Misplaced Pages

The colonization of Mars is the proposed process of establishing and maintaining control of Martian land for exploitation and the possible settlement of Mars. Most colonization concepts focus on settling, but colonization is a broader ethical concept, which international space law has limited, and national space programs have avoided, instead focusing on human mission to Mars for exploring the planet. The settlement of Mars would require the migration of humans to the planet, the establishment of a permanent human presence, and the exploitation of local resources.

No crewed missions to Mars have occurred, although there have been successful robotic missions to the planet. Public space agencies (including NASA, ESA, Roscosmos, ISRO, the CNSA, among others) have explored colonization concepts, but have primarily focused on further robotic exploration of Mars and the possibility of crewed landings. Some space advocacy groups, such as the Mars Society and the National Space Society, as well as some private organizations, such as SpaceX, have promoted the idea of colonization. The prospect of settling Mars has been explored extensively in science fiction writing, film, and art.

Challenges to settlement include the intense ionizing radiation that impacts the Martian surface, and the fine, toxic dust that covers the planet. Mars has an atmosphere, but it is unbreathable and thin. Surface temperatures fluctuate widely, between −70 and 0 °C (−94 and 32 °F). While Mars has underground water and other resources, conditions do not favor power production using wind and solar; similarly, the planet has few resources for nuclear power. Mars' orbit is the third closest to Earth's orbit, though far enough from Earth that the distance would present a serious obstacle to the movement of materiel and settlers. Justifications and motivations for colonizing Mars include technological curiosity, the opportunity to conduct in-depth observational research, the possibility that the settlement of other planets could decrease the probability of human extinction, the interest in establishing a colony independent of Earth, and the potential benefits of economic exploitation of the planet's resources.

Background

Terminology

Colonization of Mars differs from the crewed Mars exploration missions currently pursued by public space agencies, as they aim to land humans for exploration.

The terminology used to refer a potential human presence on Mars has been scrutinized since at least the 2010s, with space colonization in general since the 1977, as by Carl Sagan, who preferred to refer to settlements in space as cities, instead of colonies because of the implied colonialism; the US State Department had already made clear to avoid the use of the term because of the colonialist meaning. Today "settlement" is preferred out of similar reasons, trying to avoid the broad sociopolitical connotations of colonization.

Today the term is most prominently used by Robert Zubrin and the SpaceX Mars colonization program, with the term Occupy Mars also being used, aspiring for an independent Mars colony, despite limiting international space law.

Mission concepts

Landers and rovers have successfully explored the surface of Mars and delivered information about conditions on the ground. The first successful lander, the Viking 1 lander, touched down on the planet in 1976.

Crewed missions to Mars have been proposed, but no person has set foot on the planet, and there have been no return missions. Most of the human mission concepts as currently conceived by national governmental space programs would not be direct precursors to colonization. Programs such as those being tentatively planned by NASA, Roscosmos, and ESA are intended solely as exploration missions, with the establishment of a permanent base possible but not yet the main goal. Colonization requires the establishment of permanent habitats that have the potential for self-expansion and self-sustenance. Two early proposals for building habitats on Mars are the Mars Direct and the Semi-Direct concepts, advocated by Robert Zubrin, an advocate of the colonization of Mars.

At the February 2017 World Government Summit, the United Arab Emirates announced a plan to establish a settlement on Mars by 2117, led by the Mohammed bin Rashid Space Centre.

Comparisons between Earth and Mars

Gravity and size

The surface gravity of Mars is just 38% that of Earth. Although microgravity is known to cause health problems such as muscle loss and bone demineralization, it is not known if Martian gravity would have a similar effect. The Mars Gravity Biosatellite was a proposed project designed to learn more about what effect Mars' lower surface gravity would have on humans, but it was cancelled due to a lack of funding.

Mars has a surface area that is 28.4% of Earth's, which is only slightly less than the amount of dry land on Earth (which is 29.2% of Earth's surface). Mars has half the radius of Earth and only one-tenth the mass. This means that it has a smaller volume (≈15%) and lower average density than Earth.

Magnetosphere

Due to the lack of a magnetosphere, solar particle events and cosmic rays can easily reach the Martian surface.

Atmosphere

Atmospheric pressure on Mars is far below the Armstrong limit at which people can survive without pressure suits. Since terraforming cannot be expected as a near-term solution, habitable structures on Mars would need to be constructed with pressure vessels similar to spacecraft, capable of containing a pressure between 30 and 100 kPa. The atmosphere is also toxic as most of it consists of carbon dioxide (95% carbon dioxide, 3% nitrogen, 1.6% argon, and traces totaling less than 0.4% of other gases, including oxygen).

This thin atmosphere does not filter out ultraviolet sunlight, which causes instability in the molecular bonds between atoms. For example, ammonia (NH₃) is not stable in the Martian atmosphere and breaks down after a few hours. Also due to the thinness of the atmosphere, the temperature difference between day and night is much larger than on Earth, typically around 70 °C. However, the day/night temperature variation is much lower during dust storms when very little light gets through to the surface even during the day, and instead warms the middle atmosphere.

Water and climate

Water on Mars is scarce, with rovers Spirit and Opportunity finding less than in Earth's driest desert.

The climate is much colder than Earth, with mean surface temperatures between 186 and 268 K (−87 and −5 °C) (depending on the season and latitude). The lowest temperature ever recorded on Earth was 184 K (−89.2 °C) in Antarctica.

Because Mars is about 52% farther from the Sun, the amount of solar energy entering its upper atmosphere per unit area (the solar constant) is around 43.3% of what reaches the Earth's upper atmosphere. However, due to the much thinner atmosphere, a higher fraction of the solar energy reaches the surface as radiation. The maximum solar irradiance on Mars is about 590 W/m compared to about 1000 W/m at the Earth's surface; optimal conditions on the Martian equator can be compared to those on Devon Island in the Canadian Arctic in June. Mars' orbit is more eccentric than Earth's, increasing temperature and solar constant variations over the course of the Martian year. Mars has no rain and virtually no clouds, so although cold, it is permanently sunny (apart from during dust storms). This means solar panels can always operate at maximum efficiency on dust-free days.

Global dust storms are common throughout the year and can cover the entire planet for weeks, blocking sunlight from reaching the surface. This has been observed to cause temperature drops of 4 °C for several months after the storm. In contrast, the only comparable events on Earth are infrequent large volcanic eruptions such as the Krakatoa event which threw large amounts of ash into the atmosphere in 1883, causing a global temperature drop of around 1 °C. These dust storms would affect electricity production from solar panels for long periods, and interfere with communications with Earth.

Temperature and seasons

Mars has an axial tilt of 25.19°, similar to Earth's 23.44°. As a result, Mars has seasons much like Earth, though on average they last nearly twice as long because the Martian year is about 1.88 Earth years. Mars' temperature regime is more similar to Earth's than to any other planet's in the solar system. While generally colder than Earth, Mars can have Earth-like temperatures in some areas and at certain times.

Soil

The Martian soil is toxic due to relatively high concentrations of chlorine and associated compounds, such as perchlorates, which are hazardous to all known forms of life, even though some halotolerant microorganisms might be able to cope with enhanced perchlorate concentrations by drawing on physiological adaptations similar to those observed in the yeast Debaryomyces hansenii exposed in lab experiments to increasing NaClO₄ concentrations.

Survivability

Plants and animals cannot survive the ambient conditions on the surface of Mars. However, some extremophile organisms that survive in hostile conditions on Earth have endured periods of exposure to environments that approximate some of the conditions found on Mars.

Length of day

The Martian day (or sol) is very close in duration to Earth's. A solar day on Mars is 24 hours, 39 minutes and 35.244 seconds.

Conditions for human habitation

Conditions on the surface of Mars are closer to the conditions on Earth in terms of temperature and sunlight than on any other planet or moon, except for the cloud tops of Venus. However, the surface is not hospitable to humans or most known life forms due to the radiation, greatly reduced air pressure, and an atmosphere with only 0.16% oxygen.

In 2012, it was reported that some lichen and cyanobacteria survived and showed remarkable adaptation capacity for photosynthesis after 34 days in simulated Martian conditions in the Mars Simulation Laboratory (MSL) maintained by the German Aerospace Center (DLR). Some scientists think that cyanobacteria could play a role in the development of self-sustainable crewed outposts on Mars. They propose that cyanobacteria could be used directly for various applications, including the production of food, fuel and oxygen, but also indirectly: products from their culture could support the growth of other organisms, opening the way to a wide range of life-support biological processes based on Martian resources.

Humans have explored parts of Earth that match some conditions on Mars. Based on NASA rover data, temperatures on Mars (at low latitudes) are similar to those in Antarctica. The atmospheric pressure at the highest altitudes reached by piloted balloon ascents (35 km (114,000 feet) in 1961, 38 km in 2012) is similar to that on the surface of Mars. However, the pilots were not exposed to the extremely low pressure, as it would have killed them, but seated in a pressurized capsule.

Human survival on Mars would require living in artificial Mars habitats with complex life-support systems. One key aspect of this would be water processing systems. Being made mainly of water, a human being would die in a matter of days without it. Even a 5–8% decrease in total body water causes fatigue and dizziness, and with a 10% decrease comes physical and mental impairment (See Dehydration). A person in the UK uses 70–140 litres of water per day on average. Through experience and training, astronauts on the ISS have shown it is possible to use far less, and that around 70% of what is used can be recycled using the ISS water recovery systems. (For instance, half of all water is used during showers.) Similar systems would be needed on Mars but would need to be much more efficient, since regular robotic deliveries of water to Mars would be prohibitively expensive (the ISS is supplied with water four times per year). Potential access to on-site water (frozen or otherwise) via drilling has been investigated by NASA.

Effects on human health

Mars presents a hostile environment for human habitation. Different technologies have been developed to assist long-term space exploration and may be adapted for habitation on Mars. The existing record for the longest continuous space flight is 438 days by cosmonaut Valeri Polyakov, and the most accrued time in space is 1,111 days by Oleg Kononenko. The longest time spent outside the protection of the Earth's Van Allen radiation belt is about 12 days for the Apollo 17 Moon landing. This is minor in comparison to the 1100-day journey to Mars and back envisioned by NASA for possibly as early as the year 2028. Scientists have also hypothesized that many different biological functions can be negatively affected by the environment of Mars. Due to higher levels of radiation, there are a multitude of physical side-effects that must be mitigated. In addition, Martian soil contains high levels of toxins which are hazardous to human health.

Physical effects

The difference in gravity may negatively affect human health by weakening bones and muscles. There is also risk of osteoporosis and cardiovascular problems. Current rotations on the International Space Station put astronauts in zero gravity for six months, a comparable length of time to a one-way trip to Mars. This gives researchers the ability to better understand the physical state that astronauts going to Mars would arrive in. Once on Mars, surface gravity is only 38% of that on Earth. Microgravity affects the cardiovascular, musculoskeletal and neurovestibular (central nervous) systems. The cardiovascular effects are complex. On Earth, blood within the body stays 70% below the heart, but in microgravity this is not the case due to nothing pulling the blood down. This can have several negative effects. Once entering into microgravity, the blood pressure in the lower body and legs is significantly reduced. This causes legs to become weak through loss of muscle and bone mass. Astronauts show signs of a puffy face and chicken legs syndrome. After the first day of reentry back to earth, blood samples showed a 17% loss of blood plasma, which contributed to a decline of erythropoietin secretion. On the skeletal system which is important to support body posture, long space flight and exposure to microgravity cause demineralization and atrophy of muscles. During re-acclimation, astronauts were observed to have a myriad of symptoms including cold sweats, nausea, vomiting and motion sickness. Returning astronauts also felt disoriented. Once on Mars with its lesser surface gravity (38% percent of Earth's), these health effects would be a serious concern. Upon return to Earth, recovery from bone loss and atrophy is a long process and the effects of microgravity may never fully reverse.

Radiation

Dangerous amounts of radiation reach Mars' surface despite it being much further from the Sun compared to Earth. Mars has lost its inner dynamo giving it a weaker global magnetosphere than Earth. Combined with a thin atmosphere, this permits a significant amount of ionizing radiation to reach the Martian surface. There are two main types of radiation risks to traveling outside the protection of Earth's atmosphere and magnetosphere: galactic cosmic rays (GCR) and solar energetic particles (SEP). Earth's magnetosphere protects from charged particles from the Sun, and the atmosphere protects against uncharged and highly energetic GCRs. There are ways to mitigate solar radiation, but without much of an atmosphere, the only solution to the GCR flux is heavy shielding amounting to roughly 15 centimeters of steel, 1 meter of rock, or 3 meters of water, limiting human colonists to living underground most of the time.

The Mars Odyssey spacecraft carries an instrument, the Mars Radiation Environment Experiment (MARIE), to measure the radiation. MARIE found that radiation levels in orbit above Mars are 2.5 times higher than at the International Space Station, or much higher than the combined global fallout of the thousands of nuclear weapons testing. The average daily dose was about 220 μGy (22 mrad)—equivalent to 0.08 Gy per year. A three-year exposure to such levels would exceed the safety limits currently adopted by NASA, and the risk of developing cancer due to radiation exposure after a Mars mission could be two times greater than what scientists previously thought. Occasional solar proton events (SPEs) produce much higher doses, as observed in September 2017, when NASA reported radiation levels on the surface of Mars were temporarily doubled, and were associated with an aurora 25-times brighter than any observed earlier, due to a massive, and unexpected, solar storm. Building living quarters underground (possibly in Martian lava tubes) would significantly lower the colonists' exposure to radiation.

Much remains to be learned about space radiation. In 2003, NASA's Lyndon B. Johnson Space Center opened a facility, the NASA Space Radiation Laboratory, at Brookhaven National Laboratory, that employs particle accelerators to simulate space radiation. The facility studies its effects on living organisms, as well as experimenting with shielding techniques. Initially, there was some evidence that this kind of low level, chronic radiation is not as dangerous as once thought; and that radiation hormesis occurs. However, results from a 2006 study indicated that protons from cosmic radiation may cause twice as much serious damage to DNA as previously estimated, exposing astronauts to greater risk of cancer and other diseases. As a result of the higher radiation in the Martian environment, the summary report of the Review of U.S. Human Space Flight Plans Committee released in 2009 reported that "Mars is not an easy place to visit with existing technology and without a substantial investment of resources." NASA is exploring a variety of alternative techniques and technologies such as deflector shields of plasma to protect astronauts and spacecraft from radiation.

Psychological effects

Due to the communication delays, new protocols need to be developed in order to assess crew members' psychological health. Researchers have developed a Martian simulation called HI-SEAS (Hawaii Space Exploration Analog and Simulation) that places scientists in a simulated Martian laboratory to study the psychological effects of isolation, repetitive tasks, and living in close-quarters with other scientists for up to a year at a time. Computer programs are being developed to assist crews with personal and interpersonal issues in absence of direct communication with professionals on Earth.

Terraforming

The terraforming of Mars is the hypothetical set of planetary engineering projects that would modify Mars to allow terrestrial life to survive free of protection or mediation. Proposals for the terraforming of Mars have been put forward, but there is considerable debate about their feasibility and the ethics associated with terraforming.

Minimum size of a colony

No consensus exists about the minimum viable size of a colony required to ensure that inbreeding would not occur. Through mathematical modelling of the time spent by people on work in a colony, Jean-Marc Salotti concluded that the minimum number for a colony on Mars is 110. This is close to other studies of the genetic problems involved in the longer journey to Proxima Centauri b (6,000+ years). Other studies, focused on interstellar settlement, have concluded that minimum viable populations or a desirable number of colonists range from 198 to as high as 10,000.

To be self-sustaining, a colony would have to be large enough to provide all the necessary living services. These include:

• Ecosystem management: producing appropriate gases, controlling air composition pressure and temperature, collecting and producing water, growing food and processing organic wastes.
• Energy production: this includes extracting methane for vehicles and, if photovoltaic cells are used to produce energy, this would include the extraction and processing of silicates, to augment or replace any original equipment.
• Industry: extracting and processing appropriate ores, manufacturing tools and other objects; producing clothes, medicine, glass, ceramics, and plastics.
• Building: even if the base is constructed before arrival, it will need frequent adaptation according to the evolution of the settlement as well as inevitable replacement.
• Social activities: this includes raising children and educating them, health care, preparing meals, cleaning, washing, organizing the work and making decisions. Time for sport, culture and entertainment can be minimized but not eliminated.

Transportation

Interplanetary spaceflight

Mars requires less energy per unit mass (delta V) to reach from Earth than any planet except Venus. Using a Hohmann transfer orbit, a trip to Mars requires approximately nine months in space. Modified transfer trajectories that cut the travel time to four to seven months in space are possible with incrementally higher amounts of energy and fuel compared to a Hohmann transfer orbit, and are in standard use for robotic Mars missions. Shortening the travel time below about six months requires higher delta-v and an increasing amount of fuel, and is difficult with chemical rockets. It could be feasible with advanced spacecraft propulsion technologies, some of which have already been tested to varying levels, such as Variable Specific Impulse Magnetoplasma Rocket, and nuclear rockets. In the former case, a trip time of forty days could be attainable, and in the latter, a trip time down to about two weeks. In 2016, a University of California, Santa Barbara scientist said they could further reduce travel time for a small robotic probe to Mars to "as little as 72 hours" with the use of a laser propelled sail (directed photonic propulsion) system instead of the fuel-based rocket propulsion system.

During the journey, the astronauts would be subject to radiation, which would require a means to protect them. Cosmic radiation and solar wind cause DNA damage, which significantly increases the risk of cancer. The effect of long-term travel in interplanetary space is unknown, but scientists estimate an added risk of between 1% and 19% (one estimate is 3.4%) for males to die of cancer because of the radiation during the journey to Mars and back to Earth. For females the probability is higher due to generally larger glandular tissues.

Landing on Mars

Mars has a surface gravity 0.38 times that of Earth, and the density of its atmosphere is about 0.6% of that on Earth. The relatively strong gravity and the presence of aerodynamic effects make it difficult to land heavy, crewed spacecraft with thrusters only, as was done with the Apollo Moon landings, yet the atmosphere is too thin for aerodynamic effects to be of much help in aerobraking and landing a large vehicle. Landing piloted missions on Mars would require braking and landing systems different from anything used to land crewed spacecraft on the Moon or robotic missions on Mars.

If one assumes carbon nanotube construction material will be available with a strength of 130 GPa (19,000,000 psi) then a space elevator could be built to land people and material on Mars. A space elevator on Phobos (a Martian moon) has also been proposed.

Phobos as a space elevator for Mars

Phobos is synchronously orbiting Mars, where the same face stays facing the planet at ~6,028 km above the Martian surface. A space elevator could extend down from Phobos to Mars 6,000 km, about 28 kilometers from the surface, and just out of the atmosphere of Mars. A similar space elevator cable could extend out 6,000 km the opposite direction that would counterbalance Phobos. In total the space elevator would extend out over 12,000 km which would be below Areostationary orbit of Mars (17,032 km). A rocket launch would still be needed to get the rocket and cargo to the beginning of the space elevator 28 km above the surface. The surface of Mars is rotating at 0.25 km/s at the equator and the bottom of the space elevator would be rotating around Mars at 0.77 km/s, so only 0.52 km/s of Delta-v would be needed to get to the space elevator. Phobos orbits at 2.15 km/s and the outer most part of the space elevator would rotate around Mars at 3.52 km/s.

Equipment needed for colonization

Colonization of Mars would require a wide variety of equipment—both equipment to directly provide services to humans and production equipment used to produce food, propellant, water, energy and breathable oxygen—in order to support human colonization efforts. Required equipment will include:

• Basic utilities (oxygen, power, local communications, waste disposal, sanitation and water recycling)
• Habitats
• Storage facilities
• Workspaces
• Airlock, for pressurization and dust management
• Resource extraction equipment—initially for water and oxygen, later for a wider cross section of minerals, building materials, etc.
• Equipment for energy production and energy storage, some solar and perhaps nuclear as well

• Food production spaces and equipment
• Propellant production equipment, generally thought to be hydrogen and methane through the Sabatier reaction for fuel—with oxygen oxidizer—for chemical rocket engines
• Fuels or other energy source for use with surface transportation; such as Methanol or carbon monoxide/oxygen (CO/O₂) engines have been suggested for early surface transportation use as both carbon monoxide and oxygen can be straightforwardly produced by zirconium dioxide electrolysis from the Martian atmosphere without requiring use of any of the Martian water resources to obtain hydrogen
• Off-planet communication equipment
• Equipment for moving over the surface—Mars suit, crewed rovers and possibly Mars aircraft.

Basic utilities

In order to function, the colony would need the basic utilities to support human civilization. These would need to be designed to handle the harsh Martian environment and would either have to be serviceable while wearing an EVA (extra vehicular activity) suit or housed inside a human habitable environment. For example, if electricity generation systems rely on solar power, large energy storage facilities will also be needed to cover the periods when dust storms block out the sun, and automatic dust removal systems may be needed to avoid human exposure to conditions on the surface. If the colony is to scale beyond a few people, systems will also need to maximise use of local resources to reduce the need for resupply from Earth, for example by recycling water and oxygen and being adapted to be able to use any water found on Mars, whatever form it is in.

Communication with Earth

Communications with Earth are relatively straightforward during the half-sol when Earth is above the Martian horizon. NASA and ESA included communications relay equipment in several of the Mars orbiters, so Mars already has communications satellites. While these will eventually wear out, additional orbiters with communication relay capability are likely to be launched before any colonization expeditions are mounted.

The one-way communication delay due to the speed of light ranges from about 3 minutes at closest approach (approximated by perihelion of Mars minus aphelion of Earth) to 22 minutes at the largest possible superior conjunction (approximated by aphelion of Mars plus aphelion of Earth). Real-time communication, such as telephone conversations or Internet Relay Chat, between Earth and Mars would be highly impractical due to the long time lags involved. NASA has found that direct communication can be blocked for about two weeks every synodic period, around the time of superior conjunction when the Sun is directly between Mars and Earth, although the actual duration of the communications blackout varies from mission to mission depending on various factors—such as the amount of link margin designed into the communications system, and the minimum data rate that is acceptable from a mission standpoint. In reality most missions at Mars have had communications blackout periods of the order of a month.

A satellite at the L₄ or L₅ Earth–Sun Lagrangian point could serve as a relay during this period to solve the problem; even a constellation of communications satellites would be a minor expense in the context of a full colonization program. However, the size and power of the equipment needed for these distances make the L4 and L5 locations unrealistic for relay stations, and the inherent stability of these regions, although beneficial in terms of station-keeping, also attracts dust and asteroids, which could pose a risk. Despite that concern, the STEREO probes passed through the L4 and L5 regions without damage in late 2009.

Recent work by the University of Strathclyde's Advanced Space Concepts Laboratory, in collaboration with the European Space Agency, has suggested an alternative relay architecture based on highly non-Keplerian orbits. These are a special kind of orbit produced when continuous low-thrust propulsion, such as that produced from an ion engine or solar sail, modifies the natural trajectory of a spacecraft. Such an orbit would enable continuous communications during solar conjunction by allowing a relay spacecraft to "hover" above Mars, out of the orbital plane of the two planets. Such a relay avoids the problems of satellites stationed at either L4 or L5 by being significantly closer to the surface of Mars while still maintaining continuous communication between the two planets.

Robotic precursors

The path to a human colony could be prepared by robotic systems such as the Mars Exploration Rovers Spirit, Opportunity, Curiosity and Perseverance. These systems could help locate resources, such as ground water or ice, that would help a colony grow and thrive. The lifetimes of these systems would be years and even decades, and as recent developments in commercial spaceflight have shown, it may be that these systems will involve private as well as government ownership. These robotic systems also have a reduced cost compared with early crewed operations, and have less political risk.

Wired systems might lay the groundwork for early crewed landings and bases, by producing various consumables including fuel, oxidizers, water, and construction materials. Establishing power, communications, shelter, heating, and manufacturing basics can begin with robotic systems, if only as a prelude to crewed operations.

Mars Surveyor 2001 Lander MIP (Mars ISPP Precursor) was to demonstrate manufacture of oxygen from the atmosphere of Mars, and test solar cell technologies and methods of mitigating the effect of Martian dust on power systems.

Before any people are transported to Mars on the notional 2020s Mars transportation infrastructure envisioned by SpaceX, a number of robotic cargo missions would be undertaken first in order to transport the requisite equipment, habitats and supplies. Equipment that would be necessary would include "machines to produce fertilizer, methane and oxygen from Mars' atmospheric nitrogen and carbon dioxide and the planet's subsurface water ice" as well as construction materials to build transparent domes for initial agricultural areas.

Stages

In the literature there has been a differentiation of the different stages Mars settlement would encompass:

1. Pre-settlement: small outpost (near-term future)
2. In-settlement: permanent settlement (medium-term future)
3. Post-settlement: self-sufficient society (long-term future)

Economics

Economic drivers and prerequisites

The rise of reusable launch vehicles in the 2020s has substantially reduced the cost of access to space. With a published price of US$62 million per launch of up to 22,800 kg (50,300 lb) payload to low Earth orbit or 4,020 kg (8,860 lb) to Mars, SpaceX Falcon 9 rockets are already the "cheapest in the industry". SpaceX's reusability includes the Falcon Heavy and future methane-based launch vehicles including the Starship. SpaceX was successful in developing the reusable technology with Falcon 9 and Falcon Heavy and as of April 2024, it was rapidly advancing towards reusability of Starship. This is expected to "have a major impact on the cost of access to space", and change the increasingly competitive market in space launch services.

Alternative funding approaches might include the creation of inducement prizes. For example, the 2004 President's Commission on Implementation of United States Space Exploration Policy suggested that an inducement prize contest should be established, perhaps by government, for the achievement of space colonization. One example provided was offering a prize to the first organization to place humans on the Moon and sustain them for a fixed period before they return to Earth.

Local resource extraction and trade with Earth

No evidence of abundant resources on Mars with value to Earth has been collected. The distance between Mars and Earth would present a considerable challenge to potential trade between the planets.

Local trade

Some early Mars colonies might specialize in developing local resources for Martian consumption, such as water and/or ice. Local resources can also be used in infrastructure construction. One source of Martian ore currently known to be available is metallic iron in the form of nickel–iron meteorites. Iron in this form is more easily extracted than from the iron oxides that cover the planet.

Another inter-Martian trade good during colonization could be manure, as soil will be very poor for growing plants.

Solar power is a candidate for power for a Martian colony. Solar insolation (the amount of solar radiation that reaches Mars) is about 42% of that on Earth, since Mars is about 52% farther from the Sun and insolation falls off as the square of distance. However, Mars' thin atmosphere would allow almost all of that energy to reach the surface as compared to Earth, where the atmosphere absorbs roughly a quarter of the solar radiation. Sunlight on the surface of Mars would be much like a moderately cloudy day on Earth.

Mining the asteroid belts from Mars

Since Mars is much closer to the asteroid belt than Earth, it would take less Delta-v to get to the Asteroid belt and return minerals to Mars. One hypothesis is that the Moons of Mars (Phobos and Deimos) are actually asteroid captures from the Asteroid belt.

16 Psyche in the main belt could have over 10,000 quadrillion dollars worth of minerals. On October 13, 2023, NASA launched the Psyche orbiter, which is set to reach the asteroid by August 2029.

511 Davida could have $27 quadrillion worth of minerals and resources. Using the moon Phobos to launch spacecraft is energetically favorable and a useful location from which to dispatch missions to main belt asteroids.

Mining the asteroid belt from Mars and its moons could help in the colonization of Mars.

Possible settlement locations

Poles

It has been proposed to set up a first base at a Martian pole, which would allow access to water.

Caves

Caves would naturally provide a degree of insulation from Martian hazards for humans on the planet. These hazards include radiation, impactor events, and the wide range in temperatures on the surface.

Mars Odyssey found what appear to be natural caves near the volcano Arsia Mons. It has been speculated that settlers could benefit from the shelter that these or similar structures could provide from radiation and micrometeoroids. Geothermal energy is also suspected in the equatorial regions.

A team of researchers which presented at Geological Society of America Connects 2022 identified some 139 caves worth exploring as potential shelters. Each was within 60 miles (100 km) of a location ideal for use as a landing site and had been imaged in high-resolution by HiRISE.

Lava tubes

Several possible Martian lava tube skylights have been located on the flanks of Arsia Mons. Earth based examples indicate that some should have lengthy passages offering complete protection from radiation and be relatively easy to seal using on-site materials, especially in small subsections.

Hellas Planitia

Hellas Planitia is the lowest lying plain below the Martian geodetic datum. The atmospheric pressure is relatively higher in this place when compared to the rest of Mars.

Impact of human presence

There has been a lively discussion about how human presence on Mars would relate to possible indigenous life on Mars. More fundamentally even the very understanding of human life and in relation to extraterrestrial life, and their different worths have been discussed.

Planetary protection

Robotic spacecraft to Mars are required to be sterilized, to have at most 300,000 spores on the exterior of the craft—and more thoroughly sterilized if they contact "special regions" containing water, otherwise there is a risk of contaminating not only the life-detection experiments but possibly the planet itself.

It is impossible to sterilize human missions to this level, as humans are host to typically a hundred trillion microorganisms of thousands of species of the human microbiome, and these cannot be removed while preserving the life of the human. Containment seems the only option, but it is a major challenge in the event of a hard landing (i.e. crash). There have been several planetary workshops on this issue, yet no final guidelines for a way forward. Human explorers would also be vulnerable to back contamination to Earth if they become carriers of microorganisms should Mars have life.

Political and legal context

In the 1967 United Nations Outer Space Treaty, it was determined that no country may take claim to space or its inhabitants.

NASA had to deal with several cuts in funding. During the presidency of Barack Obama, the objective for NASA to reach Mars was pushed to the background. In 2017, president Donald Trump promised to return humans to the Moon and eventually Mars, and increased the NASA budget by $1.1 billion, to mostly focus on development of the new Space Launch System.

It is unforeseen how the first human landing on Mars will change the current policies regarding the exploration of space and occupancy of celestial bodies. Since the planet Mars offers a challenging environment and dangerous obstacles for humans to overcome, the laws and culture on the planet will most likely be different from those on Earth. With Elon Musk announcing his plans for travel to Mars, it is uncertain how the dynamic of a private company possibly being the first to put a human on Mars will play out on a national and global scale.

Ethics

It has been argued that settling Mars may divert attention from solving problems on Earth that may also become problems on Mars, with the reasoning that plans about Mars are always about the plans we have for Earth. Jeff Bezos, founder of Blue Origin, SpaceX's competitor in commercial spaceflight, has rejected Mars colonization as a mere "Plan B", suggesting instead to preserve Earth through space development and moving all heavy industrial activity to space.

It has been pointed out that the impact of human settlement on Mars, with regards to planetary protection, a crucial issue in space exploration, has not been comprehensively answered.

It has been argued that there are physical and social consequences that need to be addressed with regards to long-term survival on the surface of Mars. Former President Barack Obama has characterized Mars as more inhospitable than Earth would be "even after a nuclear war", with others pointing out that Earth and underground shelters on Earth could still provide better conditions and protection for more people from apocalyptic scenarios. Mars colonization has been called a 'dangerous delusion' by Lord Martin Rees, a British cosmologist/astrophysicist and the Astronomer Royal of the United Kingdom. Musk has stated that staying on Mars is a life threatening endeavor that needs to be glorious to be worth it. Exploration of Mars has also been argued to be better left to the already successful robotic missions, with crewed missions simply being too expensive, dangerous and boring.

Colonialism

Space colonization in general has been discussed as a continuation of imperialism and colonialism, especially regarding Mars colonial decision making, reasons for colonial labor and land exploitation have been questioned with postcolonial critique. Seeing the need for inclusive and democratic participation and implementation of any space and Mars exploration, infrastructure, or colonialization, many have called for dramatic sociological reforms and guarantees to prevent racism, sexism, and other forms of prejudice.

The narrative of space exploration as a "New Frontier" has been criticized as an unreflected continuation of settler colonialism and manifest destiny, continuing the narrative of colonial exploration as fundamental to the assumed human nature.

The predominant perspective of territorial colonization in space has been called surfacism, especially comparing advocacy for colonization of Mars opposed to Venus.

Dangers during pregnancy

One possible ethical challenge that space travelers might face is that of pregnancy during the trip. According to NASA's policies, it is forbidden for members of the crew to engage in sex in space. NASA wants its crew members to treat each other like coworkers would in a professional environment. A pregnant member on a spacecraft is dangerous to all those aboard. The pregnant woman and child would need additional nutrition from the rations aboard, as well as special treatment and care. The pregnancy would impinge on the pregnant crew member's duties and abilities. It is still not fully known how the environment in a spacecraft would affect the development of a child aboard. It is known however that a fetus would be more susceptible to solar radiation in space, which would likely have a negative effect on its cells and genetics. During a long trip to Mars, it is likely that members of a craft may engage in sex due to their stressful and isolated environment.

Advocacy

Mars colonization is advocated by several non-governmental groups for a range of reasons and with varied proposals. One of the oldest groups is the Mars Society who promote a NASA program to accomplish human exploration of Mars and have set up Mars analog research stations in Canada and the United States. Mars to Stay advocates recycling emergency return vehicles into permanent settlements as soon as initial explorers determine permanent habitation is possible.

Elon Musk founded SpaceX with the long-term goal of developing the technologies that will enable a self-sustaining human colony on Mars. Richard Branson, in his lifetime, is "determined to be a part of starting a population on Mars. I think it is absolutely realistic. It will happen... I think over the next 20 years," "we will take literally hundreds of thousands of people to space and that will give us the financial resources to do even bigger things".

Author Robert Zubrin has been a major advocate for Mars exploration and colonization for many years. He is a member of the Mars society and has authored several fiction and nonfiction books about the subject. In 1996 he wrote The Case for Mars: The Plan to Settle the Red Planet and Why We Must. He continues to advocate for Mars and space exploration with his most recent book being The Case for Space: How the Revolution in Spaceflight Opens Up a Future of Limitless Possibility.

In June 2013, Buzz Aldrin, American engineer and former astronaut, and the second person to walk on the Moon, wrote an opinion, published in The New York Times, supporting a human mission to Mars and viewing the Moon "not as a destination but more a point of departure, one that places humankind on a trajectory to homestead Mars and become a two-planet species". In August 2015, Aldrin, in association with the Florida Institute of Technology, presented a "master plan", for NASA consideration, for astronauts, with a "tour of duty of ten years", to colonize Mars before the year 2040.

There are critics of the project of Mars colonization. American political scientist Daniel Deudney has argued that a fully developed Mars colony represents an existential threat to humans remaining on Earth. His book, Dark Skies: Space Expansionism, Planetary Geopolitics, and the Ends of Humanity, challenges the widespread view among advocates that a Mars colony would be friendly to the interests of humans on Earth. According to Deudney, this is merely an assumption based on the largely unexamined claim that a future Mars colony will be a straightforward extension of civilization on Earth, rather than a new kind of civilization with distinct goals, values, fears and desires.

In fiction

A few instances in fiction provide detailed descriptions of Mars colonization. They include:

• Aria (2002–2008), by Kozue Amano
• Away (2020), published by Netflix
• Climbing Olympus (1994), by Kevin J. Anderson
• Colony One Mars: A SciFi Thriller (2016), by Gerald Kilby
• First Landing (2002), by Robert Zubrin
• For All Mankind (2019), airing originally on Apple TV+, from Series 3 onwards
• Icehenge (1985), the Mars trilogy (Red Mars, Green Mars, Blue Mars, 1992–1996), and The Martians (1999), by Kim Stanley Robinson
• John Carter (2012), by Mark Andrews
• Man Plus (1976), by Frederik Pohl
• The Martian (1992) and Return to Mars (1999), by Ben Bova
• Mars (2016), by National Geographic
• Mars Diaries (2000), by Sigmund Brouwer
• Mars Underground (1997), by William K. Hartmann
• Martian Gothic: Unification (2000), developed by Creative Reality for Microsoft Windows and Coyote Developments for PlayStation, published by TalonSoft for Microsoft Windows and Take-Two Interactive for PlayStation
• Mr. Nobody (2009), by Jaco Van Dormael
• Red Faction (2001), developed by Volition, published by THQ
• Red Planet (1949), by Robert A. Heinlein
• Surviving Mars (2018), developed by Haemimont Games, published by Paradox Interactive
• Terra Formars (2011)
• TerraGenesis (2016), developed by Edgeworks Entertainment, published by Tilting Point
• The Destruction of Faena (1974), by Alexander Kazantsev
• The Expanse (2016–2021), airing originally on Syfy, then Amazon Prime
• The Martian (2011), by Andy Weir (and the 2015 film, directed by Ridley Scott)
• The Martian Chronicles (1950), by Ray Bradbury
• The Sands of Mars (1951), by Arthur C. Clarke
• The Space Between Us (2016 film), by Peter Chelsom
• Tom and Jerry: Blast Off to Mars (2005), animated science fiction comedy film by Warner Bros. Animation and Turner Entertainment
• Total Recall (1990), by Paul Verhoeven
• We Can Remember It for You Wholesale (1966), by Philip K. Dick

Interactive Mars map

See also

• Astrobotany – Study of plants grown in spacecraft
• Climate of Mars
• Colonization of the asteroid belt – Proposed concepts for the human colonization of the asteroids
• Colonization of the Moon – Settlement on the Moon
• Colonization of Venus – Proposed colonization of the planet Venus
• Effect of spaceflight on the human body – Medical issues associated with spaceflight
• Exploration of Mars
• Health threat from cosmic rays – Cancer causing exposure to ionizing radiation in spaceflightPages displaying short descriptions of redirect targets
• Human mission to Mars – Proposed concepts
• Human outpost – Human habitats located in environments inhospitable for humans
• In situ resource utilization – Astronautical use of materials harvested in outer space
• Inspiration Mars – Defunct, proposed a crewed flyby missionPages displaying short descriptions of redirect targets
• Space architecture – Architecture of off-planet habitable structures
• SpaceX Mars transportation infrastructure – Proposed human Mars program by SpaceXPages displaying short descriptions of redirect targets
• Life on Mars – Scientific assessments on the microbial habitability of Mars
• List of crewed Mars mission plans
• Mars analog habitat – Research simulating the environment on Mars
• Mars Desert Research Station – Longest-running Mars analog habitat
• Mars habitat – Facility where humans could live on Mars
• Mars Outpost
• Mars race – Attempts by various countries to land a human on Mars
• Marsification
• Martian – Depictions of the planetPages displaying short descriptions of redirect targets
• Martian soil – Fine regolith found on the surface of MarsPages displaying short descriptions of redirect targets
• Vision for Space Exploration – 2004 US human space exploration plan
• NewSpace – Spaceflight technology development not paid for by a government agencyPages displaying short descriptions of redirect targets
• Terraforming of Mars – Hypothetical modification of Mars into a habitable planet
• The Case for Mars – Robert Zubrin book on potential colonization
• Water on Mars – Study of past and present water on Mars

References

1. ^ Wall, Mike (October 25, 2019). "Bill Nye: It's Space Settlement, Not Colonization". Space.com. Retrieved July 13, 2024.
2. ^ Puumala, Mikko M.; Sivula, Oskari; Lehto, Kirsi (2023). "Moving to Mars: The Feasibility and Desirability of Mars Settlements". Space Policy. 66: 101590. Bibcode:2023SpPol..6601590P. doi:10.1016/j.spacepol.2023.101590.
3. ^ Eijk, Cristian van (2020). "Sorry, Elon: Mars is not a legal vacuum – and it's not yours, either". Völkerrechtsblog. Fachinformationsdienst für internationale und interdisziplinäre Rechtsforschung. doi:10.17176/20210107-183703-0. Retrieved July 13, 2024.
4. ^ Bartels, Meghan (May 25, 2018). "Should We Colonize Space or Decolonize It?". Newsweek. Retrieved July 13, 2024.
5. "The Case for Colonizing Mars, by Robert Zubrin". NSS. August 3, 2017. Retrieved September 16, 2024.
6. "Why go to Mars?". ESA. Retrieved September 17, 2024.
7. "Humans to Mars". NASA. March 10, 2023. Retrieved September 17, 2024.
8. Scharmen, Fred (July 3, 2017). "Highest and Best Use: Subjectivity and Climates Off and After Earth". Journal of Architectural Education. 71 (2): 184–196. doi:10.1080/10464883.2017.1340775. ISSN 1046-4883.
9. Wattles, Jackie (September 8, 2020). "Colonizing Mars could be dangerous and ridiculously expensive. Elon Musk wants to do it anyway". CNN. Retrieved September 16, 2024.
10. Mutch, T. A.; et al. (August 1976). "The Surface of Mars: The View from the Viking 1 Lander". Science. New Series. 193 (4255): 791–801. Bibcode:1976Sci...193..791M. doi:10.1126/science.193.4255.791. JSTOR 1742881. PMID 17747782. S2CID 42661323.
11. "China plans its first crewed mission to Mars in 2033". Reuters. June 24, 2021. Retrieved July 18, 2024.
12. ^ Zubrin, Robert (1996). The Case for Mars: The Plan to Settle the Red Planet and Why We Must. Touchstone. ISBN 978-0-684-83550-1.
13. "UAE's Mars 2117 is put in action". February 22, 2017. Archived from the original on July 16, 2021.
14. "Mars 2117". Archived from the original on July 16, 2021. Retrieved July 16, 2021.
15. West, John B. (1999). "Barometric pressures on Mt. Everest: New data and physiological significance". Journal of Applied Physiology. 86 (3): 1062–1066. doi:10.1152/jappl.1999.86.3.1062. PMID 10066724. S2CID 27875962.
16. Fong, MD, Kevin (February 12, 2014). "The Strange, Deadly Effects Mars Would Have on Your Body". Wired. Archived from the original on March 25, 2014. Retrieved February 12, 2014.
17. "Gravity Hurts (so Good)". NASA. 2001. Archived from the original on May 28, 2017. Retrieved July 12, 2017.
18. "Mars Mice". science.nasa.gov. 2004. Archived from the original on May 16, 2017. Retrieved July 12, 2017.
19. Phillips, Tony (January 31, 2001). "The Solar Wind at Mars". NASA. Archived from the original on August 18, 2011. Retrieved July 12, 2017.
20. "What makes Mars so hostile to life?". BBC News. January 7, 2013. Archived from the original on August 30, 2013. Retrieved October 5, 2016.
21. Keating, A.; Goncalves, P. (November 2012). "The impact of Mars geological evolution in high energy ionizing radiation environment through time". Planetary and Space Science – Eslevier. 72 (1): 70–77. Bibcode:2012P&SS...72...70K. doi:10.1016/j.pss.2012.04.009.
22. Whitehouse, David (July 15, 2004). "Dr. David Whitehouse – Ammonia on Mars could mean life". BBC News. Archived from the original on October 31, 2012. Retrieved August 14, 2012.
23. "Mars Weather". Centro de Astrobiología. 2015. Archived from the original on October 25, 2015. Retrieved May 31, 2015.
24. ^ "Opportunity Hunkers Down During Dust Storm". NASA. June 8, 2018. Archived from the original on December 5, 2018. Retrieved November 26, 2018.
25. "Why is Mars So Dry?". Universe Today. February 16, 2004. Archived from the original on November 27, 2018. Retrieved November 26, 2018.
26. Hecht, M. H. (2002). "Metastability of Liquid Water on Mars". Icarus. 156 (2): 373–386. Bibcode:2002Icar..156..373H. doi:10.1006/icar.2001.6794.
27. Webster, Guy; Brown, Dwayne (December 10, 2013). "NASA Mars Spacecraft Reveals a More Dynamic Red Planet". NASA. Archived from the original on December 14, 2013. Retrieved March 2, 2014.
28. Hamilton, Calvin. "Mars Introduction". Archived from the original on August 16, 2013. Retrieved March 8, 2013.
29. Elert, Glenn. "Temperature on the Surface of Mars". Archived from the original on November 24, 2013. Retrieved March 8, 2013.
30. Kluger, J. (1992). "Mars, in Earth's Image". Discover Magazine. 13 (9): 70. Bibcode:1992Disc...13...70K. Archived from the original on April 27, 2012. Retrieved June 12, 2015.
31. Haberle, R. M.; McKay, C. P.; Pollack, J. B.; Gwynne, O. E.; Atkinson, D. H.; Appelbaum, J.; Landis, G. A.; Zurek, R. W.; Flood, D. J. (1993). Atmospheric Effects on the Utility of Solar Power on Mars (PDF). Bibcode:1993rnes.book..845H. Archived from the original (PDF) on March 5, 2016.
32. Sharonov, V. V. (1957). "1957SvA.....1..547S Page 547". Harvard.edu. 1: 547. Bibcode:1957SvA.....1..547S.
33. "Sunlight on Mars – Is There Enough Light on Mars to Grow Tomatoes?". first the seed foundation. Archived from the original on November 26, 2018. Retrieved November 26, 2018.
34. Badescu, Viorel (2009). Mars: Prospective Energy and Material Resources. Springer Science & Business Media. p. 83. ISBN 978-3-642-03629-3. Archived from the original on December 21, 2019. Retrieved December 28, 2018.
35. Tomatosphere. "Teachers guide – Sunlight on mars – Tomatosphere". tomatosphere.org. Archived from the original on June 23, 2015. Retrieved June 12, 2015.
36. ^ Fenton, Lori K.; Geissler, Paul E.; Haberle, Robert M. (2007). "Global warming and climate forcing by recent albedo changes on Mars" (PDF). Nature. 446 (7136): 646–649. Bibcode:2007Natur.446..646F. doi:10.1038/nature05718. PMID 17410170. S2CID 4411643. Archived from the original (PDF) on July 8, 2007.
37. "Mars covered in toxic chemicals that can wipe out living organisms, tests reveal". The Guardian. July 6, 2017. Archived from the original on February 18, 2021. Retrieved November 26, 2018.
38. "Toxic Mars: Astronauts Must Deal with Perchlorate on the Red Planet". space.com. June 13, 2013. Archived from the original on November 20, 2020. Retrieved November 26, 2018.
39. Heinz, Jacob; Doellinger, Joerg; Maus, Deborah; Schneider, Andy; Lasch, Peter; Grossart, Hans-Peter; Schulze-Makuch, Dirk (August 10, 2022). "Perchlorate-specific proteomic stress responses of Debaryomyces hansenii could enable microbial survival in Martian brines". Environmental Microbiology. 24 (11): 1462–2920.16152. Bibcode:2022EnvMi..24.5051H. doi:10.1111/1462-2920.16152. ISSN 1462-2912. PMID 35920032.
40. "Can Life exist on Mars?". Mars Academy. ORACLE-ThinkQuest. Archived from the original on February 22, 2001.
41. Badescu, Viorel (2009). Mars: Prospective Energy and Material Resources (illustrated ed.). Springer Science & Business Media. p. 600. ISBN 978-3-642-03629-3. Archived from the original on December 25, 2019. Retrieved May 20, 2016. Extract of page 600 Archived April 16, 2017, at the Wayback Machine
42. Landis, Geoffrey A.; Colozza, Anthony; LaMarre, Christopher M. (June 2002). "Atmospheric Flight on Venus" (PDF). Glenn Research Center, National Aeronautics and Space Administration. Archived from the original (PDF) on October 16, 2011.
43. Baldwin, Emily (April 26, 2012). "Lichen survives harsh Mars environment". Skymania News. Archived from the original on May 28, 2012. Retrieved April 27, 2012.
44. de Vera, J.-P.; Kohler, Ulrich (April 26, 2012). "The adaptation potential of extremophiles to Martian surface conditions and its implication for the habitability of Mars" (PDF). EGU General Assembly Conference Abstracts. 14. European Geosciences Union: 2113. Bibcode:2012EGUGA..14.2113D. Archived from the original (PDF) on May 4, 2012. Retrieved April 27, 2012.
45. "Surviving the conditions on Mars". DLR. Archived from the original on March 23, 2018.
46. ^ Verseux, Cyprien; Baqué, Mickael; Lehto, Kirsi; de Vera, Jean-Pierre P.; et al. (August 3, 2015). "Sustainable life support on Mars – the potential roles of cyanobacteria". International Journal of Astrobiology. 15 (1): 65–92. Bibcode:2016IJAsB..15...65V. doi:10.1017/S147355041500021X.
47. "Extreme Planet Takes Its Toll". Mars Exploration Rovers. Jet Propulsion Laboratory, California Institute of Technology. June 12, 2007. Archived from the original on November 2, 2013. Retrieved March 12, 2014.
48. "Higher, Farther, and Longer – Record Balloon Flights in the Second Part of the Twentieth Century". U.S. Centennial Of Flight Commission. Archived from the original on April 30, 2003. Retrieved September 22, 2014.
49. "Barometric Pressure vs. Altitude Table". Sable Systems International. 2014. Archived from the original on October 25, 2007.
50. "How much water does an average person use?". South West Water. Archived from the original on April 7, 2019. Retrieved November 26, 2018.
51. Mui, K. W.; Wong, L. T.; & Law, L. Y. (2007). Domestic water consumption benchmark development for Hong Kong. Building Services Engineering Research & Technology, 28(4), p. 329.
52. Gillard, Eric (December 9, 2016). "Students Work to Find Ways to Drill for Water on Mars". NASA. Archived from the original on June 17, 2019. Retrieved January 21, 2018.
53. Schwirtz, Michael (March 30, 2009). "Staying Put on Earth, Taking a Step to Mars". The New York Times. Archived from the original on July 7, 2018. Retrieved May 15, 2010.
54. "NASA's Journey to Mars – Pioneering Next Steps in Space Exploration" (PDF). NASA. October 2015. Archived (PDF) from the original on August 10, 2019. Retrieved March 19, 2017.
55. "Speech Monitoring of Cognitive Deficits and Stress – NSBRI". NSBRI. Archived from the original on March 27, 2017. Retrieved March 18, 2017.
56. Nguyen, Nguyen; Kim, Gyutae; Kim, Kyu-Sung (2020). "Effects of Microgravity on Human Physiology". Korean Journal of Aerospace & Environmental Medicine. 30 (1): 25–29. doi:10.46246/KJAsEM.30.1.25. S2CID 225893986.
57. Aubert, A. E.; Beckers, F.; Verheyden, B. Cardiovascular function and basics of physiology in microgravity. Acta Cardiologica 2005; 60(2): 129–151.
58. Williams, D.; Kuipers. A.; Mukai, C.; Thirsk, R. Acclimation during space flight: effects on human physiology. CMAJ: Canadian Medical Association journal = journal de l’Association medicale canadienne 2009; 180(13): 1317–1323.
59. Heer, M.; Paloski, W. H. Space motion sickness: Incidence, etiology, and countermeasures. Autonomic Neuroscience 2006; 129(1): 77–79.
60. "How Will Living On Mars Affects Our Human Body?". Space Safety Magazine. February 11, 2014. Archived from the original on March 27, 2017. Retrieved March 19, 2017.
61. Simonsen, Lisa C.; Nealy, John E. (February 1991). "NASA.gov". Archived from the original on November 12, 2020. Retrieved August 6, 2020.
62. "References & Documents". Human Adaptation and Countermeasures Division, Johnson Space Center, NASA. Archived from the original on May 30, 2010.
63. Real Martians: How to Protect Astronauts from Space Radiation on Mars. Archived September 25, 2019, at the Wayback Machine Moon To Mars. NASA. 30 September 2015. Quote: " a trip to interplanetary space carries more radiation risk than working in low-Earth orbit, said Jonathan Pellish, a space radiation engineer at Goddard."
64. Study: Collateral Damage from Cosmic Rays Increases Cancer Risk for Mars Astronauts Archived October 14, 2019, at the Wayback Machine. University of Nevada, Las Vegas (UNLV). May 2017.
65. "Non-Targeted Effects Models Predict Significantly Higher Mars Mission Cancer Risk than Targeted Effects Models." Francis A. Cucinotta, and Eliedonna Cacao. Nature, Scientific Reports, volume 7, Article number: 1832. 12 May 2017. doi:10.1016/j.lssr.2015.04.002.
66. Scott, Jim (September 30, 2017). "Large solar storm sparks global aurora and doubles radiation levels on the martian surface". Phys.org. Archived from the original on September 30, 2017. Retrieved September 30, 2017.
67. Kerr, Richard (May 31, 2013). "Radiation Will Make Astronauts' Trip to Mars Even Riskier". Science. 340 (6136): 1031. Bibcode:2013Sci...340.1031K. doi:10.1126/science.340.6136.1031. PMID 23723213.
68. Zeitlin, C.; Hassler, D. M.; Cucinotta, F. A.; Ehresmann, B.; Wimmer-Schweingruber, R. F.; Brinza, D. E.; Kang, S.; Weigle, G.; et al. (May 31, 2013). "Measurements of Energetic Particle Radiation in Transit to Mars on the Mars Science Laboratory". Science. 340 (6136): 1080–1084. Bibcode:2013Sci...340.1080Z. doi:10.1126/science.1235989. PMID 23723233. S2CID 604569.
69. Chang, Kenneth (May 30, 2013). "Data Point to Radiation Risk for Travelers to Mars". The New York Times. Archived from the original on May 31, 2013. Retrieved May 31, 2013.
70. "Space Radiobiology". NASA/BNL Space Radiation Program. NASA Space Radiation Laboratory. November 1, 2011. Archived from the original on September 24, 2013. Retrieved September 16, 2007.
71. Zubrin, Robert (1996). The Case for Mars: The Plan to Settle the Red Planet and Why We Must. Touchstone. pp. 114–116. ISBN 978-0-684-83550-1.
72. ^ Gutierrez-Folch, Anita (September 17, 2009). "Space Radiation Hinders NASA's Mars Ambitions". Finding Dulcinea. Archived from the original on September 28, 2013. Retrieved April 27, 2012.
73. "Mental preparation for Mars". American Psychological Association. Archived from the original on March 27, 2017. Retrieved March 19, 2017.
74. Zubrin, Robert M.; McKay, Christopher P. "Technological Requirements for Terraforming Mars". Archived from the original on February 1, 2016. Retrieved November 1, 2006.
75. ^ Weinersmith, Kelly; Weinersmith, Zach (November 7, 2023). A City on Mars: Can we settle space, should we settle space, and have we really thought this through?. Penguin. ISBN 978-1-9848-8173-1. Retrieved July 17, 2024.
76. ^ Salotti, Jean-Marc (2020). "Minimum number of Settlers for Survival on Another planet". Nature. Scientific Reports (1): 9700. Bibcode:2020NatSR..10.9700S. doi:10.1038/s41598-020-66740-0. PMC 7297723. PMID 32546782.
77. Smith, Cameron M. (2014). "Estimation of a genetically viable population for multigenerational interstellar voyaging: Review and data for project Hyperion". Acta Astronautica. 97: 16–29. Bibcode:2014AcAau..97...16S. doi:10.1016/j.actaastro.2013.12.013. Archived from the original on April 1, 2022. Retrieved April 1, 2022.
78. Smith, Cameron M. (April 2014). "Estimation of a genetically viable population for multigenerational interstellar voyaging: Review and data for project Hyperion". Acta Astronautica. 97: 16–29. Bibcode:2014AcAau..97...16S. doi:10.1016/j.actaastro.2013.12.013.
79. Stern, David P. (December 12, 2004). "#21b, Flight to Mars: How Long? Along what Path?". From Stargazers to Starships. Phy6.org. Archived from the original on September 13, 2012. Retrieved August 1, 2013.
80. "Variable-Specific-Impulse Magnetoplasma Rocket". Tech Briefs. NASA. September 2001. Archived from the original on December 11, 2008. Retrieved March 26, 2008.
81. "Ion engine could one day power 39-day trips to Mars". New Scientist. Archived from the original on March 13, 2015. Retrieved August 25, 2017.
82. "NASA Scientist: I can get humans to Mars in a month". USA TODAY. Archived from the original on January 12, 2017. Retrieved March 1, 2016.
83. Starlight: Directed Energy for Relativistic Interstellar Missions. Archived November 9, 2019, at the Wayback Machine UCSB Experimental Cosmology Group. Accessed on 9 November 2019.
84. "Space radiation between Earth and Mars poses a hazard to astronauts". NASA. Archived from the original on June 7, 2017. Retrieved September 6, 2017.
85. Williams, Dr. David R. (September 1, 2004). "Mars Fact Sheet". NASA Goddard Space Flight Center. Archived from the original on June 12, 2010. Retrieved September 18, 2007.
86. Atkinson, Nancy (July 17, 2007). "The Mars Landing Approach: Getting Large Payloads to the Surface of the Red Planet". Archived from the original on April 30, 2010. Retrieved September 18, 2007.
87. "The Space Elevator – Chapters 2 & 7". Archived from the original on June 3, 2005.
88. ^ Weinstein, Leonard M. (2003). "Space Colonization Using Space-Elevators from Phobos" (PDF). AIP Conference Proceedings. Space Technology and Applications International Forum – Staif 2003. Vol. 654. pp. 1227–1235. Bibcode:2003AIPC..654.1227W. doi:10.1063/1.1541423. hdl:2060/20030065879. Archived (PDF) from the original on September 27, 2013. Retrieved July 7, 2017.
89. Scoles, Sarah (November 27, 2023). "Mars Needs Insects – If humans are ever going to live on the red planet, they're going to have to bring bugs with them". The New York Times. Archived from the original on November 28, 2023. Retrieved November 28, 2023.
90. Belluscio, Alejandro G. (March 7, 2014). "SpaceX advances drive for Mars rocket via Raptor power". NASAspaceflight.com. Archived from the original on September 11, 2015. Retrieved March 14, 2014.
91. https://www.researchgate.net/publication/289163413_Methanol_A_fuel_for_earth_and_mars
92. Landis (2001). "Mars Rocket Vehicle Using In Situ Propellants". Journal of Spacecraft and Rockets. 38 (5): 730–735. Bibcode:2001JSpRo..38..730L. doi:10.2514/2.3739.
93. "During Solar Conjunction, Mars Spacecraft Will Be on Autopilot". Spotlight. JPL, NASA. October 20, 2006. Archived from the original on September 27, 2013. Retrieved October 31, 2006.
94. Gangale, T. (2005). "MarsSat: Assured Communication with Mars". Annals of the New York Academy of Sciences. 1065: 296–310. Bibcode:2005NYASA1065..296G. doi:10.1196/annals.1370.007. PMID 16510416. S2CID 22087209.
95. "Sun-Mars Libration Points and Mars Mission Simulations" (PDF). Stk.com. Archived from the original (PDF) on September 27, 2013. Retrieved October 6, 2013.
96. "A Novel Interplanetary Communications Relay" (PDF). August 2010. Archived (PDF) from the original on September 27, 2013. Retrieved February 14, 2011.
97. "Marpost". www.astronautix.com. Retrieved July 12, 2024.
98. Kaplan, D.; et al. (1999). "The Mars In-Situ-Propellant-Production Precursor (MIP) Flight Demonstration" (PDF). Workshop on Mars 2001: Integrated Science in Preparation for Sample Return and Human Exploration (991): 54. Bibcode:1999misp.conf...54K. Archived (PDF) from the original on September 27, 2013. Retrieved August 30, 2012. Paper presented at Mars 2001: Integrated Science in Preparation for Sample Return and Human Exploration, Lunar and Planetary Institute, October 2–4, 1999, Houston, Texas.
99. Landis, G. A.; Jenkins, P.; Scheiman, D.; Baraona, C. "MATE and DART: An Instrument Package for Characterizing Solar Energy and Atmospheric Dust on Mars" (PDF). Archived (PDF) from the original on September 27, 2013. Retrieved August 30, 2012. Presented at Concepts and Approaches for Mars Exploration, July 18–20, 2000 Houston, Texas.
100. Gwynne Shotwell (March 21, 2014). Broadcast 2212: Special Edition, interview with Gwynne Shotwell (audio file). The Space Show. Event occurs at 29:45–30:40. 2212. Archived from the original (mp3) on March 22, 2014. Retrieved March 22, 2014. would have to throw a bunch of stuff before you start putting people there. ... It is a transportation system between Earth and Mars.
101. "Huge Mars Colony Eyed by SpaceX Founder". Discovery News. December 13, 2012. Archived from the original on November 15, 2014. Retrieved March 14, 2014.
102. Puumala, Mikko M.; Sivula, Oskari; Lehto, Kirsi (2023). "Moving to Mars: The Feasibility and Desirability of Mars Settlements". Space Policy. 66: 101590. Bibcode:2023SpPol..6601590P. doi:10.1016/j.spacepol.2023.101590. ISSN 0265-9646.
103. "SpaceX Capabilities and Services". SpaceX. 2017. Archived from the original on October 7, 2013. Retrieved March 12, 2017.
104. Belfiore, Michael (December 9, 2013). "The Rocketeer". Foreign Policy. Archived from the original on December 10, 2013. Retrieved December 11, 2013.
105. Amos, Jonathan (September 30, 2013). "Recycled rockets: SpaceX calls time on expendable launch vehicles". BBC News. Archived from the original on October 3, 2013. Retrieved October 2, 2013.
106. kentnstxl (February 12, 2024). "Reducing the Cost of Space Travel with Reusable Launch Vehicles". NSTXL. Retrieved April 8, 2024.
107. "A Journey to Inspire, Innovate, and Discover" (PDF). Report of the President's Commission on Implementation of United States Space Exploration Policy. June 2004. Archived (PDF) from the original on October 10, 2012. Retrieved December 14, 2013.
108. Landis, Geoffrey A. (2009). "Meteoritic steel as a construction resource on Mars". Acta Astronautica. 64 (2–3): 183. Bibcode:2009AcAau..64..183L. doi:10.1016/j.actaastro.2008.07.011.
109. Lovelock, James and Allaby, Michael, "The Greening of Mars", 1984.
110. "Effect of Clouds and Pollution on Insolation". Archived from the original on March 5, 2012. Retrieved October 4, 2012.
111. "Potato-Shaped Mars Moon Phobos May be a Captured Asteroid". Space.com. January 15, 2014. Archived from the original on November 30, 2022. Retrieved November 30, 2022.
112. "NASA Continues Psyche Asteroid Mission". Jet Propulsion Laboratory. Archived from the original on November 8, 2022. Retrieved November 30, 2022.
113. "Could We Use Mars as a Base for Asteroid Mining?". June 21, 2022. Archived from the original on November 30, 2022. Retrieved November 30, 2022.
114. Taylor, Anthony J.; McDowell, Jonathan C.; Elvis, Martin (2022). "Phobos and Mars orbit as a base for asteroid exploration and mining". Planetary and Space Science. 214: 105450. Bibcode:2022P&SS..21405450T. doi:10.1016/j.pss.2022.105450. S2CID 247275237.
115. "Space Mining: Scientists Discover Two Asteroids Whose Precious Metals Would Exceed Global Reserves". Forbes. Archived from the original on November 30, 2022. Retrieved November 30, 2022.
116. "Hubble Examines Massive Metal Asteroid Called 'Psyche' That's Worth Way More Than Our Global Economy". Forbes. Archived from the original on November 30, 2022. Retrieved November 30, 2022.
117. "NASA Heads for 'Psyche,' A Mysterious Metallic Asteroid That Could be the Heart of a Dead Planet". Forbes. Archived from the original on November 30, 2022. Retrieved November 30, 2022.
118. Rüede, Anne-Marlene; Ivanov, Anton; Leonardi, Claudio; Volkova, Tatiana (2019). "Systems engineering and design of a Mars Polar Research Base with a human crew". Acta Astronautica. 156. Elsevier BV: 234–249. Bibcode:2019AcAau.156..234R. doi:10.1016/j.actaastro.2018.06.051. ISSN 0094-5765. S2CID 85551985.
119. ^ Kornei, Katherine (October 29, 2022). "House-Hunting on Mars Has Already Started". The New York Times. Archived from the original on November 1, 2022. Retrieved November 1, 2022.
120. Fogg, Martyn J. (1997). "The utility of geothermal energy on Mars" (PDF). Journal of the British Interplanetary Society. 49: 403–22. Bibcode:1997JBIS...50..187F. Archived (PDF) from the original on September 27, 2013. Retrieved August 12, 2009.
121. Cushing, G. E.; Titus, T. N.; Wynne1, J. J.; Christensen, P. R. "THEMIS Observes Possible Cave Skylights on Mars" (PDF). Archived (PDF) from the original on September 15, 2011. Retrieved June 18, 2010.{{cite web}}: CS1 maint: numeric names: authors list (link)
122. Valentine, David (December 1, 2017). "Gravity fixes: Habituating to the human on Mars and Island Three". HAU: Journal of Ethnographic Theory. 7 (3). University of Chicago Press: 185–209. doi:10.14318/hau7.3.012. ISSN 2575-1433.
123. Queens University Belfast scientist helps NASA Mars project Archived October 26, 2019, at the Wayback Machine "No-one has yet proved that there is deep groundwater on Mars, but it is plausible as there is certainly surface ice and atmospheric water vapour, so we wouldn't want to contaminate it and make it unusable by the introduction of micro-organisms."
124. COSPAR PLANETARY PROTECTION POLICY Archived 2013-03-06 at the Wayback Machine (20 October 2002; As Amended to 24 March 2011)
125. When Biospheres Collide – a history of NASA's Planetary Protection Programs Archived July 14, 2019, at the Wayback Machine, Michael Meltzer, May 31, 2012, see Chapter 7, Return to Mars – final section: "Should we do away with human missions to sensitive targets"
126. Johnson, James E. "Planetary Protection Knowledge Gaps for Human Extraterrestrial Missions: Goals and Scope." (2015) Archived October 26, 2019, at the Wayback Machine
127. Safe on Mars page 37 Archived September 6, 2015, at the Wayback Machine "Martian biological contamination may occur if astronauts breathe contaminated dust or if they contact material that is introduced into their habitat. If an astronaut becomes contaminated or infected, it is conceivable that he or she could transmit Martian biological entities or even disease to fellow astronauts, or introduce such entities into the biosphere upon returning to Earth. A contaminated vehicle or item of equipment returned to Earth could also be a source of contamination."
128. "President Obama's Space Legacy: Mars, Private Spaceflight and More". Space.com. January 20, 2017. Archived from the original on April 6, 2018. Retrieved April 5, 2018.
129. "NASA.gov". December 11, 2017. Archived from the original on April 28, 2018. Retrieved April 5, 2018.
130. "Trump, Congress approve largest U.S. Research spending increase in a decade". Archived from the original on March 23, 2018. Retrieved April 5, 2018.
131. Chiles, James R. "Bigger Than Saturn, Bound for Deep Space". Airspacemag.com. Archived from the original on December 12, 2019. Retrieved January 2, 2018.
132. "Finally, some details about how NASA actually plans to get to Mars". Arstechnica.com. March 28, 2017. Archived from the original on July 13, 2019. Retrieved January 2, 2018.
133. Szocik, Konrad, Kateryna Lysenko-Ryba, Sylwia Banaś, and Sylwia Mazur. "Political and Legal Challenges in a Mars Colony." Space Policy (2016): n. pag. Web. 24 Oct. 2016.
134. ^ Chang, Kenneth (September 27, 2016). "Elon Musk's Plan: Get Humans to Mars, and Beyond". The New York Times. Archived from the original on September 29, 2016. Retrieved September 27, 2016.
135. Commercial Space Exploration: Ethics, Policy and Governance, 2015. Print.
136. ^ Bharmal, Zahaan (August 28, 2018). "The case against Mars colonisation". the Guardian. Retrieved September 14, 2024.
137. ^ CisnerosMonday, Isabella (August 21, 2023). "The Space Review: The fault in our Mars settlement plans". The Space Review. Retrieved September 14, 2024.
138. "Jeff Bezos foresees a trillion people living in millions of space colonies. Here's what he's doing to get the ball rolling". NBC News. May 15, 2019. Retrieved August 6, 2024.
139. Guenot, Marianne (March 14, 2024). "Obama takes a shot at the likes of Musk and Bezos, says we must protect Earth before colonizing Mars". Business Insider. Retrieved August 6, 2024.
140. "Elon Musk's plans for life on Mars are a 'dangerous delusion', says British chief astronomer". Sky News. March 15, 2021. Retrieved August 15, 2024.
141. Wattles, Jackie (December 12, 2023). "Colonizing Mars could be dangerous and ridiculously expensive. Elon Musk wants to do it anyway". CNN. Retrieved August 15, 2024.
142. Pearlman, Robert Z. (September 18, 2019). "NASA Reveals New Gateway Logo for Artemis Lunar Orbit Way Station". Space.com. Archived from the original on June 28, 2020. Retrieved June 28, 2020.
143. Cornish, Gabrielle (July 22, 2019). "How imperialism shaped the race to the moon". The Washington Post. Archived from the original on July 23, 2019. Retrieved September 19, 2019.
144. Spencer, Keith A. (October 8, 2017). "Against Mars-a-Lago: Why SpaceX's Mars colonization plan should terrify you". Salon.com. Archived from the original on September 19, 2019. Retrieved September 20, 2019.
145. Zevallos, Zuleyka (March 26, 2015). "Rethinking the Narrative of Mars Colonisation". Other Sociologist. Archived from the original on December 11, 2019. Retrieved September 20, 2019.
146. Spencer, Keith A. (May 2, 2017). "Keep the Red Planet Red". Jacobin. Archived from the original on November 3, 2019. Retrieved September 20, 2019.
147. Haskins, Caroline (August 14, 2018). "The racist language of space exploration". The Outline. Archived from the original on October 16, 2019. Retrieved September 20, 2019.
148. Lee, D. N. (March 26, 2015). "When discussing Humanity's next move to space, the language we use matters". Scientific American. Archived from the original on September 14, 2019. Retrieved September 20, 2019.
149. Drake, Nadia (November 9, 2018). "We need to change the way we talk about space exploration". National Geographic. Archived from the original on October 16, 2019. Retrieved October 19, 2019.
150. Tickle, Glen (March 5, 2015). "A Look Into Whether Humans Should Try to Colonize Venus Instead of Mars". Laughing Squid. Archived from the original on September 1, 2021. Retrieved September 1, 2021.
151. Warmflash, David (March 14, 2017). "Colonization of the Venusian Clouds: Is 'Surfacism' Clouding Our Judgement?". Visionlearning Blog. Archived from the original on December 11, 2019. Retrieved September 20, 2019.
152. Minkel, JR. "Sex and Pregnancy on Mars: A Risky Proposition." Space.com. Space.com, 11 February 2011. Web. 09 December 2016.
153. Schuster, Haley; Peck, Steven L. (2016). "Mars ain't the kind of place to raise your kid: Ethical implications of pregnancy on missions to colonize other planets". Life Sciences, Society and Policy. 12 (1): 10. doi:10.1186/s40504-016-0043-5. PMC 4996799. PMID 27558392.
154. Knapp, Alex (November 27, 2012). "SpaceX Billionaire Elon Musk Wants A Martian Colony Of 80,000 People". Forbes. Archived from the original on August 15, 2017. Retrieved June 12, 2015.
155. "Richard Branson on space travel: "I'm determined to start a population on Mars"". cbsnews.com. September 18, 2012. Archived from the original on June 16, 2019. Retrieved June 15, 2019.
156. Aldrin, Buzz (June 13, 2013). "The Call of Mars". The New York Times. Archived from the original on July 17, 2019. Retrieved June 17, 2013.
157. Dunn, Marcia (August 27, 2015). "Buzz Aldrin joins university, forming 'master plan' for Mars". AP News. Archived from the original on September 4, 2015. Retrieved August 30, 2015.
158. Deudney, Daniel (March 2, 2020). Dark Skies: Space Expansionism, Planetary Geopolitics, and the Ends of Humanity. Oxford, New York: Oxford University Press. ISBN 978-0-19-090334-3.

Further reading

• Buzz Aldrin and Leonard David (2013). Mission to Mars: My Vision for Space Exploration. National Geographic Books. ISBN 978-1-4262-1017-4. (at BuzzAldrin.com)
• Robert Zubrin, The Case for Mars: The Plan to Settle the Red Planet and Why We Must, Simon & Schuster/Touchstone, 1996, ISBN 0-684-83550-9
• Frank Crossman and Robert Zubrin, editors, On to Mars: Colonizing a New World. Apogee Books Space Series, 2002, ISBN 1-896522-90-4
• Frank Crossman and Robert Zubrin, editors, On to Mars 2: Exploring and Settling a New World. Apogee Books Space Series, 2005, ISBN 978-1-894959-30-8
• Resource Utilization Concepts for MoonMars; By Iris Fleischer, Olivia Haider, Morten W. Hansen, Robert Peckyno, Daniel Rosenberg and Robert E. Guinness; 30 September 2003; IAC Bremen, 2003 (29 Sept–03 Oct 2003) and MoonMars Workshop (26–28 Sept 2003, Bremen). Accessed on 18 January 2010
• MARTIAN OUTPOST: The Challenges of Establishing a Human Settlement on Mars Archived June 3, 2016, at the Wayback Machine; by Erik Seedhouse; Praxis Publishing; 2009; ISBN 978-0-387-98190-1. Also see ,
• Ice, mineral-rich soil could support human outpost on Mars; by Sharon Gaudin; 27 June 2008; IDG News Service
• Puumala, Mikko M.; Sivula, Oskari; Lehto, Kirsi (2023). "Moving to Mars: The Feasibility and Desirability of Mars Settlements". Space Policy. 66: 101590. Bibcode:2023SpPol..6601590P. doi:10.1016/j.spacepol.2023.101590.
• Woo, Carlton Yuan Bo (2023). "Review of the technologies and preparations required for Mars colonization". Theoretical and Natural Science. 13: 245–250. doi:10.54254/2753-8818/13/20240854.
• Neukart, Florian (2024). "Towards sustainable horizons: A comprehensive blueprint for Mars colonization". Heliyon. 10 (4): e26180. arXiv:2309.16806. Bibcode:2024Heliy..1026180N. doi:10.1016/j.heliyon.2024.e26180. PMID 38404830.

External links

• Mars Society
• The Planetary Society: Mars Millennium Project
• 4Frontiers Corporation
• The Mars Foundation – Archived March 1, 2012, at the Wayback Machine
• Making Mars the New Earth – National Geographic
• Should we colonize Mars? – Wikidebate in Wikiversity

v t e Human mission to Mars
List of crewed Mars mission plans
21st-century proposals	Active Mars Base Camp SpaceX Mars program Passive Austere Human Missions to Mars Mars Piloted Orbital Station Mars to Stay Former Aurora programme Constellation program Mars One Inspiration Mars Vision for Space Exploration
20th-century proposals	The Mars Project Martian Piloted Complex Aelita TMK Ride Report Space Exploration Initiative Mars Direct The Case for Mars Mars Design Reference Mission 3.0
Mars analogs (list)	MARS-500 Mars Analogue Research Station Program FMARS MDRS Arctic Mars Analog Svalbard Expedition Concordia Station HI-SEAS NEEMO
Advocacy	Caves of Mars Project Mars Institute Mars Society
Hardware concepts	Mars habitat Crewed Mars rover Mars suit Mars Excursion Module Mars lander Mars rover
Miscellany	Colonization of Mars Exploration of Mars Fiction films novels Mars cycler Mars orbit rendezvous Terraforming of Mars Mars atmospheric entry Mars flyby

• Astronomy
• Solar System
• Science

• Colonization of Mars
• Exploration of Mars
• Human missions to Mars
• Space colonization
• Mars Society