What are Craterhabs?
Craterhab is Mareekh Dynamics’ signature concept product, patented under USPTO. These are fabric domes up to several hundred meters in diameter, designed to be built over Martian craters and anchored into the compact rims of the craters to withhold nearly one bar of internal pressure, creating a micro-terraformed environment inside the craters for permanent human settlement on the red planet. Craterhabs are based on true-engineering and provide practical and cost-effective modular solutions to the large-scale human habitation on Mars.
(Artistic rendition of a base on Mars with Craterhabs. These inflatable domes with Earth-like internal pressures are only accessible through airlocks and tunnel system)
Brief description of the structure
Craterhabs are large fabric domes several hundred meters in diameter, consisting of a hexagonal skeletal framework of ultra-high strength cables system such as Spectra or Dyneema, and hexagonal segments of high tensile strength material such as aramid or Kevlar, wrapped around the Dyneema cable system and covered in a thin layer of vacuum-coating material such as polyimide or Kapton. The hemi-ellipsoid dome will be built over small Martian craters utilizing the compact rims of the craters as a firm interface to anchor the peripheries of the dome to the buried underground concrete anchors. The Craterhabs will be filled with a mixture of nitrogen and oxygen at 0.6 to 1 bar pressure to simulate the Earth’s atmosphere, creating micro-terraformed environments inside the craters. These Craterhabs will be interconnected through a surface and subsurface tunnel system.
(External appearance of a Craterhab. Note the hemi-ellipsoid shape and the intricate hexagonal pattern of Dyneema skeletal framework and the silicone-aramid hybrid main body segments)
(Side cross-section of a Craterhab. Craterhabs are designed to be built over Martian craters anchored in the crater rim to subsurface anchors and interconnected through surface and underground tunnel system)
Terrestrial utility of Craterhabs
Craterhab technology can be utilized to build true Martian simulation bases in high-altitude environments on Earth where multiple engineering testing and astronaut training objectives can be achieved prior to sending humans to Mars.
The utility of Craterhab technology can extend beyond its space application by promoting high-altitude tourism and provision of healthcare for high-altitude related medical conditions, overlapping with its space objectives as well as being completely independent of it, leading to an interesting business case for this technology.
There are three main areas of the terrestrial utility of Craterhabs.
1. Mars simulation bases
(An artistic impression of a base on Mars. Similar simulation bases with true engineering can be constructed in very high-altitude regions on Earth with thin atmosphere and harsh environment for developing engineering techniques and astronaut training)
Mars is distant and formidable. The window to travel to Mars opens once every 26 months, and the journey takes months. For human missions, in current technology, the transit time is expected to be around 7 months. Humans will not only have to take all their supplies with them to last for years on the harsh surface of Mars, we must go there with an intent to stay for long term, and build infrastructure that should remain viable for decades for the future replacement crew. Not only that, the number of humans going to live on Mars need to meet a certain minimum threshold to ensure sustenance almost completely independent of Earth. There is no easy going back to Earth both in time as well as in space. Therefore, it is necessary to develop large-scale habitation solutions to cater for the long-term stay for a large number of people on the red planet.
Humans are not going to Mars to discover new or apply untested technologies there, not at least in the first few decades of our presence on the red planet. Everything that needs to be done on Mars, must be developed and tested right here on Earth first, using true engineering principles, and should be well rehearsed in an environment as closely mimicking Mars as possible.
Craterhab Technology offers large-scale surface habitation solutions for Mars through creation of massive internally pressurized environments. This takes away much of the complex engineering needs for the elaborate sub-infrastructure (such as accommodation or manufacturing infrastructure) as it would be located inside the Craterhabs in an environment closely resembling Earth in temperature and pressure.
One of the key requirements for the structure of a Craterhab is its ability to withstand 1 bar of internal pressure against the near vacuum of the Martian atmosphere, where the pressures are less than 1 percent of Earth’s atmospheric pressure at sea level. This is equivalent to 10 tons of internal inflation pressure per square meter of the fabric structure trying to blow apart the dome, demanding serious engineering design and construction, and choice of superior material. The actual internal pressure inside the Craterhab is likely to be maintained at 0.5 - 0.6 bar to reduce the structural load on the fabric dome. This pressure is still sufficient for long term human habitation and plant growth, and reduces the material and construction cost.
A well-rehearsed construction technique and astronaut training on Earth is the key for a successful human habitation on Mars. Unfortunately, testing structural integrity of material by maintaining 0.5-1 bar pressure difference between internal and external pressures in environments with nearly 1 bar atmospheric pressure such as at sea level or medium altitudes up to 2500m would mean maintaining an internal pressure of 1.5 to 2 bars. This may make such simulation or training structures unsuitable for long-term habitability and training of astronauts on Earth, due to the risks involved with being exposed to above-sea level pressures of 1.5 to 2 bar for prolonged periods.
However, there are high plateau regions in places like western Ali region of Tibet or areas of Andes bordering Chile and Bolivia where altitudes exceed 5000m. These places have atmospheric pressure of almost 0.5 bar. In addition, these places are dry, cold and remote, and offer the most Mars-like environments Earth can offer. Biggest advantage perhaps of these high altitude regions is the low atmospheric pressure they offer from the Craterhab perspective. At these locations, it is possible to build Craterhabs and maintain comfortable 1 bar of internal pressure while being able to still maintain a pressure difference of 0.5 bar as compared to the external pressure, thus enabling the creation of nearly the same shear forces and structural stresses on the Craterhab material as would be on Mars. Maintaining 1 bar of internal pressure means astronauts can live inside these simulation Craterhabs for long periods of time. This would mean they will remain relatively ‘unacclimatized’ for the outside environment, and will require pressurized rovers and suits to excurse the surrounding environments as they would do on Mars. During training, they will learn to live a shirt-sleeved lifestyle inside a Craterhab but requiring space suits and pressurized rovers for outdoor activities, exactly how they would live and work on Mars. This is in contrast to many simulation bases where the true engineering and environmental parameters are not met.
These simulation bases will provide ideal grounds for material testing, construction methods, and astronaut training for future colonization on Mars.
2. High altitude tourism
(A group of trekkers in a high-altitude region in Pakistan. Plateau regions in many parts of the world can reach over 4000 m subjecting visitors to the risk of altitude related syndromes due to low atmospheric pressure)
What is the first thing La Paz, the capital of Bolivia, does to you when you arrive there? It “takes your breath away!” for its natural beauty with the snow-covered peaks of the surrounding Andes and for its thin air. The city of La Paz is situated at an altitude of 3500m above sea level. But that is not even the point of entry into the country for most of the international travelers to Bolivia. The La Paz International Airport is in fact situated at an even higher altitude of 4100m in the city of El Alto situated at the edge of the plateau of the Altiplano adjacent to the capital city of La Paz. This is the altitude any international traveler experiences upon entry into Bolivia.
The number of tourists visiting Bolivia is nearly one million per year, and increasing. Still, this is dwarfed by a huge margin by the number of tourists visiting Lhasa, the capital of Tibet Autonomous Region in China at an altitude of 3600m, with an average of 35 million visitors per year.
Regions above 3500m have atmospheric pressures two-third that at sea level. This reflects a two-third oxygen fraction as well. The partial pressure of oxygen in air we breathe at sea level is nearly 160mm Hg. At two-third atmospheric pressure, it is barely above 100 mm Hg which is mere 13-14% of total atmospheric pressure at sea level. This has serious implications and it is no surprise that La Paz is dubbed the “Hypoxia Capital of the World.”
(A graphic representation of the relation of atmospheric pressure with altitude. Atmospheric pressures can be nearly half that at the sea level in few very high-altitude plateau regions in the world)
Tourists visiting Lhasa or La Paz or any other place in the world exceeding 3500 m altitude are at risk of developing a condition known as Acute Mountain Sickness or AMS. This happens directly as a result of hypoxia which can lead to headaches, nausea, fatigue, dizziness and poor concentration. In most cases, it resolves within 3 days, but in few cases, especially in people with poor lung condition, this can lead to life threatening High Altitude Pulmonary Edema (HAPE) or High-Altitude Cerebral Edema (HACE), which if left untreated with supplemental oxygen, diuretics and steroids, may lead to death. Even for tourists who do not develop AMS, they are still at risk of developing hypoxia at night during their sleep, and many hotels in Lhasa and La Paz contain oxygen cylinders and masks should any visitor need them. No one wants to be in situations like this where one gets into the risk of getting sick or having to carry an oxygen cylinder while visiting such remote and high-altitude regions far from home. Low atmospheric pressure and low oxygen partial pressures at these high altitudes must always be considered prior to travel.
(La Paz (left, 3500 m- 4100 m) and Lhasa (right, 3600 m) are among the highest metro areas in the world with a population of a million or more individuals)
Craterhab technology can help prevent development of AMS in tourists by providing pressurized internal environments of enormous volumes and covering large areas. These domes can maintain nearly one bar of internal pressure of air, and can be several hundred meters in diameter. This provides large enough internal volume to incorporate hotels, shopping centres, restaurants, theme parks, hospitals or any combination of these, where tourists can spend a significant amount of time during their visit, thus significantly reducing or even completely eliminating the risk of developing AMS and its related complications.
(Large Craterhabs can comfortably incorporate residential areas, and other amenities such as shopping centers, hospitals or theme parks inside their pressurized volumes)
3. Healthcare
Residents of high-altitude regions of the world such as Altiplano or Tibet are well acclimatized for a life at high altitudes. This includes natural genetic and acquired adaptations such as increased lung capacities and higher concentration of red blood cells and increased oxygen carrying capacity of the haemoglobin. However, in case of respiratory or cardiovascular illnesses, or with aging, there can be a rapid loss of this adaptation leading to poor ability to oxygenate the body from the low oxygen levels in the environment. This can lead to Chronic Mountain Sickness or CMS. This adversely affects the overall general health and life expectancy and quality of life.
(Residents of Altiplano (left) and Tibet (right) remain at risk of developing CMS, and lower life expectancy)
Craterhab Technology can help treat many of the effects of CMS on general health through creation of large area and volume habitats for mini-suburbs or apartments for people suffering from CMS where residents can live and breathe normally in internally maintained pressure similar to those at sea levels. The advantage of such facilities is that residents can live and move around without the confines of treatment rooms or carrying supplemental oxygen at all times. This will have an immensely positive effect on the general mental and physical health of individuals, improving quality of life and enjoying life to the fullest without having to live through the health effects of CMS.
Such large-scale pressurized habitats may provide solutions for many other medical ailments where living in low pressure environments of high-altitude plateaus may be a huge disadvantage.
Halfway-to-Mars (H2M)
Halfway-to-Mars or H2M is our space tourism initiative with our partners GoSpace in China. GoSpace or Bei Jing Golden Ocean International Cultural Tourism has previously been involved with developing space related tourism initiative that included developing a pressurized suit for space diving i.e. diving from the edge of space. We are now working with them to conceive a tourism concept of developing Mars simulation bases not only for training of astronauts destined for Mars, but also tourists wanting to experience what it would be like to live on Mars, from living inside pressurized habitats, to the outdoor excursions in pressurized rovers and space suits, use of airlock system, living in remoteness and isolation, and learn teamwork and cooperation.
(A Mars simulation base on Earth. Trainee astronauts and space tourists will live inside pressurized Craterhabs and do outdoor excursions in pressurized suits and rovers, just like they will do on Mars)
The envisioned H2M project involves creation of Craterhab habitat systems several hundred meters in diameter and maintaining at least 0.5 bar pressure difference between inside and outside pressures. So, while maintaining a 1 bar pressure inside, the outside pressure needs to be 0.5 bar, which is the pressure at an altitude of 5200 m or above. Southern flank of Altiplano and Western part of Tibet offer such altitudes where such Mars simulation bases can be constructed. The Craterhabs will be designed to withstand 0.5 bar of internal inflation pressure with a safety factor of at least 2.5. On Mars the outside atmospheric pressure is 0.01 bar and therefore a pressure of 0.5 bar at these altitudes on Earth is literally half-way between Earth and Mars, hence the choice of the name of the initiative, Halfway-to-Mars. Inside the Craterhabs, 1 bar pressure will be maintained providing the most Earth-like internal environment in one of the harshest environments on Earths for its temperature, pressure and solar radiation. Craterhabs will incorporate all amenities of life including residential apartments, parks, hospitals, shopping areas, admin blocks, gyms, libraries, movie theaters, workshops and anything else that is needed. The trainee astronauts and tourists will learn ways to grow crops inside Craterhabs, drill subsurface glaciers or permafrost to extract water and use solar power with battery backups for power requirements. Since the residents of these Craterhabs will be relatively unacclimatized being spending most of their time inside Craterhabs, so an excursion outside the Craterhab will require pressurized rovers and suits, just the way it will be needed on Mars. This is necessary as it will not only facilitate the trainee astronauts and future explorers and settlers on Mars getting used to the Martian environment and lifestyle, it will also help create safety guidelines to pave the way for a future Mars settlement. If the H2M project becomes operational in the next decade or so, many of the trainee astronauts from this program will actually be the first batch of humans to settle on Mars, fully trained and ready, and will fearlessly venture into making the humanity's next giant leap a reality.
(A Starship approaching Mars, humanity’s next destination marking the birth of the Interplanetary Age. Picture source: www.cnet.com)
Conclusion
Craterhab Technology is a promising engineering concept which will not only enable establishment of human settlement on Mars but also has a utility in terrestrial applications for high-altitude tourism and healthcare, and for the training of astronauts and testing of engineering technologies for permanent human habitation on Mars.