The field of deep space exploration is entering a crucial window period for leapfrog development towards long-term extraterrestrial habitation. In-situ resource utilization, power generation and storage, and life resource conversion are becoming increasingly crucial for the next phase of continuous human Mars exploration, relying on the simultaneous progress of theoretical methods, mission architectures, and engineering technologies. In comparison to Earth, the Martian atmosphere has lower pressure (∼600 Pa) and temperature (∼210 K). It is primarily composed of carbon dioxide (∼96%), with nitrogen (∼2%) and argon (∼2%) as secondary components. These gases can serve as a heat transfer medium and are in-situ sources of carbon and oxygen elements. Researchers believe that Martian air as the working medium for the space nuclear system, integrated with heat-to-electricity and chemical conversion, is paving the way for multimodal resource transformation on Mars. The implementation path- way includes three main steps: (1) Mar- tian atmospheric capture; (2) in-situ power generation and storage; and (3) life -support resources transformation, which may afford a fruitful insight.
1. MARTIAN ATMOSPHERIC CAPTURE
Martian atmosphere capture and pressurization: This can be achieved through three methods: mechanical compression, cryogenic capture, and adsorption compression. The rarefied Martian atmosphere (600 - 800 Pa) is compressed to the working pressure (>100 kPa). Each of the three methods has its own advantages and disadvantages in terms of energy consumption, compression ratio, and reliability. A comprehensive consideration of factors such as impurity tolerance, power supply, mission lifespan, and waste heat availability is required.
2. IN-SITU POWER GENERATION AND STORAGE
The reliance on solar energy for long-term manned missions in the extreme environment of Mars requires reevaluation. The Martian atmosphere serves as an ideal working medium for the secondary circuit of a space micro nuclear reactor. Its efficiency and power density are expected to surpass those of helium-xenon mixed gas, enabling a power supply at the level of hundreds of kilowatts. Coupled with high-energy-density lithium-Martian gas batteries for energy storage, it can alleviate the problems of power fluctuation and power distribution.
3. LIFE-SUPPORT RESOURCES TRANSFORMATION
The low-temperature waste heat from the recycling power generation module is used to provide heating for the Mars base. The medium-temperature CO 2 exhaust gas is combined with hydrogen (through electrolysis of groundwater ice) through the Sabatier reaction to produce methane fuel and water. The high-temperature CO 2 is electrolyzed in a solid oxide electrolysis cell to generate oxygen, meeting the life resource requirements of humans for heat/oxygen/fuel during human stay on Mars.
To further illustrate the practical application potential of the design framework, the energy requirements of the early manned Mars missions of the National Aeronautics and Space Administration are referenced, and a preliminary model is developed to evaluate the flow, power flow, and component weight of key nodes within the system. On the basis of verifying the engineering feasibility, it is revealed that in-situ atmospheric utilization has the potential to save more than twenty tons of payload (approximately 60% of the fuel weight of the Mars manned ascent and return vehicle) in the first future manned Mars exploration mission. It can be regarded as an infrastructure that is deployed by the spacecraft before the arrival of human astronauts.
The first crewed mission to Mars may be carried out within the next few decades. Currently, the in-situ resource utilization technology of the Martian atmosphere is still in the conceptual research stage. To bridge the gap, the following directions are recommended: (1) Explore the physical properties of multiple components in the Martian atmosphere, establish a test platform for simulating the thermophysical properties of the atmosphere, and improve the data to guide the development of thermal components; (2) Develop key components, including integrated compression-expansion-power rotating units, space microreactors, high-temperature CO₂ corrosion-resistant materials, long-service-life electrochemical systems, and Martian dust removal devices; (3) Conduct high-efficiency/high-power density integrated design of the system and optimize the material flow matching path in view of the low-pressure and low-gravity environment on Mars; (4) Combine artificial intelligence to establish an automatic control method for the energy system in extreme environments to adapt to the Mars changing environment fluctuations.
National Science Review
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