Activities on Mars
The two themes that fuel the exploration of Mars are: its planetary evolution, change and life, and human colonization of Mars. All space exploration is broken down into three phases: 1) obtain environmental knowledge necessary for human exploration, 2) human landings and exploration of Mars, and 3) the building of a permanent base and global exploration.
Scientists will search for fossils to help with the understanding of previous life on the planet and the geologic changes that have occurred on Mars. By learning about the planetís geology, scientists know what is needed to support a human presence and establish the time frame of the internal and surface processes that Mars has had in its history.
Landing on Mars is very important because of the need to explore an interesting site while staying in a safe, low-elevation area for launching and radiation-protection reasons. Mars has several geological features of interest, including Valles Marineris, the Tharsis Bulge, and Mons Olympus. The northern hemisphere is mainly plains while the southern hemisphere is heavily cratered. See Landing Site.
Mars Semi Direct
Another plan for the exploration of Mars is called the Semi-Direct plan. Unlike the Mars Direct plan, the first launch delivers an unfueled Mars Ascent Vehicle (MAV) and cargo to the surface of the planet while the fueled ERV is placed in orbit. The MAV starts to make fuel for exploration and experimentation when the crew arrives. The crew arrives on Mars and stays for about 1.5 years before they use the MAV to ascend and rendezvous with the ERV to take them home.
In the Semi-Direct plan, the crew does not have access to the ERV hab during the 1.5 year stay on the surface, and there has to be an important rendezvous with the ERV on the way back home. However, this plan only requires about 1/3 the amount of propellant manufacturing on the surface. The ERV can also be make much bigger, allowing for better accommodations or a larger crew.
On the first mission two transfer and surface habs are available, each able to support the crew for the entire surface stay. Two complete MAVs and ERVs are available as well. The total amount of water equals three times the minimum requirement and there is enough food for a four year surface-stay. Because oxygen can be produced on Mars, space suit design can be modified for use on the Martian surface, simplifying it so that it works more like SCUBA gear.
A Future on Mars
The Mars Direct and Mars Semi-Direct mission plans are structured so that humans are constantly exploring and experimenting on the surface of Mars. Because of this, it is not unlikely that in the future there will either be one large base, several medium bases, or numerous small outposts on the Red Planet. The only obstacles to overcome in order to have these colonies are three technological advancements: a process to extract water from the regolith (as water does exist on Mars in the form of permafrost, ice, hydrates, and water vapor), the establishment of a greenhouse culture on the surface, and the modification of the MAV with landing gear and aero protection for ascending through the Martian atmosphere. With the MAV thus modified, it can act as a ferry between the surface of the planet and orbiting ERVs, which bring new crews and supplies from Earth. The MAV can also help in the exploration of the planet since it will have a further reach than the original rovers. If no hydrogen is brought from Earth, then the importance of extracting water from the planet is doubled as it will also contribute to making fuel.