Eventually, humans will most likely journey to Mars. Getting astronauts to the Martian surface and returning them safely to Earth, however, is an extremely difficult engineering challenge. A thorough understanding of the Martian environment is critical to the safe operation of equipment and to human health, so the Mars Exploration Program will begin to look at these challenges in the coming decade.

Astronaut Safety in the Hostile Martian Environment

The safety of astronauts is of paramount importance to NASA. Mars lacks an ozone layer, which on Earth shields us from lethal doses of solar ultraviolet radiation. We do not have good information about the amount of ultraviolet radiation that reaches the Martian surface.

A more detailed understanding of the radiation environment will provide the information necessary to assess the effects of UV radiation on astronauts, as well as help engineers design protective space suits and habitats.

We do know that the Martian soil contains "superoxides." In the presence of ultraviolet radiation, superoxides break down organic molecules. While superoxides' effect on astronauts is probably not serious, their impact and that of any other unique chemical aspects of the Martian soil must be assessed before human exploration of Mars can begin.

Robotic Spacecraft Will Pave the Way for Human Exploration of Mars

To pave the way for human exploration, 2001 Mars Odyssey will begin to analyze the radiation environment on Mars. This mission and the Mars Reconnaissance Orbiter will continue to search for water resources that, if discovered, could be used to support future human explorers. Eventually, robotic spacecraft, rovers, and drills could be used to access water resources in advance of, and during, human exploration.

Advanced entry, descent and landing techniques that reduce the G-forces on landers will also be developed for spacecraft and astronaut safety.

While robotic exploration will pave the way for the long-term possibility of human missions to Mars, much of the necessary scientific and technological work for this goal is carried out by NASA's Johnson Space Center. For more information about eventual human missions to the Red Planet, visit NASA's Human Spaceflight Web section on Mars Exploration and Beyond.