Can be used anywhere in the galaxy to return you quickly to your home in case of an emergency, or if you're lost. This is a excellent tool for new players, who haven't learned the navigation well enough. However, if you don't know your way through the part of the galaxy you're in (including experienced players) this is a great ability to have.
It can also help when you are heading to the centre of the galaxy, because if you make a mistake (ran out of repair mega packs etc.) it can take you straight to your homeworld. It can also be useful when exploring Black Holes. This is also helpful when you get to Sol, because the player will probably have little or almost no energy left (depending on Sol's proximity to homeworld), you can get the Manifest Destiny award and quickly return to your homeworld.
It has the shortest cooldown time out of all special abilities.
While you can continue to fly for about 7 seconds after activating this tool, you cannot use any other tools or take any damage. A bug exists where, if destroyed before entering the portal, a player's ship will respawn as normal, but be unable to leave the planet. The bug can be resolved by quitting the game and returning to the save.
Allies also benefit from using the portal, but do not actually enter the portal when it is used. Instead, allies will appear to fly from the location at which the portal was used to the homeworld at high speed.