Health Bar and Suit Status bar
These two bars are located below the Quick Bar, and behave in a similar fashion to the Health and Hunger Bar in Minecraft.
When you take damage, Both your health and suit status go down. If your suit status is completely depleted, you wont be able to regenerate your health. The only way you can get your suit status back up is if you have a Battery, Power Crystal, or Energy Orb, which are in order from slowest regeneration to fastest.
Your health depletes when you take damage, similar to the suit status; however, if your health is completely depleted, you will die. The only way you can bring your health back up is if your suit status is not completely empty.
Death is an in-game mechanic that occures when your players health is depleted.
When you die, your Astronaut's body, and anything you are holding will become and stay red and you will also slowly sink into the ground, like other defeated Mobs, until you tap "Ok" on the pop up that appears, which says, "You have died".
After tapping "Ok", you are sent back to the Moon selection Menu, at which you can go back to the moon, in which you were defeated. You will not lose any of the items you currently have, and will be re-spawned into your moon. The spawn point actually varies, but will always stay in a general area. Any Mobs in that area will stay there, they will not despawn and will probably kill you again until defeated. If you leave your house next to spawn, you will probably be able to find it.