A lot of Space Marine equipment is very old and very holy. Mostly No-one knows in the Imperium apart from parts of the "Cult of the Machine god", how to make any more of some things they use, like the powerful Dreadnought armour, which is why the space marines send off mechanically gifted Space marines to the "Adeptus Mechanicus" to train in order to become an elite of the machine god, and in battle they repair and recover such things as their Rhino Troop Carriers, or their other tanks. Space Marines wear special suits of armour, often holy, called power armour, to help them fight better. All Space Marines are genetically engineered to be very tough. They can live for a very long time, and have an extra heart and an extra set of lungs. They are also trained to be very brave and religious, as well as being trained to be good at shooting and fighting. Some Space Marines have psychic powers (think magic powers) - these are called Librarians in most chapters, they can have powers such as in the case of one from the "Dark Angels" Chapter, shoot what appears to be flamethrower blasts from his eyes and mouth. There are also Space Marines who act like priests, called Chaplains, who forward the worship of the God Emperor of Man.