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From: NL0BPL@NL3DAV.ZH.NLD.EU
To  : SPACE@NLD





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# On : 20-9-1999 18:31:18
# UTC: 20-9-1999 16:31:18

* Exploring Mars *


Why explore?
Throughout recorded history, explorers have pushed back the edge of the frontier and cut the
trails for others to follow through new territories.

As the 20th Century closes, history will record that in the 1960s humankind opened the vast
frontier beyond Earth's atmosphere. Although the Apollo program blazed a trail of exploration
to the Moon, the development of space has only reached into low-Earth orbit.

It is difficult for people and machines to travel in extreme environments and endure harsh
conditions, and it is difficult for the leaders who must champion and fund the programs that
lead to discovery and reward.

The Space Shuttle and International Space Station Programs, and the communication and
scientific satellite networks established in orbit around the Earth, all are stepping stones
that will enable explorers to venture once again beyond our home planet.

Several reasons guide mankind to explore the solar system. First, we extend the search for our
origins and evidence of life beyond Earth. Knowledge of our past and understanding of our
future improves. Our presence across the solar system expands. We fulfill our quest for
knowledge and experience. Finally, we open opportunities for commercial development.

During the first decades of the 21st Century, explorers from Earth could set foot on the Moon
and Mars and expand the human frontier. Is there life elsewhere in the solar system? Maybe not
now, but there will be....


Advanced Scouts
Before humans can live and work on the Martian or lunar surfaces, forerunners must be developed
to obtain scientific and technical data. This early exploration phase entails sending robotic
missions to gather information about the characteristics of the lunar and Martian environments.

In 1996 NASA began a renewed exploration of the Moon and Mars with robotic spacecraft that may
ultimately result in humans walking on the Martian surface in the 21st Century.

Satellite and robotic missions to Mars provide a "basic reference book for Mars scientists."
Prior to Neil Armstrong setting foot on the Moon, more than a dozen robotic lunar missions
gathered information enabling scientists and engineers to build the spacecraft, space suits
and life-support systems necessary for human exploration of the lunar surface.

The Lunar Prospector, launched on January 6, 1998, orbited the Moon, studying its entire
chemical composition. Other objectives included determining the Moon's origin and evolution and
searching for resources useful to future human explorers. On July 31, 1999, the satellite was
intentionally crashed into the lunar South Pole in the hopes of detecting
water vapor, none was found.


The highly successful Pathfinder mission, launched December 4, 1996; landed Mars July 4, 1997
provided scientists with details of the Martian atmosphere and surface no ground-based lab
could provide. Furthermore, data from the Mars Global Surveyor – launched November 1996 –
have allowed scientists to construct the first global three-dimensional map of the Martian
surface.

NASA plans to launch a Martian robotic mission every two years to continue this trailblazing
activity. In addition, scientists and engineers will use extreme environments on Earth, both
natural and human-made, to test needed technologies and practice living and working on other
planets.


Human Crew
While the robotic exploration of the solar system has been mapped out in some detail, the
human exploration plan is a work in progress. Currently, NASA's efforts in human space flight
are focused on the Space Shuttle and International Space Station Programs. Both of these
programs are important to the development of a capability for human exploration
beyond low-Earth orbit.

Crew self-sufficiency is critical to a long-duration mission, simply because the distance from
Earth impedes or makes impossible the traditional level of communications and support by
controllers on Earth. The crews will need a specialized set of skills, training and support
systems to meet the new challenges of such missions.

Considerable effort will be required to determine requirements for crew size and composition.
Planners will have to consider the tasks required of the crew, safety and risk factors, and the
dynamics of interaction by people from widely different backgrounds and cultures. Significant
crew training will be required to ensure that the humans remain productive throughout the
mission.

The physical health and safety of crew members while they travel to, and return from, the Moon,
Mars and beyond are key concerns. The explorers must be protected from the space radiation
environment and from the harmful effects of reduced gravity on the human body. To maintain the
fitness and productivity of the crew, medical care, exercise and proper nutrition must be
provided during long stays in isolated and distant places.

Factors such as atmospheric pressure and composition, temperature, acceleration, deceleration
and impact force studied during the Apollo Program provide valuable data for engineers planning
human missions beyond low-Earth orbit. Human performance during long-duration missions is
crucial, but a mission to Mars and beyond deserves special attention to detail.

 A combination of Earth facilities and flight-based research must provide data reflecting human
physiological responses. As a result, countermeasures and treatments will be developed to
offset the symptoms of reduced gravity on the body. For instance, the space shuttle and the
International Space Station will be used for both short-term and long-term simulations and
tests on human crews. Future lunar missions will provide additional research vital to
sustaining humans in space on long trips.

As the challenges of sustaining humans in space are resolved, advances in fundamental science,
medicine and technology will follow.


read Exploring Mars part II for more information..



bron: http://spaceflight.nasa.gov/mars/human_crew/index.html




          			 JordiBrouwer
				jordier@dds.nl
                	         icq 44583500