Ship additions are anything that you put in an empy, armourless ship that isn't a weapon. They are:
Reactors, Armour, Drives, and Mainframes.
Earth's ships are powered by fusion reactors (a technology that actually works by 2650). The lowest amount of power needed for a starship is a gigawatt; and so that's the lowest energy level of reactor. Reactors can range anywhere from the single gigawatt to a planned reactor that would produce an entire terawatt of power; so there's no way to put them all in a list.
Earth's scientists have come up with many alloys and armours over the years; and, in order of age, they are:
Steel: Fairly self-explanatory. Steel plating on the exposed hull of a ship. Enough will block explosives and kinetic energy, but not heat-based weapons.
Titanium: Another metal to make plating out of. It can block the same explosives as steel with less metal, and is more heat-resistant than steel; but is ,ore vulnerable to kintic weapons.
Vanadium-Steel Alloy: The alloy that pretty much dominated the first few cneturies of Earth-based spaceflight. It's heavy, but it's fairly heat-resistant and it's good for both blocking explosives and kinetic attacks.
Vanadium-titanium Alloy: A better version of the above that does the same with less metal. This is the current pi nnacle of Earth-based armour engineering.
Composite Alloy: A slightly shiny and great at heat conducting alloy made to absorb heat, and dissapate it to heatsinks scattered on the outside of the ship. Is great for blocking a laser or plasma, but not much else. It's commonly layered with other types of armour, for good measure.
Earth's ships' reactors produce waste atoms, which are then expelled out the end of the ship, resulting in the ship moving forwards.
Ion drive: The most basic form of the above principle.
Phase drive: A more advanced version that draws ions from other parts of the ship as well, resulting in moar speed.
Chemical Rockets: The oldest way of propelling a spaceship. Now only used by fighter/bombers, dropships and escape pods.
Most large Earth ships have mainframes, which process data, run calculations for shen to fire artillery barrages, ect.
Mainframe: Handles the day-day functions of the ship, as well as any quick calculus equations that need solving when timing artillery.
MEGA-variant Mainframe: A beefed-up mainframe capable of supporting a small AI (small meaning that it dowsn't know much, keeping the file size down).
GIGA-variant mainframe: An even more beefed-up version capable of supporting a full AI (one that doesn't have a hard limit on how much data it can gather).