Mars is very similar to the Earth in terms of atmospheric and geophysical features. The presence of atmosphere on Mars, its nearly 24 hour day, and a surface gravity equivalent to 40% of the Earth's, make this planet the most hospitable planet in the solar system after Earth. Mars is also well known for the possibility of finding life, past or present. All these reasons have already motivated a large number of missions toward this planet such as the Mariner Missions (1960-1996), the Mars Pathfinder (landed on July 4, 1997), the Mars Global Surveyor (in orbit since 1997), the Mars Surveyor (2001), and the Mars Sample return mission in 2005. This is clearly the way to answer the need of our society to understand its origins, the origin of the universe, of the stars, of the planets, the origins of life.

As presented in the strategy roadmap, our interest toward Mars is mainly scientific. However, these robotic missions are also aimed at preparing future human missions (Mars 2001) . Human presence on Mars is essential for several scientific objectives, here developed, but the mission duration, or the length of human presence on the planet, will strongly depend on the availability of useable resources, or on the invested means, in the case of a totally autonomous mission.

Getting to Mars

Step 1 of our strategy considers Martian resources as mandatory to ensure self-sufficiency for subsequent human missions. These resources will be accessible and useable. Water on Mars will be used for human consumption, but primarily will be devoted to the production hydrogen and oxygen by electrolysis, to be used as propellant. Robotic missions are currently operating in Mars orbit (NASA Mars Global Surveyor Mission, etc). Future robotic missions will be needed to precisely quantify the volume of useable water on Mars, and determine its location and accessibility. These missions will also have an objective to validate the feasibility of other technologies or processes such as methanation (section 2.5.3). But if no water is found on Mars or in case water is non-accessible, use of NEOs water is envisioned. Water can be extracted from determined NEOs and shipped to Mars to answer the needs.

The resources required for settling on Mars will be first shipped from Earth or from the Moon and NEOs. As settlements grow in capability, these resources will be extracted and processed on Mars itself as part of step 2 of our strategy. Geothermal reservoirs on Mars, (Robert Zubrin, 1996) if they exist, could supply power and heat for humans and greenhouses. These greenhouses would also benefit from the 24 hour Martian day and would further increase the autonomy of Martian settlements. The location of outposts will depend on their scientific potential and their proximity to useful resources (water, minerals, geothermal reservoir).

Mars Tourism

Once humans have tapped Martian resources, the next step is Mars tourism. The feasibility of tourism on Mars will depend on safety and profitability. One must keep in mind that such journeys from Earth to Mars will be long (about 6 to 9 months for a one way trip) and will require the development of large and costly spacecraft. On the other hand, interest for space tourism is relatively high (Zegrahm Space Voyages, Press release, 1999). This will require a multi-base infrastructure on Mars to allow Mars visitors to discover the planet.

One of several valleys that cut through the smooth and cratered plains of the Xan, Terra region of Mars. The valley is about 2.5 km (1.6 miles) wide.

If space tourism on Mars is not worthwhile, Martian settlements will remain dedicated to scientific activities such as:

Life Sciences Research

The presence of life on Mars, past or present, has not yet been proved. However, there exists evidence to support it. This hypothesis is mainly based on the presence of erosion features like canyons (Nanedi Valles) produced by past water flows (Cowen, R. 1997). Water is essential for any known kind of biological life and these canyons prove that at one time, water was flowing on Mars. If life on Mars is attested, it will suggest that life could also be present elsewhere in our universe!

Comparative Planetology

We currently do not know a lot about the geological structure of Mars. We have, and still get a lot of information from satellite missions (Viking, Mariner, Pathfinder, Mars, Phobos, etc). But we need to do in situ research, walk around the planet, explore the canyons, look in detail at different rocks to better understand the small-scale geological and geophysical phenomenon and compare them to identical or similar observations on Earth. As an example, the asteroid impacts on Mars, i.e. the craters could be studied as factors in the evolution of the Earth. Human perception and analysis is far more advanced than for robots. Therefore, the best results for such studies will by obtained by humans and not by robots even if their use as primary missions will be more than welcome to define and explore interesting areas for further investigation.

The study and tracing of the Martian climate and how it may be related to the future of the Earth climate will also be performed. Even if there are large differences between Mars and Earth, their atmospheres share a lot of similar characteristics (Carr, 1991). Chemical studies, by measuring the isotope ratios of elements such as nitrogen, argon, and xenon of the Martian atmosphere, will help determine how the Martian atmosphere evolved over time.

The small-scale information we will get from on-ground studies is the first step to globally comprehend the evolution or history of any planet, in this case Mars. By comparison with the same kind of observations on Earth, it will provide us useful information about the evolution of our own planet and about its history.

Study of Phobos and Deimos

The Martian moons appear to have surface materials similar to many asteroids in the outer asteroid belt, which leads most scientists to believe that Phobos ("fear") and Deimos ("panic") are captured asteroids. Studying them could provide us with new information about asteroids, and help us to better understand the evolution of the solar system. Another activity to be performed on these two satellites will be to study and map their mineral composition for possible resource utilization.

Human Aspects

The most current proposal for sending humans to Mars is discussed in the NASA Mars Reference Mission (Stephen J. Hoffman, David I. Kaplan, 1998). The objective is to learn about Mars and its capability to support humans in the future. Crew size and composition was determined in a top-down manner. Three missions are planned in succession. It is proposed that three manned vehicles will be launched from Earth to Mars in each of four launch opportunities starting in 2007. The first launches will send supplies to Mars orbit and the surface. During the second launch opportunity more supplies will be sent plus the first of the human crews. By the fourth launch opportunity, the third crew will be sent and the basic infrastructure will be in place to support a permanent presence on Mars. In the report four different life support systems were considered: open loop, physical/chemical, bio-regenerative and cached stocks of consumable goods. Independent of which systems are used it is necessary to have redundancy, and to continue research to develop systems that are increasingly independent of supplies from Earth.

As previously discussed some of the challenges facing humans going to Mars include long term exposure to microgravity and radiation. With current propulsion systems it is estimated to take 6-9 months to reach Mars with a manned vehicle. It is still unknown whether exposure to microgravity for such extended periods of time will hamper the ability of the crews to perform useful work upon arriving on Mars. Alternative solutions include the development of better propulsion systems to get the manned vehicles to Mars in a shorter time frame. Alternatively, installing artificial gravity on the spaceship has also been suggested (Garshnek, 1997).

Once on Mars, the crew will benefit from the 24 hour Martian day, which is close to that of Earth. Such a feature is a real advantage as it will not disturb the human biological clock and thus will be one less factor to consider in the negative psychological impact on humans. The infrastructure could be designed to allow light to penetrate by using large bay windows. The Mars atmosphere will not be sufficient to protect humans against radiation (Paul O. Wieland, 1993). The required shielding will be of course less stringent on Mars than on the Moon but will be nevertheless required. Mini-magnetospheres generated around the habitats could be a way to insure a tailored radiation shielding (section 2.6.3). A precursor mission must be sent to Mars with 'tissue proportional counters' to measure the radiation threat (section 2.3.3).

NEXT >