Suggestion: We need water, which can be used for physical properties, including drinking for astronauts, diving or ascending for submarines, etc. It can be used in the form of articles or ocean water. I like to use submarines. Submarines need water to dive or ascend in water. So I hope you can make this update.😃
you can XML edit an ion engine to have 0 thrust, and to consume a negative ammount of water, which allows you to make ballast tanks, i did a sub like that once, let me know if you want me to teach you how to do it