On the 20th of April 2021, carbon dioxide in Mars’ atmosphere was converted by MOXIE (the Mars Oxygen In-Situ Resource Utilization Experiment) into enough oxygen for an astronaut to breath for about 10 minutes. The whole process took about 3 hours. Moreover, considering that for every 7 tons of rocket fuel, 25 tons of oxygen is needed, this technology could radically impact the weight constraints associated with travelling to the red planet.
(https://go.nasa.gov/2QLL2SR, https://bit.ly/3xPiCYM)