The McKay-Zubrin plan for terraforming Mars in 50 years was cited by Elon Musk.
Orbital mirrors with 100 km radius are required to vaporize the CO2 in the south polar cap. If manufactured of solar sail-like material, such mirrors would have a mass on the order of 200,000 tonnes. If manufactured in space out of asteroidal or Martian moon material, about 120 MWe-years of energy would be needed to produce the required aluminum.
The use of orbiting mirrors is another way for hydrosphere activation. For example, if the 125 km radius reflector discussed earlier for use in vaporizing the pole were to concentrate its power on a smaller region, 27 TW would be available to melt lakes or volatilize nitrate beds. This is triple the power available from the impact of a 10 billion tonne asteroid per year, and in all probability would be far more controllable. A single such mirror could drive vast amounts of water out of the permafrost and into the nascent Martian ecosystem very quickly. Thus while the engineering of such mirrors may be somewhat grandiose, the benefits to terraforming of being able to wield tens of TW of power in a controllable way would be huge.
Energy for making the aluminum can use near-term multimegawatt nuclear power units, such as the 5 MWe modules now under consideration for NEP spacecraft.
Westinghouse is researching a small roughly 35-ton 25-megawatt Megapower reactor called the Vinci molten salt reactor.
Remove Poison Percholorate from Martian Soil
There is also a need to remove the poison perchlorate from the Martian soil. This could be done with the right bacteria. The right earth bacteria can survive on Mars and breakdown the toxins.
Alternative – bacteria to make Ammonia and methane
A possible improvement to the ammonia asteroidal impact method would use bacteria which can metabolize nitrogen and water to produce ammonia. If an initial greenhouse condition were to be created by ammonia object importation, it may be possible that a bacterial ecology could be set up on the planet’s surface that would recycle the nitrogen resulting from ammonia photolysis back into the atmosphere as ammonia, thereby maintaining the system without the need for further impacts. Similar schemes might also be feasible for cycling methane, another short-lived natural greenhouse gas which might be imported to the planet.
Alternative- One gigawatt reactor to make halocarbon – CF4 to trigger warming effect
Greenhousing Mars via the manufacture of halocarbon gases on the planet’s surface may well be the most practical option. Total surface power requirements to drive planetary warming using this method are calculated and found to be on the order of 1000 MWe, and the required times scale for climate and atmosphere modification is on the order of 50 years.
I wrote this paper in 1993 with Chris McKay. It shows why #Mars can be terraformed. There is positive feedback- we warm Mars a few degrees C with CF4. this will cause CO2 to outgas from the soil.That will warm Mars more, releasing more CO2,resulting in a Runaway greenhouse effect
— Robert Zubrin (@robert_zubrin) August 1, 2018
The amount of a greenhouse gas needed to heat a planet is roughly proportional to the square of the temperature change required, driving Mars into a runaway greenhouse with an artificial 4 K temperature rise only requires about 1/200th the engineering effort that would be needed if the entire 55 K rise had to be engineered by brute force.
The dynamics of the regolith gas-release process are only approximately understood, and the total available reserves of CO2 won’t be known until human explorers journey to Mars to make a detailed assessment.
Large domed cities and greenhouses should be built on Mars while we wait
There is a new study which indicates that domed cities and colonies of various sizes could have the right temperature for liquid water with a 2-3 centimeter dome of silica aerogel without additional heating. They would heat up under the dome by 50 degrees kelvin without any heaters. Just the greenhouse effect would heat the area under the dome.
Regions on the surface of Mars could be modified in the future to allow life to survive there with much less infrastructure or maintenance than via other approaches. The creation of permanently warm regions would have many benefits for future human activity on Mars, as well as being of fundamental interest for astrobiological experiments and as a potential means to facilitate life-detection effort.
Large Domes Have Been Made on Earth
Mars has one-third of the gravity of Earth so making larger domes will be easier on Mars.
Singapore’s new national sports stadium (completed in 2014) is the world’s largest free-spanning dome, measuring 310-meters (1017 feet) across, and its roof can be opened or closed to suit the tropical climate.
The 55,000 capacity National Stadium has a 19,500 sq-meter (4.8 acres) retractable roof, which can open or close in just 20 minutes. The roof is made with a multi-layer ETFE pillow. The moving roof incorporates a matrix of LED lights, making it one of the largest addressable LED screens in the world.
The EFTE for the roof is a 0.15mm to 0.25mm-thick Fluon ETFE fluoropolymer film. Fluon ETFE Film is made of a high-performance thermoplastic fluoropolymer, and features excellent transparency, non-stick and insulation properties, and resistance to heat, chemicals and weather.
The Seagaia Ocean Dome (measured 300 meters in length and 100 meters in wide) was one of the world’s largest indoor waterparks, located in Miyazaki, Miyazaki, Japan.
Previously NASA scientist Jim Green proposed a concept of placing a magnetic dipole satellite with a 1-2 tesla magnet placed in an orbit between Mars the Sun would allow Mars to restore its atmosphere. Simulations indicate that within years, the planet would be able to achieve half the atmospheric pressure of Earth. The magnetic field would also protect Mars colonists from some solar radiation.
Without solar winds stripping away at the planet, frozen carbon dioxide at the ice caps on either pole would begin to sublimate (change from a solid into a gas) and warm the equator. Ice caps would begin to melt to form an ocean.
The atmosphere of Mars is relatively thin and has a very low surface pressure.
Silica aerogel can mimics Earth’s atmospheric greenhouse effect to warm Mars to a temperature where the ice melts and Earth plants can survive. Through modeling and experiments, the researchers show that a 2- to 3-centimeter-thick shield of silica aerogel could transmit enough visible light for photosynthesis, block hazardous ultraviolet radiation, and raise temperatures underneath permanently above the melting point of water, all without the need for any internal heat source.
Regions of the Martian surface could be made habitable with a material — silica aerogel — that mimics Earth’s atmospheric greenhouse effect. Through modeling and experiments, the researchers show that a two to three-centimeter-thick shield of silica aerogel could transmit enough visible light for photosynthesis, block hazardous ultraviolet radiation, and raise temperatures underneath permanently above the melting point of water, all without the need for any internal heat source.
There was a National Space Agency study for 25-mile wide domed city on the moon. A similar scale domed city could be built on Mars.