The molten salt CO2 capture and electrochemical transformation (MSCC-ET) process has been demonstrated as an effective approach to capturing and converting CO2 into oxygen and C/CO [1-2]. The effective CO2 capture and electrochemical conversion rely on the high-temperature molten carbonate electrolytes and the cost-effective inert oxygen-evolution anode. In recent years, we have focused on the electrolyte engineering to modulate the reactions at both the cathode and anode as well as the CO2 capture efficiency [3-4]. Besides, we insist on developing iron- and nickel-base oxygen-evolution inert anodes in terms of revealing the fundamental principles and basic guidelines for choosing proper materials and fabrication processes [5]. By doing so, we can prepare functional carbon materials or CO at the cathode with a high current efficiency of over 90%, and produce oxygen at the inert anode. In addition, the kilo-ampere scale electrolyzer was built to produce oxygen, carbon or CO with an energy efficiency of over 50%. Therefore, the molten carbonate CO2 electrolyzer shows its potential to convert CO2 on the Mars to produce oxygen and fuels to support the future exploration of outer space.