By far the most credible case for asteroid mining is water & carbon compounds. A little H, O, and C, and you have conventional hydrocarbon propellant + LOX. I

By far the most credible case for asteroid mining is water & carbon compounds. A little H, O, and C, and you have conventional hydrocarbon propellant + LOX. I don't know what the actual claim that is being made here is; This seems to redirect ultimately to a lay press release from a state space agency rather than to a scientific paper. There do seem to be a number of competing articles on electrochemical synthesis of ethylene from CO2. https://www.carboncapturejournal.com/news/artificial-photsynthesis-device-turns-co2-into-ethylene-with-record-efficiency/6430.aspx https://www.carboncapturejournal.com/news/artificial-photsyn... https://www.nature.com/articles/s41467-024-50522-7 https://www.nature.com/articles/s41467-024-50522-7 https://lanzatech.com/lanzatech-produces-ethylene-from-co2-changing-the-way-we-make-products-today/ https://lanzatech.com/lanzatech-produces-ethylene-from-co2-c... https://techport.nasa.gov/projects/93860 https://techport.nasa.gov/projects/93860 https://news.umich.edu/in-step-toward-solar-fuels-durable-artificial-photosynthesis-setup-chains-two-carbons-together/ https://news.umich.edu/in-step-toward-solar-fuels-durable-ar... https://www.eurekalert.org/news-releases/717409 https://www.eurekalert.org/news-releases/717409