Minebase is a Forge mod for Minecraft 1.7, and attempts to implement the mechanics of Moonbase Commander. To start, take the two blocks from the creative tab and place the solid one with the transparent one on top. This is your first launcher. To select a projectile, right-click the bottom block of the launcher with the projectile's item. To launch it, right-click the top block of the launcher. Your position relative to the launcher determines the angle and power - it launches in the direction you're facing if you look directly through the center of the launcher, and power is proportional to the distance you are from it.
The available projectiles are:
Hub (item=chest): A building that has a launcher of its own built in.
Bomb (item=arrow): Goes boom where it lands.
Bridge (item=wool): If lands in water, covers it with wool. Note that when launching hubs, anti-airs and shields, the path taken by the projectile must never go over water.
Anti-air (item=obsidian): Building that shoots down projectiles that get too close. Has a delay between projectiles it can react to (5 seconds, if all is well).
Shield (item=diamond block): Building that shoots down projectiles that get too close. Does not have a delay.
Tower (item=ender eye): A cobblestone tower to look down from.