|Manned expedition to Mars:
MOSCOW. (RIA Novosti political commentator Andrei Kislyakov) - The 1920s
are remembered not only for their political upheavals but also for a new
interest in exploring other planets.
Imaginative authors of all calibers wove intricate fantasies about
exploring the length and breadth of Mars in their books. The budding movie
industry made its contribution, too. But it is only a century later, in
the 2020s, that humankind has hope of finally touching down on the Red
That a flight to Mars is a reality is beyond question. Its duration has
also been calculated - using the optimum trajectory it will take 350 days
there and 350 to get back, plus 20 to 30 days spent on the planet's
surface. But the exact date is still only a guess. Optimists say 2017-2018
is the nearest "ballistic window" for an Earth-Mars mission, but
pessimists consider it unrealistic, above all for technological reasons: a
spacecraft must be built, engines developed, and the whole mass weighing
hundreds of tons placed on a path to Mars. Nevertheless a manned
expedition to Mars is being prepared with such a schedule in mind. In
Russia it is part of the Federal Space Program.
An advanced development project called "A Manned Expedition to
Mars" was drafted in 2005. Vitaly Semyonov, chief designer at the
Keldysh Center and one of the project developers, said the research
already conducted has revealed one important feature: the schedule and
costs of a Martian mission depend mainly on the type of propulsion unit.
Scientists have considered different options, including liquid rocket
engines burning oxygen and hydrogen; nuclear rocket engines with liquid
hydrogen as working medium; and nuclear and solar power units to drive
electric propulsion engines. The choice fell on the solar unit with thin
film elements based on amorphous silicon. The nuclear unit is viewed as a
Initially, it is planned to mount five expeditions using the same orbital
spacecraft. All expeditions will include a multiple solar-powered tug.
Their aim will be to select and prepare the site for a Martian base.
Scientists believe that the location of the site must above all meet the
requirements of safe landing and take-off. Another important factor is the
terrain on which a habitable facility will be located to ensure its
anti-radiation protection. The terrain must also make easier the
monitoring of asteroid-cometary impacts and their dangers for base
residents. A further essential requirement is the presence of liquid water
at shallow depths. Lastly, an analysis of geological data from Mars has
pinpointed the most likely spots with traces of life. It is not
inconceivable that these areas will be most attractive for siting the
first extra-terrestrial base.
But before the mission gets off the ground, scientists will have to solve,
in addition to engineering challenges, a multitude of medical and
biological problems. In a strategy for and the planning of a manned
expedition to Mars the human factor is the top priority. It is the weakest
and most exposed link of the mission, crucial for the whole project.
Medical and biological aspects of the expedition therefore pose a new
challenge to scientists.
Many of the established principles, methods and means of space travel are
unacceptable for a manned Mars mission. What sets it apart is different
communications techniques with the Earth, a variety of gravity effects, a
limited period of adaptation to gravity before landing on Mars, enhanced
radiation, and the absence of a magnetic field.
The 438-day flight aboard the Mir orbiter by physician Valery Polyakov at
the end of last century showed that there are no fundamental medical or
biological restrictions to extended space missions. Radiation, however, is
another matter. Its effects intensify manifold when the vehicle leaves the
protection of the Earth's magnetosphere. This demands a special
anti-radiation facility. It might be a radiation shelter that would absorb
charged particles or an artificial electromagnetic field built up around
Presently, the developers are inclined to opt for structural protection by
placing tanks with fuel, water and other supplies around the living
quarters. This affords a rate of protection of about 80-100 g/sq cm.
Another problem is food. It would seem years of practice have taken care
of it, and there is no need to reinvent the wheel. The crew of a space
ship will use freeze-dried products which need a little water and heating
before being put on the table. But, fine and delightful as such dishes may
be, they should be mixed with some normal food.
The idea of keeping caged fowl aboard the vehicle for cosmonauts to eat
their eggs, quail eggs preferably, had to be abandoned. Experiments showed
that newly hatched chicks never adapted to zero gravity. Fish and
shellfish fared better, but they grow too slowly, and so cosmonauts are
unlikely to eat fresh fish on their way to Mars. What is certain is that
the interplanetary ship will have a greenhouse, though a small one. The
optimum choice of crops will be crucial.
It has been calculated that a cosmonaut needs 2.5 liters of water daily,
which means the vehicle will have to have a supply of several tons. Some
of the water will be recirculated. An ideal arrangement would be a
closed-circuit physical and chemical system to ensure cycles of
substances. But this appears to belong to a distant future.
Other problems are psychological. With great distances involved, a radio
signal will take 20 to 30 minutes to travel each way. Mission Control will
simply have no time to intervene in an emergency. The Earth will at best
provide advice, but all decision-making will be the responsibility of the
spacecraft. But before a crewed Martian expedition lifts off, scientists
will try to solve many of these problems during the Mars-500 mission.
It will be an imitation, not a real flight: a crew of six will spend 520
days in a ground facility consisting of five hermetically sealed
communicating modules. One of them will imitate the Martian surface. The
modules are loaded with devices to register various parameters inside and
to monitor the health of the test subjects. Scientists need to know how
human beings act in teams and handle non-standard situations. All results
- starting with the behavior pattern of the crew and ending with their
diet - will be examined by specialists. This will take care of most likely
situations and ways of dealing with them during the flight. A crew is
currently being recruited for the "ground interplanetary
mission". Ninety volunteers from 19 countries have already stepped
forward. They are mainly men, with only eight women and one married
couple. The explanation appears simple: physiologically and
psychologically women have fewer chances than men to be among the first to
step on Mars. Th
e experiment will involve six people, although a real mission to the
planet will have a crew of four.
Remarkably, soon after Russia announced the Mars-500 experiment, the
United States, too, began inviting volunteers for an imitation flight. The
American experiment is scheduled to begin on May 1, 2007. Test subjects
will spend four months on it.
The European Space Agency is developing its own concept of an expedition
to Mars, so far uncrewed. China has plans to explore and utilize Mars. In
short, a space race is getting off the start line again. The only question
is, why should we fly to Mars at all?
"Most scientific achievements in space are credited to automatic
devices, not manned missions," says Lev Zeleny, director of the
Russian Academy of Sciences Space Research Institute. He believes,
however, a human being is bound to land on Mars, even if the event makes
no rational sense. The sensations of a person stepping down on the surface
of another planet are so precious as to have no value scale to appreciate