MARS COLONIZATION

Mars is the focus of much scientific study about possible human colonization. The surface conditions of Mars and past presence of water ice make it arguably a feasible endeavor. Permanent human habitation on other planets, including Mars, is one of most prevalent themes in science fiction. Permanent human habitation on other planets, including Mars, is one of most prevalent themes in science fiction. As technology advances, and concerns about humanity's future on Earth increase, arguments favoring space colonization gain momentum. Other reasons for colonizing space include economic interests, long-term scientific research best carried out by humans as opposed to robotic probes, and sheer curiosity.

Both private and public organizations have made commitments to researching the viability of long-term colonization efforts and to taking steps toward a permanent human presence on Mars. Space agencies engaged in research or mission planning include NASA, ESA, Roscosmos, Indian Space Research Organisation and the China National Space Administration, as well as private organizations such as SpaceX, Lockheed Martin, and Boeing.

With a radius of 2,106 miles (3,390 kilometers), Mars is about half the size of Earth. If Earth were the size of a nickel, Mars would be about as big as a raspberry. From an average distance of 142 million miles (228 million kilometers), Mars is 1.5 astronomical units away from the Sun. One astronomical unit (abbreviated as AU), is the distance from the Sun to Earth. From this distance, it takes sunlight 13 minutes to travel from the Sun to Mars.

As Mars orbits the Sun, it completes one rotation every 24.6 hours, which is very similar to one day on Earth (23.9 hours). Martian days are called sols—short for "solar day." A year on Mars lasts 669.6 sols, which is the same as 687 Earth days. Mars' axis of rotation is tilted 25 degrees with respect to the plane of its orbit around the Sun. This is another similarity with Earth, which has an axial tilt of 23.4 degrees. Like Earth, Mars has distinct seasons, but they last longer than seasons here on Earth since Mars takes longer to orbit the Sun (because it's farther away). And while here on Earth the seasons are evenly spread over the year, lasting 3 months (or one quarter of a year), on Mars the seasons vary in length because of Mars' elliptical, egg-shaped orbit around the Sun. Spring in the northern hemisphere (autumn in the southern) is the longest season at 194 sols. Autumn in the northern hemisphere (spring in the southern) is the shortest at 142 days. Northern winter/southern summer is 154 sols, and northern summer/southern winter is 178 sols.

When the solar system settled into its current layout about 4.5 billion years ago, Mars formed when gravity pulled swirling gas and dust in to become the fourth planet from the Sun. Mars is about half the size of Earth, and like its fellow terrestrial planets, it has a central core, a rocky mantle and a solid crust.

Mars has a dense core at its center between 930 and 1,300 miles (1,500 to 2,100 kilometers) in radius. It's made of iron, nickel and sulfur. Surrounding the core is a rocky mantle between 770 and 1,170 miles (1,240 to 1,880 kilometers) thick, and above that, a crust made of iron, magnesium, aluminum, calcium and potassium. This crust is between 6 and 30 miles (10 to 50 kilometers) deep.

The Red Planet is actually many colors. At the surface we see colors such as brown, gold and tan. The reason Mars looks reddish is due to oxidization—or rusting—of iron in the rocks, regolith (Martian “soil”), and dust of Mars. This dust gets kicked up into the atmosphere and from a distance makes the planet appear mostly red. Interestingly, while Mars is about half the diameter of Earth, its surface has nearly the same area as Earth’s dry land. Its volcanoes, impact craters, crustal movement, and atmospheric conditions such as dust storms have altered the landscape of Mars over many years, creating some of the solar system's most interesting topographical features. A large canyon system called Valles Marineris is long enough to stretch from California to New York—more than 3,000 miles (4,800 kilometers). This Martian canyon is 200 miles (320 kilometers) at its widest and 4.3 miles (7 kilometers) at its deepest. That's about 10 times the size of Earth's Grand Canyon.

Mars is home to the largest volcano in the solar system, Olympus Mons. It's three times taller than Earth's Mt. Everest with a base the size of the state of New Mexico. Mars appears to have had a watery past, with ancient river valley networks, deltas and lakebeds, as well as rocks and minerals on the surface that could only have formed in liquid water. Some features suggest that Mars experienced huge floods about 3.5 billion years ago. There is water on Mars today, but the Martian atmosphere is too thin for liquid water to exist for long on the surface. Today, water on Mars is found in the form of water-ice just under the surface in the polar regions as well as in briny (salty) water, which seasonally flows down some hillsides and crater walls.

Mars has a thin atmosphere made up mostly of carbon dioxide, nitrogen and argon gases. To our eyes, the sky would be hazy and red because of suspended dust instead of the familiar blue tint we see on Earth. Mars' sparse atmosphere doesn't offer much protection from impacts by such objects as meteorites, asteroids and comets. The temperature on Mars can be as high as 70 degrees Fahrenheit (20 degrees Celsius) or as low as about -225 degrees Fahrenheit (-153 degrees Celsius). And because the atmosphere is so thin, heat from the Sun easily escapes this planet. If you were to stand on the surface of Mars on the equator at noon, it would feel like spring at your feet (75 degrees Fahrenheit or 24 degrees Celsius) and winter at your head (32 degrees Fahrenheit or 0 degrees Celsius). Occasionally, winds on Mars are strong enough to create dust storms that cover much of the planet. After such storms, it can be months before all of the dust settles.

Scientists don't expect to find living things currently thriving on Mars. Instead, they're looking for signs of life that existed long ago, when Mars was warmer and covered with water.

Overview of History

Mars has Two moons.

Asaph Hall was about to give up his frustrating search for a Martian moon one August night in 1877, but his wife Angelina urged him on. He discovered Deimos the next night, and Phobos six nights after that.Ninety-four years later, NASA's Mariner 9 spacecraft got a much better look at the two moons from its orbit around Mars. The dominant feature on Phobos, it found, was a crater six miles (10 kilometers) wide—nearly half the width of the moon itself. It was given Angelina's maiden name: Stickney.

Overview of MARS Moon

Mars' moons are among the smallest in the solar system. Phobos is a bit larger than Deimos, and orbits only 3,700 miles (6,000 kilometers) above the Martian surface. No known moon orbits closer to its planet. It whips around Mars three times a day, while the more distant Deimos takes 30 hours for each orbit. Phobos is gradually spiraling inward, drawing about six feet (1.8 meters) closer to the planet each century. Within 50 million years, it will either crash into Mars or break up and form a ring around the planet. To someone standing on the Mars-facing side of Phobos, Mars would take up a large part of the sky. And people may one day do just that. Scientists have discussed the possibility of using one of the Martian moons as a base from which astronauts could observe the Red Planet and launch robots to its surface, while shielded by miles of rock from cosmic rays and solar radiation for nearly two-thirds of every orbit. Like Earth's Moon, Phobos and Deimos always present the same face to their planet. Both are lumpy, heavily-cratered and covered in dust and loose rocks. They are among the darker objects in the solar system. The moons appear to be made of carbon-rich rock mixed with ice and may be captured asteroids.

Phobos has only 1/1,000th as much gravitational pull as Earth. A 150-pound (68 kilogram) person would weigh two ounces (68 grams) there. Yet NASA's Mars Global Surveyor has shown evidence of landslides, and of boulders and dust that fell back down to the surface after being blasted off the moon by meteorites.

How Mars Moons Got Their Names

Hall named the moons for the mythological sons of Ares, the Greek counterpart of the Roman god, Mars. Phobos means fear or panic (think "phobia"), and Deimos means flight (as in running away after an overwhelming defeat). Fitting names for the sons of a war god.

Mars has two small moons, Phobos and Deimos, that may be captured asteroids. They're potato-shaped because they have too little mass for gravity to make them spherical. Close up on potato-shaped Phobos Mars' largest moon Phobos as seen by Mars Reconnaissance Orbiter in 2008. The moons get their names from the horses that pulled the chariot of the Greek god of war, Ares. In ancient Greek, Phobos means "flight," and Deimos means "fear." Phobos, the innermost and larger moon, is heavily cratered, with deep grooves on its surface. It is slowly moving towards Mars and will crash into the planet or break apart in about 50 million years. Deimos is about half as big as Phobos and orbits two and a half times farther away from Mars. Oddly-shaped Deimos is covered in loose dirt that often fills the craters on its surface, making it appear smoother than pockilometersarked Phobos.

EXPLORATION OF MARS

Exploration of Mars and eventual human travel to it are nothing new. While manned missions have remained financial and logistical near-impossibilities, unmanned missions began in 1960. There have been 56 Mars missions so far, of which 26 have been successful — a testament to the difficulty in reaching the red planet.

Mars has historically been unfriendly to Earth’s attempts to visit it. More missions have been attempted to Mars than to any other place in the Solar System except the Moon, and about half of the attempts have failed. Some of these failures occurred because Mars was the first planet Earth attempted to explore, and the early exploration attempts taught us many lessons that have made subsequent missions more successful. But many failures have occurred relatively recently, proving again and again that space exploration is very, very difficult. But since 1996, Mars exploration has undergone a Renaissance, with data from four orbiters and four landed missions developing a revolutionary new view of Mars as an Earth-like world with a complex geologic history.

MISSION TO THE MOON OF MARS

Missions dedicated to explore the two moons of Mars, Phobos and Deimos. Many missions to Mars have also included dedicated observations of the Moons, while this section is about missions focused solely on them. There have been three unsuccessful dedicated missions and many proposals. Because of the proximity of the Mars moons to Mars, any mission to them may also be considered a mission to Mars from some perspectives. There have been at least three proposals in the United States Discovery Program, including PADME, PANDORA, and MERLIN. The ESA has also considered a sample return mission, one of the latest known as Martian Moon Sample Return or MMSR, and it may use heritage from an asteroid sample return mission.

LIST OF FUTURE MISSIONS TO MARS

LIST OF SUCCESSFUL MISSIONS TO MARS

LIST OF HUMAN FUTURE MISSIONS TO MARS

A human mission to Mars has been the subject of science fiction, aerospace engineering, and scientific proposals since the 19th century. Plans include landing on Mars for exploration at a minimum, with the possibility of sending settlers and terraforming the planet and/or exploring its moons Phobos and Deimos also considered. The exploration of Mars has been a goal of national space programs for decades. Conceptual work for missions that would involve human explorers has been ongoing since the 1950s, with planned missions typically being stated as taking place 10 to 30 years in the future when they are drafted. The list of crewed Mars mission plans shows the various mission proposals that have been put forth by multiple organizations and space agencies in this field of space exploration. Plans have varied from scientific expeditions, in which a small (2 to 8) group visits Mars for a period of a few weeks or year, to the permanent colonization of Mars.

In the 2010s, numerous US, European, and Asian agencies were developing proposals for human missions to Mars. Mars in fiction is a frequent target of exploration and settlement in books, graphic novels, and films.

List of crewed Mars mission plans

This list of crewed Mars mission plans is a listing of concept studies for a crewed mission to Mars during the 20th and 21st centuries. It is limited to studies done with engineering and scientific knowledge about the capabilities of then current technology, typically for high-budget space agencies like NASA. Mission profiles include crewed flybys, crewed landers, or other types of Mars system encounter strategies.

Concepts

Many mission concepts for expeditions to Mars were proposed in the late 20th century. David Portree's history volume Humans to Mars: Fifty Years of Mission Planning, 1950–2000 discusses many of these. Portree notes that every 26 Earth months a lower energy Earth to Mars transfer opportunity opens, so missions typically coincide with one of these windows. In addition, the lowest available transfer energy varies on a roughly 16-year cycle, with a minimum in the 1969 and 1971 launch windows, rising to a peak in the late 70s, and hitting another low in 1986 and 1988. Also of note, the Mariner 4 Mars flyby in 1965 provided radically more accurate data about the planet; a surface atmospheric pressure of about 1% of Earth's and daytime temperatures of −100 degrees Celsius (−148 degrees Fahrenheit) were estimated. No magnetic field or Martian radiation belts were detected. The new data meant redesigns for planned Martian landers, and showed life would have a more difficult time surviving there than previously anticipated. Later NASA probes in the 1970s, 80s, and 90s confirmed the findings about Mars environmental conditions. The first engineering analysis of a crewed mission to Mars was made by Wernher von Braun in 1948. It was originally published as Das Marsprojekt in West Germany in 1952, and as The Mars Project in English in the United States in 1953. Von Braun's Mars "flotilla" included ten 4,000-ton ships with 70 crew members. The expected launch year was 1965.

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