So the problem i chose is how you get oxygen in mars. So there were two options I thought of. Plants and oxygen tanks. So when i thought of the oxygen tank option it was more expensive and effort. every few months they have to bring oxygen tanks and it uses more people. So the one option i was left with was the plant option. What i thought of was a simple mechanism. So make a medium sized room that can fit a moderate amount of plants. Put light bulbs above it that can generate blue LED lights. Make sure the room is transparent so that during the day when sunlight is available it can be used. The LED blue lights can be used at night. Make a small hole for a tube. In the day/night the photosynthesis can make oxygen and load up oxygen in a oxygen tank. So that you can load up a oxygen tank in the place you are staying and you can get oxygen. And when you need to go out you can use the oxygen tank that you loaded.

https://www.nasa.gov/