, undergoing intensive preparation for the flight, and a ready-made Atlas-V launch vehicle was waiting inside the assembly shop of the cosmodrome!
The absurd situation was saved by NASA lawyers, who found a loophole in the laws, according to which the launch of an interplanetary probe meets the criteria excluding MAVEN from the list of forced budget cuts. The five-year work of the staff of the University of Colorado and the space research laboratory of the University of Berkeley was not in vain - an interplanetary station worth $ 671 million (the creation of the probe itself cost $ 485 million, another 187 million were spent on prelaunch preparation and purchase of the Atlas-V launch vehicle) was safely sent to the intended target.
MAVEN became the 45th mission to Mars and the tenth NASA orbital reconnaissance mission in the vicinity of the Red Planet. The name of the probe is a complex abbreviation for Mars Atmosphere and Volatile EvolutioN, which fully reflects the tasks of the upcoming expedition. MAVEN is designed to study the atmosphere of Mars - a thin gaseous shell, whose pressure in the near-surface layer is only 0.6% of the Earth's atmosphere, and the gas composition is completely unsuitable for human breathing (the Martian atmosphere is almost entirely - 95% - carbon dioxide).
A snapshot of the Viking apparatus, 1976
But even this flimsy atmosphere continues to disappear continuously - the small gravity of Mars is not able to keep the gas shell around the planet. Every year the cosmic wind "blows away" its upper layers into space, dooming Mars to transform into a solidified block of stone, similar to the Moon or Mercury.
But when should this happen? And what was Mars like in the distant past, when its gas shell was not yet so strongly discharged? What is the rate of disappearance of the Martian atmosphere in absolute terms?
This is what the MAVEN spacecraft should figure out: moving around Mars in an elliptical orbit with a pericenter of 150 km and an apocenter of 6200 km, it should determine the current state of the upper layers and the nature of their interaction with the solar wind. Establish the exact rate of loss of atmosphere, as well as the factors affecting this process. Determine the ratio of stable isotopes in the atmosphere, which should "shed light" on the history of the Martian climate. Indirectly, this will be able to answer the question: did conditions exist in the past that allowed the presence of liquid water on the surface of Mars?
The only thing that saddened NASA specialists is that the new orbital probe, due to its extremely elongated orbit, cannot be used as a repeater of signals from rovers.
MAVEN undergoes centrifuge tests
There are 8 state-of-the-art instruments on board the probe:
- a set for studying particles and fields (three analyzers of particles of the "solar wind", a sensor of Langmuir waves (plasma oscillations) and a pair of induction magnetometers);
- an ultraviolet spectrometer, which allows to remotely determine the parameters of the atmosphere and ionosphere of a distant planet;
- neutral and ionic mass spectrometer for studying the isotopic composition of the atmosphere of Mars.
Impressive scientific equipment and life support systems, including an attitude control system, an on-board computer, solar panels and equipment for communication with the Earth, providing data exchange at speeds up to 10 Mbit / s - all fit in a housing measuring 2, 3 x 2, 3 x 2 m (probe width with open solar panels - 11 m). The mass of devices, systems and scientific equipment is 809 kg.
Was Mars similar to Earth in the distant past? MAVEN will definitely clarify this issue. The main thing is to safely get to your destination. And this, as practice shows, is very difficult …
Chronicle of flights to Mars
Mars is the most visited and most studied celestial body, surpassing even the moon close to us by these criteria. Researchers are attracted by a lot: the relatively short flight time (even with existing technologies - less than a year). Suitable surface conditions: no extreme pressures and temperatures, acceptable background radiation, illumination and gravity. Of all the planets, Mars is most suitable for the search for extraterrestrial life (even in the distant past), and in the future it is suitable for landing a manned expedition on its surface.
However, the path to the Red Planet is littered with accidents and debris from spacecraft: out of 45 launched expeditions, just over half reached the Red Planet. And only a few were able to fully fulfill the planned program.
Space does not forgive haste and the slightest mistakes. Many of the "explorers of Mars" failed their mission at the start. This mainly refers to the space race of the 60s, when, on the instructions of the party and government, it was required at all costs to launch the apparatus and achieve priority in space. As a result, the stations "Mars 1960A", "1960B", "Mariner-8" died in the Earth's atmosphere due to accidents with carrier rockets.
Even more stations were able to get into reference orbit, but could not reach the departure trajectory: someone got stuck on LEO, like Phobos-Grunt, and later returned to Earth in the form of a dazzlingly bright fireball; someone did not pick up the necessary speed for a flight to Mars and disappeared without a trace in the vast heliocentric orbits ("Mariner-3"). In total, out of 45 launched probes, only 31 (including MAVEN) were able to reach the calculated trajectory to the flight to Mars. To the credit of our country, the first of the spacecraft to set a course for the Red Planet was the Soviet probe Mars-1 (launched on November 1, 1962). Unfortunately, the next paragraph tells about him.
Model of the interplanetary automatic station "Mars-1"
The real nightmare begins during the months-long flight to Red Flight. One wrong command - and the device, having lost orientation, loses the ability to communicate with the Earth, turning into useless space debris. A similar nuisance occurred with the Mars-1 station - a nitrogen leak from the cylinders of the attitude control system: communication with the station was lost at a distance of 106 million km from the Earth. Another device - "Zond-2" - suffered from incomplete disclosure of solar panels: the resulting power outages caused the onboard equipment to malfunction, "Zond-2" quietly died out before the eyes of its creators. According to ballistic calculations, on August 6, 1965, an unguided probe was supposed to pass in the vicinity of Mars.
The Japanese probe Nozomi perished very hard and terribly in the vastness of space. The lack of their own launch vehicle of the necessary power became a bad omen when sending an expedition to a distant planet, nevertheless, the cunning Japanese hoped to gain the necessary speed through complex gravitational maneuvers in the vicinity of the Earth and the Moon. Of course, everything did not go according to plan - "Nozomi" went off course. The Japanese managed to calculate a new trajectory and again direct the station to Mars, even if they were 4 years behind schedule. Now the main thing is to hold out in outer space for a long time. Alas … A powerful solar flare damaged the fragile filling of the probe. By the time of approaching Mars, hydrazine froze in the tanks - it was not possible to issue a braking impulse, and Nozomi, in despair, passed 1000 km above the surface of the Red Planet, without ever entering a near-Martian orbit.
Under very offensive circumstances, the American probe "Mars Observer" (1993) was lost - communication with it was interrupted just a few days before arriving at Mars. The most likely cause is an engine explosion due to leakage of fuel components.
The first to overcome the difficult distance and transmit a close-up photograph of the Red Planet was the American probe Mariner 4, which flew in the vicinity of Mars in July 1965.
A number of vehicles were lost already in the orbit of Mars.
On March 27, 1989, communication with the Soviet station Phobos-2 was lost, which by that time had already been in Mars orbit for 57 days. During its work, "Phobos-2" transmitted to the Earth unique scientific results on the thermal characteristics of Phobos, the plasma environment of Mars and the erosion of its atmosphere under the influence of the "solar wind". Alas, the main task of the mission - the landing of mini-probes PrOP-F and DAS on the surface of Phobos - failed.
In 1999, under curious circumstances, the American station "Mars Climate Orbiter" perished, having burned out on the first orbit in the atmosphere of the Red Planet. An internal NASA investigation showed that the working groups of specialists used different measurement systems - metric and traditional Anglo-Saxon (feet, pounds, inches). Since then, NASA has banned American units of measurement - all calculations are made exclusively in kilograms and meters.
The landing platform doors close around the folded Opportunity rover, 2003
Very big trouble awaits anyone who dares to land on the surface of Mars - the treacherous atmosphere is too weak to rely on the strength of parachute lines, but still too dense to approach the surface at cosmic speed. It may sound unusual, but Mars is one of the most complex celestial bodies in terms of landing!
Landing takes place in several stages: braking engines, aerodynamic braking in the upper atmosphere, a decelerating parachute, brake engines again, soft landing engines / airbags or a unique “air valve”. The problem of stabilization is a separate line.
The heaviest man-made object that could be delivered to the planet's surface was the MSL rover, better known as "Curiosity" - an apparatus weighing 900 kg (weight in the gravitational field of Mars - 340 kg). But, let's be honest, the flight specialists and outside observers were stunned by the complexity of the landing scheme and the problems encountered during descent in the planet's atmosphere.500 thousand lines of program code, 76 squibs in a certain sequence, the separation of the rover from the platform hanging in the air with the jet engines turned on and a soft descent from a height on nylon cables. Fantastic!
Planet Mars: no water, no vegetation, inhabited by American robots.
Self-portrait of the Curiosity rover
Many heroes were able to survive vibration and huge overloads at the stages of launch and acceleration to Mars, withstood the severe cold of outer space, but died when trying to land on an insidious celestial body. So, for example, the Soviet "Mars-2" crashed, becoming the first man-made object on the surface of Mars (1971).
The first station to make a soft landing on the surface of Mars was the Soviet Mars-3. Alas, due to the arisen corona discharge, the station went out of order 14 seconds after landing.
The European probe "Beagle-2" (the landing module of the orbital probe "Mars-Express") disappeared without a trace in 2003 - the device boldly stepped into the crimson atmosphere of the planet, but after that it never made contact with the Earth …
Mars keeps its secrets securely.
P. S. As of November 21, 2013, two Mars rovers are operating on the surface of the Red Planet - Opportunity (MER-B) and Curiosity (MSL). The first worked in those conditions for 3586 days - 39 times longer than the estimated period and crawled over the surface of 38 kilometers during this time.
There are three spacecraft in Mars orbit: Mars-Odysseus, Mars Orbital Reconnaissance (MRO), and the European probe Mars-Express. The Odysseus lasted the longest - its mission has been going on for the thirteenth year.
A new shift is racing to help the veterans - the Indian probe Mangalyaan (launched on November 5, 2013), as well as the aforementioned MAVEN. Let's hope that in the near future Russia will also take an active part in the "Martian regatta" - for 2016 and 2018. two joint Russian-French expeditions "Exomars" are planned (a cooperation agreement was signed on March 14, 2013). In the same 2018, the updated and more advanced Phobos-Grunt 2 station should go to Mars. This time everything will go well.
HiRISE high-resolution camera aboard the Martian Reconnaissance Orbital (MRO)
Opportunity rover footprints captured by MRO
A panorama of the Greeley Haven area. View of Cape York and Endeavor Crater. The panorama was taken by the Opportunity rover during wintering in 2012.
